Synthesis of core-shell nanoparticles using organic surface-functionalized gold and Au@SiO2 nanoparticles as multifunctional initiators in atom transfer radical polymerization

Gold and Au@SiO2 nanoparticles were synthesized and surface-functionalized by initiators for atom transfer radical polymerization (ATRP), either using a thiol or a trialkoxysilane anchor group for the immobilization of the initiating functionality. The thus obtained initiator-capped gold systems were applied in polymerizations of various monomers, such as styrene, methacrylic acid trimethyloxysilyl propylester and isoprene and copolymers thereof. The final inorganic-organic core-shell nanoparticles were characterized applying different techniques such as electron microscopy and light scattering. Kinetic studies of the polymerizations revealed that they were highly controlled and therefore the thickness of the polymer shell could be easily adjusted. The obtained nanoparticles formed stable suspensions in various organic solvents and can therefore be used as building blocks for polymer nanocomposites.