Dynamic interfacial tension of triblock copolymers solutions at the water-hexane interface

摘要

Equilibrium and dynamic surface tension of non-ionic triblock copolymers, Pluronics, varying in the number of poly(ethylene oxide) and poly(propylene oxide) groups have been measured by means of drop profile tensiometry at the water-hexane interface. The experimental data have been explained on the basis of a theory previously developed for protein solutions [1]. This model assumes the coexistence of different adsorbed states at the interface, depending on the surface coverage. It has been shown that the best fit is achieved when a polylayer adsorption is considered. Reasonable values of the adsorption layer thickness and realistic values of the diffusion coefficient are obtained which validate the model proposed.