Preparation of polymer-silicon(100) hybrids via interface-initiated reversible addition-fragmentation chain-transfer (RAFT) polymerization

Abstract

The surface modification of (100)-oriented single crystal silicon with covalently bonded (Si-C bonded) polymer brushes by interface-mediated reversible addition-fragmentation chain transfer (RAFT) polymerization was demonstrated. The simple approach of immobilizing the thiocarbonyl-thioether compound on a hydrogen-terminated Si (100) surface via the radical stabilizing group provided stable Si-C bonded chain transfer agent (CTA). The orthogonal surface chemistry or spatial ordering of the block sequence in grafted diblock copolymers, produced by the interface-initiated RAFT polymerization, was revealed by X-ray photoelectron spectroscopy (XPS) and by Ar+ beam etching and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). 2-hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA) were selected as the model monomers for the preparation of polymer-Si hybrids via interface-initiated (RAFT) graft polymerization.