Polymer particles with core-shell structure

P(St-NVP)

based on styrene (St) and N-vinyl-2-pyrrolidone (NVP) were prepared through emulsion polymerization using potassium persulflate (KPS) as the initiator

methylenebisacrylamide (MBA) as the crosslinker in the presence of polystyrene (PSt) seed latex particles synthesized by surfactant-free emulsion polymerization.Using the P(St-NVP) particles as template

P(St-NVP)/Ag composites were obtained by chemical deposition.The morphology

component

structure and catalytic performance of the composite particles were characterized and investigated by Fourier transform infrared spectroscopy

X-ray diffraction

scanning electron microscopy

transmission electron microscopy

laser diffraction particle size analysis and UV-visible spectroscopic techniques.The results revealed that the P(St-NVP)/Ag composite particles were of spherical particles with quite narrow size distribution.The particle size was between 400 nm and 700 nm

depending on the preparation conditions.The size decreased with the increase in the amount of the crosslinker and the concentration of the seed latex polymer.Ag nanoparticles of about 10 nm in diameter were well coated on the surface of

or implanted inside

the particles due to the complexation of functional groups on polymer chains.The observed diffraction peaks of the composite particles showed that the Ag particles were of face centered cubic crystal structure.The composite particles with Ag nanoparticles were used as the oxidant in 4-nitrophenol reduction to 4-aminophenol with NaBH4 as the reducer

and the reduction was significantly enhanced with the presence of Ag nanoparticles.