ABSTRACTStarch is regarded as one of the most promising biopolymers to replace the fossil resources. However, due to the poor mechanical properties, high sensitivity to humidity, and low barrier property, the development of starch-based materials has been limited. In this study, they improved the mechanical and barrier properties of starch film with reduced graphene oxide (RGO) modified by sodium dodecyl benzene sulfonate (SDBS). The hydrophilia of modified RGO (r-RGO) was improved and result in a good dispersion in oxidized starch (OS) matrix. The tensile strength of the r-RGO-4/OS film increased to 58.5 MPa which was more than three times of the OS film (17.2 MPa). Besides, both the water vapor and oxygen barrier properties of r-RGO/OS film were improved greatly compared with OS and GO/OS films. Moreover, the r-RGO/OS film could protect against UV light effectively due to its lightproof performance. In conclusion, the r-RGO/OS composite film has great potential applications in packaging industry. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44910.

Demands for high strength integrated materials have substantially increased across various kinds of industries. Inspired by the relationship of excellent integration of mechanical properties and hierarchical nano/microscale structure of the natural nacre, a simple and facile method to fabricate high strength integrated artificial nacre based on sodium carboxymethylcellulose (CMC) and borate cross-linked graphene oxide (GO) sheets has been developed. The tensile strength and toughness of cellulose-based hybrid material reached 480.5 ± 13.1 MPa and 11.8 ± 0.4 MJm–3 by a facile in situ reduction and cross-linking reaction between CMC and GO (0.7%), which are 3.55 and 6.55 times that of natural nacre. This hybrid film exhibits better thermal stability and flame retardancy. More interestingly, the hybrid material showed good water stability compared to that in the original water-soluble CMC. This type of hybrid has great potential applications in aerospace, artificial muscle, and tissue engineering.Keywords: artificial nacre; bio-based; graphene oxide; high strength and toughness; in situ reduction and cross-linking;

•A CS-AgNWs film is prepared by using efficacious Solution Casting Method.•CS-AgNWs film showed more tensile strength and less resistivity than CS-AgNPs film.•Prepared biofilm with good conductivity also exhibited antimicrobial activity.•Current research present multifunctional CS-AgNWs film.A bio-based hybrid film containing chitosan (CS) and silver nanowires (AgNWs) has been prepared by a simple casting technique. X-ray diffraction (XRD), Fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and UV–visible spectroscopy were employed to characterize the structure of bio-based film. The bio-based hybrid film showed unique performance compared with bare chitosan film. The incorporated nano-silver could improve the strength properly. The results revealed that AgNWs in CS film, improved its tensile strength more than 62% and Young modulus 55% compared with pure chitosan film. On the other hand tensile strength was increased 36.7% with AgNPs. Importantly, the film also exhibited conductivity and antibacterial properties, which may expand its future application.

•The MMT-CS/QDs solution and films possess strong fluorescence intensity.•The MMT-CS/QDs solution and films present good storage stability.•The fluorescence wavelength was controllable by refluxing with different time.A method was presented for fabricating the fluorescent nanocomposites containing CdTe quantum dots (QDs) and montmorillonite (MMT)-chitosan (CS). MMT-CS/CdTe QDs nanocomposites were prepared via a simple, versatile and robust approach combination of covalent and electrostatic assembly methods (Scheme 1). The negatively charged MMT was initially modified with positively charged CS through electrostatic assembly, followed by incorporation of CdTe-QDs into the MMT-CS nanosheets by covalent connections between the amino groups of CS and the carboxylic acid groups of thioglycollic acid (TGA). The X-ray diffraction (XRD), High resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and the FTIR were used to prove the QDs have intercalated into the MMT-CS matrix. The fluorescence emission spectra showed that the MMT-CS/CdTe QDs nanocomposites had the best fluorescence intensity compared with the bare CdTe QDs and CS-QDs.

In this work, novel hybrid microbeads composed of chemically reduced graphene oxide (CRGO) and alginate were fabricated, which could encapsulate enzymes by a simple non-covalent adsorption–entrapment method. Compared with alginate gel beads, the intervention of CRGO in the alginate gel enhanced its mechanical strength, effectively prevented the leakage of enzyme, and greatly enhanced the stability and environmental tolerance. Compared with free enzymes or those on a single carrier, the enzyme encapsulated in these hybrid microbeads can retain its optimum activity within a broad range (temperature 45–60 °C, pH 4–6). Additionally, the microbeads can be easily recycled by simple filtration and filled into a column to achieve a continuous fixed-bed enzyme catalytic reaction.

Here we report a simple and efficient approach to fabricate a new biocatalytic system by co-immobilizing multi-enzyme on chemically reduced graphene oxide (CRGO) via non-covalent bonds. The obtained artificial biocatalyst was characterized by UV/Vis, FTIR, AFM, TEM and SEM. Compared with native and graphene oxide (GO) bounded enzymes, it was found that the glucose oxidase (GOD) or glucoamylase (GA) immobilized on CRGO exhibited significantly higher enzymatic activity, due to the positive effect of the CRGO carrier. This multi-enzyme microsystem was employed as a biocatalyst to accomplish the starch-to-gluconic acid reaction in one pot, and the yield of gluconic acid could reach 82% within 2 hours. It was also proved that the stability of the multi-enzyme biocatalyst immobilized on CRGO was dramatically enhanced compared with the GO microsystem. About 85% of the activity of the artificial biocatalyst could be preserved after four cycles. These results demonstrated the feasibility of the novel strategy to construct bio-microsystems with multi-enzyme on 2D CRGO via non-covalent bonds to accomplish some complex conversions.

