Micellar behavior of anionic surfactants with sulfonate function in aqueous solutions

Using different reaction conditions of photo-sulfochlorination of n-alkanes, various samples of anionic surfactants of sulfonates type have been obtained. Their micellar behavior was researched and the relationship between their isomeric distribution and so, their chemical structures and micellar behaviors were more thoroughly explored. Their critical micelle concentrations (CMC) were determined with surface tension measurements, the surface activities (gamma CMC) were obtained, the surface absorption amounts (Gamma m) and the molecular areas (Am) at the interface of air-water gained by using Gibbs' equation. In addition, under the conditions of adding electrolyte NaCl, the critical micellar concentrations (CMCs) of two samples were also examined, and the effects of the addition of electrolyte on their micellar behaviors were studied. The experiment results show that the samples rich in secondary isomers have characteristic micellar behavior: CMC are higher, and the abilities to decrease surface tension are better, which well compared to common anionic surfactants, especially Hostapur 60, commercially available. Besides, the effects of addition of electrolyte on the micellar behaviors of the anionic surface-active agents are similar to common anionic surfactants.