AMPHIPHILIC COMB-SHAPED DIBLOCK POLYMER BRUSHES ONSi(100) SUBSTRATES VIA SURFACE-INITIATED ATOM TRANSFER RADICAL POLYMERIZATION

Abstract

Amphiphilic comb-shaped 2-hydroxyethyl methacrylate-graft-poly(styrene)-block-poly(poly (ethylene glycol) monomethacrylate) ( P ( HEMA )–g– PS –b– P ( PEGMA )) copolymer brushes, covalently tethered on Si (100) substrate, have been successfully prepared by (i) UV-induced hydrosilylation of 4-vinylbenzyl chloride (VBC) with the hydrogen-terminated Si (100) ( Si – VBC surface), (ii) surface-initiated atom transfer radical polymerization (ATRP) of 2-hydroxyethyl methacrylate (HEMA) to give the Si – VBC –g– P ( HEMA ) surface, (iii) coupling of 2-bromoisobutyryl bromide with the HEMA units via esterification to provide the comb-shaped macroinitiators ( Si – VBC –g– P ( HEMA )– R 3 Br ) for the subsequent ATRP, (iv) surface-initiated ATRP of styrene (St) to produce the Si – VBC –g– P ( HEMA )–g– PS surface, and (v) the persisting of an active PS chain end can be used as the initiator for the subsequent ATRP of poly(ethylene glycol) monomethacrylate (PEGMA) to give the amphiphilic Si – VBC –g– P ( HEMA )–g– PS –b– P ( PEGMA ) brush surface. The chemical composition and functionality of the silicon surface were tailored by the well-defined comb-shaped PS and P (PEGMA) brushes.