Synergistic Effect of Cocamidopropyl Betaine and Sodium Lauroyl Sarcosinate

Abstract

In this study, we investigated the synergistic effect of a zwitterionic surfactant (cocamidopropyl betaine) and amino acid surfactant (sodium lauroyl sarcosinate) by measurements of surface tension, rheological properties, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The results confirm the formation of wormlike micelles in the mixed system, which leads to superior surface activity as compared to that of an individual surfactant. Stable and dynamic viscoelastic measurements were also performed to explore the characteristics of wormlike micelles at different mole fractions, pH values, and temperatures. The results indicate that the strongest wormlike structure formed under the conditions of X1 = 0.5, pH = 4.7, and CT = 600 mmol/L. The size and morphology of the mixed micelles were obtained by DLS and TEM. The results of this work offer insight into the interaction between zwitterionic and amino acid surfactants, which will contribute to the design of complex surfactants.