Chemico-physical and biological properties of gemini surfactants.

A review with 74 refs.; recently the research of new types of surfactants has led to the synthesis of the gemini surfactants, both anionic and cationic, showing very interesting properties. They are constituted by two not-terminal hydrophilic groups and two hydrophobic groups per mol., sepd. by a spacer. The application of these mols. in industrial processes could lead to a dramatic redn. in the concn. of surface-active material for the same performance. Because of the great interest of gemini surfactants, both from an applicative and a speculative point of view, the literature about the synthesis, the chemicophys. and biol. properties of this class of compds. is briefly reviewed. Particular attention is devoted to the thermodn. properties of the homologous series of amphiphilic N,N'-bisdimethyl-1,2-ethanediamine derivs., of general formula CnH(2n+1)OOCCH2(CH3)2N+ CH2CH2N+(CH3)2CH2-COOCnH2n+/ 2Cl-, where the subscript n stands for the no. of carbon atoms of the alkyl chain bound to the carboxyl group.