Surface Tension and Micellization of Aqueous Alkyl Polyglucosides Solutions: Influence of the Molecular Structure and the Addition of Electrolyte

Abstract

Abstract Sugar-based surfactants have recently attracted considerable interest. In this work, the surface tension and critical micelle concentration (CMC) of alkyl polyglucosides (APGs) with differences in both alkyl chain lengths and average degree of polymerization (DP) were measured, and the effects of sodium chloride and sodium hydroxide on the surface tension and CMC of aqueous solutions of APGs were investigated. The alkyl chain length has a far stronger influence on the CMC than the degree of headgroup polymerization. The addition of sodium chloride to solutions of APGs has a relatively small effect compared with ionic surfactants. The observed effects of sodium hydroxide were explained in terms of the salting out of the hydrocarbon chains of APGs and the hydrotropic effect due to a negative charge on APGs micelles resulting in the deprotonation of the glucose fraction in strong alkaline system.