Surface Activity and Cleavability of Gemini Surfactants Featuring Hydrophilic Spacer Groups

摘要

In this study we prepared and characterized a series of novel ester-linked gemini surfactants, featuring ester bonds in their structures, through the reactions of polyethylene glycol (PEG400) with various fatty acids (C8–C18). These gemini surfactants exhibit excellent surface activities, as evidenced by their surface tension, wetting power, and low-foaming and buffer abilities. We examine the influence of the concentrations of the ester-linked gemini surfactants on the surface tension, from which we obtain the critical micelle concentrations. Under basic conditions, each of these cleavable surfactants decomposes into a water-insoluble fatty acid and two water-soluble products; in contrast, they are stable under neutral and acidic conditions.