Wormlike micelles with pH-induced rheological property formed by cationic surfactant/anthranilic acid mixed aqueous solution

•A pH-induced micellar system by OTAB and AA•The microstructure transition is the cause of the pH-induced properties.•The binding capacity of AA to OTAB changes as the pH varies.

The pH-induced rheological property of octadecy trimethyl ammonium bromide with anthranilic acid was investigated. The viscoelasticity property and structural transformation of molecular self-assembly were comprehensively discussed by means of rheological measurements, dynamic light scattering and cryogenic-transmission electron microscopy. On the basis of surface tension results, the change of viscoelasticity was explained by calculating the packing parameter of P. UV-vis results confirmed that the pH-dependent interaction between the aromatic ring of anthranilic acid and the head group result in the transition between WLMs and spherical micelles, thus altering the viscoelasticity of WLMs.