Gemini surfactants have a dimeric structure of a conventional surfactant (1+1 type), so they have so many structural factors affecting to their surface properties, such as symmetry, spacer, diastereo-isomerism. The discussions of the influence of this factors on their surface properties, that is “molecular structure-surface properties relationship”, are significant for the developments of that applications, but it is very difficult, because the systematic preparation methods for Gemini are developed insufficiently. In this paper, the factors were picked up and “molecular structure-surface properties relationship” was discussed in partially with the preparation of Gemini for discussion.

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Gemini surfactants are known to have high surface activities such as lower critical micelle concentration (cmc) and higher efficiency in lowering the surface tension than conventional surfactants, and show unique aggregation behavior such as premicellar aggregate formation and spontaneous vesicle formation at low concentration in solution. Although most gemini surfactants that have been reported so far, contain hydrocarbon chains as hydrophobic group, the authors pay attention to fluorinated gemini surfactants with one or two fluorocarbon chains in a molecule, and have been researching. Only a few reports are available with regard to research on fluorinated gemini surfactants. Design and synthesis, surface-active properties such as cmc and ability in reducing the surface tension, and aggregation properties in aqueous solution for (1) fluorinated anionic gemini surfactants with carboxylate salts, (2) fluorinated cationic gemini surfactants with quaternary ammonium salts, (3) hybridgemini surfactants with different chains of fluorocarbon and hydrocarbon are reviewed in the present study.

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The use of gemini surfactants, instead of conventional monomeric ones, allows for the reduction of the total consumption of surfactants in chemical products owing to their excellent adsorption and molecular association capabilities in aqueous media. Nevertheless, the number of commercially available gemini surfactants is very limited. This is mainly because the costs associated with the synthesis and purification of gemini surfactants are prohibitive. In order to facilitate the widespread use of the gemini surfactants in a variety of applications, the development of low-cost strategies for the synthesis and purification is essential. Recently, we have developed oleic acid-based gemini surfactants using the reduced cost strategy. In this short review, we introduce the surfactants from the standpoints of their development backgrounds, syntheses, interfacial properties, and potential applications.

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