1Department of Chemistry, Faculty of Science, Zanjan University, P.O.Box 45195-313 Zanjan, I. R. IRAN
2ECPM, Université Louis Pasteur, 25, Rue Bequrel, 67200 Strasbourg, FRANCE
The kinetics of the potassium thiocyanate transport mediated by dicyclohexyl-18-crown-6 (L) through a bulk liquid membrane is studied experimentally and theoretically. The proposed model is based on the assumption of a pure diffusion of the complex salt [K·L]+SCN¯ through the liquid membrane stagnant films at the interfaces. It illustrates the connection between liquid-liquid extraction equilibrium data and transport rates. The evaluation of the transfer coefficient allows to evaluate the organic stagnant films thickness, the stationary state transport rate and the time lag.