Well-defined polymer–Si/SiO2 hybrids via surface-initiated atom transfer radical polymerization and their relevance to nanotechnology
Abstract-Well-defined (nearly monodispersed) polymer-Si and -SiO2 hybrids can be prepared via surface-initiated atom transfer radical polymerization (ATRP) both in the presence and absence of a silane coupling agent. The simple approach of UV-induced hydrosilylation of 4-vinylbenzyl chloride (VBC) or 4-vinylaniline (VAn) with the hydrogen-terminated Si(100)/Si(111) surface (Si-H surface) provided a stable, Si-C-bonded monolayer of ‘monofunctional’ ATRP initiators. The halogen-terminated Si(100) or Si(111) (Si(100)–X or Si(111)–X, X=Cl, Br) surfaces were also effective initiators for the preparation of well-defined polymer-Si hybrids via surface-initiated ATRP. The chlorinated SiO2 surfaces of glass and Si(100)/Si(111) wafers were also effective initiators for surface-initiated ATRP. Finally, well-defined core-shell nanospheres could be prepared via surfaceinitiated ATRP from the silane-coupled silica nanosparticles. The resulting nano-hybrids could be used to prepare cross-linked polymer hollow nanospheres and to fabricate nanoporous ultra-low dielectric constant fluoropolymer films.