Co-reporter:Chenjing Jin, Jie Han, Fangyuan Chu, Xiaoxia Wang, and Rong Guo
Langmuir May 9, 2017 Volume 33(Issue 18) pp:4520-4520
Publication Date(Web):April 15, 2017
DOI:10.1021/acs.langmuir.7b00640
Au@Fe3O4@PANI hybrid shells with controllable polyaniline (PANI) coatings as advanced supported catalysts have been fabricated. Specifically, Fe3O4 and Au nanoparticles were assembled on SiO2 templates, followed by conducting polymer PANI coating, leading to the formation of Au@Fe3O4@PANI hybrid shells after the template removal. The resultant supported Au nanocatalysts not only maintain hollow structures but also possess high saturation magnetization (65.46 emu/g). Catalytic tests toward the reduction of 4-nitrophenol in the presence of NaBH4 indicate that PANI and Fe3O4 not only endow high stability and recyclability but also can largely improve the catalytic activity of Au nanoparticles because of their synergetic effects. It is believed that Fe3O4@PANI hybrid shells can be regarded as multifunctional supports for noble metal nanocatalysts with a remarkably improved catalytic performance.
Co-reporter:Yanan Li, Chenjing Jin, Ganyin Yuan, Jie Han, Minggui Wang, and Rong Guo
Langmuir August 1, 2017 Volume 33(Issue 30) pp:7486-7486
Publication Date(Web):July 11, 2017
DOI:10.1021/acs.langmuir.7b01742
Multifunctional nanocatalysts of Au@Fe3O4/m-SiO2 yolk@shell hybrids had been developed through a template-assisted synthesis, where Fe3O4 nanoparticles (∼12 nm) and m-SiO2 shells were sequentially assembled on surfaces of Au/SiO2 core/shell templates, followed by selective etching of the inner SiO2 cores, leading to the formation of Au@Fe3O4/m-SiO2 yolk@shell hybrids. The Fe3O4 nanoparticles were implanted in the inner surfaces of m-SiO2 shells with partially exposed surfaces to the inner cavity. The novel design not only ensures a high surface area (540.0 m2/g) and saturation magnetization (48.6 emu/g) of the hybrids but also enables interaction between Au and Fe3O4 nanoparticles. Catalytic tests toward the reduction of 4-nitrophenol in the presence of NaBH4 indicated that Au@Fe3O4/m-SiO2 yolk@shell nanocatalysts not only showed high stability and recyclability but also maintained improved catalytic activity as a result of the synergetic effect resulting from Au and Fe3O4 interactions.
Co-reporter:Jian Zhang;Jie Han;Minggui Wang
Journal of Materials Chemistry A 2017 vol. 5(Issue 8) pp:4058-4066
Publication Date(Web):2017/02/21
DOI:10.1039/C6TA10499A
Multifunctional magnetic adsorbents containing MnO2 and polyaniline (PANI) with optimized adsorption properties toward heavy metal ions have been developed. In particular, Fe3O4 spheres were chosen as the magnetic core, followed by PANI and MnO2 coating, realizing the formation of Fe3O4/PANI/MnO2 core–shell hybrids. The as-synthesized Fe3O4/PANI/MnO2 core–shell hybrids showed a hierarchical structure with a large surface area and high magnetic saturation value. In comparison with Fe3O4/PANI and Fe3O4/MnO2 core–shell hybrids, Fe3O4/PANI/MnO2 core–shell hybrids displayed the highest adsorption capacity toward heavy metal ions (including Cd(II), Zn(II), Pb(II) and Cu(II)), thanks to the integrated physical and chemical adsorption behaviors resulting from MnO2 inorganic oxide and the PANI polymer. The developed multifunctional Fe3O4/PANI/MnO2 adsorbents synthesized by a facile and economic route are believed to show high potential in environmental remediation for heavy metal removal.
Co-reporter:Jie Han, Minggui Wang, Yimin Hu, Chuanqiang Zhou, Rong Guo
Progress in Polymer Science 2017 Volume 70(Volume 70) pp:
Publication Date(Web):1 July 2017
DOI:10.1016/j.progpolymsci.2017.04.002
Recent research has established growing research interest in subject of conducting polymer (CP)-based hybrids due to their novel properties and potential applications in diverse fields. The incorporation of CPs with other materials can produce new hybrids showing distinct properties that are not observed in the individual components. Among numerous CP-based hybrids, CP and noble metal nanoparticle (NMNP) hybrids have attracted the most intensive attention in the past few years. The numerous functional groups and tunable chemical structures through redox in the main chains of CPs, make them as ideal supporters for NMNPs. The compact interactions and synergistic effects between CPs and NMNPs contribute to the increased performances in diverse applications. The purpose of this review focuses on state-of-the-art synthetic strategies, mechanisms and applications involved in CP-NMNP hybrids. Herein, CPs used are polyaniline (PANI), polypyrrole (PPY), polythiophene (PTH) and their derivatives; while NMNPs mainly refer to Au, Ag, Pt and Pd nanoparticles. Specifically, the topics include: 1) strategies and mechanisms involved in the synthesis of CP-NMNP hybrids; 2) potential applications of CP-NMNP hybrids in fields of catalysis, sensor, surface-enhanced Raman scattering (SERS), device and others. Finally, prospects and challenges for making advanced CP-NMNP hybrids are discussed.
Co-reporter:Panpan Zhu, Yuanhua Ding, Rong Guo
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2017 Volume 531(Volume 531) pp:
Publication Date(Web):20 October 2017
DOI:10.1016/j.colsurfa.2017.07.082
The photodynamic therapy and gene transportation across cell membrane are closely related with the binding behavior of the photoactive vectors on DNA. Here, the binding characteristics of an isoquinoline-based photoactive ionic liquid surfactant, lauryl isoquinolinium bromide ([C12iQuin]Br), with DNA was investigated for the first time by various analytical techniques. It was found that the DNA molecules are strongly compacted at a low [C12iQuin]Br concentration, and then undergo a complete coil-to-globule structure transition upon further addition of [C12iQuin]Br, which was verified by cryo-TEM. Based on the 1H NMR and 2D NOESY spectra, it can be concluded that the photoactive [C12iQuin]Br is an AT-specific minor groove binder. At a lower [C12iQuin]Br concentration, the isoquinolinium ring of [C12iQuin]Br would be arranged facing to the plane of the minor groove of DNA, and the hydrophobic tails of [C12iQuin]Br would be arranged parallel to the minor groove. The hydrophobic interaction between the hydrocarbon chains of the bound [C12iQuin]Br and DNA bases provides the dominate driving force in the binding process. The unique binding mode of [C12iQuin]Br on DNA causes the formation of the new photoactive structures of [C12iQuin]Br-DNA complexes, which would promise the novel applications in the photodynamic therapy or the gene transportation.Schematic illustration of the coil-to-globule structure transition and binding mechanism of DNA induced by photoactive ionic liquid surfactant [C12iQuin]Br.Download high-res image (166KB)Download full-size image
Co-reporter:Lingling Ge;Jingjing Li;Songtao Zhong;Yue Sun;Stig E. Friberg
Soft Matter (2005-Present) 2017 vol. 13(Issue 5) pp:1012-1019
Publication Date(Web):2017/02/01
DOI:10.1039/C6SM02690G
Single, Janus, and Cerberus emulsions are prepared in one system consisting of three oils: silicone (SO), fluorocarbon (FO) and ethoxylated trimethylolpropane triacrylate (ETPTA) with mutual solubility. An aqueous solution of Pluronic F127, which is an poly(ethylene oxide)/poly(propylene oxide) co-polymer of average composition EO97PO68EO97, was employed as the continuous phase. The three-dimensional phase diagram of the oils was determined, and different oil compositions within the various regions of the phase diagram were emulsified by one-step vortex mixing with an F127 aqueous solution. The result showed single, Janus, and Cerberus emulsions within the different regions of the phase diagram; i.e. the emulsions reflected the equilibrium system. The topology of the Cerberus droplets is to an overwhelming extent linear-singlet and exclusively lobe order of EF/FO/SF. Since the results indicate a significant effect of the equilibrium interfacial tensions on the drop topology, thermodynamic calculations were made using the experimentally determined interfacial tensions. The results, as expected, show that the Cerberus emulsions are thermodynamically preferred over separate drops of the individual oils. In addition, the calculations demonstrate that the order of lobes within a drop is thermodynamically favored.
Co-reporter:Minggui Wang;Jie Han;Yimin Hu
RSC Advances (2011-Present) 2017 vol. 7(Issue 25) pp:15513-15520
Publication Date(Web):2017/03/06
DOI:10.1039/C7RA00985B
Mesoporous C, N-codoped TiO2 (C/N-TiO2) hybrid shells incorporated with graphite carbon were synthesized using polystyrene spheres as templates, followed by polyaniline (PANI) and TiO2 coating, and then post-treatments of etching and calcination, where PANI functioned as both C and N doping sources and supplied the graphite carbon. Compared with pure TiO2 and C-doped TiO2 (C-TiO2) hybrid shells, C/N-TiO2 hybrid shells exhibited enhanced photocatalytic activity in the degradation of organic dyes and H2 production under visible light irradiation, which could be attributed to the enhanced visible light absorption and charge separation efficiency associated with the codoped-C and N and the presence of graphite carbon. It is believed that the strategy presented here will provide a promising route for the construction of other C/N-semiconductor hybrid shells for broader applications.
Co-reporter:Na Han, Shiyi Cao, Jie Han, Yimin Hu, Xiaohong Zhang and Rong Guo
Journal of Materials Chemistry A 2016 vol. 4(Issue 7) pp:2590-2596
Publication Date(Web):14 Jan 2016
DOI:10.1039/C5TA10258H
We present a proof-of-concept demonstration of surface cavities for incorporation of noble metal nanoparticles with remarkable catalytic performance involved in liquid phase catalytic reactions. Mesoporous Ni(OH)2 (m-Ni(OH)2) nanowires with surface cavities have been chosen as multifunctional supports for Au nanoparticles with a well controlled size (2 nm) and high dispersity through a facile room-temperature in situ reduction process without any additional stabilizer. In addition to immobilizing Au nanoparticles, the cavities also can prevent aggregation of neighboring noble metal nanoparticles, thus ensuring high stability/recyclability for Au/m-Ni(OH)2 supported nanocatalysts. The results from catalytic reactions involved in the reduction of 4-nitrophenol in the presence of NaBH4 using Au/m-Ni(OH)2 as the catalyst demonstrated its remarkable catalytic performance due to its nanoscale configuration.
Co-reporter:Shiyi Cao, Na Han, Jie Han, Yimin Hu, Lei Fan, Chuanqiang Zhou, and Rong Guo
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 9) pp:6040
Publication Date(Web):February 16, 2016
DOI:10.1021/acsami.5b11955
Mesoporous hybrid shells of carbonized polyaniline (CPANI)/Mn2O3 with well-controlled diameter and high surface area have been synthesized through surface protected calcination processes. Originating from polystyrene template, PANI, MnO2, and SiO2 were sequentially loaded, followed by template removal and calcination, resulting in the desired CPANI/Mn2O3 hybrid shells. The introduction of SiO2 shell was established to play the determining role in maintaining the configuration during calcination process under high temperature. The CPANI/Mn2O3 hybrid shells showed outstanding electrocatalytic activity toward oxygen reduction reaction (ORR), with the onset potential at +0.974 V (versus RHE), the specific current at 60.8 mA/mg, and an overall quasi 4-electron transfer, which are comparable to those of the benchmark Pt/C. The remarkable ORR performance was attributed to the high specific surface area, the surface oxidation state of Mn, and composition-codependent behavior.Keywords: carbonization; hollow spheres; Mn2O3; oxygen reduction reaction; polyaniline
Co-reporter:Minggui Wang, Jie Han, Yimin Hu, Rong Guo, and Yadong Yin
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 43) pp:29511
Publication Date(Web):October 12, 2016
DOI:10.1021/acsami.6b10480
Carbon-incorporated mesoporous NiO/TiO2 (NiO/TiO2/C) hybrid shells as low-cost and highly efficient visible light photocatalysts have been developed. The NiO/TiO2/C hybrid shells were synthesized by choosing polystyrene nanospheres as templates, followed by TiO2 and NiO coating, and finally the calcination post-treatment to carbonize PS with the aid of metal oxides. Polystyrene nanospheres serve dual purposes as both a template to ensure the hollow structure and the electrically conductive graphite carbon source. Evaluation of their photocatalytic activity by organic pollutes (rhodamine B, methylene blue, and phenol) degradation and H2 production under visible light demonstrated the superior photocatalytic performance, thanks to the enhanced visible-light absorption and exciton separation associated with the incorporation of electrically conductive graphite carbon.Keywords: carbon; mesoporous shells; NiO; photocatalyst; TiO2
Co-reporter:Lingling Ge, Stig E. Friberg, Rong Guo
Current Opinion in Colloid & Interface Science 2016 Volume 25() pp:58-66
Publication Date(Web):October 2016
DOI:10.1016/j.cocis.2016.05.001
•The preparation is reviewed of Janus emulsions by vibrational emulsification.•The potential is indicated for large scale emulsification.•The relevance is evaluated of a correlation between equilibrium interfacial tensions and drop topology.•The potential is outlined for large scale production of anisotropic particles of complex shape.•The association to other complex drop topologies is examined.Emulsion science has recently experienced several profound changes. At first, interfacial thermodynamics has been found to play a significant role in the behavior of multiple emulsions, leading to an unexpected effect on their traditional medium energy preparation as well as to an extension of their preparation into large volumes. In order to illustrate these changes, the present article is initiated by a brief review of the correlation between the equilibrium interfacial tensions and the configuration of Janus emulsions prepared by one-step vibrational mixing, and extends to the phase inversion of Janus droplets inside its interfacial tension range, followed by an assessment of the progress in the preparation of Janus emulsions and their application to fabricate complex anisotropic particles in scale.
Co-reporter:Lei Fan, Li Yang, Xiangying Ni, Jie Han, Rong Guo, Chuanfang (John) Zhang
Carbon 2016 Volume 107() pp:629-637
Publication Date(Web):October 2016
DOI:10.1016/j.carbon.2016.06.067
In order to maximize supercapacitor performances, it is essential to engineer the electrode architecture with shortened ion-diffusion paths and high content of pseudocapacitive sites. By incorporating redox-active species into low-dimensional carbon materials, both the specific capacitances and rate capabilities can be improved. In this study, a self-sustaining, flexible mat consisting of nitrogen-enriched carbon fiber (NCF) network was successfully produced through the co-electrospinning of a polyacrylonitrile (PAN)/polyvinylpyrrolidone (PVP)/SiO2 blended solution, followed by pyrolysis and SiO2 removal processes. Despite its low surface area (<60 m2/g), the NCF exhibits high nitrogen content (17.3 wt%) and interconnected meso-macroporous nanostructure, resulting in high pseudocapacitance (242 F/g at 0.2 A/g), fast rate capability, and excellent cycling performance (99% of initial capacitance after 5000 cycles). The electrical double-layer capacitance and pseudocapacitance can be easily decoupled. The binder-free NCF based symmetric supercapacitor demonstrates a purely capacitive responses and high rate handling. We attribute the excellent electrochemical performances to the good conductivity and shortened ion diffusion paths of carbon fiber backbone, and pseudocapacitive edge-concentrated nitrogen species.
Co-reporter:Na Qiu, Yan Liu, Rong Guo
Electrochimica Acta 2016 Volume 212() pp:147-154
Publication Date(Web):10 September 2016
DOI:10.1016/j.electacta.2016.06.136
•An electrochemical sensor based on 3D graphene/SDBS hemimicelle nanocomposite was constructed.•Wide linear ranges and low detection limits for lead ion are obtained.•The nanocomposite exhibits outstanding electronic and specific area properties due to 3D graphene.•The nanocomposite can accumulate metal ions due to SDBS hemimicelles.For the first time, a novel lead ion electrochemical sensor based on three-dimensional grapheme foam/sodium dodecyl benzene sulfonate hemimicelle (3D GF/SDBS HM) nanocomposite has been developed. This nanocomposite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared (FTIR) spectroscopy and contact angle measurements, which demonstrated that SDBS hemimicelles were attached on the surface of the 3D graphene foam. Electrochemical properties of the nanocomposite modified electrode were characterized by cyclic voltammetry and electrochemical impedance spectroscopy. This electrochemical sensing interface exhibited excellent stripping performance for the analysis of Pb2+ with the detection limit of 0.0145 nM, combining the advantageous of 3D graphene foam (well-defined macroporous structure, high electrical conductivity and specific area) together with the unique accumulating and depositing features of hemimicelle. The sensor was further applied to the determination of lead ion in real water samples with satisfactory results.
