Hydration and diffusion of cations in nanopores

The hydration structure and dynamics of Na+ and K+ ions surrounded by water play an important role in many chemical processes. In this paper, the results obtained with the Molecular Dynamics Simulation of five Na+/K+ ions ratio (100/0; 70/30; 50/50; 30/70 and 0/100) in aqueous solution confined by a flexible prismatic network of van der Waals particles are reported. We highlight anomalous behaviour of the K+ in relation to hydration and residence time when this is part of the aqueous solution with Na+ in the ionic ratios (70/30; 50/50 and 30/70). Also, it has been found that, in the same ion ratio series, the diffusion coefficient decreases for Na+ and increases for the K+. (c) 2005 Elsevier B.V. All rights reserved.