Research on viscoelastic properties of SLG-LHSB system: Effects of pH and concentration on micelles in the system

[Display omitted] •Depending on the pH, sodium lauroyl glutamate can exist in three distinct states.•A high-viscosity viscoelastic system based on natural surfactants has been successfully created.•Depending on the concentration, the SLG/LHSB compound system can form worm-like micelles of various length and quantity. The pH and the state of SLG in aqueous solution are strongly connected. When the pH was below 5.5, it would be transformed into N-lauroyl glutamic acid (LGA) with limited solubility; when the pH was between 5.5 and 6.5, SLG was the major component in the system; and when the pH was above 6.5, disodium lauroyl glutamate predominated (DLG). Because SLG and lauramidopropyl hydroxy sulfobetaine (LHSB, also known as lauramidopropyl hydroxy Sultaine) can combine to generate mixed micelles that can solubilize insoluble materials, the compound system outperformed the single system in terms of dissolving. The viscosity of the SLG and LHSB compound system changed dramatically with pH, corresponding to the change in SLG components with pH. The viscoelastic properties of the composite system were investigated by using steady-state and oscillatory shear sweep rheological measurements. The zero-shear viscosity (η0) had a strong dependence on the concentration of the compound system. The compound system began to form worm-like micelles at 0.05 mol/L. When the system concentration hit 0.35 mol/L, the worm-like micelles began to break, and their length reduced while their quantity rose. (Cryogenic-transmission electron microscopy (Cryo-TEM) confirmed the formation of worm-like micelles. The system demonstrated benign features and outstanding foaming performance in the foam performance and irritation tests.