Analysis of carrier-mediated transport through supported liquid membranes using functionalized polyorganosiloxanes as integrated mobile/fixed-site carrier systems

A new quantitative model is developed which describes the kinetics and mechanism of transport of a weak organic acid derivative through an integrated solvent/carrier supported liquid membrane (SLM). The transport model is based upon simultaneous occurrence of both mobile and fixed-site jumping carrier mechanisms, and incorporates the assumption of diffusion-limited transport. The theoretical model is verified by comparison with experimental data obtained from a facilitated transport study of ethyl lactate through a supported amine functionalized polyorganosiloxane SLM. The transport parameters, which include the product of solute partition coefficient and diffusion coefficient (KpDs), the equilibrium extraction constant (Kex), and the effective diffusivity of solute–carrier complex due to both mobile and jumping carrier mechanisms (Dm+Dj), have been determined, and excellent agreement is achieved between predicted and experimental data in most of the studies.