NEW AMPHOTERIC SURFACTANTS CONTAINING A 2-HYDROXYALKYL GROUP .2. DEPENDENCE OF PHYSICOCHEMICAL PROPERTIES ON THE PH VALUE FOR N-(2-HYDROXYETHYL)-N-(2-HYDROXYALKYL)-BETA-ALANINES

The dependence of physicochemical properties on the pH of micellar solutions for N-(2-hydroxyethyl)-N-(2-hydroxyalkyl)-β alanines (HAA) was studied by means of a differential titration method (DTM), Fourier transform infrared (FTIR) spectra, and measurements of critical micelle concentration, surface tension, and foaming power. The aspect of the dissociation of HAA was pursued by DTM. The mutual transformation among cationic, zwitterionic, and anionic forms with the change of pH range was confirmed by FTIR spectroscopy. The micelle formation energy was determined at each pH value. Further, the dependence of surface active properties on the pH value for the adducts of ethylene oxide to Na-HAA was also investigated. © 1979 American Oil Chemists' Society.