Well-Defined Amphiphilic Polymer-Si(100) Hybrids via Surface-Initiated Atom Transfer Radical Polymerization

Abstract

Well-defined amphiphilic graft polymer brushes containing fluoropolymer segments have been successfully prepared by (i) UV-induced coupling of 4-vinylbenzyl chloride (VBC) with the hydrogen-termined Si(100) (Si-VBC surface), (ii) surface-initiated atom transfer radical polymerization (ATRP) of 2-hydroxyethl methacrylate (HEMA) to produce the Si–VBC–g–P(HEMA) surface as the backbone of macroinitiator for further ATRPs, (iii) coupling of 2-bromoisobutyrl bromide with the HEMA polymer(P(HEMA)) by the esterification to produce the macroinitiators for the subsequent ATRP(Si–VBC–g–P(HEMA)-R3Br), (iv) surface-initiated ATRP of 2,2,3,3,4,4,4-heptafluorobutyl acrylate (HFBA) to produce the Si–VBC–g–P(HEMA)–g–P(HFBA) surface, and (v) the active P(HFBA) chain ends being used as the initiator for the subsequent ATRP of poly(ethylene glycol) monomethacrylate (PEGMA) to produce the amphiphilic Si–VBC–g–P(HEMA)–g–P(HFBA)–b–P(PEGMA) brush surface. The chemical composition and functionality of the silicon surface were characterised by X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and ellipsometry.