| Poly(N-isopropylacrylamide) (PNIPAAm) macromonomer with a vinyl end group was obtained by free radical polymerization and end capping reaction. The PNIPAAm grafted polyacrylonitrile/polystyrene (PNAS) microspheres having unusual morphologies can be prepared by dispersion copolymerization of AN with St using PNIPAAm macromonomer as reaction stabilizer. Then Au nanoparticles were located evenly onto surfaces of the PNAS microspheres, which were prepared by in situ reduction of Au3+ at 50℃. The ultrafine dispersed particles of Au can be easily prepared by in-situ synthesis on soluble protective polymers (PNAS) via the reduction of the corresponding gold ions Au3+ by ethanol when the coordination interaction took place between the gold colloids and carbonyl comes from amide of PNIPAAm. The properties of Au nanoparticles located polymeric microspheres have been studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transformation infrared (FTIR) and Ultra-violet (UV) spectroscopy. Moreover, the size of Au nanoparticles can be controlled between 2 to 30 nm. The use of the gold catalyst in the oxidation of glucose resulted in high selectivity with respect to gluconic acid, through high efficiency liquid chromatography (HPLC), the result showed good catalytic activity and long-term stability were obtained; Au nanoparticles located on polymer microspheres with unusual morphology (Au-PNAS) as a catalyst, NaBH4 for reducing agent, deionized water as solvent, to reseach catalytic reduction of nitrophenol performance at different temperatures and different morphologies. The catalytic properties were characterized by UV and fluorescence spectrometer. The result showed that Au-PNAS as a catalyst has excellent performance, it can fully deoxygenize nitrophenol to aminophenol, and can oxidize the aminophenol to nitrophenol in 2h by changing condition.It showed that Au-PNAS had dual catalytic effect. |
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