Co-reporter:Zhongchun Li, Xuan Ji, Jie Han, Yimin Hu, Rong Guo
Journal of Colloid and Interface Science 2016 Volume 477() pp:46-53
Publication Date(Web):1 September 2016
DOI:10.1016/j.jcis.2016.05.038
A facile hydrothermal process is developed for the synthesis of NiCo2S4/reduced graphene oxide (RGO) hybrid and NiCo2S4 hollow spheres. The morphology and microstructure are characterized by powder X-ray diffraction (XRD), Raman spectra, transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected area electron diffraction (SAED), and energy dispersive spectrometry (EDS) mapping. NiCo2S4 nanoparticles with the diameter of about 20–30 nm were in-situ grown on RGO sheets. NiCo2S4 hollow spheres were obtained with the diameter of about 300–400 nm and the width of shell in the range of 30–40 nm in the absence of graphene oxide (GO). GO as a substrate material can offer abundant active sites for nucleation of NiCo2S4 and can be reduced to RGO, providing excellent electron transfer path and high conduction, which enable the fast surface redox reaction. Supercapacitor based on NiCo2S4/RGO hybrid shows a high specific capacitance of 1804.7 F/g at a current density of 0.5 A/g. Due to the high capacitive performance of NiCo2S4/RGO hybrid, the NiCo2S4/RGO//AC asymmetric supercapacitor (ASC) possesses an extended voltage window of 1.5 V, high energy density of 24.4 W h/kg at a power density of 750 W/kg in 2 mol/L KOH electrolyte. NiCo2S4/RGO hybrid can serve as a promising electrode material for high performance supercapacitors.A facile hydrothermal route was developed to growth of NiCo2S4 nanoparticles on the RGO sheets with excellent capacitive performance for supercapacitors.
Co-reporter:Chenjing Jin, Yun Qu, Minggui Wang, Jie Han, Yimin Hu, and Rong Guo
Langmuir 2016 Volume 32(Issue 18) pp:4595-4601
Publication Date(Web):April 22, 2016
DOI:10.1021/acs.langmuir.6b01269
Hydrophilic Fe3O4–Au Janus nanoparticles have been synthesized through a facile aqueous solution-based Fe3O4 seed-mediated chemical reduction route, where Au nanoparticles can be in situ formed on surfaces of PVP-modified Fe3O4 nanoparticles by adopting the well-known citrate reduction route. The diameter of Au nanoparticles can be controllably tuned in the range of 3–12 nm by simply changing the initial molar ratio between sodium citrate and auric acid. The as-fabricated hydrophilic Fe3O4–Au Janus nanoparticles have shown excellent catalytic performance with high catalytic activity and recyclability due to the synergetic effect between Au and Fe3O4 nanoparticles.
Co-reporter:Yan Liu, Longjiao Qiao, Yinping Xiang, and Rong Guo
Langmuir 2016 Volume 32(Issue 11) pp:2582-2590
Publication Date(Web):February 28, 2016
DOI:10.1021/acs.langmuir.6b00302
The adsorption behavior of imidazolium-based ionic liquid surfactant ([C12mim]Br) on silica nanoparticles (NPs) has been studied with turbidity, isothermal titration microcalorimetry, fluorescence spectroscopy, and dynamic light scattering (DLS) measurements. Both the electrostatic attraction and the hydrogen bonding interaction between silica NP and [C12mim]Br play crucial roles during [C12mim]Br monomers binding to silica NPs at low surfactant concentration, and the hydrophobic effect leads to formation of micelle-like aggregates on silica NP surfaces with the further increase of surfactant concentration. Furthermore, it is found that sodium halide salts favor the adsorption of [C12mim]Br on silica NP surfaces by decreasing the electrostatic repulsions. Anions with more hydrophobicity and the ability to form hydrogen bonding have more pronounced effect. Compared with DTAB, [C12mim]Br has much stronger binding ability with silica NPs at pH 7.0. More interestingly, [C12mim]Br can still form micelle-like aggregates on silica NP surfaces, but DTAB cannot at pH 2.0. The hydrogen bonding between the imidazolium ring and silica NPs is the principal contributor to these observations. Our results will contribute to the elucidation of silica NP/cationic surfactant interaction from molecular scale and the widely applications of silica NP/surfactant systems in practice.
Co-reporter:Zhongchun Li;Jie Han;Lei Fan
Colloid and Polymer Science 2016 Volume 294( Issue 4) pp:681-689
Publication Date(Web):2016 April
DOI:10.1007/s00396-015-3826-y
The α-Ni(OH)2 nanowires (α-Ni(OH)2 NWs) and nanoparticles (α-Ni(OH)2 NPs) were grown on reduced graphene oxide (RGO) sheets by adjusting the reduction degree of the substrates. The α-Ni(OH)2 NWs/RGO composite was achieved by using graphene oxide (GO) as the substrate. In contrast, the α-Ni(OH)2 NPs/RGO composite was obtained when RGO was applied as the support. The difference in morphology can be attributed to the fact that the hydrophilic function of GO is larger than that of RGO, and sp2 carbon atom concentration in α-Ni(OH)2 NPs/RGO is higher than that in α-Ni(OH)2 NWs/RGO. When α-Ni(OH)2 NWs/RGO and α-Ni(OH)2 NPs/RGO composites were used as electrode materials for supercapacitors, the α-Ni(OH)2 NPs/RGO exhibits superior electrochemical performance than α-Ni(OH)2 NWs/RGO, which is attributed to the fact that the specific surface area, conductivity, and sp2 carbon atom concentration of α-Ni(OH)2 NPs/RGO are larger than those of α-Ni(OH)2 NWs/RGO. The α-Ni(OH)2 NPs/RGO composite is a promising candidate as electrode material for high performance supercapacitor.
Co-reporter:Lingling Ge;Xia Li;Stig E. Friberg
Colloid and Polymer Science 2016 Volume 294( Issue 11) pp:1815-1821
Publication Date(Web):2016 November
DOI:10.1007/s00396-016-3946-z
Janus emulsions are prepared by one-step vibrational mixing of two immiscible oils, silicone oil, SO, with density of 0.964 g/cm3 and sunflower oil saturated with dimethyl phthalate, VO (DMP), with density of 0.991 g/cm3, and an aqueous solution of sodium dodecyl sulfate as continuous phase. The destabilization of Janus emulsion is followed by the change of layer dimension as well as the microscope image, illustrating the two main aspects of creaming and coalescence. The fundamental impasse of the final separation of the Janus drop oils against unfavorable free energy change is resolved by a numerical analysis on a model emulsion with realistic interfacial tension values to show a thermodynamically favored path to the final destabilization process.
Co-reporter:Zhongchun Li;Yun Qu;Minggui Wang;Yimin Hu;Jie Han
Colloid and Polymer Science 2016 Volume 294( Issue 8) pp:1325-1332
Publication Date(Web):2016 August
DOI:10.1007/s00396-016-3897-4
The NiCo2S4 hollow spheres were prepared by an oil/water (O/W) interface-assisted hydrothermal process using CoCl2 · 6H2O, NiCl2 · 6H2O, ethanediamine, and carbon disulfide (CS2) as raw materials. Powder X-ray diffraction (XRD), UV–Vis absorption spectrum, transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected area electron diffraction (SAED), energy dispersive spectrometry (EDS), N2 adsorption-desorption isotherm, and X-ray photoelectron spectroscopy (XPS) were measured to characterize the morphology and microstructure of the prepared NiCo2S4 hollow spheres. When applied as the electrode material for supercapacitor, the NiCo2S4 hollow spheres show outstanding performances. The specific capacitance of the NiCo2S4 hollow spheres is 1753.2 F/g at a current density of 1 A/g. Of the capacity, 77.8 % were retained when the current density increased from 1 to 10 A/g. At a current density of 3 A/g, the specific capacitance of the NiCo2S4 hollow sphere electrode is about 1350.5 F/g after suffering 1000 continuous cycles. The supercapacitor possesses high energy density of 39.0 Wh/kg at a power density of 200 W/kg. The as-prepared NiCo2S4 hollow sphere electrode exhibits high specific capacitance, rate capacity, energy density, and good cycle stability, making it a promising electrode material for high-performance supercapacitors.
Co-reporter:Quanwen Zha;Qiulan Xie;Yimin Hu;Jie Han;Lingling Ge
Colloid and Polymer Science 2016 Volume 294( Issue 5) pp:841-849
Publication Date(Web):2016 May
DOI:10.1007/s00396-016-3841-7
Three metallosurfactants Cn–Cu–Cn (n = 8, 12, 16) were synthesized via two-step in this paper. All of these surfactants were characterized by ultimate analysis, 1H NMR, FT-IR, LC-MS, elemental analysis. In addition, the three surfactants can form vesicles under sonication at a relatively high concentration, and their aggregation behavior and the stability of Cn–Cu–Cn vesicles were investigated by surface tension, electrical conductivity, FT-IR, negative staining–TEM. Results showed that C12–Cu–C12 vesicles with average size of ∼60 nm had good stability over inorganic salt, temperature, and aging time. Doxorubicin hydrochloride was incorporated into C12–Cu–C12 vesicles with a remarkably high efficiency of above 70 %, and the delivery system has obvious sustained release effect.
Co-reporter:Lingling Ge, Shuhui Lu, Jie Han and Rong Guo
Chemical Communications 2015 vol. 51(Issue 35) pp:7432-7434
Publication Date(Web):26 Feb 2015
DOI:10.1039/C5CC00935A
Anisotropic particles, with morphology from crescent to moon shape and size from micrometer to nanometer scale, are fabricated in batch scale with Janus emulsion as template. The strategy is also useful in the synthesis of Janus particles with chemically distinct hemispheres.
Co-reporter:Zhongchun Li, Jie Han, Lei Fan, Minggui Wang, Shengyang Tao and Rong Guo
Chemical Communications 2015 vol. 51(Issue 15) pp:3053-3056
Publication Date(Web):24 Dec 2014
DOI:10.1039/C4CC09225B
By exploiting a facile and controllable anion exchange strategy, mesoporous α-Ni(OH)2 nanowires with multinanocavities in surfaces have been successfully developed. The novel nanoscale morphology has been proven to be responsible for their excellent capacitive performances.
Co-reporter:Yimin Hu, Lingling Ge, Jie Han and Rong Guo
Soft Matter 2015 vol. 11(Issue 28) pp:5624-5631
Publication Date(Web):22 May 2015
DOI:10.1039/C5SM01084E
A highly viscoelastic fluid formed by the ionic liquid-type surfactant 1-hexadecyl-3-nonyl imidazolium bromide ([C16imC9]Br) in water in the absence of any additive was studied. The phase behavior and morphology of aggregates were studied by a combination of rheological techniques, small-angle X-ray scattering (SAXS), cryo-etch-scanning electron microscopy (cryo-etch-SEM) and freeze-fractured transmission electron microscopy (FF-TEM). [C16imC9]Br aqueous solutions showed interesting rheological behavior as a function of both concentration and temperature, which invoked a transition between wormlike micelles and hydrogels. With the increase in [C16imC9]Br concentration, the aqueous solution could form viscoelastic wormlike micelles (50–80 mM), hydrogels (90–110 mM) and wormlike micelles (120–180 mM). As the temperature increased, the hydrogels (90–110 mM) could also transit to wormlike micelles. The unusual phase transition between wormlike micelles and elastic hydrogels was postulated to be the change of the average micellar length.
Co-reporter:Zhongchun Li, Jie Han, Lei Fan and Rong Guo
CrystEngComm 2015 vol. 17(Issue 9) pp:1952-1958
Publication Date(Web):23 Jan 2015
DOI:10.1039/C4CE02548B
Ni7S6 hollow spheres with mesoporous shells were successfully synthesized by a novel and facile hydrothermal process without any template or surfactant using nickel chloride hexahydrate and sodium thioglycolate as starting materials. The morphology and microstructure of the samples were examined by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected area electron diffraction (SAED), energy dispersive spectroscopy (EDS), and N2 adsorption–desorption isotherm measurement. A bubble template-based ripening process was proposed for the formation of Ni7S6 hollow spheres with mesoporous shells. When applied as electrode materials for supercapacitors, the as-prepared Ni7S6 hollow spheres with mesoporous shells exhibited tremendous pseudocapacitance of 2329.5 F g−1 at 2 mV s−1 and 2283.2 F g−1 at 1 A g−1. A capacity retention of 97.1% was achieved even after 1000 cycles. The maximum energy density is 50.7 W h kg−1 at a current density of 1 A g−1. The excellent capacitive performance is attributed to their unique hollow structure with mesoporous shells providing fast ion and electron transfer, and high electronic conduction. These results suggest that the Ni7S6 hollow spheres with mesoporous shells are highly promising candidates for supercapacitor electrodes.
Co-reporter:Yan Liu, Xifang Liu, Huiyuan Mao and Rong Guo
RSC Advances 2015 vol. 5(Issue 101) pp:83486-83493
Publication Date(Web):22 Sep 2015
DOI:10.1039/C5RA11231A
Here, we developed a facile and green method to fabricate porous double cashew-shaped calcium oxalate (CaOx) in the presence of amphiphilic phosphoproteins. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and Fourier transform infrared (FTIR) spectroscopy. The influences of the protein concentration and pH on the final morphology and phase transformation of CaOx crystals were systematically studied. A possible formation mechanism of the porous double cashew-shaped CaOx was proposed. Furthermore, the environmentally friendly and cheap CaOx with hierarchical structures exhibits high efficient and selective adsorption of Congo red. The high efficiency and selectivity is attributed to the unique structure, and the hydrogen bond between Congo red and the embodied proteins in double cashew-shaped CaOx.
Co-reporter:Yan Liu, Longjiao Qiao, Lili Liu, Rong Guo
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2015 Volume 474() pp:92-100
Publication Date(Web):5 June 2015
DOI:10.1016/j.colsurfa.2015.01.056
•Reduced pH can assemble glutamic acid stabilized gold nanoparticles into superstructures.•The presence of small amount of NaBr can inhibit such assembling behavior.•A possible assembly mechanism for the network superstructure is proposed.•pH induced superstructures exhibit high surface-enhanced Raman scattering activity.Triggered by pH changes, glutamic acid (Glu)-stabilized gold nanoparticles (GNPs) assemble into one-, two-, and three-dimensional (1D, 2D, and 3D) superstructures. The multidimensional network superstructures are formed via the nanospheres fusing into one another. The main driving force for the fabrication of these superstructures is the attractive (cross-linking) force, provided by the neutral carboxylic group of glutamic acid molecules. Interestingly, the presence of a small amount of NaBr can inhibit such assembling behavior of GNPs efficiently because Br− can replace some Glu molecules from GNPs surfaces and weaken the linking effect of the neutral carboxylic group of Glu on GNPs. In addition, the pH induced superstructures could be used as surface-enhanced Raman scattering (SERS) substrates with high activity. The new insights into the pH and chemical tunability of the interparticle linking interactions of Glu bound on gold nanoparticles provide implications to the exploitation of the Glu–nanoparticle system for biological detection and biosensors.
Co-reporter:Yimin Hu, Jie Han, Lingling Ge, and Rong Guo
Langmuir 2015 Volume 31(Issue 46) pp:12618-12627
Publication Date(Web):November 4, 2015
DOI:10.1021/acs.langmuir.5b03382
The search for functional supramolecular aggregations with different structure has attracted interest of chemists because they have the potential in industrial and technological application. Hydrophobic interaction has great influence on the formation of these aggregations, such as hexagonal liquid crystals, wormlike micelles, hydrogels, etc. So a systematical investigation was done to investigate the influence of alkyl chain length of surfactants on the aggregation behavior in water. The aggregation behavior of 1-hexadecyl-3-alkyl imidazolium bromide and water has been systematically investigated. These ionic liquid surfactants are denoted as C16–Cn (n = 2, 3, 4, 6, 8, 9, 10, 12, 14, 16). The rheological behavior and microstructure were characterized via a combination of rheology, cryo-etch scanning electron microscopy, polarization optical microscopy, and X-ray crystallography. The alkyl chain has great influence on the formation of surfactant aggregates in water at the molecular level. With increasing alkyl chain length, different aggregates, such as hexagonal liquid crystals, wormlike micelles, and hydrogels can be fabricated: C16–C2 aqueous solution only forms hexagonal liquid crystal; C16–C3 aqueous solution forms wormlike micelle and hexagonal liquid crystal; C16–C4, C16–C6 and C16–C8 aqueous solutions only form wormlike micelle; C16–C9 aqueous solution experiences a transition between wormlike micelle and hydrogel; C16–C10, C16–C12, C16–C14 and C16–C16 only form hydrogel. The mechanism of the transition of different aggregation with increasing alkyl chain length was also proposed.
