•CPF/GO-LDH is well fabricated by an exfoliation-restacking method.•The interlayer distances are discussed on the basis of electrostatic interaction.•The composite displays a sustained slow release.•CPF/GO-LDH could be potentially applied for controlled-release of the pesticide.A series of the graphene oxide-ZnAl-layered double hydroxide composites loaded with pesticide chlorpyrifos (CPF/GO-LDH) were fabricated by an exfoliation-restacking method. CPF/GO-LDH composites were characterized by powder X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and transmission electron microscopy (TEM), thermogravimetry analysis and differential scanning calorimetry (TGA-DSC). The interlayer distances of CPF/GO-LDH with various GO/LDH mass ratios were in the range of 0.70–0.87 nm, which were analyzed on the basis of electrostatic interaction between LDH nanosheets and GO substrate. The combustion temperature of CPF in the composites was enhanced 130–170 °C. Release behaviors of CPF/GO-LDH composites in buffer solutions were investigated and analyzed. The sustainable slow releases were observed during the whole stage studied, and the release rates and equilibrium release amounts of CPF were closely dependent on release mediums and GO/LDH mass ratios. The release behaviors of CPF/GO-LDH were fitted with pseudo second-order and parabolic diffusion models. The present study suggested that the CPF/GO-LDH could be potentially applied for controlled-release of the pesticide.

•Zwitterionic surfactants can be well intercalated into NiZn-layered hydroxide salts.•The relative low pH is beneficial to prepare NZL-DCB, NZL-DSB and NZL-DAP.•The higher temperature and longer time may cause presence of ZnO phase.•DCB, DSB and DAP probably form an overlapped bilayer in the gallery.Three zwitterionic surfactants, dodecyl dimethyl carboxylbetaine (DCB), dodecyl dimethyl sulfobetaine (DSB) and N-dodecyl-β-aminoprpionate (DAP), intercalated into NiZn-layered hydroxide salts (NZL-DCB, NZL-DSB and NZL-DAP) were synthesized by the coprecipitation method. The effect of surfactant content, pH, temperature and time of hydrothermal treatment on preparation was investigated and discussed. The NZL-DCB, NZL-DSB and NZL-DAP were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry analysis and differential thermal analysis (TGA/DTA). The results showed that basal spacings of NZL-DCB, NZL-DSB and NZL-DAP were around 3.45, 3.68 and 3.94 nm, respectively. DCB, DSB and DAP probably form an overlapped bilayer in the gallery. TGA/DTA data indicated that NZL-DCB, NZL-DSB and NZL-DAP displayed three loss weight stages: loss of adsorbed and structural water, dehydroxylation of matrix and decomposition of nitrate ions, decomposition and combustion of surfactants. Furthermore, chemical analysis data, BET surface area and scanning electron microscopic (SEM) were also measured and analyzed.

We have systematically investigated the effect of alcohols (ethanol, propanol, butanol, and pentanol) on the structure of the water/AOT/IPM system using conductivity, dynamic light scattering (DLS), and small-angle X-ray scattering (SAXS) techniques. The results show that no percolation phenomenon is observed in the water/AOT/IPM system, whereas the addition of ethanol (propanol and butanol) induces apparently percolation. The threshold water content (Wp) depends closely on the alcohol type and concentration. The effect of alcohols on the conductance behavior is discussed from the physical properties of alcohols, the interfacial flexibility, and the attractive interactions between droplets. The hydrodynamic diameter of droplets (dH) obtained from DLS increases markedly with the increase in water content (W0); however, it decreases gradually with increasing alcohol chain length and concentration. SAXS measurements display distinctly the shoulder, the low hump peaks, and the heavy tail phenomenon in the pair distance distribution function p(r) profile, which rely strongly on the alcohol species and its concentration. The gyration radius (Rg) increases with increasing W0, and decreases with the increase of alcohol chain length and concentration. Schematic diagram of the conductance mechanism of water/AOT/IPM/alcohol systems is primarily depicted. Three different phases of the discrete droplets, the oligomers, and the isolated ellipsoidal droplets existed in the different W0 ranges correspond to three different stages in the conductivity–W0 curve. Coupling the structure characteristics of reverse micelles obtained from DLS and SAXS techniques with conductivity could be greatly helpful to deeply understand the percolation mechanism of water/AOT/IPM/alcohols systems.