2000/07/03 by Yoram Burak, Y. Burak, David Andelman +1 · 4 citations
Chemistry · Engineering · Physics and Astronomy · #Aqueous solution #Charge (physics) #Charge density #Electrostatics and Colloid Interactions #Ion #Ionic bonding #Nanopore and Nanochannel Transport Studies #Solvent #Surface (topology) #Surface charge #Surfactants and Colloidal Systems #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1063/1.1331569
published as J. Chem. Phys. 114, 3271 (2001) · 12 figures in 16 files. 19 pages. Submitted to J. Chem. Phys., July 2000
arxiv created 2000/07/03 · openalex publication_date 2001/02/15 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We study discrete solvent effects on the interaction of two parallel charged surfaces in ionic aqueous solution. These effects are taken into account by adding a bilinear nonlocal term to the free energy of Poisson–Boltzmann theory. We study numerically the density profile of ions between the two plates, and the resulting interplate pressure. At large plate separations the two plates are decoupled and the ion distribution can be characterized by an effective Poisson–Boltzmann charge that is smaller than the nominal charge. The pressure is thus reduced relative to Poisson–Boltzmann predictions. At plate separations below ∼20 Å the pressure is modified considerably, due to the solvent mediated short-range attraction between ions in the system. For high surface charges this contribution can overcome the mean-field repulsion giving rise to a net attraction between the plates.