Temperature-induced phase transition at the polymer-water interface

Temperature-induced phase transition of polymer shows the bulk swelling change in the polymer network, which may induce the change of polymer surface properties. The contact angle measurements at the polymer-water interface were performed to observe the temperature-induced phase transition at the polymer-water interface using two-liquid technique. The dispersive and nondispersive components of surface free energy of polymer were measured above or below the phase transition temperature (lower critical solution temperature). A semi-interpenetrating polymer networks composed of sodium alginate and poly(N,N-dimethylaminoethyl methacrylate-co-ethyl acrylamide) were used as a model polymer system. (C) 2001 Elsevier Science Ltd. All rights reserved.