Surfactants are widely used in both industry and everyday life, and their properties in aqueous solutions have received considerable attention [1]. Ionic liquids (ILs) are a class of organic salts with melting points equal to or below I 00°C. Recently, a new type of ILs that is able to form micelles in aqueous solution has been reported. These ILs have attracted much attention because they seem to possess the properties of both lLs and surfactants, thus they are termed surface active ionic liquids (SAILs) [2]. In aqueous solutions, amphiphilic molecules of surfactants self-aggregate together to minimize the contact area of the hydrophobic segment and water and form different types of aggregates. Introduction of additives provides additional degrees of freedom with them to control the self-aggregation of surfactants and the properties of the resulting formulation [3,4]. In order to study the effects of organic solvents on the aggregation and surface behaviors of cationic surfactants in aqueous solutions, the surface and micellar properties of aqueous solutions of SAIL l-dodecyl-3-methylimidazolium bromide ([C12mim]Br) and cationic surfactant dodecyltrimethylammoniumbromide (DTAB) were investigated in the presence of several organic solvents by experimentally measured electrical conductivities and surface tensions at 298.15 K. The organic solvents studied include methanol, ethanol, 1 ,2ethandiol, 1-propanol, 1 ,2propandiol and 1-butanol.
