STRUCTURE AND PROPERTIES OF CONFINED LIQUIDS - A MOLECULAR-MODEL OF THE CLAY WATER INTERFACE

Grand canonical Monte Carlo simulations are used to model the layering of water molecules confined between two mica particles. In the range of interparticle separations studied, the number of hydration layer (2-3) increases suddenly during the swelling process, inducing an oscillation of the hydration forces. The stability of the clay-water interface is related to the solvent organization and depends on the composition and surface state of the clay particles. Particular attention is devoted to the influence of the location of the neutralizing potassium counterions on the properties of the mica-water interface. The different models show an unswelling behavior of the mica-potassium-water system, in agreement with experimental evidence.