Dual effects of cationic surfactant on the wormlike micelle formation of catanionic surfactants mixtures: An experiment and simulation study

The formation of wormlike micelles in mixed anionic 2-(N-erucacyl-N-methyl amido) acetate (EMAA) and cationic trioctylmethylammonium bromide (OTAB) surfactants in aqueous solutions and their rheological properties have been investigated. The variety of viscosity depending on the molar ratio has been explained and related to the lengths of wormlike micelle. Molecular dynamics simulation results suggest that the spherical micelles fusion is a crucial stage for the formation of wormlike micelle. The change of solvent accessible surface area (SASA) and the Zeta potential depending on the molar ratio leads to the different barrier height of micelle fusion, and further induces the different lengths of wormlike micelle. Our studies have lighted new views on the understanding of the self-assembly of catanionic surfactants mixture.