Patterned Immobilization of Thermoresponsive Polymer

Abstract

The thermoresponsive polymer poly(N-isopropylacrylamide) was immobilized in a specific pattern on a polystyrene matrix by photolithography. N-Isopropylacrylamide was copolymerized with acrylic acid. The copolymer was coupled with azidoaniline. The low critical solution temperature of the copolymer was lowered by incorporation of azidophenyl groups. The derivatized copolymer was then immobilized on a polystyrene matrix. The surface wettability of the immobilized polystyrene matrix changed with temperature, whereas that of untreated polystyrene matrix was insensitive to temperature. The measurement of contact angle showed that the surface of the immobilized matrix was hydrophobic at 37 °C but hydrophilic at 10 °C. Micropatterned immobilization of the copolymer on the polystyrene matrix surface was carried out using a photomask. The surface micropattern was clearly observed by phase-contrast microscopy at 37 °C. At low temperatures, hydration of graft chains erased the micropattern. The polystyrene matrix wi...