Research of Surface Chemical Properties and Micellization Behavior of Sodium N-Lauroylglycine

摘要

Amphoteric surfactant, sodium N-lauroylglycine, was synthesized and symbolized as SLG. The surface chemical properties and micelle behaviors of SLG in 0-0.5 mol · L~(-1) aqueous solution of sodium chloride were investigated by surface tension measurements at 298-313 K. The critical micelle concentrations (cmc) of pure surfactant were determined in 0-0.5 mol · L~(-1) sodium chloride aqueous solution. Fluorescence and micelle aggregation number (N_(agg)) measurements have been used to investigate the variations of micro-polarity and micellization behavior. The added NaCl has a tendency to increase the attractive interaction between the surfactant molecules in both the micel-lar phase and the adsorption layer. The Gibbs free energy of micellization (ΔGm~0) is negative for all investigated systems, and the thermodynamic parameters of SLG indicate that the micellization of SLG is entropy driven.