AN ALGORITHM FOR THE CALCULATION OF THE ELECTROSTATIC POTENTIAL DISTRIBUTION OF ION-PENETRABLE MEMBRANES CARRYING FIXED CHARGES

An algorithm for the calculation of the electrostatic potential distri bution governed by the Poisson-Boltzmann equation is presented. The al gorithm is applicable to both a single planar surface and two parallel , identical, planar surfaces. The surface under consideration is coate d with an ion-penetrable membrane, which bears fixed charges. Both uni formly distributed fixed charges and nonuniformly distributed fixed ch arges due to the dissociation of the functional groups in the membrane are considered. The liquid phase contains an arbitrary a:b electrolyt e or mixed a:b and c:d electrolytes. The result obtained for two paral lel surfaces is readily applicable to the estimation of both the elect rostatic pressure and the interaction free energy between these surfac es. (C) 1995 Academic Press, Inc.