Preparation Of PS-b-PHEMA Brushes Via Atom Transfer Radical Polymerization

In this dissertation,(11-(2-bromo-2-methyl)propionyloxy)undecy ltrichlorosilane monolayer was prepared on silicon wafer.The PS-b-PHEMA copolymer brushes were obtained via in-situ atom transfer radical polymerization on the modified silicon wafer.First,esterification of 10-undecen-1-ol with 2-bromoisobutyryl bromide was followed by hydrosilylation with trichlorosilane to yield (11-(2-bromo-2-methyl)propionyloxy)undecyltrichloro-silane.(11-(2-bromo-2-methyl)propionyloxy)undecyltrichlorosilane monolayer was grafted onto activated silicon wafer through reaction of (11-(2-bromo-2-methyl)propionyloxy)-undecyltrichlorosilane with hydroxyl group of the wafer.Second,the polystyrene brushes were obtained by in-situ atom transfer radical polymerization on the modified silicon wafer with CuBr/PMDETA complex as catalyst system.At last,the block copolymer brushes consisting of polystyrene and poly(2-hydroxyethyl methacrylatey)blocks were obtained by atom transfer radical polymerization of HEMA with the PS brush as the macroinitiator in the presence of CuCl/PMDETA complex.The results of X-ray photoelectron spectroscopy,atomic force microscope and contact angles showed that PS-b-PHEMA brushes were obtained successfully.Furthermore,the results of gel permeation chromatography revealed that a linear increase in number average molec the number average molecular weights of the obtained PS and PHEMA increased linearly with monomer conversion,indicating that the graft polymerization proceeded in a living fashion.