The dynamic behavior of poly(N-isopropylacrylamide) at the air/water interface

The dynamic surface tension of poly(N-isopropylacrylamide) (PNIPAM) homopolymers has been studied as functions of total polymer concentration, molecular weight, temperature, and interfacial area oscillation frequency. PNIPAM lowers the surface tension of water both below and above the lower critical solution temperature (LCST). In the latter case, colloidal polymer particles in the bulk phase diffuse to the interface to unwrap and spread to …