The evolution of self-assemblies in the mixed system of oleic acid–diethylenetriamine based on the transformation of electrostatic interactions and hydrogen bonds

Abstract

With the aid of pH variation, the fine control of the electrostatic interaction and hydrogen bond was realised in the mixed system of oleic acid and diethylenetriamine. Owing to the transformation of the intermolecular interactions, the corresponding building blocks changed from DETA²⁺@2OA⁻via the coexistence of DETA@2OA⁻ and DETA⁺@OA⁻ to DETA@2OA⁻. Therefore, diverse microstructures and phase behaviors in this mixed surfactant system were obtained at the different pH values. It is found that the fine control of the electrostatic interaction and hydrogen bond is efficient for tailoring the self-assembled structures in this cationic–anionic surfactant system, including vesicles, bilayers, networks formed by aggregated vesicles and fibers.