Study on synthesis, properties, and aggregation behavior of sodium alkyl glycoside sulfate

Abstract

In this work, sodium dodecyl and tetradecyl glycoside sulfate (APGS-Na) was synthesized by sulfating dodecyl and tetradecyl glycoside (APG1214) with chloro-sulfonic acid (CSA). The product was then characterized using FT-IR, 1H NMR, MS, and elemental analysis. Response surface methodology (RSM) was used to explore the sulfation modification conditions in order to achieve the maximum APG1214 conversion rate (84.79% with the molar ratio of CSA to APG1214: 2.17:1, reaction temperature: 16 °C, and reaction period: 2 h). Further studies were performed to establish the relationship between the pertinent structure and physicochemical characteristics, such as Krafft point, equilibrium surface tension, dynamic surface tension, aggregation behavior of micelles and lyotropic liquid crystals (LLCs), as well as application characteristics like foam property, emulsification, detergency, and irritability. The results demonstrated that the Krafft point of APGS-Na was below 0 °C, and the surface tension (γcmc ) was 39.4 mN·m−1 when the critical micellar concentration (CMC) was 2.40 g·L−1. At low concentration, the adsorption process was controlled by a diffusion step, different to a mixed kinetic-diffusion adsorption mechanism at high concentration, can form large size micelles and attractive LLCs in water. Moreover, the surfactant is nonirritant, with excellent foaming and decontamination capability. Accordingly, APGS-Na is expected to be widely used in diverse fields as a green anionic glycoside surfactant.