Hybrid silica nanoparticles with hyperbranched polymer and polyelectrolyte shells

Abstract

We present the synthesis of hyperbranched polymer–silica hybrid nanoparticles by self-condensing vinyl polymerization (SCVP) via atom transfer radical polymerization (ATRP) from silica surfaces. ATRP initiators were covalently linked to the surface of silica particles, followed by SCVP of an initiator-monomer (“inimer”) which has both a polymerizable acrylic group and an initiating group in the same molecule. Well-defined polymer chains were grown from the surface to yield hybrid nanoparticles composed of silica cores and hyperbranched polymer shells having multifunctional bromoester end groups. Self-condensing vinyl copolymerization of the inimer and tert-butyl acrylate from the functionalized silica nanoparticles created branched poly(tert-butyl acrylate)–silica nanoparticles. Novel hybrid nanoparticles with branched polyelectrolytes, poly(acrylic acid)–silica, were obtained after hydrolysis of linear segments of the branched poly(tert-butyl acrylate).