Facilitated Transport of Small Carbohydrates through Plasticized Cellulose Triacetate Membranes. Evidence for Fixed-Site Jumping Transport Mechanism

Facilitated transport through liquid membranes has been investigated for more than 30 years as a potential separations technology. 1 Although liquid membranes have many promising attributes, there has been little industrial application. The major problem is membrane breakdown due to leaching of the membrane components into the aqueous phases. 2,3 Most attempts to overcome this problem have tried to increase the membrane partition ratio by covalently attaching the transport carriers to highly lipophilic or polymeric chains. 4 An alternative approach is to incorporate the transport carriers in plasticized polymeric membranes. 5-10 Although plasticized membranes are used extensively in ion-selective electrodes, they have received only minor attention as materials for separations. The general expectation with plasticized membranes is that the gel-like nature of the membrane increases viscosity which inhibits leaching. 7