Synthesis and Properties of a New Alkylbenzenesulfonate Gemini Surfactant

A new alkylbenzenesulfonate Gemini surfactant was synthesized based on long chain alkyl carboxylic acid,aniline and 1,6-hexamethylene diisocyanate.The structure and purities of the product were confirmed by FT-IR,1H NMR and ESI-MS.The properties of Gemini synthesised(abbreviated as GeminiⅠ,GeminiⅡ and Gemini Ⅲ when their hydrophobic chain numbers were 8,10,12) were studied by steady-state fluorescence probe and surface tension method.At 25 ℃,the critical micelle concentrations(cmc's) were obtained as 1.2,0.19 and 0.006 mmol·L-1 for GeminiⅠ,GeminiⅡ and Gemini Ⅲ respectively,using the surface tension method.The cmc's of title compounds decreased when the hydrophobic chain increased,and were 1-3 times lower than the corresponding monomeric surfactants,showing excellent micelle-forming property.Similar results were conducted from the steady-state fluorescence probe method.The surface area of the product at the air/water interface was larger than that of Geminis with similar structure reported.