Effects of Inorganic and Organic Salts on Aggregation Behavior of Cationic Gemini Surfactants

• Published in: The journal of physical chemistry. B Vol. 114; no. 46; pp. 14955 - 14964
• Main Authors: Yu, Defeng, Huang, Xu, Deng, Manli, Lin, Yiyang, Jiang, Lingxiang, Huang, Jianbin, Wang, Yilin
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 25.11.2010
• Subjects: B: Surfactants, Membranes
• ISSN: 1520-6106; 1520-5207; 1520-5207
• DOI: 10.1021/jp106031d

All salts studied effectively reduce critical micelle concentration (CMC) values of the cationic gemini surfactants. The ability to promote the surfactant aggregation decreases in the order of C6H5COONa > p-C6H4(COONa)2 > Na2SO4> NaCl. Moreover, only C6H5COONa distinctly reduces both the CMC values and the surface tension at CMC. For 12-4-12 solution, the penetration of C6H5COO− anions and charge neutralization induce a morphology change from micelles to vesicles, whereas the other salts only slightly increase the sizes of micelles. The 12-4(OH)2-12 solution changes from the micelle/vesicle coexistence to vesicles with the addition of C6H5COONa, whereas the other salts transfer the 12-4(OH)2-12 solution from the micelle/vesicle coexistence to micelles. As compared with 12-4-12, the two hydroxyls in the spacer of 12-4(OH)2-12 promote the micellization of 12-4(OH)2-12 and reduce the amounts of C6H5COONa required to induce the micelle-to-vesicle transition.