Self-assembly of quaternary ammonium gemini surfactants in cyclohexane upon reinforcement by simple counterions. 2018

Sheng-Lu Deng, and Jian-Xi Zhao, and Zhi-Xiu Wen
Institute of Colloid and Interface Chemistry, College of Chemistry and Chemical Engineering, Fuzhou University Fuzhou Fujian 350108 China jxzhao.colloid@fzu.edu.cn.

The quaternary ammonium gemini surfactants 12-s-12 (s = 2, 6, and 10) can produce homogeneous cyclohexane solutions with the assistance of salts, sodium benzoate (NaBez), sodium salicylate (NaSal), or sodium 2-bromoethanesulphonate (NaBres). In these samples, 12-s-12/salt formed aggregates and their structures were assigned by SAXS measurements together with POM observations. Among the three salts, both NaBez and NaBres had similar effects on assisting aggregate formation, but NaSal favoured the generation of aggregates of 12-s-12 with lower interface curvature. For example, both 12-2-12/NaBez and 12-2-12/NaBres formed an I2 liquid crystalline (LC) phase with an Fm3m structure, but 12-2-12/NaSal generated a H2 LC phase. Both 12-6-12/NaBez and 12-6-12/NaBres generated a H2 LC phase, while 12-6-12/NaSal yielded both H2 and V2 phases with Pn3m symmetry, both of which co-existed in solution. The special effect of NaSal was attributed to its ortho-hydroxyl in the benzene ring. This favoured the formation of intermolecular hydrogen bonds among the NaSal molecules attracted to the quaternary ammonium head of 12-s-12. The water molecules joined between the NaSal molecules to build hydrogen-bonding bridges, which further increased the size of the 12-s-12 head. This benefited the formation of aggregates with lower surface curvature. In the systems of both NaBez and NaBres, the spacer length of the gemini surfactants dominated the morphology of the formed aggregates, wherein the effect of the salt was significantly weaker. Finally, the visco-elasticity of samples with similar aggregates was measured and the rheological behaviour discussed.

UI MeSH Term Description Entries

Related Publications

Sheng-Lu Deng, and Jian-Xi Zhao, and Zhi-Xiu Wen
February 2023, Molecules (Basel, Switzerland),
Sheng-Lu Deng, and Jian-Xi Zhao, and Zhi-Xiu Wen
January 2024, Journal of oleo science,
Sheng-Lu Deng, and Jian-Xi Zhao, and Zhi-Xiu Wen
June 2013, Langmuir : the ACS journal of surfaces and colloids,
Sheng-Lu Deng, and Jian-Xi Zhao, and Zhi-Xiu Wen
April 2011, Langmuir : the ACS journal of surfaces and colloids,
Sheng-Lu Deng, and Jian-Xi Zhao, and Zhi-Xiu Wen
October 2007, Langmuir : the ACS journal of surfaces and colloids,
Sheng-Lu Deng, and Jian-Xi Zhao, and Zhi-Xiu Wen
April 2008, Langmuir : the ACS journal of surfaces and colloids,
Sheng-Lu Deng, and Jian-Xi Zhao, and Zhi-Xiu Wen
March 2015, Langmuir : the ACS journal of surfaces and colloids,
Sheng-Lu Deng, and Jian-Xi Zhao, and Zhi-Xiu Wen
October 1994, Science (New York, N.Y.),
Copied contents to your clipboard!