Co-reporter:Minggui Wang, Jie Han, Huixin Xiong, and Rong Guo
Langmuir 2015 Volume 31(Issue 22) pp:6220-6228
Publication Date(Web):May 21, 2015
DOI:10.1021/acs.langmuir.5b01099
Yolk@shell nanostructures of Au@r-GO/TiO2 with mesoporous shells were prepared by a sol–gel coating process sequentially with GO and TiO2 on Au/SiO2 core/shell spheres, followed by calcination and template removal, where the silica interlayer acts as a template not only to produce the void space but also to promote the coating of the r-GO and TiO2 layer. The evaluation of visible light photocatalytic activities in dye decomposition and water-splitting H2 production demonstrated their superior photocatalytic performance, which indicates their potential as powerful photocatalysts.
Co-reporter:Jie Han, Song Lu, Chenjing Jin, Minggui Wang and Rong Guo
Journal of Materials Chemistry A 2014 vol. 2(Issue 32) pp:13016-13023
Publication Date(Web):18 Jun 2014
DOI:10.1039/C4TA01795A
The development of catalysts with improved stability and efficiency is increasingly important for both economic and environmental reasons. Herein, Fe3O4/PANI/m-SiO2 hybrid core/shell spheres have been successfully synthesized as novel and robust reactive catalyst supports to produce highly stable and recyclable noble metal nanocatalysts. Specifically, Fe3O4/PANI/m-SiO2 hybrid core/shell spheres were firstly fabricated, followed by the addition of noble metal ions to initiate the redox reaction between PANI and noble metal ions to yield noble metal nanoparticles on PANI surfaces. The Fe3O4 core and mesoporous SiO2 shell of the Fe3O4/PANI/m-SiO2 hybrid supports can significantly improve the recycling efficiency and greatly reinforce the stability of catalyst nanoparticles against coagulation, respectively. Various parameters, such as the thickness of the PANI coating and the etching time of the SiO2 dense shell, were considered in optimizing the catalyst supports. Furthermore, the high stability and recyclability of Fe3O4/PANI/Au/m-SiO2 hybrid catalysts involved in liquid phase reactions were established, implying their potential applications in the field of catalysis.
Co-reporter:Jie Han, Minggui Wang, Rong Chen, Na Han and Rong Guo
Chemical Communications 2014 vol. 50(Issue 61) pp:8295-8298
Publication Date(Web):22 Apr 2014
DOI:10.1039/C4CC01532K
Novel Au–polymer hollow hybrids having a single Au nanoparticle encapsulated in each porous polymer shell with superior catalytic efficiency and recyclability have been demonstrated.
Co-reporter:Lingling Ge, Wanqing Shao, Shuhui Lu and Rong Guo
Soft Matter 2014 vol. 10(Issue 25) pp:4498-4505
Publication Date(Web):08 Apr 2014
DOI:10.1039/C4SM00456F
Droplet topology of a Janus emulsion in a vegetable oil (VO)/silicone oil (SO)/Tween 80 aqueous solution (Aq) system prepared in a one-step high energy mixing was investigated, mainly by image observation. Quantitative information of the topology was analyzed referring to the curvature of VO/SO interface, the location of contact plane, and the volume ratio of VO/SO within individual droplets. The results show that the “stable Janus emulsion” region in the phase map enlarges with surfactant concentration. The average volume ratio of two oil lobes within an individual Janus droplet agrees with the emulsion composition in the “stable Janus emulsion” region, which means that the droplet topology can be controlled by the emulsion preparation process within realistic limits. The volume ratio of VO/SO within individual droplet ranges from about 0.54 to 0.17 in the VO/SO/3 wt% Tween 80(Aq) system, beyond which separate VO and SO droplets are observed. The topology of a Janus droplet is found to be determined by both the contact angle of three liquids in the contact line and the location of the contact plane. The contact angle of the oil cap is determined by the interfacial tension referring to the local equilibrium. The location of the contact plane is the dominant factor determining the volume ratio of two oil lobes. Composition change in the emulsion results in the corresponding tune of the location of contact plane and subsequently, the volume ratio of two oils within Janus droplets.
Co-reporter:Yan Liu, Huiyuan Mao, Xifang Liu, Longjiao Qiao and Rong Guo
CrystEngComm 2014 vol. 16(Issue 37) pp:8841-8851
Publication Date(Web):29 Jul 2014
DOI:10.1039/C4CE00772G
To gain more insight into protein structure–function relationships that govern biomineralization is an exciting and challenging task. The influence of casein protein on the crystallization of calcium oxalate has been investigated in order to determine the roles of amphiphilicity and phosphate groups of proteins in the morphology and the phase control of the calcium oxalate crystals. The crystals obtained were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction, and thermal gravimetric analysis. The results show that calcium oxalate monohydrate (COM) was obtained in the absence of proteins, while the obtained crystals were calcium oxalate dihydrate (COD) in the presence of casein. Casein can be assumed to take a key role during dumbbell-shaped COD formation where it serves as an effective stabilizing agent for COD and assembles nanorods into dumbbell COD. Compared to controls containing casein hydrolysate or bovine serum albumin (BSA), the stabilizing effect of casein arises from the electrostatic attraction between phosphate groups as well as carbonate groups (especially the former) and the calcium ions of COD. The assembling effect of casein mainly comes from the hydrophobic interaction between casein molecules bound to COD nanorod surfaces. In addition, the presence of casein inhibits the crystallization process of calcium oxalate significantly. Our studies may contribute to the understanding of the specific role of amphiphilic phosphoproteins in the biomineralization process.
Co-reporter:Xiaohong Zhang;Xinying Peng;Lingling Ge;Lei Yu
Colloid and Polymer Science 2014 Volume 292( Issue 5) pp:1111-1120
Publication Date(Web):2014 May
DOI:10.1007/s00396-013-3151-2
The micellization behavior of the ionic liquid lauryl isoquinolinium bromide ([C12iQuin]Br) in aqueous solution has been assessed using surface tension, electrical conductivity, and 1H nuclear magnetic resonance (NMR) measurements. The results reveal that the critical micelle concentration (CMC) and constant surfactant tension (γcac) are lower than that of butyl isoquinolinium bromide ([C4iQuin]Br), octyl isoquinolinium bromide ([C8iQuin]Br, and lauryl pyridinium bromide ([C12Pyr]Br). 1H NMR spectra show the evidence of paralleled π-stacking of adjacent isoquinoline rings. To elucidate the effect of the π–π interactions on the aggregation process, thermodynamic parameters such as the standard free energy, enthalpy, and entropy of aggregation have been discussed. These parameters are evaluated from the CMC with temperature by fitting these values to expressions derived from a micellization thermodynamic model. The enthalpy–entropy compensation phenomenon has been observed in the micellization process of [C12iQuin]Br in water, and the presence of isoquinoline cations is responsible for the decrease in the ΔHmic∗, compared with [C12Pyr]Br which has the same alkyl chain and counter-ion.
Co-reporter:Yan Liu, Liu Yang, Huiyuan Mao, Rong Guo
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2014 Volume 441() pp:581-588
Publication Date(Web):20 January 2014
DOI:10.1016/j.colsurfa.2013.10.012
•The structure and property of β-casein micelle (CM) can be controlled by [Cnmim]Br.•The controlling effect is significantly affected by chain architecture of [Cnmim]Br.•[C8mim]Br interacts with β-CM much more strongly than [C4mim]Br.•Hydrophobic interaction matters much during the binding of [Cnmim]Br to β-CM.The comparative studies on the interactions of β-casein micelles (β-CMs) with imidazolium-based ionic liquids (ILs) containing different hydrophobicity (1-octyl-3-methylimidazolium bromide [C8mim]Br and 1-butyl-3-methylimidazolium bromide [C4mim]Br) have been carried out using turbidity, dynamic light scattering (DLS), transmission electron microscopy (TEM), conductivity, steady-state fluorescence and isothermal titration microcalorimetry (ITC) measurements. The structure and microenvironmental polarity of β-CM can be controlled by the addition of ILs. The controlling effect depends much on the alkyl chain that attached to the imidazolium ring and the polarity of the IL. The partitioning of IL molecules in different locations of β-CM depends on the concentration and chain characteristics of ILs. In addition to the electrostatic attraction, the binding of the cationic [Cnmim]+ headgroup to β-CM should be dominated by the hydrophobic interaction among the alkyl tails of the IL and the hydrophobic domain of β-CM. Also, C2-H of [Cnmim]+ could easily participate in hydrogen bonding interaction with the carboxylic moiety of protein molecules. The complementary results obtained from the multitechnique approaches proved useful in drawing out the mechanism of interaction between amphiphilic protein aggregates and ionic liquid with different chain architecture in different IL concentration regimes, which will in turn facilitate the use of protein–IL systems in foods, pharmaceuticals, biotechnology and related industries.The structure and the microenvironmental polarity of β-casein micelle are controlled by [Cnmim]Br.
Co-reporter:Yan Liu, Min Yuan, Longjiao Qiao, Rong Guo
Biosensors and Bioelectronics 2014 Volume 52() pp:391-396
Publication Date(Web):15 February 2014
DOI:10.1016/j.bios.2013.09.020
•Protein-magnetite nanoparticles possess enhanced peroxidase-like activity.•Glucose biosensor based on biocompatible protein-Fe3O4 nanocomposite is developed.•The biosensor exhibits an excellent performance toward glucose detection in a colorimetric way.An efficient colorimetric biosensor for glucose based on peroxidase-like protein-Fe3O4 and glucose oxidase nanocomposites is reported in this work. Compared with bare MNPs, peroxidase-like casein-MNPs exhibit good catalytic properties, stability, dispersibility. Casein incorporated on MNPs notably improves the affinity toward both H2O2 and TMB, proved by variation in the determined kinetic parameters. As low as 0.2 μM H2O2 can be detected with a linear range from 0.5 μM to 200 μM H2O2. More importantly, the casein/MNP nanocomposite was further used to immobilize GOx and to construct a glucose biosensor for the one-step determination of glucose. This method is simple, inexpensive, highly sensitive, and selective for glucose detection, with a detection limit of 1.0 μM over a linear range from 3 μM to 1000 μM.
Co-reporter:Jie Han, Minggui Wang, Shiyi Cao, Ping Fang, Song Lu, Rong Chen and Rong Guo
Journal of Materials Chemistry A 2013 vol. 1(Issue 42) pp:13197-13202
Publication Date(Web):09 Sep 2013
DOI:10.1039/C3TA12545A
MnO2/polyaniline (PANI) coaxial nanocables were fabricated through an oxidative template route, where MnO2 nanorods were selected as the reactive templates for polymerization of aniline in acidic aqueous solution. It was found that PANI could be coated on the surfaces of MnO2 nanorods, accompanied by dissolution of the MnO2 cores, leading to the formation of coaxial nanocable structures. Consequently, the compositions and structures of the MnO2/PANI coaxial nanocables could be simply controlled by determining the reaction time. Thermogravimetric analysis, Fourier transform infrared spectrometry, X-ray diffraction, ultraviolet-visible spectrophotometry, and N2 adsorption–desorption techniques were used to characterize the MnO2/PANI coaxial nanocables. Furthermore, the catalytic activities of the MnO2/PANI coaxial nanocables in the oxidative decolorization of Rhodamine B were also investigated.
Co-reporter:Jie Han, Rong Chen, Minggui Wang, Song Lu and Rong Guo
Chemical Communications 2013 vol. 49(Issue 98) pp:11566-11568
Publication Date(Web):18 Oct 2013
DOI:10.1039/C3CC46139D
Au–conducting polymer core–shell nanostructures have been transformed into yolk–shell nanostructures with enhanced catalytic activity through facile swelling–evaporation processes without any sacrificial template.
Co-reporter:Jie Han, Jie Dai, Chuanqiang Zhou and Rong Guo
Polymer Chemistry 2013 vol. 4(Issue 2) pp:313-321
Publication Date(Web):21 Aug 2012
DOI:10.1039/C2PY20536J
Well-defined and individual polyaniline (PANI) nanotubes have been synthesized by the oxidative polymerization of aniline in dilute solution in the presence of low-concentration cationic surfactant cetyltrimethylammonium bromide (CTAB). The role of the surfactant in the formation of the PANI nanostructures was discussed by changing its concentration in the reaction system, and the polymerization processes of low-concentration aniline in the dilute CTAB medium were deduced to explain the formation mechanism of the PANI nanotubes. Furthermore, noble metal (Au, Ag, Pt or Pd) nanoparticles that were supported on the as-synthesized PANI nanotubes have been achieved by utilizing the reactivity of PANI towards noble metal ions. Control over the size of noble metal nanoparticles, typical Au nanoparticles, that were uniformly supported on the surfaces of the PANI nanotubes has been realized by introducing a functional doping acid as the linkage. In addition, PANI nanotube/Au nanoparticle composites were found to serve as effective catalysts to activate the reduction of 4-nitrophenol (4NP) in the presence of NaBH4, and the size effects of the catalyst on the catalytic activity were also investigated.
Co-reporter:Yan Liu, Liu Yang and Rong Guo
Soft Matter 2013 vol. 9(Issue 13) pp:3671-3680
Publication Date(Web):22 Feb 2013
DOI:10.1039/C2SM27134F
The interaction of β-casein micelles (β-CMs) with imidazolium based ionic liquid (IL) surfactant ([C12mim]Br) has been studied using turbidity, isothermal titration microcalorimetry, fluorescence spectroscopy, dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements. Below c1, the individual [C12mim]Br monomers bind onto the β-CM shell close to the hydrophobic core to form a β-CM–[C12mim]Br (monomer) complex. The hydrophobic tail of [C12mim]Br leads to a significant decrease in the environmental polarity of β-CM. Just over c1, [C12mim]Br molecules aggregate into micelle-like aggregates on the micellar shell. This leads to the collapse of the N-terminal of β-casein and strengthens the hydrophobicity of the protein molecules, resulting in a more compact structure of β-CM. With a continuous increase in[C12mim]Br concentration, β-CMs associate with each other into a network-like structure. Beyond c3, the net positive charges on the complexes, owing to the binding of more cationic surfactant molecules, lead to redissociation of the complexes, corresponding to the formation of the new nano-sized β-CM–[C12mim]Br complexes. All the β-casein molecules are saturated by [C12mim]Br aggregates above cs, and free [C12mim]Br micelle-like aggregates appear in the bulk phase above critical aggregation concentration (cac). From a combination of experimental results and discussion on various interactions in the β-CM–[C12mim]Br system, the hydrophobic interaction between the hydrophobic tail of ILs and the hydrophobic domain of β-CM, the electrostatic attraction between [C12mim]+ and negative charged amino acid residues on β-CM shell, and the hydrogen bonding between [C12mim]+ and carboxylic moiety on β-CM shell are the main forces for [C12mim]Br binding to β-CM. Modifications in the physicochemical properties of β-CM upon the addition of [C12mim]Br will expand and enhance the overall capabilities and applications of β-CM.
Co-reporter:Chuanqiang Zhou, Jie Han, Rong Guo
Journal of Colloid and Interface Science 2013 Volume 397() pp:80-87
Publication Date(Web):1 May 2013
DOI:10.1016/j.jcis.2013.01.052
Drying condensed colloid suspension droplet on a horizontal glass substrate has been developed as a simple strategy to fabricate highly-ordered colloidal crystals. A uniform film obtained at above room temperature possessed a face-center-cubic (fcc) crystalline structure and excellent photonic properties. It was found that raising the drying temperature has resulted in a reduction in the lattice spacing of fcc colloidal crystals. The formation reason of uniform fcc colloidal crystals was directly related to the high drying temperature and the large colloid concentration. A ring-shaped stain generated by drying at room temperature has exhibited other highly-ordered microstructures with colloidal crystals, such as body center cubic (bcc) structure.Graphical abstractHighlights► Drying condensed suspension droplet above 30 °C produced uniform colloidal crystals. ► Raising drying temperature could reduce the lattice spacing of colloidal crystals. ► Formation of uniform film was due to limited outward diffusion of solvent in drying. ► Uniform film dried at 30 °C was fcc feature but stain got at 25 °C had bcc lattices.
Co-reporter:Ayat A. Bozeya;Abeer F. Al-Bawab;Stig E. Friberg
Colloid and Polymer Science 2013 Volume 291( Issue 8) pp:1933-1938
Publication Date(Web):2013 August
DOI:10.1007/s00396-013-2932-y
The system water–benzene–ethanol was used to illustrate the complexity of spontaneous emulsification, when water-poor emulsions are brought in contact with water. In the first case, an O/W emulsion located close to the plait point in the system was used. The aqueous phase in the emulsion was incompatible with water, and a strong spontaneous emulsification to an O/W between the two liquids took place in the water layer close to the interface between layers. In the second case, a W/O emulsion, also close to the plait point, was brought in contact with water. Now, the spontaneous emulsification between the water and the oil phase of the original emulsion to an O/W emulsion also took place in the water layer forming a distinct emulsion layer beneath the interface.
