Synthesis of amphiphilic hyperbranched polyglycerol polymers and their application as template for size control of gold nanoparticles

Amphiphilic thioether-containing core-shell polymers were synthesized by two-step reaction of hyperbranched polyglycerol (PG): first the hydroxyls of PG were O-alkylated with 1-bromo-3-chloropropane by improved Williamson reaction, and 31.6% of the hydroxyls were transformed to allyl groups and 22.4% of hydroxyls to 3-chloropropyl; then the residual 3-chloropropyl groups were efficiently S-alkylated with 1-dodecanethiol. Thus the amphiphilic polymers composed of hydrophobic thioethercontaining shell and hydrophilic PG core were formed and could be used as template for the synthesis of zero-valent gold nanoparticles by the coordination interaction between gold species and thioether. The resulting colloids were stable and the size of the encapsulated gold nanoparticles could be adjusted by changing the molecular weight/size of the PG core of the amphiphilic derivatives. (c) 2006 Wiley Periodicals, Inc.