Adsorption properties and aggregation behavior of mixed system of anionic/cation surfactants with different structures

Abstract This article introduces the anionic surfactants branched alcohol ether potassium phosphate (A13E5P-K), linear alcohol ether potassium phosphate (A12E5P-K) and cationic surfactants dodecyl dimethyl benzyl ammonium chloride (1227) with a rigid benzene ring, dodecyl dimethyl hydroxyethyl ammonium chloride (K3) with flexible hydroxyethyl adsorption properties and self-assembly of binary mixtures (A13E5P-K/1227, A12E5P-K/1227, A13E5P-K/K3, A12E5P-K/K3). Studies have shown that, compared with a single surfactant, all mixed systems have higher surface activity and interactions are more attractive. The thermodynamic parameters exhibited that the micellization of the mixed system is an enthalpy-driven spontaneous process. Further, the self-assembled structures in the system, including spherical micelles, branched rodlike micelles, rodlike micelles, vesicles and tubules, could be regulated effectively by changing the mixing ratio of the binary system. The excellent surface activity and aggregate transformation of the systems are expected to be applied in drug delivery, dye entrapment and release, enhanced oil recovery and so on.