Mesoporous silica–cellulose hybrid composites were prepared by surface sol–gel coating process on nature cellulose substance. The template CTAB (hexadecyl trimethyl ammonium Bromide) in the silica film can be removed by extraction to obtain high specific surface area (80.7 m2 g–1), which is 2 orders of magnitude higher than that of raw cellulose. In the following, the enzyme-mimetic catalyst and chromogenic agent were introduced onto the hybrid system. Just as the peroxidase, the resultant hybrid material exhibits extraordinary sensitivity for the H2O2 and shows an immediate and obvious color change. The detection limit is about 1 μmol L–1 by the naked eye.Keywords: enzyme-mimetic catalyst; H2O2 detection; hybrid nanostructures; mesoporous silica;

A green and effective approach for comprehensive component utilization of lignocellulosic biomass has been described, based on the hydrolysis of lignocellulosic biomass with a carbonaceous solid acid (CSA) derived from the hydrolyzed biomass residues under microwave irradiation. The as-synthesized CSA was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and energy dispersive X-ray (EDX), which proved that the acid groups (–SO3H, –COOH) were successfully introduced onto the surface of CSA. Significantly, the CSA showed excellent catalytic hydrolysis performance for the lignocellulosic biomass under microwave irradiation, especially for the conversion of hemicellulose of the biomass. Microwave irradiation could greatly enhance the catalytic performance in our system. Various reaction parameters, such as temperature, reaction time, the amount of CSA and the ratio of solid to liquid, were evaluated. At mild temperatures (383–413 K), the cellulose and hemicellulose in the corncobs could be decomposed into corresponding sugars. The maximum glucose yield, xylose yield and arabinose yield could reach 34.6, 77.3 and 100%, respectively. The CSA can be recycled and reused. This approach may offer a promising strategy for the hydrolysis of lignocellulosic biomass in the future.

Highly homogeneous TiO2@phenolic resol hybrid nanocomposites are fabricated by a solvothermal method. In such nanostructures, the TiO2 particles are tightly grafted on the surface of nano mesoporous phenolic resols to form uniform heterostructures. Significantly, a charge transfer complex was formed at the interface of the TiO2 and the nano mesoporous phenolic resols, which led to visible-light absorption over the full range. The nano hybrid material exhibited excellent performance for the photocatalytic degradation of dyes and produced photocurrent signals under visible-light. The investigation of the mechanism indicated that the O2˙− was the main active species during the photochemical process. The hybrid nanocomposites also showed considerably high stability in the photocatalysis. It is expected that this approach can provide a new strategy for the design of some bio-inspired catalysts for sustainable technology.

Concentrated H3PW12O40 (HPW) was first employed to decompose cellulose under microwave irradiation at low temperatures. 75.6% yield of glucose was obtained at 90 °C under microwave irradiation for 3 h, which was considerably high under such mild conditions using phosphotungstic acid as a catalyst. With the same effective acid concentration, HPW gave the highest cellulose conversion and glucose yield among the Brønsted acid catalysts, indicating that the strong Brønsted acid played an important role during cellulose hydrolysis. In the hydrolysis of cellulose with HPW as catalysts, microwave irradiation led to higher glucose yields than the conventional heating method. The recovery and reusability of HPW were investigated by extraction with diethyl ether from the reaction solution. At the same time, the performance of the concentrated HPW for real lignocellulosic biomass (corncob, corn stover and bagasse) hydrolysis was also investigated.

Highly homogeneous TiO2@phenolic resol hybrid nanocomposites are fabricated by a solvothermal method. In such nanostructures, the TiO2 particles are tightly grafted on the surface of nano mesoporous phenolic resols to form uniform heterostructures. Significantly, a charge transfer complex was formed at the interface of the TiO2 and the nano mesoporous phenolic resols, which led to visible-light absorption over the full range. The nano hybrid material exhibited excellent performance for the photocatalytic degradation of dyes and produced photocurrent signals under visible-light. The investigation of the mechanism indicated that the O2˙− was the main active species during the photochemical process. The hybrid nanocomposites also showed considerably high stability in the photocatalysis. It is expected that this approach can provide a new strategy for the design of some bio-inspired catalysts for sustainable technology.

In this work, novel hybrid microbeads composed of chemically reduced graphene oxide (CRGO) and alginate were fabricated, which could encapsulate enzymes by a simple non-covalent adsorption–entrapment method. Compared with alginate gel beads, the intervention of CRGO in the alginate gel enhanced its mechanical strength, effectively prevented the leakage of enzyme, and greatly enhanced the stability and environmental tolerance. Compared with free enzymes or those on a single carrier, the enzyme encapsulated in these hybrid microbeads can retain its optimum activity within a broad range (temperature 45–60 °C, pH 4–6). Additionally, the microbeads can be easily recycled by simple filtration and filled into a column to achieve a continuous fixed-bed enzyme catalytic reaction.

Cellulosic materials are becoming more and more important in our daily life. However, if cellulose in its natural form such as paper is to be applied in advanced applications, it should exhibit unique characters in mechanical performance, barrier properties, etc. This paper describes a new method to design and fabricate a pure cellulosic composite with excellent mechanical and barrier properties via simple coating and cross-linking between original paper and regenerated cellulose. The cellulosic composite overcomes the shortcomings of the low mechanical and barrier performance of original paper. This material had an ultrahigh tensile strength, a high elongation and toughness at break of 76 MPa, 12% and 7 MJ m−1, and 13 MPa, 11% and 0.75 MJ m−3 under wet conditions, which were greater than those of original paper (dry: 20 MPa, 2.8%, 0.3 MJ m−3; wet: 1.08 MPa, 2.8%, 0.028 MJ m−3). Besides, the composite papers showed good barrier properties for small molecules such as polar molecules (H2O) and non-polar molecules (O2). Interestingly, the as-synthesized material exhibited shape-retention when the material was wetted with water.