The correlation between the surface-active characteristics of SAFOL 23 – alcohol – water systems and the length of the alkyl radical of the alcohol

Abstract

The effect of isobutyl and isoamyl alcohols on the surface-active characteristics of SAFOL 23 nonionic surfactant was studied. The surface tension isotherms (STI) of an aqueous solution of surfactant and its wateralcohol compositions are obtained. The structure of mixed micelles and the values of the surfactant interaction factor in the micelle, based on the STIs of SAFOL 23 – alcohol – water systems, were calculated. The dependence of surface activity on the SAFOL 23: alcohol ratio passes through a maximum, which is associated with the transition of alcohol from co-surfactant to co-solvent due to the increase in its quantity. The wetting process of high dispersed polytetrafluoroethylene (PTFE) by SAFOL 23 – alcohol – water compositions was studied, contact angle isotherms were constructed. The PTFE surface was hydrophilized by compositions at ratios which comply with surface activity maximum. SAFOL 23 is more adsorbed on the surface of the solid phase than on the liquid-gas interface. The appending of alcohol into an aqueous solution of surfactant changes the ratio between hydrophilic and lipophilic groups of the composition, which affects cloud point. It significantly expands the range of application of surfactants and allows the use of SAFOL 23 as a solubilizer, emulsifier and wetting agent.