Effects of molecular structures on aggregation behavior of Gemini surfactants in aqueous solutions

Abstract

Gemini surfactants consist of two amphiphilic moieties covalently connected by a spacer at the level of the head groups. Compared with the corresponding monomeric surfactants, gemini surfactants exhibit higher surface activity, possess unique structural variations, display special aggregate transitions, and form variable aggregate structures. Their aggregation ability and aggregate structures can be effectively adjusted by varying their molecular structures, which results in different intra- or intermolecular interactions. This short review is focused on the behavior of gemini surfactants in aqueous solutions reported in recent years, and summarizes the effects of different molecular structures, including spacers, hydrophobic chains, hydrophilic headgroups, counterions, and functional groups. The mechanisms and trends of the interactions in gemini surfactants are also presented.