Co-reporter:Yan Liu, Min Yuan, Lili Liu, Rong Guo
Sensors and Actuators B: Chemical 2013 176() pp: 592-597
Publication Date(Web):
DOI:10.1016/j.snb.2012.08.058
Co-reporter:Yan Liu, Lili Liu, Min Yuan, Rong Guo
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2013 Volume 417() pp:18-25
Publication Date(Web):20 January 2013
DOI:10.1016/j.colsurfa.2012.08.050
Casein micelle stabilized sub-10 nm gold nanoparticles (GNPs) which are hydrophilic and biocompatible, were synthesized in aqueous medium by chemical reduction of HAuCl4 in the presence of amphiphilic protein aggregates, casein micelles. The prepared GNPs were evidenced by UV–vis spectroscopy, TEM, FTIR, and XRD analysis. The size of the GNPs can be controlled easily by adjusting casein concentration and the environment pH in the system. Furthermore, casein micelle stabilized GNPs function as effective catalyst to activate the reduction of 4-nitrophenol (to form 4-aminophenol) in the presence of NaBH4. The catalytic activity of GNPs depends upon the nanoparticle size, the casein concentration and the pH used for synthesis. On the basis of their excellent colloidal stability and catalytic function, and biocompatible surface, the casein micelle-stabilized GNPs hold great promise for being used in nanoscience and biomedical applications.Graphical abstractHighlights► Sub-10 nm sized gold nanoparticles (GNPs) stabilized by protein are prepared. ► Size of GNPs can be controlled by pH and casein concentration. ► GNPs exhibit catalytic activity for the reduction of aromatic nitro compounds. ► Catalytic activity of GNPs depends on GNP size, the casein concentration and pH used for synthesis.
Co-reporter:Duo Wei, Lingling Ge, Yuanhua Ding, Rong Guo
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2013 Volume 421() pp:16-25
Publication Date(Web):20 March 2013
DOI:10.1016/j.colsurfa.2012.12.032
Interactions between hydrophilic modified ibuprofen (Ibuprofen-PEG800, IP800) and copolymers (poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide), PEO–PPO–PEO) were systematically investigated by nuclear magnetic resonance (NMR), dynamic light scatter (DLS), and freeze-fractured transmission electron microscopy (FF-TEM). EO19PO69EO19 (P123) and EO76PO29EO76 (F68) were chosen to explore the effect of chain lengths of copolymers on the interaction by comparison with EO100PO65EO100 (F127) previously studied by us. For P123 with shorter PEO chains compared to F127, the general microstructural transition of P123/IP800 complex was quite similar to F127 irrespective of the initial conformation state of the copolymer. In P123 micelle dominated solutions, it was found that about 13 IP800 molecules were required to disarrange P123 micelles, while about 7 sufficed to disrupt F127 micelles. For F68 with shorter PPO chains compared to F127, there were no loosely coiled aggregates formed in F68 unimer dominated solutions. In the intermediate state of F68 aggregation, an increase of IP800 concentration or temperature induced the formation of the loose F68 micelle/IP800 complex, and eventually disintegrated the complex to form small complex as several IP800 molecules adsorbing on F68 unimers while the complexes with a skeleton of IP800 micelles and copolymer chains threading through were formed in F127 and P123 systems.Highlights► Interaction of modified ibuprofen with different composition copolymers is compared. ► Shorter PEO chains promote the formation of loosely coiled complex. ► About 7 IP800 molecules can disrupt F127 micelles but about 13 for P123 micelles. ► Shorter PPO chains promote the interaction.
Co-reporter:Lingling Ge, Qi Wang, Duo Wei, Xiaohong Zhang, and Rong Guo
The Journal of Physical Chemistry B 2013 Volume 117(Issue 48) pp:15014-15022
Publication Date(Web):November 14, 2013
DOI:10.1021/jp405838v
The aggregation of ionic liquid-based double-tailed surfactant, 1,3-dioctylimidazolium bromide ([Doim]Br) and its interaction with pluronic copolymer F127 were systematically investigated by nuclear magnetic resonance (NMR), surface tension, dynamic light scattering (DLS), and isothermal titration calorimetry (ITC). It was found that the [Doim]Br aggregates are composed with the alkyl chains embedded in the micellar core and with the imidazolium rings parallel and staggered on the hydrophilic layer of micelles, which was generally different from the single-tailed IL [omim]Br. The hydrogen bonding between protons attached to the imidazolium rings and anion Br– was enhanced upon the aggregation of [Doim]Br. The aggregation of F127 was promoted by addition of [Doim]Br, which was more efficient than the single-tailed surfactant. At lower [Doim]Br content, [Doim]Br monomers embedded deeply into F127 micelle core. At higher [Doim]Br concentrations, the F127 micelles were disassociated, and then F127 chains penetrated into [Doim]Br micelle. In addition, the microstructure of F127/[Doim]Br complex can also be tuned by temperature.
Co-reporter:Lei Fan, Le Tang, Huifang Gong, Zhiheng Yao and Rong Guo
Journal of Materials Chemistry A 2012 vol. 22(Issue 32) pp:16376-16381
Publication Date(Web):20 Jun 2012
DOI:10.1039/C2JM32241B
Monodisperse carbon nanoparticles encapsulated in hollow NiO nanostructures (C@NiO) have been successfully synthesized by calcination from a Ni(OH)2 covered carbon (C@Ni(OH)2) precursor. The as-prepared products at each stage were extensively characterized and carefully discussed. The electrochemical properties of the carbon encapsulated in hollow NiO nanostructures were investigated using cycling voltammetry and charge–discharge techniques. The specific capacitance of the obtained C@NiO electrode was about 988.7 F g−1 at a current density of 0.5 A g−1. It shows better performance than hollow NiO spheres obtained in oxygen atmosphere. Furthermore, the C@NiO electrode shows a good capacitive retention of ca. 90.7% after 1000 charge–discharge cycles.
Co-reporter:Jie Han, Lu Wang and Rong Guo
Journal of Materials Chemistry A 2012 vol. 22(Issue 13) pp:5932-5935
Publication Date(Web):27 Feb 2012
DOI:10.1039/C2JM16583J
Polystyrene@Polyaniline@Au/m-SiO2 yolk/shell nanostructures containing numerous sub-10 nm gold nanoparticles in each particle as highly stable/recyclable polymer-supported gold catalysts have been suggested.
Co-reporter:Yan Liu, YongJian Cui, HuiYuan Mao, and Rong Guo
Crystal Growth & Design 2012 Volume 12(Issue 10) pp:4720
Publication Date(Web):August 27, 2012
DOI:10.1021/cg3005213
Phosphoproteins have specific and prominent influences on mediating the crystallization of calcium carbonate. In this research, a new kind of calcium carbonate crystal with a novel self-organized spiky dumbbell-like superstructure was synthesized in the presence of one typical phosphoprotein-casein. A complex self-assembly process for the formation of the hierarchical superstructures in the presence of casein has been proposed. The effects of the concentration of calcium ion, the reaction time, and temperature are investigated. The results indicate that phosphate groups of casein play important roles in directing growth and self-assembly of hierarchical superstructures. Our studies may contribute to the understanding of the specific role of phosphoprotein in the biomineralization process. We also believe that our studies will provide new insights into controlling the structure and morphology of minerals under easily attainable reaction conditions in the presence of phosphoprotein.
Co-reporter:Jie Han, Ping Fang, Wenjuan Jiang, Liya Li, and Rong Guo
Langmuir 2012 Volume 28(Issue 10) pp:4768-4775
Publication Date(Web):February 16, 2012
DOI:10.1021/la204503b
A facile one-step method was proposed for the successful synthesis of Ag-nanoparticle-loaded mesoporous silica SBA-15 composites, where silver ions and their corresponding reductant aniline were added in the traditional synthetic system of mesoporous silica SBA-15 containing P123 as the surfactant and TEOS as the silica source. Mesoporous silica SBA-15 and Ag nanoparticles were spontaneously formed with Ag nanoparticles embedded in channels and even implanted in frameworks of mesoporous silica SBA-15. A tentative formation process was then proposed according to experimental observations. Furthermore, catalytic activities of Ag-nanoparticle-loaded silica SBA-15 composites toward the reduction of 4-nitrophenol in the presence of NaBH4 and the reduction of H2O2 were also investigated.
Co-reporter:Yan Liu, YongJian Cui, and Rong Guo
Langmuir 2012 Volume 28(Issue 14) pp:6097-6105
Publication Date(Web):March 14, 2012
DOI:10.1021/la300320r
Amorphous calcium carbonate (ACC) plays important roles in biomineralization, and the phosphoproteins extracted from biogenic stable ACC can induce and stabilize synthetic ACC in vitro. Here, mineralization of square-shaped ACC plates with micrometer-sized channels has been reported in the presence of the amphiphilic phosphoprotein casein. Casein can be assumed to take a key role during ACC plate formation, where it serves as an effective stabilization agent for ACC and assembles spherical ACC particles into ACC plates. The stabilizing effect of casein arises from the electrostatic attraction between phosphate groups as well as carbonate groups (especially the former) and the calcium ions, preventing the transformation from unstable ACC to the more stable crystalline phase of CaCO3. The assembling effect of casein mainly comes from the hydrophobic interaction between casein molecules bound on CaCO3 particle surface. The inclusion of casein in ACC plates revealed by the thermogavimetric analysis confirms the proposed stabilizing and assembling mechanism. The ability to fabricate such novel hierarchical structured ACC holds the promise for creating more complex micro- and nanostructured materials by use of biological proteins with special structure.
Co-reporter:Jie Han, Ping Fang, Jie Dai, and Rong Guo
Langmuir 2012 Volume 28(Issue 15) pp:6468-6475
Publication Date(Web):March 23, 2012
DOI:10.1021/la300619d
Polyaniline (PANI) hollow nanospheres with controllable incontinuous nanocavities ranging in size from 10 to 50 nm as a novel hollow nanostructure have been successfully fabricated by chemical polymerization of aniline with chloroaurate acid as the oxidant and citric acid as the doping acid. Experimental factors, such as concentration and kind of oxidant and doping acid, were investigated to illustrate their effect on morphology of PANI. According to experimental results and time-dependent investigations, a possible formation mechanism involved was then proposed. The adaptability of this route to hollow nanostructures with multicavities of other conducting polymer was also revealed. Furthermore, the adsorption properties of PANI hollow nanospheres toward lead ions in water were investigated.
Co-reporter:Jie Han, Liya Li, Ping Fang, and Rong Guo
The Journal of Physical Chemistry C 2012 Volume 116(Issue 30) pp:15900-15907
Publication Date(Web):July 9, 2012
DOI:10.1021/jp303324x
A facile and scalable one-step strategy has been proposed for patterning ultrathin MnO2 nanorods (3 nm in diameter) on surfaces of almost all major classes of electronic conducting polymer nanofibers merely using conducting polymer nanofibers and KMnO4 as raw materials. The loading amount and patterning of MnO2 nanorods on surfaces of conducting polymers of typical polyaniline (PANI) nanofibers can be controlled by simply altering the KMnO4 concentration. Mechanisms involved in the formation of PANI–MnO2 composites were further revealed according to experimental results. In comparison with PANI nanofibers, the specific capacitance of PANI–MnO2 composites has substantially increased by almost fourfold, with values as high as 417 F g–1 achieved. The combination of ultrathin MnO2 nanorods and PANI nanofibers into one-dimensional hierarchical nanostructures show excellent electrochemical properties for energy storage applications, which evidence their potential application as supercapacitors.
Co-reporter:Huixin Xiong and Rong Guo
Environmental Science & Technology 2011 Volume 45(Issue 1) pp:235-240
Publication Date(Web):December 3, 2010
DOI:10.1021/es1019146
Iron oxyhydroxides as the efficient scavengers for heavy metals have been extensively investigated in iron-rich acid sulfate waters in the presence of Acidithiobacillus ferrooxidans (A. ferrooxidans, an especially important chemolithoautotroph for bioleaching and desulfurization of coal). In this study, we observed the morphology and elemental composition of cells in stationary phase and examined the dynamic variation of iron oxyhydroxides produced in cultures of A. ferrooxidans incubated in modified 9K medium initially including 0.15 M of ferrous iron, in the absence/presence of 0.2 M of chloride (NaCl/FeCl2). Results showed that chloride acclimation had little effect on cellular morphology and elemental uptake that was mainly related to culture medium. Furthermore, schwertmannite with the typical morphology of aggregated spheres covered by some “pincushions” was precipitated first in bacterial cultures in the favorable pH range of 2.9 ± 0.1 to 2.6 ± 0.1. Some of schwertmannite could be transformed to lozenge-shaped jarosite, due to a successively decreasing of pH values. However, the jarosite transformation represented a lag period of 5 and 4 days in the chloride-rich cultures with sulfate at a low level, compared to the cultures with sulfate at a high level, which could be attributed to the influence of sulfate requirement and chloride acclimation.
Co-reporter:Jie Han;Lu Wang
Macromolecular Rapid Communications 2011 Volume 32( Issue 9-10) pp:729-735
Publication Date(Web):
DOI:10.1002/marc.201000780
Co-reporter:J. Han, J. Dai, R. Guo
Journal of Colloid and Interface Science 2011 Volume 356(Issue 2) pp:749-756
Publication Date(Web):15 April 2011
DOI:10.1016/j.jcis.2011.01.038
Two kinds of different-shaped poly(o-phenylenediamine) (PoPD) polymers: solid and hollow sub-microspheres with both size of about 700 nm synthesized by a solution route without any additional directing agents, were employed as efficient adsorbents for removal of Pb(ІІ) ions from water. Firstly, chemical structures of PoPD sub-microspheres were performed by Fourier-transform infrared (FT-IR), UV–vis, 1H NMR spectra, X-ray diffraction (XRD) and GPC analysis. When used as adsorbents, both PoPD hollow and solid sub-microspheres showed high adsorptivity and adsorption capacity towards Pb(ІІ) ions in water, and mechanisms of adsorption behaviors were revealed by XRD and X-ray photoelectron spectra (XPS). It was found that the pH and concentration of Pb(ІІ) ion solution, as well as contact time and adsorbent dosage affect the degree of adsorption. Adsorption isotherms and kinetics of Pb(ІІ) ions onto PoPD sub-microspheres were also investigated according to experimental data. Comparative investigations of adsorption behaviors revealed that hollow sub-microspheres showed enhanced adsorptivity adsorption capacity towards Pb(ІІ) ions as compared with solid sub-microspheres typical at low adsorbent dosage. PoPD hollow sub-microspheres also showed good adsorptivity for other heavy-metal ions, such as Hg(ІІ), Cd(ІІ) and Cu(ІІ), which implied their potential applications as effective adsorbents for heavy-metal ions in water.Graphical abstractAdsorption behaviors of PoPD hollow and solid sub-microspheres towwards Pb(ІІ) ions in water have been investigated in detail, where enhanced adsorption performances of PoPD hollow sub-microspheres have been evidenced..Research highlights► PoPD hollow and solid sub-microspheres with similar size have been synthesized. ► Comparative adsorption properties of Pb(ІІ) ions onto PoPD have been investigated. ► PoPD also show high adsorption capacity for other heavy-metal ions.
Co-reporter:Fan Lei, Tang Le and Guo Rong
CrystEngComm 2011 vol. 13(Issue 24) pp:7246-7251
Publication Date(Web):28 Sep 2011
DOI:10.1039/C1CE05735A
In this article, the tube-like nickel oxide materials was synthesized by decomposition of nickel oxalate which was prepared by a facile hydrothermal method. Some experimental parameters affecting the morphology were studied. The electrochemical capacitive properties of the nickel oxide macrotubes were investigated using cycling voltammetry and charge/discharge techniques with KOH as electrolytes. The specific capacitance of the obtained nickel oxide macrotube electrode was measured to be as high as 701.2 F g−1 at a current density of 0.5 A g−1. The effect of calcination temperature and current density on the specific capacities were also studied. Furthermore, the obtained nickel oxide shows a good capacitive retention of ca. 93% after 1000 charge/discharge cycles.
