Synthesis and Properties of a Sulfonic Acid-Containing Gemini Surfactant

Abstract

A novel sulfonic acid-containing gemini surfactant, 6,6′-(butane-1,4-diylbis(oxy)) bis(3-nonylbenzenesulfonic acid), 9BA-4-9BA, was synthesized in high purity and high yield using a facile preparation pathway, and characterized by FTIR, ¹H NMR, and elemental analysis. The content of two sulfonic acid groups was measured by the acid-base titration. DSC and TGA were used to reveal the thermal properties and the product purity. The surface properties of 9BA-4-9BA were evaluated by equilibrium surface tension measurement. It shows that its CMC was 0.65 mmol/L, while the C₂₀ of 0.018 mmol/L was above two orders of magnitude lower than that of traditional monomeric surfactants such as SDS and SDBS, indicating excellent efficiency of micelle formation and reduced surface tension.

Keywords:

• Characterization
• gemini surfactant
• surface properties
• synthesis

Acknowledgments

This work was financially supported by National Natural Science Foundation of China (Grant number 50573004).

Notes

^a SDS1: sodium dodecylsulfate; SDS2: sodium dodecylsulfonate; from Ref.^{[ 26 ]}

^b SDBS: sodium dodecylbenzene sulfonate, from Ref.^{[ 27 ]}