论文部分内容阅读
Spherical polyelectrolyte brushes(SPBs) consisting of polystyrene(PS) core and poly(2-aminoethyl methacrylate hydrochloride)(PAEMH) shell were prepared by photo-emulsion polymerization. Au nanoparticles(Au-NPs) with controlled size and size distribution were synthesized in situ using SPBs as nanoreactors. Via layer-by-layer deposition technique on the surface of SPBs, nano-composite particles with Au/Ag-NPs bilayer and Au/Ag/Au-NPs trilayer were prepared. The structures of the as-prepared Au/Ag multilayer SPBs were characterized by UV-Vis spectroscopy, TEM, ICP-AES and DLS. The charge reversal of the nano-composite particles observed by zeta potential confirmed the success of layer-by-layer assembly. The Au/Ag-NPs bilayer nano-composite particles showed high catalytic efficiency with an apparent activation energy of about 41.2 k J/mol in the reduction reaction of 4-nitrophenol to 4-aminophenol in the existence of sodium borohydride monitored. The catalytic activity of Au/Ag-NPs multilayer SPBs close to that of Au-NPs SPBs and much higher than that of Ag-NPs SPBs reveals its potential applications in cost-effective catalysts with high-performance.
Spherical polyelectrolyte brushes (SPBs) consisting of polystyrene (PS) core and poly (2-aminoethyl methacrylate hydrochloride) (PAEMH) shell were prepared by photo-emulsion polymerization. Au nanoparticles situ using SPBs as nanoreactors. Via layer-by-layer deposition technique on the surface of SPBs, nano-composite particles with Au / Ag-NPs bilayer and Au / Ag / Au-NPs trilayer were prepared. The structures of the as-prepared Au / Ag multilayer SPBs were characterized by UV-Vis spectroscopy, TEM, ICP-AES and DLS. The charge reversal of the nano-composite particles observed by zeta potential confirmed the success of layer- by-layer assembly. The Au / Ag- NPs bilayer nano-composite particles showed high catalytic efficiency with an apparent activation energy of about 41.2 kJ / mol in the reduction reaction of 4-nitrophenol to 4-aminophenol in the existence of sodium borohydride monitored. The catalytic activity of Au / Ag- NPs multila yer SPBs close to that of Au-NPs SPBs and much higher than that of Ag-NPs SPBs reveals its potential applications in cost-effective catalysts with high-performance.