| This dissertation has studied the purification, surface chemical properties, effection of NaX and application properties ofα-sulphonated fatty acid methyl ester:MES.The purification of MES, which was obtained at the second step, wassharactrized by IR. Through two-phase titrimetric method to determine the active matter content and it was 98.5%. The critical surface tension(γcmc) and critical micelle concentration(cmc) was measured at 25℃, 0.1 mol·L-1NaBr, and the result was 37.72 mN·m-1, 9.8×10-5 mol·L-1separately. By calculation, the maximum surface excess concentration (Γmax) and the minimum area per surfactant molecule (Amin) was 3.77×10-10 mol·m-2, 0.44nm2 separately. It showed perfect surface chemical properties.Performance of MES aqueous solution system containing disodium salt ofα-sulfo-fatty acid of different concentrations was studied through measurement of surface chemical properties as well as forming performance, detergency, calcium soap dispersion performance and wettablity et al at 298K. Results showed that, its surface chemical performance and application performance are all better than that containing disoduim. However, from the economic point of view, the effect of small amount of disodium salt in the blend aqueous solution system is tolerable.The micellar properties for the concentration near above the cmc have been characterized by the aggregation number, Nagg using a steady state fluorescence quenching method. Results showed that, the aggregation number of MES was increassing with the increasing of electrolyte(NaX) concentration and temperauter. The micropolarities of mixed systems were determined from the ratio of intensity of peaks (I1/I3) of the pyrene fluorescence emission spectrum.The surface tensions of MES/NaXwere determined under different temperatures by drip volumn method. It was found that cmc had dropped from 2.01×10-4 mol·L-1 to 8.93×10-5 mol·L-1 with the increasing of NaBr concentration, andγcmc was rarely affected.Meanwhile, result indated that the effect of NaBr was greatest. Through the caculational of micelle thermodynamic parameters,it was concluded that the forming of micelle was driven by entropy.
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