Progress in synthesis and application of zwitterionic Gemini surfactants

Zwitterionic Gemini surfactants have the Gemini molecular structure in which there are both multiple lipophilic groups and multiple hydrophilic groups. However, their hydrophilic groups have different charges. Due to the special molecular structure, this kind of surfactants possesses excellent properties, including high surface activities, isoelectric point (IP), low critical micelle concentration (CMC), less toxicity, low irritating, biodegradability, bioactive, interface modification, and so on. In this review, synthetic strategies of three kinds of zwitterionic Gemini surfactants, i.e., anioniccationic, cationic-nonionic and anionic-nonionic Gemini surfactants, are discussed, and their potential applications in life sciences, chemical industry and enhanced oil recovery (EOR) are illustrated. Their future development is also prospected.