Work of adhesion and activity of aqueous solutions of ternary mixtures of hydrocarbon and fluorocarbon nonionic surfactants at the water–air and polymer–water interfaces

Abstract

The values of the surface tension and contact angle on the polytetrafluoroethylene surface (PTFE) of aqueous solutions of the ternary mixtures of hydrocarbon surfactants, TX100 and TX165, and fluorocarbon FSN100 at different mole fractions of surfactants in the bulk phase were applied for the studies of the correlation between the adsorption of surfactants at the solution–air and polymer–solution interfaces, the work of adhesion determined from the Young–Dupree equation, the parameter of the intermolecular interactions and the spreading coefficient of aqueous solutions of the studied mixtures on the PTFE surface. For this purpose the values of the total mole fraction and activity of surfactants at the polymer–solution interface obtained from the Sprow and Prausnitz equation were compared to those at the solution–air one. Also on the basis of the mole fraction of the particular surfactants at the PTFE–solution and water–air interface and on the assumption of the additivity of the adhesion work, the work of adhesion of the fluorocarbon tail to the PTFE surface as well as the Lifshitz–van der Waals component of the PTFE surface tension were calculated.