Physicochemical investigation of the clouding behavior and thermodynamics of p-tert-alkylphenoxy poly (oxyethylene) ether micelles in aqueous environment and in the presence of diols

Cloud point (CP) measurements of nonionic surfactant namely p-tert-alkylphenoxy poly (oxyethylene) ether (TX-100) were carried out in the absence and presence of organic additives such as diols (1,2-ethanediol; 1,2-propanediol and 2,3-butanediol) and polyols (glycerol, glucose, fructose and sorbitol). For (diol + TX-100 + water) system, cloud points (CP) were found to be increased with the increase in concentration of diols for both (4 and 10)% TX-100 solutions and found to follow the order: CP1,2-propanediol > CP2,3-butanediol > CP1,2-ethanediol. For (polyols + TX-100 + water) system, the depression of cloud point (CP) was observed with increase of polyol concentrations for both (4 and 10)% of TX-100 solutions and the trend almost follows the order: CPglycerol < CPglucose < CPfructose < CPsorbitol. The values of ΔGc° were found to be positive for all the systems studied. The ΔHc° and ΔSc° values were found to be positive in the presence of diols while those were found to be almost negative in the presence of polyols during clouding of TX-100.