Abstract
Herein, the cloud points (CPs) of tween 80 (Tw 80) in water/(water + diols [ethanediol, propanediol, and butanediol])/(water + polyols [glucose, fructose, and sorbitol]) systems were measured. For diols-Tw 80-water system and polyols-Tw 80-water system, the CP values were obtained to reduce gradually with increasing content of diols and polyols at a particular concentration of Tw 80. For a certain concentration of Tw 80 having different contents of diols, the observed increment H-c(0), as well as increment S-c(0) values, were negative over the range of concentration of diols studied, and the negative values of increment H-c(0) and increment S-c(0) were reduced with the enhancement of the content of diols. The values of increment H-c(0) were negative, which indicate the process was exothermic. The clouding process of Tw 80 in the presence of different diols is mainly enthalpy-controlled process, while the contributions of enthalpy tend to reduce with enhancing of the contribution of diols. In the case of polyols-Tw 80 mixture in an aqueous environment, the increment G(c)(0) values were achieved positive. The values of increment H-c(0) and increment S-c(o) were obtained negative for studied systems, while the negative values reduce with enhancing of polyol (glucose and fructose) concentrations. For sorbitol-Tw 80 system, the values of increment H-c(0) were observed to be negative and the negative magnitudes reduce with enhancing of sorbitol concentrations. The thermodynamic parameters of transfer are also evaluated and illustrated in detail.