Factors affecting the solubility of nonionic emulsifiers

Abstract

The effect of detergents, electrolytes, and organic liquids on the cloud point of Triton X-100, a nonionic emulsifier of the alkylphenol/polyethylene oxide type, is described. The lowering of the cloud point in dilute aqueous solution by electrolyte is a linear function of the ionic strength. The observed salting-out effect for the alkali metal and multivalent cations is roughly in the order of decreasing ion hydration. Crystalline nonelectrolytes cause only slight cloud point changes. Nonpolar liquids and anionic detergents significantly raise the cloud point of the nonionic emulsifier. As the polarity of the organic solubilizate is increased by introduction of double bonds and more polar constituent groups, the increase in cloud point is less marked. Aromatics and polar aliphatics even cause the cloud point to be sharply decreased. The cloud points of mixtures of nonionic emulsifiers lie intermediate between the cloud points of solutions of the pure components.