Co-reporter:Yan Liu, Rong Guo
Materials Chemistry and Physics 2011 Volume 126(Issue 3) pp:619-627
Publication Date(Web):15 April 2011
DOI:10.1016/j.matchemphys.2011.01.008
A straightforward and economically viable approach was developed to biomimetic synthesis of gold nanocrystals by using casein micelles (CMs) without additional reductant. The UV–vis, TEM, SAED, FTIR, DLS and XRD techniques were employed to systematically characterize Au nanocrystals synthesized. Isotropic gold nanoparticle (GNP) and gold nanoplates in good yields (up to 90%) with different sizes can be obtained easily by adjusting the experimental condition. Spherical nanoparticles were obtained with tunable mean sizes at higher pH and casein concentrations. The high colloidal stability of the spherical GNP is attributed to the formation of CM/GNP hybrid under some experimental condition. At lower pH, reaction temperature and casein concentrations, single-crystalline gold nanoplates in good yields (up to 90%) are obtained. The growth of these nanostructures is attributed to an interplay between the faceting tendency of the protein molecules/micelles and the growth kinetics. More importantly, the morphological evolution of large gold nanoplates at different reaction times has been followed, and compared with some earlier protein systems, different formation mechanisms in casein micelles are obtained. The results demonstrate that both the property of individual protein molecules and protein aggregates play important roles in controlling the formation of gold nanocrystals by using amphiphilic protein.Research highlights► Gold nanocrystals were synthesized by using casein micelles without additional reductant. ► GNP and gold nanoplates in good yields were obtained by adjusting the experimental condition. ► The high colloidal stability of the spherical GNP is attributed to the formation of CM/GNP hybrid. ► Nanocrystals growth is caused by the faceting tendency of the protein and the growth kinetics.
Co-reporter:Jie Han, Jie Dai, Liya Li, Ping Fang, and Rong Guo
Langmuir 2011 Volume 27(Issue 6) pp:2181-2187
Publication Date(Web):February 16, 2011
DOI:10.1021/la200256j
Uniform poly(2-aminothiophenol) nanofibers embedded with highly dispersed gold nanoparticles have been fabricated through a facile templateless one-step method. The diameter of composite nanofibers can be controlled in the range of 200−80 nm by simply tuning the speed of mechanical stirring during materials synthesis. Results from our work will provide insight into the shape-controlled synthesis of other nanomaterials by simply introducing mechanical agitation. Removal of gold nanoparticles in composite nanofibers leads to polymer nanotubes with continuous or incontinuous nanocavities depending on mechanical stirring speeds. Furthermore, morphology-dependent catalytic performances of such composites are also investigated.
Co-reporter:Yuxia Chen;Yan Liu;Shuyong Xian
Journal of Solution Chemistry 2011 Volume 40( Issue 1) pp:48-60
Publication Date(Web):2011 January
DOI:10.1007/s10953-010-9631-9
The interactions between protein and surfactant aggregates have been the subject of intensive studies due to their potential applications in biological systems. Here we report the interactions of hemoglobin (Hb) with vesicles and tube-like aggregates formed from mixtures of a histidine-derived bolaamphiphile and a cconventional surfactant dodecyltrimethylammonium bromide (DTAB). This study was performed using a combination of UV–vis spectroscopy, steady and synchronous fluorescence spectroscopy, circular dichroism, and microcalorimetry measurements. The secondary structure of the protein is disturbed, and then the partially unfolded protein is capable of penetrating the vesicles and tube-like aggregates, this is mainly the result of hydrogen bonding and hydrophobic interactions between Hb and the H2D/DTAB aggregates. The polar portion of the unfolded protein chains is near to the polar head of the amphiphile in the aggregate’s membrane. Hb is converted to hemichrome in the vesicles, and the heme monomer is solubilized in tube-like aggregates after escaping from the hydrophobic cavity of Hb.
Co-reporter:Yan Liu;Yang Liu
Journal of Solution Chemistry 2011 Volume 40( Issue 6) pp:1140-1152
Publication Date(Web):2011 June
DOI:10.1007/s10953-011-9712-4
Cyclodextrins offer the potential of modulating protein–surfactant interactions. In our work, the effect of cyclodextrin (CD) on the interaction between bovine serum albumin (BSA) and the anionic surfactant sodium dodecyl benzene sulfonate (SDBS) has been studied by isothermal titration calorimetry (ITC), fluorescence spectra and circular dichroism measurements. The presences of cyclodextrin can slightly hinder the strong interactions between BSA and SDBS by the combination of electrostatic and hydrophobic interactions between BSA and SDBS. Furthermore, the effectiveness of α-CD is lower than that of β-CD, due to the lower association constant between α-CD and surfactant. The presence of both α- and β-CD totally hinders the nonspecific interactions between BSA and SDBS, because the hydrophobic interaction between cyclodextrin and surfactant is stronger than that between BSA and surfactant.
Co-reporter:Ayat Bozeya, Abeer Al-Bawab, Stig E. Friberg, Rong Guo
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2011 Volume 373(1–3) pp:110-115
Publication Date(Web):3 January 2011
DOI:10.1016/j.colsurfa.2010.10.037
Water and a geranyl acetate solution of a non-ionic surfactant, a commercial C12EO4, were brought into contact in amounts to give a combination of a lamellar liquid crystal and an oil phase of equal weights at equilibrium and the equilibration transport between the layers was followed by measuring the change in layer heights with time. The initial reaction, lasting approximately two months, transferred surfactant from the oil phase to combine with water to form a birefringent layer initially containing excess water over the fraction in the liquid crystal in equilibrium with both water and oil phase. After this period the composition of the oil phase had reached a level corresponding to equilibrium with both water and a lamellar liquid crystal, while the birefringent phase, although a liquid crystal, still contained less water fraction than required for equilibrium. The final equilibration process of transferring the excess water to the formed liquid crystal was extremely slow with an estimated time to reach equilibrium of several years.Graphical abstractResearch highlights▶ Evaporation of emulsions. ▶ Deviations from equilibrium conditions. ▶ Determining the growth and reduction of the phase volumes. ▶ Slow inclusion of compounds into solid and liquid crystal. ▶ Evaluation was done of the behavior of emulsion after application on solid surface.
Co-reporter:Yuanhua Ding, Chengyi Li, Rong Guo
Ultrasonics Sonochemistry 2010 Volume 17(Issue 1) pp:46-54
Publication Date(Web):January 2010
DOI:10.1016/j.ultsonch.2009.02.011
Pomponlike La2(MoO4)3 microstructures assembled with single-crystalline nanoflakes have been facilely fabricated via a surfactant-assisted ultrasound route for the first time. Various synthesis conditions were examined, such as the surfactant concentration, the molecular structure of surfactants, and the pH value. The obtained pomponlike microstructures were characterized by X-ray diffraction (XRD), (field-emission) scanning electron microscopy [(FE)SEM], transmission electron microscopy (TEM), and nitrogen adsorption/desorption isotherms. It has been revealed that a minimum concentration of sodium dodecylsulfate (SDS) was required for the formation of pomponlike La2(MoO4)3 microstructures. When the SDS concentration is above 0.02 mol L−1, the pomponlike microstructures become more perfect, and the size is also increased with the increasing SDS concentration. Under the same sonication, similar pomponlike microstructures were obtained when a cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), was used instead of the anionic surfactant SDS, indicating that the hydrophobic alkyl chains are an important factor for the formation of the pomponlike La2(MoO4)3 microstructures. It is also found that the pomponlike La2(MoO4)3 microstructures can only be obtained within an optimal pH range of 8.0–9.0 under sonication. Based on TEM, Fourier transform infrared spectroscopy (FT-IR) and solubilization experiment, a formation mechanism of pomponlike La2(MoO4)3 microstructures was proposed, in which the collaborative action of surfactants and sonication plays a key role. Furthermore, the porosity of the pomponlike La2(MoO4)3 microstructures were discussed.
Co-reporter:Yan Liu, Yang Liu, Rong Guo
Journal of Colloid and Interface Science 2010 Volume 351(Issue 1) pp:180-189
Publication Date(Web):1 November 2010
DOI:10.1016/j.jcis.2010.07.032
Cyclodextrin (CD) modulated interactions between ionic surfactants with opposite charge and bovine serum albumin (BSA) at specific and nonspecific binding stages have been studied by isothermal titration calorimetry (ITC), fluorescence spectra and circular dichroism spectral measurements. At the specific binding stage with high affinity, the effectiveness of both α- and β-CD for hindering BSA–SDS interactions is quite weak; however, CD is more effective in hindering BSA–CTAB specific interactions. This is due to the cooperative electrostatic and hydrophobic interaction between BSA and SDS, and to the absence of the cooperative interaction between BSA and CTAB at the specific binding stage. For both BSA–SDS and BSA–CTAB systems (especially in the former system), α-CD is more effective in hindering BSA–surfactant interactions than β-CD. At the nonspecific binding stage, the addition of both α- and β-CD can hinder totally both BSA–SDS and BSA–CTAB hydrophobic interactions. This is caused by the more specific hydrophobic interaction between CD and surfactant compared with the hydrophobic interaction between BSA and surfactant. Our results show that the CD effect on the protein–surfactant interaction depends on both the nature of the protein–surfactant interaction and the complexing ability of CD with surfactant.Graphical abstractIllustration of the mechanism for modulating the specific interaction between BSA and surfactant by cyclodextrin, (A) BSA–SDS, (B) BSA–CTAB.Research highlights► CD has different effect on protein-surfactant specific and nonspecific interaction. ► CD effect depends on the nature of the protein–surfactant specific interaction. ► Cooperative interaction between BSA and SDS is hard to inhibit by CD. ► CD effect depends also on CD–surfactant (with linear tail) association constant.
Co-reporter:Wenjie Liu
Photochemistry and Photobiology 2010 Volume 86( Issue 4) pp:835-843
Publication Date(Web):
DOI:10.1111/j.1751-1097.2010.00752.x
Abstract
The influence of UV-irradiation on the interaction of hemoglobin (Hb) with Triton X-100 is investigated by UV–Vis absorption spectroscopy, fluorescence spectroscopy and freeze-fractured transmission electron microscopy. It is found that in Triton X-100/H2O systems Hb can convert to hemichrome but heme is not present, whereas in Triton X-100/n-C5H11OH/H2O microemulsion Hb can convert to hemichrome and then induce the heme monomer to leave the hydrophobic cavity of Hb. UV-irradiation can also convert Hb to hemichrome, and subsequently make heme to be photodegraded, in which the conversion rate depends on the structure of the surfactant aggregates. Furthermore, in order to understand the mechanism of photostabilization of Hb in Triton X-100 systems, the photostabilization of heme in the Triton X-100 aqueous solutions and Triton X-100/n-C5H11OH/H2O microemulsions has been studied.
Co-reporter:Yuanhua Ding, Lin Zhang, Ju Xie and Rong Guo
The Journal of Physical Chemistry B 2010 Volume 114(Issue 5) pp:2033-2043
Publication Date(Web):January 20, 2010
DOI:10.1021/jp9104757
The binding characteristics and molecular mechanism of the interaction between a typical ionic liquid (IL), 1-butyl-3-methylimidazolium chloride ([bmim]Cl), as a green solvent and DNA were investigated for the first time by conductivity measurements, fluorescence spectroscopy, dynamic light scattering (DLS), cryogenic transmission electron microscopy (cryo-TEM), circular dichroism spectroscopy, 31P nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared spectroscopy, isothermal titration calorimetry (ITC), and quantum chemical calculations. It was found that the critical aggregation concentration of [bmim]Cl is decreased in the presence of DNA, and the addition of [bmim]Cl induced a continuous fluorescence quenching of the intercalated probe ethidium bromide (EtBr), indicating that the interaction between the ionic liquid and DNA is sufficiently strong to exclude EtBr from DNA. DLS results show that [bmim]Cl can induce a coil-to-globule transition of DNA at a low IL concentration, which was confirmed by the cryo-TEM images of DNA−IL complexes. With [bmim]Cl added, the resulting globular DNA structures and the extended DNA coils are first compacted, and then grow in size. During the binding process, DNA maintains the B-form, but the base packing and helical structure of DNA are altered to a certain extent. The 31P NMR and IR spectra indicate that the cationic headgroups of bmim+ groups interact with the phosphate groups of DNA through electrostatic attraction, and the hydrocarbon chains of bmim+ groups interact with the bases through strong hydrophobic association. ITC results reveal the interaction enthalpy between [bmim]Cl and DNA and show that the hydrophobic interaction between the hydrocarbon chains of [bmim]Cl and the bases of DNA provides the dominant driving force in the binding. On the basis of quantum chemical calculations, it can be inferred that at a low IL concentration, the cationic headgroups of [bmim]Cl would be localized within several angstroms of the DNA phosphates, whereas the hydrophobic chains would be arranged parallel to the DNA surface. When the IL concentration is above 0.06 mol/L, the cationic headgroups are near DNA phosphates, and the hydrocarbon chains are perpendicularly attached to the DNA surface.
Co-reporter:Jie Han;Yan Liu;Lu Wang
Journal of Polymer Science Part A: Polymer Chemistry 2010 Volume 48( Issue 17) pp:3903-3912
Publication Date(Web):
DOI:10.1002/pola.24177
Abstract
This article describes a versatile two-step method for gold/polyaniline derivative core/shell nanocomposites with the aid of nonionic surfactant F127. First, F127 and monomer were introduced to gold colloids followed by the addition of oxidant to initiate the polymerization of monomer to afford a conducting polymer shell around each gold nanoparticle. Experimental parameters, such as kinds and concentrations of surfactant and monomer, gold core size and shape, reaction time, were systematically investigated to disclose the underground mechanisms involved in the formation of gold/polymer core/shell nanocomposites. Furthermore, Fourier transform infrared, ultraviolet–visible, X-ray diffraction, and X-ray photoelectron spectroscopy techniques were used to characterize the gold/polymer core/shell nanocomposites. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3903–3912, 2010
Co-reporter:Jie Han, Liya Li, and Rong Guo
Macromolecules 2010 Volume 43(Issue 24) pp:10636-10644
Publication Date(Web):November 23, 2010
DOI:10.1021/ma102251e
A facile and effective route has been proposed to synthesize gold nanoparticles with controllable size that uniformly deposited on surfaces of polyaniline (PANI) nanofibers, where PANI nanofibers themselves act as both supporter and reductant. Effects of reagent concentration, reaction time, and temperature on size and uniformity of gold nanoparticles are investigated. Furthermore, a functional doping acid of typical thioglycolic acid (TA) that introduced in PANI nanofibers shows good potential for improvement in uniformity of composites and control over gold nanoparticle size. Fourier transform infrared (FTIR), X-ray diffraction (XRD), and ultraviolet−visible (UV−vis) spectra are used to characterize PANI nanofiber/gold nanoparticle composites. Adaptability of this approach for making PANI nanofiber composites with other noble metal nanoparticles, such as platinum, silver, and palladium nanoparticles, is also studied. A possible formation mechanism involved has been then proposed. Furthermore, PANI nanofiber/gold nanoparticle composites are found to serve as effective recycled catalysts to activate the reduction of 4-nitrophenol (4NP) in the presence of NaBH4, where size of gold nanoparticles is found to play the determining role on catalytic activity.
Co-reporter:Ping Guo and Rong Guo
Journal of Chemical & Engineering Data 2010 Volume 55(Issue 9) pp:3590-3597
Publication Date(Web):May 27, 2010
DOI:10.1021/je100209x
The structural changes of wormlike micelles composed of Tween 80 and Brij 30 in the presence of a common ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) were studied. Upon addition of bmimBF4, the viscosities of the wormlike micelle systems decrease, or in other words, more Brij 30 is needed to attain a similar viscosity value. The changes of the storage/loss modulus and the relaxation time also show that the viscoelastic properties of the wormlike micelles decrease with increasing bmimBF4 concentration. We believe that these results are attributed to a wormlike-rod/spherical micellar transition in the wormlike micelle solution, which is further confirmed by freeze-fracture transmission electron microscopy (FF-TEM) images. Additionally, the location of bmimBF4 in mixed micelles was also studied to explain the structure transition in the above systems.
Co-reporter:Duo Wei, Lingling Ge and Rong Guo
The Journal of Physical Chemistry B 2010 Volume 114(Issue 10) pp:3472-3481
Publication Date(Web):February 23, 2010
DOI:10.1021/jp910315e
The solubility of ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID), is enhanced by synthesizing ibuprofen ester with a water-soluble polymer, poly(ethylene glycol) (PEG), and the product obtained functions as a nonionic surfactant (IBF-PEG800, IP800). The morphology and aggregation behavior of IP800 micelles and IP800/PEG complexes in aqueous solution are investigated by 1H NMR technology, dynamic light scattering (DLS), isothermal titration calorimetry (ITC), and fluorescence resonance energy transfer (FRET). The microstructure of IP800 micelles is strongly related to the concentration of IP800. IP800 monomers can form looser micelles at relatively low concentrations and much tighter micelles at high concentrations. And the binding model of PEG with looser IP800 micelles dramatically depends on the molecular weight and concentration of PEG: PEG with lower molecular weight (MW ≤ 2000 Da) inserts to the interface of the hydrophilic corona and hydrophobic core of IP800 micelles; PEG with higher molecular weight (MW > 2000 Da) binds to the surface of IP800 micelles, and one long PEG chain (6000 < MW ≤ 20000 Da) wraps several IP800 micelles. Besides, the ratio of short chain PEG400 to IP800 micelles of the IP800/PEG complex is about 15:1 at a fixed concentration of IP800 (0.05 mM), and for the long chain PEG20000 it is 1:3−1:4.
