Impact of organic polar solvents (DMSO and DMF) on the micellization and related behavior of an anionic (AOT), cationic (CEM2AB) and cationic gemini surfactant (16-5-16)

The impact of cosolvents like aquo-organic media has a great focus of discursion in the field of chemical, industrial and pharmaceutical processes along with amphiphilic materials. Detailed study of dimethylsulfoxide and N,N-dimethyl formamide on the self-assembly and the energetic of three surfactants, anionic dioctyl sodium sulfosuccinate (AOT), cationic cetyl ethylhydroxy dimethylammonium bromide (CEM(2)AB) and cationic gemini N,N'-cetyl-N,N,N',N'-tetramethyl-N-N'-pentanediyl diammonium dibromide (16-5-16) is clearly described by conductometric, tensiometric, spectro photometric, fluorimetric and calorimetric techniques. All of the surfactants used have equivalent tails, although type and size of their head groups are different. The solvent composition -dependent properties are identified, and their quantifications are elaborated. The micellization process is assessed in terms of different solvent parameters and zeta potential values are also attempted through dynamic light scattering method (DLS). The values of both critical micelle concentration (cmc) and degree of dissociation increase with increasing concentration of cosolvent. The effect of solvent on free energy contribution to micellization, tail transfer Gibbs free energy, Gibbs adsorption energy etc, was studied. The enthalpy of micellization is estimated directly with the help of microcalorimeter for the lower range of DMSO solution. For AOT in aqueous medium, endothermic plot is observed whereas the other plots are exothermic in nature. Some micellar interfacial parameters were also our study of interest. The careful design of these conjugates exhibits properties which help to serve our focus. All of these results which are demonstrated is a new kind of endeavor. (C) 2017 Elsevier B.V. All rights reserved.