Cationic gemini surfactant homologues alkanediyl-alpha,omega-bis(dodecyldiethylammonium bromide), [C12H25(CH3CH2)(2)N(CH2)(5)N(CH2CH3)(2)C12H25]Br-2 (where S = 2, 4, 6, 8, 10, 12, 16, 20), referred to as C12C5C12(Et) were synthesized systematically. This paper focused on various properties of the above gemini surfactants in order to give a full understanding of this series of surfactants. The following points are covered: (1) surface properties, which include (i) effect of the spacer carbon number on the general properties and (ii) the effect of added NaBr on the general surface properties; (2) aggregation behavior in bulk solution, including (i) morphologies of above gemini surfactants classed as having short spacers, middle-length spacers and long spacers and (ii) superior vesicle stability against high NaBr concentration for the long spacer gemini surfactants; (3) thermodynamic properties during micellization and the effect of spacer carbon number on them; and (4) perspectives for the further use and application of these compounds. (C) 2012 Elsevier Inc. All rights reserved.