Co-reporter:Ping Guo and Rong Guo
Journal of Chemical & Engineering Data 2010 Volume 55(Issue 11) pp:5023-5030
Publication Date(Web):August 20, 2010
DOI:10.1021/je100611z
The enhancement of wormlike micellar structure after the addition of O-carboxymethylchitosan (OCMCS) or hydrophobically modified O-carboxymethylchitosan (hm-OCMCS) has been studied by rheology and freeze-fracture transmission electron microscopy (FF-TEM). The results show that the viscoelastic properties of the wormlike micelles composed of Tween 80 and Brij 30 increase significantly after the addition of OCMCS. However, as the OCMCS molecules are hydrophobically modified, the viscosity enhancement is reduced and even diminishes with an increase of the length of aliphatic chains. FF-TEM was also used to provide a direct investigation of the microstructure changes of wormlike micelles after the addition of OCMCS and hm-OCMCS. Combined with the rheological behavior of OCMCS and hm-OCMCS, it is speculated that these results originate from a greater degree of intra-aggregation of polymers after hydrophobic modifications, which results in a weaker interaction between polymers and micelles. Additionally, the influence of temperature on the rheological behavior of polymer/wormlike micelle systems also demonstrates the intra-aggregation of polymers is the main impact factor in these systems.
Co-reporter:Yan Liu, Lili Liu and Rong Guo
Langmuir 2010 Volume 26(Issue 16) pp:13479-13485
Publication Date(Web):July 26, 2010
DOI:10.1021/la101219r
We report a facile method for the fabrication of spongelike gold/amino acid nanocomposites by the addition of NaBr to glutamic acid-stabilized gold nanoparticles (GNPs) at room temperature. The gold/glutamic acid (Glu) nanocomposite is characterized by TEM, SEM, UV−vis spectroscopy, and XRD measurements. The results suggest that the three-dimensional spongelike gold/Glu nanocomposites with mean diameter of 50 nm are formed via the nanospheres fusing into one another. The driving force for the fabrication of spongelike gold/amino acid nanocomposites is the van der Waals attractive forces of Br− partially coated GNPs. Furthermore, the obtained spongelike gold nanocomposites can be used as surface-enhanced Raman scattering (SERS) substrates with high SERS activity and stability for detecting Rhodamine 6G (R6G) molecules. Hence, NaBr-mediated preparation of SERS substrates described in this work has potential applications in chemical and biological analysis as well as medical detection.
Co-reporter:Jie Chen;Lingling Ge;Stig E. Friberg
Colloid and Polymer Science 2010 Volume 288( Issue 4) pp:423-431
Publication Date(Web):2010 February
DOI:10.1007/s00396-009-2137-6
Three-phase geranyl acetate emulsions stabilized by a non-ionic surfactant, Laureth 4, were prepared with a constant weight fraction of a lamellar liquid crystal and varied aqueous to oil phase weight ratios according to the phase diagram. The appearance and micrographs of the drop pattern versus time were recorded. As expected, emulsions with the lower values of the water to oil (W/O) ratio appeared to be of the W/O variety while the two more stable emulsions with the highest W/O ratio appeared as oil to water (O/W). Considering the surfactant exclusive solubility in the oil, this result was unexpected and the emulsions were investigated as to their structure. Unpredictably, all the emulsions were of the O/W kind; including the highest ratio of oil to water. The reason for this unanticipated outcome was the lamellar liquid crystal being dispersed into the aqueous phase at the slightest perturbation.
Co-reporter:Jie Han;Yan Liu
Advanced Functional Materials 2009 Volume 19( Issue 7) pp:1112-1117
Publication Date(Web):
DOI:10.1002/adfm.200801018
Abstract
A novel method has been developed to synthesize gold nanoparticles with tunable size and morphology supported on both inner and outer surfaces of poly(o-phenylenediamine) (PoPD) hollow microspheres, which act as both reductant and template/stabilizer. The size of gold nanoparticles supported on shells of PoPD hollow microspheres can be tuned from 3 to 15 nm by changing the concentration of the gold source, HAuCl4. Gold nanorods supported on shells of PoPD hollow microspheres can also be fabricated by introducing a well-known seed-growth strategy. In addition, silver nanoparticles supported on shells of PoPD hollow microspheres can also be successfully fabricated using the same strategy, which indicates the diversity of this proposed method for polymer hollow microspheres supporting noble metal nanoparticles. The products are characterized by X-ray diffraction and contact angle analysis. Furthermore, the catalytic activity of the obtained PoPD-microsphere-supported gold nanoparticles for aerobic alcohol oxidation is investigated. The results demonstrate that such polymer-supported gold nanoparticles can be used as reusable catalysts with high catalytic activity for aerobic alcohol oxidation in water.
Co-reporter:Chuanqiang Zhou;Jie Han
Macromolecular Rapid Communications 2009 Volume 30( Issue 3) pp:182-187
Publication Date(Web):
DOI:10.1002/marc.200800585
Co-reporter:Lei Fan and Rong Guo
Crystal Growth & Design 2009 Volume 9(Issue 4) pp:1677-1682
Publication Date(Web):February 6, 2009
DOI:10.1021/cg800237a
Large-scale three-dimensional cadmium sulfide (CdS) spheres composed of hexagon-based pyramids were synthesized through a facile solution-phase reaction from CdCl2, thioacetamide, and a polymer, where the polymer acted as both a dispersant and coating agent. The reaction conditions influencing the synthesis of these three-dimensional (3D) CdS nanostructures such as reaction temperature, reaction time, the concentration of the polymer, and the kinds of precursors used were investigated. The phase composition, the morphology, and the structure of CdS nanostructures were examined by X-ray diffraction, X-ray photoelectron spectra, field emission scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. The possible formation mechanism of the novel CdS spheres was proposed based on the above analysis. The room-temperature Raman spectrum and photoluminescence spectra of the obtained CdS nanocrystals were also studied.
Co-reporter:Jie Han;Yan Liu
Journal of Applied Polymer Science 2009 Volume 112( Issue 3) pp:1244-1249
Publication Date(Web):
DOI:10.1002/app.29583
Abstract
Au/poly(o-toluidine) (POT) core/shell composite spheres have been successfully fabricated by chemical polymerization route in aqueous solution without the aid of surfactant or functional acids using HAuCl4 as the oxidant. By altering the concentration of oxidant, the amount of Au nanoparticles inside each POT sphere can be tuned from tens to one. Moreover, uniform POT hollow spheres with one opening in each polymer surface can be obtained under extremely low concentration of oxidant. The chemical structures of Au/POT composites were confirmed by Fourier transform infrared (FTIR), UV-vis, and X-ray diffraction (XRD) spectroscopies. Moreover, the formation mechanisms of Au/POT core/shell composites and POT hollow spheres were also discussed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Co-reporter:Jie Han, Yan Liu, Liya Li and Rong Guo
Langmuir 2009 Volume 25(Issue 18) pp:11054-11060
Publication Date(Web):May 29, 2009
DOI:10.1021/la901373t
A facile solution route was proposed for the successful synthesis of uniform poly(o-phenylenediamine) (PoPD) submicrospheres with an average diameter of 700 nm. Utilizing the reactivity of dedoped PoPD submicrospheres for gold salt HAuCl4, gold nanoparticles can be synthesized in the presence of PoPD without additional reductant for HAuCl4. Furthermore, PoPD submicrospheres with abundant amino groups and π electrons in benzene rings on their surfaces can significantly stabilize gold nanoparticles, which will lead to the formation of PoPD submicrosphere-supported gold nanoparticles. Reaction conditions, such as addition of poly(vinylpyrrolidone) and concentration of HAuCl4, were found to affect the size of gold nanoparticles. Products were characterized by Fourier-transform infrared (FT-IR) and X-ray diffraction (XRD) spectroscopies. The synthesized PoPD submicrosphere-supported gold nanoparticles with different size were used to evaluate their catalytic performances for benzyl alcohol. Results revealed that PoPD submicrosphere-supported gold nanoparticles showed high yield and selectivity for benzyl alcohol to aldehyde conducted under air and in water media. The factors, such as catalyst size and amount, solvent, temperature, alkali type, and reaction time, were all systematically investigated to elucidate their effects on the yield and selectivity of catalytic benzyl alcohol reactions.
Co-reporter:Lingling Ge, Rong Guo and Xiaohong Zhang
The Journal of Physical Chemistry B 2009 Volume 113(Issue 7) pp:1993-2000
Publication Date(Web):January 22, 2009
DOI:10.1021/jp808218j
Lamellar-to-isotropic phase transition is observed in the system of TX-100/n-C8H17OH/H2O induced by neutral water-soluble polymer poly(ethylene glycol) (PEG) with molecular weight ranging from 400 to 20 000. The location of PEG in the lamellar liquid crystal and the microstructure change of the lamellar phase during phase transition are investigated by means of 2H NMR, small-angle X-ray diffraction (SXRD), rheology, polarized optical microscopy (POM), and freeze−fracture transmission electron microscopy (FF-TEM). Calculations based on the “swelling model” show that 0.92−2.58 wt % PEG2000 penetrates into the amphiphile layer and the rest resolve in the water layer. Both of these two kinds of locations induce the lamellar-to isotropic phase transition. The longer the chain length of PEG, the higher the efficiency is. In addition, a critical molecular weight of PEG is observed before phase transition occurs, with which the disturbance of PEG on the microstructure of lamellar liquid crystal is most prominent. The critical molecular weight of PEG is independent of the thickness of water layer. The value is 2000 for the system of TX-100/n-C8H17OH/H2O.
Co-reporter:Chuanqiang Zhou, Jie Han and Rong Guo
Macromolecules 2009 Volume 42(Issue 4) pp:1252-1257
Publication Date(Web):January 27, 2009
DOI:10.1021/ma802191n
We reported the synthesis of nanostructure-covered rectangular submicrotubes of polyaniline in the doping state via the oxidation polymerization of aniline in the acidic solution of anionic surfactant. Both the concentrations of surfactant and inorganic acid employed in this preparing system are relatively low, which were essential to the successful fabrication of polyaniline hierarchical structures. We discussed the temperature dependence of polyaniline morphology and found that this synthesis admitted a wide range from 20 to 40 °C. After observing their growth processes, a tentative interpretation has been proposed to elucidate the formation of the tubular hierarchical structures in such a system. It was also found in this report that both SDS and HCl had profound impacts on the morphology of resulting product.
Co-reporter:Juqun Xi
Journal of Solution Chemistry 2009 Volume 38( Issue 12) pp:
Publication Date(Web):2009 December
DOI:10.1007/s10953-009-9469-1
In this paper, the interactions of an isoflavone molecule, Genistein (Gen), with Pluronic F127 at different pH values have been investigated using laser light scattering techniques, film analysis methods, UV-vis spectroscopy and transmission electron microscopy. The TEM images and the DSL studies indicate the formation of a Gen/F127 complex induced by the solubilization of Gen in micelles, and the stability of the Gen/F127 complex decreases with the increase of pH. At pH of 6.4, the turbidity of the Gen/F127 complex solution is significantly reduced in the presence of 0.31 mol⋅L−1 ethylene glycol, indicating the existence of hydrogen bonds between Gen and the F127 copolymer. Experiments on controlled release demonstrate that Gen-loaded F127 micelles act as a drug carrier, giving slow release to the surrounding solution over a period of time. Rapid release can be triggered by increasing the pH of the micelle solutions
Co-reporter:Hui Yue, Ping Guo and Rong Guo
Journal of Chemical & Engineering Data 2009 Volume 54(Issue 10) pp:2923-2929
Publication Date(Web):August 21, 2009
DOI:10.1021/je900023t
The phase behavior of the sodium dodecyl sulfate (SDS)/Brij 30/H2O system is shown by a phase diagram. The system can form micelle, reverse micelle, anisotropic lamellar, and hexagonal liquid crystal regions. The rheological behavior of the viscoselastic solution follows the Maxwell model at lower shear frequencies and deviates from it at higher shear frequencies in the oscillatory frequency sweeping experiment, which is the typical property of wormlike micelles entangled to form a transient network. In addition, the results are evaluated by dynamic light scattering and freeze-fracture images, which are consistent with the rheological behavior.
Co-reporter:Genping Song;Jie Han;Jie Bo
Journal of Materials Science 2009 Volume 44( Issue 3) pp:715-720
Publication Date(Web):2009 February
DOI:10.1007/s10853-008-3175-z
Polyaniline (PANI) nanostructures were synthesized in lamellar liquid crystal (LLC) formed by different surfactants. It was found that PANI presented lamellar nanostructures by using the template of LLC formed by ionic surfactant of sodium dodecyl sulfonate (SDS) or hexadecyltrimethylammonium bromide (CTAB), whereas PANI spheric nanostructures were obtained within the LLC template formed by the nonionic surfactant of Triton X-100. The formation mechanisms of PANI nanostructures were discussed. Besides, the lubricating effect of PANI in LLC template was also investigated, and the results showed that spheric PANI had better lubricative performance than lamellar PANI.
Co-reporter:Lei Fan and Rong Guo
Crystal Growth & Design 2008 Volume 8(Issue 7) pp:2150
Publication Date(Web):June 14, 2008
DOI:10.1021/cg701096g
Novel dendritic silver crystals, which consist of several branches with lengths up to 10 μm, have been successfully synthesized by a simple wet chemical route using l-ascorbic acid as reductant in cetyltrimethylammonium bromide (CTAB) and sodium dodecyl benzyl sulfonate (SDBS) mixed surfactant solution at room temperature. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and UV−vis absorption spectroscopy have been used to characterize the obtained silver products. It is found that the architecture of silver crystals is drastically influenced by the molar ratio, concentration of CTAB/SDBS, and the concentration of the precursors. It is revealed that the mixed-surfactant solution might play both capping reagent and dispersion reagent roles.
Co-reporter:Weiya Liu and Rong Guo
Molecular Pharmaceutics 2008 Volume 5(Issue 4) pp:588-597
Publication Date(Web):May 30, 2008
DOI:10.1021/mp7001413
Dimerization and antioxidant activity of morin in the Triton X-100 micelles were studied by electronic absorption, ATR-FTIR spectra, cyclic voltammetric, DSC, freeze−fracture TEM, molecular modeling and ab initio quantum calculations. Morin can be solubilized in the Triton X-100 micelles and show selective dimerization in Triton X-100 micelles with different structures. In Triton X-100 spherical micelles, morin always exists in the form of dimer, and in Triton X-100 rodlike micelles, it is always in the form of monomer. The solubilization of morin dimer in Triton X-100 spherical micelles changes the micelle morphology from spherical to cubelike, and the size of the single micelle is also increased, while morin monomer links the Triton X-100 rodlike micelles and forms a kind of network micelle structure with the size of the “rod” unchanged. Solubilized and concentrated in Triton X-100 micelles, morin can protect human serum albumin from the damage induced by hydroxyl radicals effectively and even can form a kind of protein complex with human serum albumin showing more thermal stability.Keywords: ab initio quantum calculation; antioxidant activity; dimerization; DSC; freeze−fractured TEM; HSA; hydroxyl radical; Morin; Triton X-100 micelle;
Co-reporter:Yuanhua Ding, Zhuqing Chen, Ju Xie, Rong Guo
Journal of Colloid and Interface Science 2008 Volume 327(Issue 1) pp:243-250
Publication Date(Web):1 November 2008
DOI:10.1016/j.jcis.2008.07.057
The adsorption behavior of thionine on gold nanoparticles of two different mean diameters, 18 and 5 nm, was compared by using UV–vis spectroscopy, fluorescence spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), and quantum chemical calculations. It is found that the addition of small particles makes the monomer peak of thionine finally disappear, and the corresponding dimer peak is significantly increased. Small gold nanoparticles make the equilibrium between the monomer and H-type dimer forms of thionine move largely toward the dimer forms. Due to the stronger binding between thionine and small gold nanoparticles, the fluorescence quenching of thionine by small particles is enhanced compared to large particles, and the quenching is both static and dynamic. TEM images indicate that the addition of thionine results in a heavy clustering for small particles, and the resulting thionine–gold nanoclusters of about 45 nm were obtained. Quantum chemical calculations, which were based on the density functional theory (DFT) at the B3LYP level, and infrared spectroscopic studies show that the nitrogen atoms of the NH2 moieties of thionine bind to the gold nanoparticle surfaces. For 18 and 5 nm particles, the surface-to-volume atomic ratios are about 0.0597 and 0.2148, respectively. The higher surface-to-volume atomic ratio and the higher surface free energy result in stronger binding of thionine on small particle surfaces, which can be used to modulate the arrangement of dye molecules on particle surfaces, and thus control the properties of organic–inorganic nanocomposite materials.The size effect of gold nanoparticles on the adsorption characteristics of thionine was investigated, and analyzed according to the binding model for thionine–Au complex obtained from quantum chemical calculations.
