Wetting of Solids by Aqueous Solutions of Surfactant Binary Mixtures: 2. Wetting of High-Energy Surface

Wetting of glass by aqueous solutions of binary mixtures of cationic and nonionic surfactants was studied in the range of overall concentrations c0 = 10–8–10–2 M at the molar fraction of cationic surfactant α = 0.2, 0.5, and 0.8. It was established that the character of glass wetting is determined by the presence of cationic surfactant in the mixture: contact angle isotherms θ(c0) exhibit maximum, as in the case of individual cationic component solutions. Maximal θ values are virtually independent of the nature of cationic surfactant and its molar fraction in the mixture. It was shown that the synergistic effect in glass wetting is controlled by the chemical structure of surfactant cation.