gemini surfactant is a molecule composed of two identical hydrophilic head groups and hydrophobic tail groups, equivalent to two single chain surfactants, that are covalently connected by a spacer. The spacer can vary in length and chemical structure, be rigid or flexible, and be hydrophobic or hydrophilic. The term ‘gemini surfactant’ was first applied to molecules consisting of a hydrocarbon tail, an ionic group, a rigid spacer, a second ionic group, and another hydrocarbon tail [1]. However, molecules with non-rigid spacers and headgroups that are not ionic have also been synthesized and referred to as gemini or dimeric surfactants.