Co-reporter:Jie Han;Yan Liu
Journal of Polymer Science Part A: Polymer Chemistry 2008 Volume 46( Issue 2) pp:740-746
Publication Date(Web):
DOI:10.1002/pola.22459
Co-reporter:Juqun Xi
Journal of Solution Chemistry 2008 Volume 37( Issue 1) pp:107-118
Publication Date(Web):2008 January
DOI:10.1007/s10953-007-9217-3
In this paper, the effect of varying hydrophobic chain lengths on the acid-base equilibrium of an isoflavone, puerarin, in cationic micelles has been studied. The interaction of puerarin with three types of micelles of identical positively charged head groups and varying tail lengths, viz., DTAB, TTAB and CTAB, shows that there is a shift in the apparent pKa in the direction that favors the displacement of the acid-base equilibrium of puerarin towards the base form. The relative location depth of puerarin in micelles is determined according to their dielectric values (D) taking into account that lower D values correspond to deeper location. It is evident that the reduction of polarity favors the deprotonation of puerarin. The isothermal titration calorimetry measurements show that the effect of puerarin on the thermodynamic properties of micellization is enhanced in the order CTAB>TTAB>DTAB and the results illustrate that puerarin has more affinity for micelles with greater chain length.
Co-reporter:Chuanqiang Zhou, Jie Han and Rong Guo
Macromolecules 2008 Volume 41(Issue 17) pp:6473-6479
Publication Date(Web):August 13, 2008
DOI:10.1021/ma800500u
Polyaniline multidimensional architectures from plate-like structures to flower-like superstructures have been successfully tailored by the oxidation polymerization in dilute aniline solution at room temperature, when the molar ratio of oxidant to monomer was altered in the range of 0.1:1−0.8:1. It was found that at low molar ratio (0.1:1−0.3:1) plate-like structures could be synthesized, while the as-synthesized product at the higher molar ratio (0.4:1−0.8:1) was flower-like superstructures; and the effect of monomer concentration on the shape of plate-like or flower-like architectures was also investigated. More importantly, their growth processes have been followed by measuring the morphological evolutions and chemical structures of products with the different reaction times, and then a plausible interpretation to their formation was brought forward through discussing the polymerization courses at two molar ratios (0.2:1 and 0.6:1). Besides, the molecular weight and conductivity of products obtained were also measured in this report.
Co-reporter:Lingling Ge, Rong Guo and Xiaohong Zhang
The Journal of Physical Chemistry B 2008 Volume 112(Issue 46) pp:14566-14577
Publication Date(Web):July 8, 2008
DOI:10.1021/jp802717p
Formation and structure transition of the complex composed of triblock copolymer F127 and nonionic surfactant TX-100 have been investigated by 1H NMR spectroscopy, dynamic light scattering (DLS), and isothermal titration calorimetry (ITC). Three TX-100 concentration regions are identified, within which TX-100/20 mg/mL F127 complex undergoes different temperature-induced structure transitions. In low concentration region (<9.42 mM), F127 single molecular species (unimers) wrap around TX-100 micelles forming F127/TX-100 complex with TX-100 micelle as the skeleton at a lower temperature (5 °C), and the skeleton transfers to F127 micelle at higher temperature (40 °C); in intermediate TX-100 concentration region (9.42−94.85 mM), the skeleton of F127/TX-100 complex transfers from TX-100 micelle successively into F127 micelle and TX-100 micelle again upon heating. The interaction of F127 with TX-100 is saturated in high TX-100 concentration region (>157.57 mM), and free TX-100 micelles coexist with larger clusters of F127/TX-100 complexes. In addition, TX-100-induced F127/TX-100 complex formation and structure transition are also investigated at constant temperatures. The results show that within 5−10 °C, F127 unimers mainly adsorb on the surface of TX-100 micelles just like normal water soluble polymers; in the temperature region of 15−25 °C, TX-100 micelles prompts F127 micelle formation. Within 30−40 °C, TX-100 inserts into F127 micelles leading to the breakdown of F127 aggregates at higher TX-100 concentrations, and the obtained unimers thread through TX-100 micelles forming complex with TX-100 micelle as skeleton.
Co-reporter:Lei Fan
The Journal of Physical Chemistry C 2008 Volume 112(Issue 29) pp:10700-10706
Publication Date(Web):June 26, 2008
DOI:10.1021/jp8022259
Novel CdIn2S4 hollow spheres with small bipyramids aggregating on their surface had been successfully synthesized via a facile hydrothermal process without any template or surfactant. The crystal structure, morphology, and optical properties of the products were characterized by X-ray diffraction, X-ray photoelectron spectra, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, UV−vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy. The reaction conditions influencing the synthesis of these CdIn2S4 hollow sphere structures, such as reaction temperature, reaction time, and the kinds of solvent used, were investigated. Furthermore, on the basis of a series of observations, phenomenological elucidation of a mechanism for the growth of the CdIn2S4 hollow spheres has been presented.
Co-reporter:Chuanqiang Zhou;Jie Han;Genping Song
Journal of Polymer Science Part A: Polymer Chemistry 2008 Volume 46( Issue 11) pp:3563-3572
Publication Date(Web):
DOI:10.1002/pola.22695
Abstract
A one-step route has been reported for the fabrication of poly(aniline-co-pyrrole) (PACP) copolymer hollow nanospheres via the oxidation polymerization of a mixture of aniline and pyrrole in the presence of Triton X-100. It was found that the variations in polymerization conditions, such as the concentrations of Triton X-100 and comonomers, and [pyrrole]/[aniline] molar ratios, could change the size and uniformity of copolymer hollow nanospheres. The result of DLS has attested the presence of the spherical Triton X-100 micelles swelled by the comonomers in reaction system, and such micelles might play template for the formation of hollow nanospheres, followed by developing a possible formation mechanism. The chemical structures and crystallinity of products were characterized by FTIR, UV–visible, 1H NMR spectra, and XRD patterns, respectively, to prove the copolymer chemical structures of hollow nanospheres. The thermal-stability and solubility of PACP were improved compared with homopolymers (polyaniline and pyrrole). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3563–3572, 2008
Co-reporter:J. Han;R. Guo;G. Song
Advanced Materials 2007 Volume 19(Issue 19) pp:2993-2999
Publication Date(Web):5 SEP 2007
DOI:10.1002/adma.200602635
Nanostructure-based leaf-like polyaniline (PANI) (see figure) has been fabricated successfully in the presence of surfactant F127. It is found that the building blocks of leaf-like PANI can be tuned from nanofibers (ca. 25 nm in diameter) to nanotubes (ca. 100 nm in diameter) with increasing monomer concentration. The proposed synthetic method will provide insight into the synthesis of oriented nanostructures of polymer materials by the soft-template strategy.
Co-reporter:Yan Liu, Rong Guo
Journal of Colloid and Interface Science 2007 Volume 315(Issue 2) pp:685-692
Publication Date(Web):15 November 2007
DOI:10.1016/j.jcis.2007.07.018
The interaction of the anionic surfactant sodium dodecyl sulfate (SDS) with 2.0 mg/ml casein was first investigated using isothermal titration calorimetry (ITC), dynamic light scattering (DLS), and fluorescence spectra. ITC results show that individual SDS molecules first bind to casein micelles by the hydrophobic interaction. The micelle-like SDS aggregate is formed on the casein chains when SDS concentration reaches the critical aggregation concentration (c1c1), which is far below the critical micellar concentration (cmc) of SDS in the absence of casein. With the further increase of SDS concentration to the saturate binding concentration c2c2, SDS molecules no longer bind to the casein chains, and free SDS micelles coexist with casein micelles bound with SDS aggregates in the system. DLS results show that the addition of SDS leads to an increase in the hydrodynamic radius of casein micelles with bound surfactant at SDS concentration higher than 4 mM, and also an increase in the casein monomer molecule (or submicelles) at SDS concentration higher than 10 mM. Fluorometric results suggest the addition of SDS leads to some changes in the binding process of hydrophobic probes to casein micelles.The isothermal titration curves for titrating 200 mM SDS into (■) 0; (●) 0.25; (▴) 0.5; (▾) 1.0; (♦) 2.0; (◂) 5.0 mg/mL casein solution.
Co-reporter:Tian-Qing Liu
Chinese Journal of Chemistry 2007 Volume 25(Issue 4) pp:
Publication Date(Web):5 APR 2007
DOI:10.1002/cjoc.200790092
The influences of Triton X-100 on hemoglobin (Hb) behaviors were studied by the methods of UV-Vis spectrum, fluorescence spectrum, HPLC, conductivity, zeta potential and negative-staining transmission electron microscope in Hb/acyclovir/Triton X-100/H2O system. With the increase of Triton X-100 concentration in the system, the percentage of the free acyclovir increased from 58%–63% to 90%–94%. The static quenching constant and the association number of acyclovir to Hb decreased. The fluorescence spectrum, conductivity, zeta potential, fluorescence polarization and negative-staining morphology of Hb tended to recover to those of the original state of Hb in the same concentration of Hb. The interaction between Triton X-100 and Hb is stronger than that between acyclovir and Hb. Most Triton-X-100 was associated with Hb at low Triton X-100 concentration. But the interaction of Triton X-100 with Hb was apparently dominant in high Triton X-100 concentration. The Hb structure was unfolded and finally denatured.
Co-reporter:Genping Song, Jie Han, Rong Guo
Synthetic Metals 2007 Volume 157(4–5) pp:170-175
Publication Date(Web):March 2007
DOI:10.1016/j.synthmet.2006.12.007
Polyaniline (PANI) nanotubes (∼180 nm in diameter) were synthesized in the presence of sodium dodecylbenzenesulfonate (SDBS) as a micellar template and dopant, whereas PANI/NiO nanobelts (300–700 nm in diameter) were obtained with the addition of NiO nanoparticles (∼10 nm in diameter). Results showed that the size of PANI/NiO composite nanobelts increased with an increase content of NiO nanoparticles. XRD, Fourier transform infrared (FTIR) and UV–vis spectroscopy were used to characterize the chemical structures of PANI nanotubes and PANI/NiO nanobelts. The thermal stability and conductivity of samples were affected by the content of NiO. The coordination bonds between NiO and aniline were the key factor that resulted in the morphological change of PANI.
Co-reporter:Tianqing Liu
Colloid and Polymer Science 2007 Volume 285( Issue 6) pp:711-713
Publication Date(Web):2007 March
DOI:10.1007/s00396-006-1627-z
A stable niosome is prepared from Poly(ethylene glycol) [PEG] 6000/Tween 80/Span 80/H2O lamellar liquid crystal. The niosome structures and properties are studied by the methods of negative-staining transmission electron microscopy and small angle X-ray diffraction. A new calculating method is first put forward to obtain the microstructure and layer number of the niosome membrane. The membrane thickness and layer number of the niosome are 8–22 nm and 1–3.5 in PEG 6000/Tween 80/Span 80/H2O system.
Co-reporter:Lingling Ge;Liping Chen
Tribology Letters 2007 Volume 28( Issue 2) pp:123-130
Publication Date(Web):2007 November
DOI:10.1007/s11249-007-9256-3
The microstructure of lamellar liquid crystal composed by nonionic surfactant polyoxyethylene laurylether (Brij30), room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6) and water is investigated by deuterium nuclear magnetic resonance (2H NMR) and rheological techniques. And the lubrication properties of the lamellar mesophase are determined to illustrate their relationship with the microstructure. The results show that the structure strength of the lamellar phase is enhanced with increasing amount of Brij30, so the anti-wear capacity of the lamellar phase is improved. But, both of the structure strength and lubrication properties are impaired with increasing water content in the system due to the increased interlayer space and the penetration of water into the amphiphile bilayer. However, though the structure of the lamellar phase is disturbed by [Bmim]PF6, the lubrication properties are still improved due to the inherent lubrication properties of [Bmim]PF6.
Co-reporter:Yongsheng Wang;Xia Guo
Colloid and Polymer Science 2007 Volume 285( Issue 13) pp:1423-1431
Publication Date(Web):2007 October
DOI:10.1007/s00396-007-1698-5
A biocompatible surfactant-n-dodecylammonium α-glutamate (GDA) with biodegradable and biocompatible properties was synthesized, and the phase behavior and the structural properties of GDA/n-pentanol/water system was studied by small-angle X-ray diffraction, electron spin resonance, and freeze-fracture transmission electron microscopy (FF-TEM). In the ternary phase diagram of GDA/n-pentanol/water system, there exist three isotropic regions—O/W, bicontinuous, and W/O structures, and two anisotropic regions—hexagonal liquid crystal (HEX), and lamellar liquid crystal (LLC) regions. UV irradiation causes the decrease in the interlayer space, d, of lamellar liquid crystal and in the radius, r, of column aggregates of hexagonal liquid crystal, but it has little effect on the structure of O/W and W/O microemulsions.
Co-reporter:JuQun Xi
Science Bulletin 2007 Volume 52( Issue 19) pp:2612-2617
Publication Date(Web):2007 October
DOI:10.1007/s11434-007-0395-6
Fluorescence emission spectra, FTIR spectra, zeta potential measurements, and ab initio quantum calculation are used to study the interaction between puerarin and membranes composed of egg phosphatidylcholine (PC) liposome. The hydrophobic interactions cause the puerarin molecule to partition into lipid bilayers with its B-ring, and favor the displacement of acid-base equilibrium of puerarin towards the base form. Due to the hydrogen bond formation between the puerarin hydroxyl groups and polar groups of PC molecules on the water/membrane interface, puerarin can easily intercalate into the organized structure of phospholipids and modulate the membrane function. Our results reveal that the liposome membrane integrity is significantly higher compared with that of empty liposome.
Co-reporter:Yan Liu
Journal of Solution Chemistry 2007 Volume 36( Issue 9) pp:1079-1092
Publication Date(Web):2007 September
DOI:10.1007/s10953-007-9172-z
In cetyltrimethylammonium/n-pentanol/H2O W/O (W/O = water in oil microemulsion) mixtures and bi-continuous microemulsions, phenothiazine (PTZ) molecules exist in the membrane phase of the dispersion either with the N atom or with the S atom pointed toward the polar head of cetyltrimethylammonium (CTAB). Cyclic voltammetry has been used to investigate the effects of the compositions and structures of the microemulsions, pH, and the salt on the location distribution of PTZ in the membrane phase of the dispersion in CTAB/n-C5H11OH/H2O W/O and bi-continuous microemulsions. The results show that the location distribution of PTZ in the membrane phase of the dispersion in microemulsions is mainly dependent on the hydrogen bond between PTZ and n-C5H11OH (or the counterion), and on the electrostatic attractive interaction between the N atom in PTZ and the polar head of CTAB.
Co-reporter:Jie Han;Genping Song
Journal of Polymer Science Part A: Polymer Chemistry 2007 Volume 45(Issue 13) pp:2638-2645
Publication Date(Web):16 MAY 2007
DOI:10.1002/pola.22023
A general route, involving swelling–evaporation processes, is proposed for the generation of polymer hollow nanospheres derived from polymer nanoparticles for the first time. Different swelling reagents, such as ethanol, o-toluidine, toluene, and carbon tetrachloride, have been used to study their effect on the morphology of the resultant polymer hollow structures. The evaporation conditions, such as the temperature and pressure, can be used to tune the size and shell thickness of the polymer hollow structures. The chemical structures of the polymer have been characterized with X-ray diffraction, Fourier transform infrared, and ultraviolet–visible spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2638–2645, 2007
Co-reporter:J. Han;G. Song;R. Guo
Advanced Materials 2006 Volume 18(Issue 23) pp:3140-3144
Publication Date(Web):7 NOV 2006
DOI:10.1002/adma.200600282
Poly(o-toluidine) hollow spheres with controllable size (see figure) are synthesized in aqueous solution by the droplet template formed by the monomer itself. The size of the hollow spheres and the size of the hole in the surface of each sphere are affected by the concentration of o-toluidine and the molar ratio of initiator to monomer, respectively.
Co-reporter:Yuanhua Ding, Bin Xu, Rong Guo
Materials Chemistry and Physics 2006 Volume 98(2–3) pp:425-429
Publication Date(Web):1 August 2006
DOI:10.1016/j.matchemphys.2005.09.059
The ethylenediaminetetraacetic acid disodium salt (C10H14N2O8Na2) nanoparticles were prepared by replacing water with 3 wt% C10H14N2O8Na2 aqueous solution in the lamellar liquid crystal (LLC) of the Triton X-100/n-C10H21OH/H2O system. The particle size is about 5–6 nm with relatively narrow distribution. The existing of the C10H14N2O8Na2 nanoparticles in the lamellar liquid crystal can improve the lubrication properties of the lamellar liquid crystal of Triton X-100/n-C10H21OH/H2O system.
