Influence of head group on the interactional behavior of cationic surface active ionic liquids with pluronic F108 in aqueous medium

Abstract

The present work aims at studying the interactions between surface active ionic liquids (SAILs) 1-dodecyl-3-methylimidazolium bromide [C12mim][Br]; N-dodecyl-N-methylpiperidinium bromide, [C12mpip][Br]; N-dodecyl-N-methylpyrrolidinium bromide, [C12mpyr][Br] and pluronic F108 in aqueous medium and to draw the comparison between the effect of different SAILs with respect to head group present in them. The binding of SAILs with pluronic F108 below as well as above the critical micelle temperature (cmt) of the pluronic has been studied by isothermal titration calorimetry (ITC), dynamic light scattering (DLS) and zeta (ζ) potential measurements. A combined analysis of these techniques revealed that SAILs can bind to monomeric as well micellar pluronic F108 with [C12mim][Br] showing a higher binding affinity in comparison to the other SAILs. Further, the interactions between SAILs and pluronic F108 in mixed micelles have been studied employing surface tension and fluorescence measurements, Various micellar, interfacial and thermodynamic parameters have being obtained for mixed systems of SAILs with pluronic F108. The interactions between F108-SAIL binary mixtures have been found to be non-ideal and strongly synergistic. The modifications in the physicochemical properties of pluronic F108 upon addition of SAILs are expected to enhance and expand the industrial and pharmaceutical applications of pluronics.