The Fabrication of Polystyrene/Silver composite

Based on the two capabilities of reducing silver ion and initiating polymerization possessed by APS, we design an in-situ silver/polystyrene composite synthesis method, and, and we further investigate the reaction mechanism of this system.
When we add silver nitrate/APS into the polystyrene latex dispersions, silver ions were reduced by APS, forming nanoparticles on the polystyrene microspheres’ surfaces and submicron-sized incomplete dendrites in water phase. Through XRD and TEM dark images we can determine their crystal structures. What’s more, in this two-step synthesis system, we explain the relation between silver ion reduction and two reducing agents, APS and functional groups on the PS microspheres.
In the styrene dispersion, silver nitrate/APS first generate free radicals through redox-initiation, and initiate the polymerization of styrene. At the same time, it is possible that APS oxidizes styrene to form a byproduct, benzaldehyde, and we do observe it in FTIR spectrum. After styrene monomer’s depletion, remaining APS is able to reduce silver ions thus forming silver nanoparticles on PS surfaces and submicron-sized rods in water phase. This is an in-situ synthesis system. We can determine silver’s crystal structure by XRD and TEM diffraction patterns. The functional groups on the PS surfaces also help to trigger the silver ion reduction.
Finally we use GPC to determine the molecular weight of PS, and TGA/DTA to analyze the composition of the composite.