Co-reporter:Tian-Qing Liu
Chinese Journal of Chemistry 2006 Volume 24(Issue 5) pp:620-626
Publication Date(Web):16 MAY 2006
DOI:10.1002/cjoc.200690119
The effects of cetyltrimethylammonium bromide (CTAB) on the properties of hemoglobin (Hb) at low CTAB concentration were studied in Hb/acyclovir/CTAB system by the methods of UV-Vis spectrum, fluorescence, zeta potential, conductivity and negative-staining transmission electron microscope (TEM). With the increase of CTAB concentration, the UV peak intensity at 276 nm, the intrinsic fluorescence, the zeta potential of Hb and the system conductivity were all enhanced. Hb was easily oxidized to oxyHb and hemichrome. In Hb/acyclovir/CTAB system, CTAB made the UV-Vis spectrum, fluorescence, conductivity and conformation of Hb tend to be returned to those of the original Hb but the zeta potential not to do so. The UV absorption peak of Hb-acyclovir complex disappeared, and the tight structure of Hb aroused by acyclovir was refolded. When CTAB concentration was higher than 5×10−5 mol/L, the two absorption peaks at 536 and 576 nm appeared again, and the Hb structure became looser again.
Co-reporter:Weiya Liu, Rong Guo
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2006 Volume 274(1–3) pp:192-199
Publication Date(Web):15 February 2006
DOI:10.1016/j.colsurfa.2005.09.009
Interaction of quercetin, one kind of flavonoid, with TritonX-100 organized molecular assemblies was investigated by electronic absorption spectra, fluorescence emission spectra, cyclic voltammetric measurements, freeze-fracture TEM (FF-TEM) images and the ab initio quantum calculation. Quercetin is located in the TritonX-100 micelles with the phenyl groups (B-ring part), which leads to the extension of π conjugation of the whole molecule and the enhancement of its ESPT fluorescence process. The embedment of two hydroxyl groups on the phenyl into a more hydrophobic microenvironment makes the oxidation peak of quercetin move to a higher potential with a decreased peak current. The binding of quercetin with TritonX-100 micelle is a spontaneous (ΔG < 0) and endothermic process (ΔH > 0), and the hydrophobic force is the main driving force for its location.
Co-reporter:Zhong Chun Li;Tian Qing Liu
Journal of Polymer Science Part A: Polymer Chemistry 2006 Volume 44(Issue 8) pp:2388-2394
Publication Date(Web):1 MAR 2006
DOI:10.1002/pola.21343
Electrochemical polymerization of aniline was performed by the method of ultramicroelectrode cyclic voltammetry in the lamellar liquid crystal and hexagonal liquid crystal of SDS/n-C5H11OH/H2SO4(aq) system. The results indicate that the electrochemical polymerization of aniline can be catalyzed by the SDS/n-C5H11OH/H2SO4(aq) lyotropic liquid crystal. The polymerization potential of aniline is smaller in the lyotropic liquid crystal system than that in the 0.10 mol L−1 sulfuric acid solution. The catalytic efficiency and polymerization rate of aniline increase with the n-pentanol content, but decrease with the increase of the SDS content or [PhNH2/H2SO4(aq)] content. Moreover, the catalytic efficiency of the lamellar liquid crystal exceeds that of the hexagonal liquid crystal in the SDS/n-C5H11OH/H2SO4(aq) system. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2388–2394, 2006
Co-reporter:Song Gen-Ping;Bo Jie;Guo Rong
Chinese Journal of Chemistry 2005 Volume 23(Issue 8) pp:
Publication Date(Web):10 OCT 2005
DOI:10.1002/cjoc.200590997
The composite nanoparticles of polystyrene/Fe3O4 with a shell-core structure were prepared in the mixed system of Triton X-100 and SDBS. The shell of the composite nanoparticles was formed by polystyrene and the core by Fe3O4 nanoparticles. The diameter of Fe3O4 nanoparticles is about 10 nm and that of the composite nanoparticles 25-35 nm. The XRD spectra and FTIR spectra show that the enwrapping of polystyrene with Fe3O4 nanoparticles was successful.
Co-reporter:Guo Rong;Wei Xun;Liu Tian-Qing
Chinese Journal of Chemistry 2005 Volume 23(Issue 4) pp:
Publication Date(Web):11 MAY 2005
DOI:10.1002/cjoc.200590393
In the system of SDS/n-C5H5OH/n-C7H16/H2O with the weight ratio of SDS/n-C5H11OH/H2O system at 5.0/47.5/47.5, the upper phase of the system was W/O microemulsion, and the lower phase was the bicontinuous microemulsion. When the n-heptane content was less than 1%, with the increase of the n-heptane content, the capacitance (Co, Cod) in the upper phase (W/O) dropped, the capacitance (CBI, CBId) in the lower phase (BI) raised. At the same time, the W/O-BI interfacial potential (ΔE), capacitance (Ci), and charge-transfer current (ict) decreased. After the n-heptane content reached 1%, with the increase of the n-heptane content, ΔE, Ci and ict demonstrated no significant change.
Co-reporter:Li Zhong-Chun;Liu Tian-Qing;Guo Rong
Chinese Journal of Chemistry 2005 Volume 23(Issue 4) pp:
Publication Date(Web):11 MAY 2005
DOI:10.1002/cjoc.200590404
The electrochemical oxidation of L-cysteine can be catalyzed by sodium dodecyl sulfate (SDS) admicelles. The catalytic efficiency increases hardly when SDS concentration is lower than the critical admicelle concentration (CAC) and increases rapidly when SDS concentration is between CAC and the critical micelle concentration (CMC), but decreases when SDS concentration is higher than CMC. Both results of rate constant k0 and Gibbs free energy ΔG≠ accord with that of catalytic efficiency.
Co-reporter:Jun-Hong Qian
Chinese Journal of Chemistry 2003 Volume 21(Issue 10) pp:
Publication Date(Web):26 AUG 2010
DOI:10.1002/cjoc.20030211010
The hydrolysis of cephanone in SDS micelle and SDS/n-C5H11OH/H2O O/W microemulsion was studied through Uv-vis absorption spectroscopy. The change of pH value in the hydrolysis of cephanone was determined. The result shows that pH value decreases in the process of the hydrolysis, and that the SDS micelle and SDS/n-C5H11OH/H2O O/W microemulsion accelerate the hydrolysis of cephanone compared with water.
Co-reporter:Rong Guo;Ai-Hua Zou;Han-Min Yang
Chinese Journal of Chemistry 2001 Volume 19(Issue 2) pp:
Publication Date(Web):26 AUG 2010
DOI:10.1002/cjoc.20010190204
Urea can enhance the aqueous solubility of surfactant CTAB (hexadecyltrimethylammonium bromide) when it shows the hydrotrope action. It will show the hydrotrope-solubilization action when the solubilized amount of n-C5H11OH in O/W microemulsion and that of water in W/O microemulsion are increased. The mechanism of the hydrotrope-solubilization action of urea is the increase of the stability of W/O and O/W microemulsion and structural transition from the lamellar liquid crystalline phase to the bicontinuous structure.
Co-reporter:Yan Liu, Ding Ding, Yuanlin Zhen, Rong Guo
Biosensors and Bioelectronics (15 June 2017) Volume 92() pp:
Publication Date(Web):15 June 2017
DOI:10.1016/j.bios.2017.01.036
•A novel and convenient colorimetric nanosensor for detection of Cu2+ and histidine was established.•The method was based on the ‘turn-off -on’ nanozyme activity of amino acid functionalized AuNCs.•Good sensitivity and selectivity were obtained.•The mechanisms of ‘turn-off -on’ detection system was studied.Herein, we presented a facile strategy for highly sensitive and selective detection of both Cu2+ and histidine (His) by combining the peroxidase-like nanozyme activity of gold nanoclusters with amino acid's ambidentate nature. The peroxidase-like catalytic ability of histidine-Au nanoclusters (His-AuNCs) can be inhibited by the addition of Cu2+. The sensitivity of this probe to Cu2+ is significant with a linear range of 1–100 nM, and a low detection limit of 0.1 nM. More interestingly, His-AuNC/Cu2+ undergoes recovery of the activity upon exposure to free His, because His/Cu2+ complex is more stable due to the participation of the imidazole ring of His. The method displays a good selectivity toward histidine over all the other amino acids, with a wide linear relationship in the range of 20 nM–2 μM, and a low detection limit of 20 nM. The feasibility of the probe for the rapid analysis of copper ion and His in human serum has been demonstrated with satisfactory results. With the merits of high sensitivity and selectivity, simplification, low cost, and visual readout with the naked eye, this novel 'turn-off/turn-on' sensing approach based on the amino acid's ambidentate nature is potentially applicable to metal ions, amino acids and peptides in biological and environmental areas.
Co-reporter:Na Han, Shiyi Cao, Jie Han, Yimin Hu, Xiaohong Zhang and Rong Guo
Journal of Materials Chemistry A 2016 - vol. 4(Issue 7) pp:NaN2596-2596
Publication Date(Web):2016/01/14
DOI:10.1039/C5TA10258H
We present a proof-of-concept demonstration of surface cavities for incorporation of noble metal nanoparticles with remarkable catalytic performance involved in liquid phase catalytic reactions. Mesoporous Ni(OH)2 (m-Ni(OH)2) nanowires with surface cavities have been chosen as multifunctional supports for Au nanoparticles with a well controlled size (2 nm) and high dispersity through a facile room-temperature in situ reduction process without any additional stabilizer. In addition to immobilizing Au nanoparticles, the cavities also can prevent aggregation of neighboring noble metal nanoparticles, thus ensuring high stability/recyclability for Au/m-Ni(OH)2 supported nanocatalysts. The results from catalytic reactions involved in the reduction of 4-nitrophenol in the presence of NaBH4 using Au/m-Ni(OH)2 as the catalyst demonstrated its remarkable catalytic performance due to its nanoscale configuration.
Co-reporter:Lei Fan, Le Tang, Huifang Gong, Zhiheng Yao and Rong Guo
Journal of Materials Chemistry A 2012 - vol. 22(Issue 32) pp:
Publication Date(Web):
DOI:10.1039/C2JM32241B
Co-reporter:Jie Han, Minggui Wang, Shiyi Cao, Ping Fang, Song Lu, Rong Chen and Rong Guo
Journal of Materials Chemistry A 2013 - vol. 1(Issue 42) pp:NaN13202-13202
Publication Date(Web):2013/09/09
DOI:10.1039/C3TA12545A
MnO2/polyaniline (PANI) coaxial nanocables were fabricated through an oxidative template route, where MnO2 nanorods were selected as the reactive templates for polymerization of aniline in acidic aqueous solution. It was found that PANI could be coated on the surfaces of MnO2 nanorods, accompanied by dissolution of the MnO2 cores, leading to the formation of coaxial nanocable structures. Consequently, the compositions and structures of the MnO2/PANI coaxial nanocables could be simply controlled by determining the reaction time. Thermogravimetric analysis, Fourier transform infrared spectrometry, X-ray diffraction, ultraviolet-visible spectrophotometry, and N2 adsorption–desorption techniques were used to characterize the MnO2/PANI coaxial nanocables. Furthermore, the catalytic activities of the MnO2/PANI coaxial nanocables in the oxidative decolorization of Rhodamine B were also investigated.
Co-reporter:Jie Han, Song Lu, Chenjing Jin, Minggui Wang and Rong Guo
Journal of Materials Chemistry A 2014 - vol. 2(Issue 32) pp:NaN13023-13023
Publication Date(Web):2014/06/18
DOI:10.1039/C4TA01795A
The development of catalysts with improved stability and efficiency is increasingly important for both economic and environmental reasons. Herein, Fe3O4/PANI/m-SiO2 hybrid core/shell spheres have been successfully synthesized as novel and robust reactive catalyst supports to produce highly stable and recyclable noble metal nanocatalysts. Specifically, Fe3O4/PANI/m-SiO2 hybrid core/shell spheres were firstly fabricated, followed by the addition of noble metal ions to initiate the redox reaction between PANI and noble metal ions to yield noble metal nanoparticles on PANI surfaces. The Fe3O4 core and mesoporous SiO2 shell of the Fe3O4/PANI/m-SiO2 hybrid supports can significantly improve the recycling efficiency and greatly reinforce the stability of catalyst nanoparticles against coagulation, respectively. Various parameters, such as the thickness of the PANI coating and the etching time of the SiO2 dense shell, were considered in optimizing the catalyst supports. Furthermore, the high stability and recyclability of Fe3O4/PANI/Au/m-SiO2 hybrid catalysts involved in liquid phase reactions were established, implying their potential applications in the field of catalysis.
Co-reporter:Jie Han, Lu Wang and Rong Guo
Journal of Materials Chemistry A 2012 - vol. 22(Issue 13) pp:NaN5935-5935
Publication Date(Web):2012/02/27
DOI:10.1039/C2JM16583J
Polystyrene@Polyaniline@Au/m-SiO2 yolk/shell nanostructures containing numerous sub-10 nm gold nanoparticles in each particle as highly stable/recyclable polymer-supported gold catalysts have been suggested.
Co-reporter:Jian Zhang, Jie Han, Minggui Wang and Rong Guo
Journal of Materials Chemistry A 2017 - vol. 5(Issue 8) pp:NaN4066-4066
Publication Date(Web):2017/01/04
DOI:10.1039/C6TA10499A
Multifunctional magnetic adsorbents containing MnO2 and polyaniline (PANI) with optimized adsorption properties toward heavy metal ions have been developed. In particular, Fe3O4 spheres were chosen as the magnetic core, followed by PANI and MnO2 coating, realizing the formation of Fe3O4/PANI/MnO2 core–shell hybrids. The as-synthesized Fe3O4/PANI/MnO2 core–shell hybrids showed a hierarchical structure with a large surface area and high magnetic saturation value. In comparison with Fe3O4/PANI and Fe3O4/MnO2 core–shell hybrids, Fe3O4/PANI/MnO2 core–shell hybrids displayed the highest adsorption capacity toward heavy metal ions (including Cd(II), Zn(II), Pb(II) and Cu(II)), thanks to the integrated physical and chemical adsorption behaviors resulting from MnO2 inorganic oxide and the PANI polymer. The developed multifunctional Fe3O4/PANI/MnO2 adsorbents synthesized by a facile and economic route are believed to show high potential in environmental remediation for heavy metal removal.
Co-reporter:Jie Han, Rong Chen, Minggui Wang, Song Lu and Rong Guo
Chemical Communications 2013 - vol. 49(Issue 98) pp:NaN11568-11568
Publication Date(Web):2013/10/18
DOI:10.1039/C3CC46139D
Au–conducting polymer core–shell nanostructures have been transformed into yolk–shell nanostructures with enhanced catalytic activity through facile swelling–evaporation processes without any sacrificial template.
Co-reporter:Jie Han, Minggui Wang, Rong Chen, Na Han and Rong Guo
Chemical Communications 2014 - vol. 50(Issue 61) pp:NaN8298-8298
Publication Date(Web):2014/04/22
DOI:10.1039/C4CC01532K
Novel Au–polymer hollow hybrids having a single Au nanoparticle encapsulated in each porous polymer shell with superior catalytic efficiency and recyclability have been demonstrated.
Co-reporter:Lingling Ge, Shuhui Lu, Jie Han and Rong Guo
Chemical Communications 2015 - vol. 51(Issue 35) pp:NaN7434-7434
Publication Date(Web):2015/02/26
DOI:10.1039/C5CC00935A
Anisotropic particles, with morphology from crescent to moon shape and size from micrometer to nanometer scale, are fabricated in batch scale with Janus emulsion as template. The strategy is also useful in the synthesis of Janus particles with chemically distinct hemispheres.
Co-reporter:Zhongchun Li, Jie Han, Lei Fan, Minggui Wang, Shengyang Tao and Rong Guo
Chemical Communications 2015 - vol. 51(Issue 15) pp:NaN3056-3056
Publication Date(Web):2014/12/24
DOI:10.1039/C4CC09225B
By exploiting a facile and controllable anion exchange strategy, mesoporous α-Ni(OH)2 nanowires with multinanocavities in surfaces have been successfully developed. The novel nanoscale morphology has been proven to be responsible for their excellent capacitive performances.
![DISODIUM;2-[CARBOXYLATOMETHYL(DODECYL)AMINO]ACETATE](http://img.cochemist.com/ccimg/34400/34359-86-9.png)
![DISODIUM;2-[CARBOXYLATOMETHYL(DODECYL)AMINO]ACETATE](http://img.cochemist.com/ccimg/34400/34359-86-9_b.png)
