ANALYSIS OF THE BULK AND SURFACE-INDUCED STRUCTURE OF ELECTROLYTE-SOLUTIONS USING INTEGRAL-EQUATION THEORIES

We have developed robust and efficient numerical methods for solving i ntegral equation theories for electrolyte solutions. These methods are hybrids of Newton-Raphson and Picard iterations and have been obtaine d as extended versions of the previous methods for pure solvents by so lving nontrivial problems posed by the inclusion of ions. Bulk electro lytes and electrolytes near both inert and metallic surfaces are consi dered. The basic equations previously derived for a one-component flui d near a planar wall are extended to a multicomponent fluid. Analytica l expressions for elements of the Jacobian matrices are arranged in co mpact form. A striking feature of the method for surface problems is t hat the Jacobian is determined only from bulk properties. A discussion of some special treatments that need to be considered for asymmetric anions and cations is included. These methods have been demonstrated u sing the full reference hypernetted-chain theory for various sizes of ions in a wide range of ionic concentrations. (C) 1996 Academic Press, Inc.