Adsorption behavior, spreading and thermal stability of anionic-nonionic surfactants, with different ionic headgroup

The anionic-nonionic surfactants have attracted great interest due to its particular molecular structure, To compare the effect of anionic headgroup on the performance of anionic-nonionic surfactants, the adsorption behavior at air/water and oil/water interface, spreading performance and thermal stability of anionic-nonionic surfactants, sodium alkyl polyethylene oxide carboxylate (AE(3)C), sodium alkyl polyethylene oxide sulfate (AE(3)S), and sodium alkyl polyethylene oxide sulfonate (AE(3)SO), were investigated by surface tension, interfacial tension, contact angle techniques and thermogravimetric analysis. The results of static surface tension and interfacial tension show that the AE(3)C has the best interfacial activity. Adsorption process for surfactants concentration above cmc is a mixed diffusion-kinetic adsorption mechanism, and below cmc is diffusion-controlled mechanism. Spreading ability on paraffin films of the three surfactants decreases in the order AE(3)C > AE(3)S > AE(3)SO. The thermal stability is in the sequence of AE(3)C > AE(3)SO > AE(3)S. (C) 2016 Elsevier B.V. All rights reserved.