The preparation of metal–styrene oligomer and metal–SSNa nanocomposites through single thermal process

A novel method for the preparation of hydrophilic or hydrophobic noble metal nanoparticles by virtue of the oligomer of sulfate terminated styrene oligomers or sulfate terminated sodium polystyrene sulfonate (SSNa) is developed in this study. Styrene oligomers prepared for deposition of metallic nanoparticles were synthesized using the free chain transfer polymerization (FRCTP) based on styrene/potassium persulfate/water system with carbon tetrabromide as the chain transfer agent. The SSNa was simply synthesized by sulfonation of styrene oligomers. The styrene oligomers and SSNa, applied for the reduction and stabilization of noble metal nanoparticles, show well dispersion in aqueous or organic solvent without addition of surfactant and reducing agent in the mixture. Herewith this paper proposed a possible mechanism: by heating the aqueous solution in the presence of metal ions and styrene oligomers, the sulfate group which is on the chain end of styrene oligomers decomposes to sulfite (SO32−) firstly and alcohol was synchronously produced. The reduction of metal nuclei could thus take place by means of oxidization of alcohol and the growth of metal nuclei would be succeeded because of the presence of SO32−. These polymer–metal nanocomposites were characterized by transmission electron microscopy (TEM), gas chromatography–mass spectrometry (GC–MS), and X-ray power diffraction (XRD).