Synthesis and surface properties of fluorine-containing diblock copolymer brush

Abstract

Diblock copolymer brushes of poly(2,2,2-tribluoroethyl methacrylate) and poly(tert-butyl methacrylate) (PTFMA-b-Pt-BMAX grafted on silicon oxide substrates were synthesized by surface-initiated polymerization via atom transfer radical polymerization using CuBr/PMDETA as a catalytic system. The reaction progress can be monitored by ellipsometry, contact angle analysis, [superscript 1]H-NMR analysis and gel permeation chromatography. The obtained results prompted that M [subscript w] and the thickness of both PTFMA and Pt-BMA brushes can be separately controlled as a function of reaction time and monomer to "free" initiator ratio in solution and the polymerization is living in character. The growth of each block was uniform and the thickness of the polymer brushed continuously increased after the outer block of Pt-BMA was consecutively added to the inner block of PTFMA. Diblock copolymer brushes of poly(2,2,2-trifluoroethyl methacrylate) and poly(methacrylic acid) (PTFMA-b-PMAA) were prepared by acid hydrolysis of PTFMA-b-Pt-BMA. As determined by contact angle analysis, responsive wettability of both PTFMA-b-Pt-BMA and PTFMA-b- PMAA brushes was observe after the treatment with [alpha], [alpha], [alpha]-trifluorotoluene, a good solvent for the inner block of PTFMA. The surface rearrangement was found to be reversible.