Interaction of an Acid Functionalized Magnetic Ionic Liquid with Gemini Surfactants

The micellar properties of two Gemini surfactants i.e., butanediyl-1,4-bis(dimethyldodecyl ammonium bromide (C-12-4(OH)(2)-C-12,2Br(-)) and butanediyl-1,4-bis(dimethyldohexylammonium bromide) (C-16-4-C-16, 2Br(-)) in the presence of an imidazolium based acid functionalized magnetic ionic liquid (IL) i.e., 1-acyl-3-methylimidazolium tetrachloroferrate [AcMIm]FeCl4, are studied using various techniques such as surface tension, conductivity, fluorescence and FT-IR spectroscopy. The surface adsorption parameters and thermodynamic parameters are systematically determined. The critical micelle concentration (CMC) is decreased and surface tension of CMC (gamma(cmc)) values are increased significantly in the presence of different wt% of the added IL, and the values are observed in the order as 0.07 > 0.05 > 0.02 > water. In this study, the Gibbs energy of adsorption (Delta Gads o) value was found to be greater than the Gibbs energy of micellization (Delta Gmo), showing that adsorption is more favored in aqueous Gemini surfactant systems. The FT-IR spectral results further confirm the changes produced by the magnetic IL [AcMIm]FeCl(4)on aqueous solutions of C-12-4(OH)(2)-C-12,2Br(-)and C-16-4-C-16,2Br(-). It is noteworthy that increasing the wt% of [AcMIm]FeCl(4)results in an increase in the spontaneity of CMC formation on Gemini surfactants and the IL has more affinity for C-16-4-C-16, 2Br(-)compared to C-12-4(OH)(2)-C-12,2Br(-).