A Study On The Stability And The Mass Transfer Of Liquid Surfactant Membranes During Extraction

Liquid surfactant membranes(LSMs) were invented by N. N. Li and have been used for a variety of separations. However, there exist some problems delaying the wide commercial use of LSMs such as stability. In the meantime, mass transfer mechanism during separation is still wanting so that it is impossible to design and scale-up on a reliable theoretical basis.In this paper, the interfacial physical chemistry and the stability of liquid surfactant membrane as well as the mass transfer mechanisms, in the aspects of reaction-diffusion and diffusion-mass transfer, have been studied theoretically and experimentally.Based on the concept of effective concentration of surfactants in membrane phase, a new interfacial state equation in LSM systems was proposed, i.e.where Csef represents the effective concentration of surfactants in membrane phase, which can be estimated bythe prediction values by this new interfacial state equation are in good agreement with experimental data.Based on Gibbs-Duhem equation, a new equation has been proposed, and this equation is applicable for the calculation of the composition of the mixture of surfactant and carrier at the interfaces of LSM systems.In the meantime, the relationship between interfacial tension and the total concentration of the mixture and those between interfacial tension and the...