Surface activity of amphiphiles in hydrogen fluoride — water solutions

Surface tension measurements were carried out in surfactant — hydrofluoric acid — water systems and surfactant — anhydrous hydrofluoric acid systems. Surface tension measurements show that surfactants in anhydrous hydrofluoric acid do not effect a detectable change in surface tension. Effects, known from other solvents, can only be observed when water addition takes place. The surface tension lowering, the free standard adsorption energy, and the maximum surface concentration of a surfactant increases with decreasing hydrofluoric acid concentrations. The space requirement of a separate surfactant molecule decreases at the phase border with decreasing hydrofluoric acid concentrations of the solvents. Simultaneously, the CMC values were changed to smaller surfactant concentrations.