Surface and thermodynamic parameters of sodium <i>N</i>‐acyl sarcosinate surfactant solutions

Abstract

Abstract Surface tension as a function of concentration and temperature was measured for solutions of N ‐acyl sarcosinates, RCON(CH 3 )CH 2 COONa. From the intersection points in the (γ‐log c) curves, the critical micelle concentration (CMC) was determined at 20, 35, 50, and 65°C. Structural effects on the CMC, maximum surface excess, and the minimum area per molecule at the aqueous solution/air interface are discussed. The free energy, enthalpy, and entropy of micellization and adsorption of surfactant solutions also were investigated.