Preparation of Gold Nanocrystals Having Various Morphologies under Polymeric Bulk Phase

A novel synthetic approach for gold nanocrystals using triblock copolymer as a polymeric template was described. The triblock copolymer used in this study was poly (ethylene oxide)20-poly (propylene oxide)70-poly (ethylene oxide)20 with hydroxy or thiol end-functional groups. The complexes of HAuCl4 and triblock copolymers were prepared by mixing and drying. After exposed to the sunlight for a few days, the gold nanocrystals, which have different sizes and shapes according to the ripening time, end functional groups, and gold salt concentrations, were obtained. The optical properties of the gold nanocrystals were also discussed.