Preparation of aggregation stable gold nanoparticles using star-block copolymers

Nanoparticles of improved stability against long-term aggregation were prepared using poly(styrene)-b-poly(2-vinylpyridine) (PS-b-F2VP) star-block copolymer architectures. The star-block copolymers, physically resembling diblock copolymer micelles, were synthesized by anionic polymerization and coupling with ethylene glycol dimethacrylate. They contain P2VP core segments that facilitated conversion of HAuCl₄ to single gold nanoparticles. The size distribution and long-term stability against aggregation of the gold nanoparticles were investigated both as solution and as films. UV-vis spectroscopy and transmission electron microscope images reveal long-term stability against aggregation up to 1 month.