GENERALIZED MICROSCOPIC MECHANISM OF FACILITATED TRANSPORT IN FIXED SITE CARRIER MEMBRANES

A generalized microscopic mechanism for the facilitated transport of a neutral solute through a fixed site carrier membrane is given. A series mass transfer resistance model is used to demonstrate that facilitated transport is possible even when the fixed sites are too far apart for direct solute hopping between sites and mass transport between sites is by simple solute diffusion. An effective diffusion coefficient D(AB) of the complexed penetrant is defined in terms of morphology-dependent and reversible reaction variables. Appropriate limits are taken to illustrate that the results give the appropriate observed behavior.