Abstract: A new anionic Gemini surfactant has been synthesized by the following method: firstly a “dimer" was prepared by the reaction of nonylphenol（NP）and 1,4-dibromobutane in the presence of a catalyst. The “dimer” was sulfonated with chlorosulfonic acid and then neutralized with sodium hydroxide to obtain the title-compound. Micellization of the Gemini surfactant was investigated by using drop volume method. Result showed that the critical micelle concentration (cmc) of the Gemini surfactant has a much lower value compared with those conventional monomeric surfactants. The aggregation number (N) of the micelle was determined with intrinsic fluorescence quenching method as a function of concentration. N goes through a maximum upon increasing the concentration of the Gemini surfactant, meanwhile the formation of liquid crystal is observed.

Key words: Anionic Gemini surfactant, Drop volume method, cmc, Aggregation number