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

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.