Evolution of core-shell structure using functional polystyrene and gold

A core-shell of a carboxylic functional polystyrene (PS-COOH) with gold was prepared by the combination of surface gold-seeding and subsequent shell growth in a gold solution. The PS-COOH cores were prepared by a dispersion polymerization of styrene for seed formation followed by copolymerization of styrene and methacrylic acid. In the preparation of gold shell, PS-COOH cores were initially immersed into gold nanoparticles containing solution and continuous gold shell was formed by employing a mixed aqueous solution of Au(OH)3 and NH2OH. The gold nanoparticles impregnated into the PS-COOH cores were used as gold seeds to form continuous gold shells. The characteristics of the PS-COOH/Au core-shells were investigated by SEM, TEM, EDS and XPS.