2020/02/18 by Manman Ma, Zhenli Xu, Ma, Manman +3
Chemistry · Engineering · Physics and Astronomy · #Computational Physics (physics.comp-ph) #Electrostatics and Colloid Interactions #FOS: Physical sciences #Nanopore and Nanochannel Transport Studies #Soft Condensed Matter (cond-mat.soft) #Spectroscopy and Quantum Chemical Studies
paper · pdf · doi:10.48550/arxiv.2002.07489
openalex publication_date 2020/02/18 · openalex created_date 2020/02/24 · openalex updated_date 2026/07/28
We develop a modified Poisson-Nernst-Planck model which includes both the long-range Coulomb and short-range hard-sphere correlations in its free energy functional such that the model can accurately describe the ion transport in complex environment and under a nanoscale confinement. The Coulomb correlation including the dielectric polarization is treated by solving a generalized Debye-Hückel equation which is a Green's function equation with the correlation energy of a test ion described by the self Green's function. The hard-sphere correlation is modeled through the modified fundamental measure theory. The resulting model is available for problems beyond the mean-field theory such as problems with variable dielectric media, multivalent ions, and strong surface charge density. We solve the generalized Debye-Hückel equation by the Wentzel-Kramers-Brillouin approximation, and study the electrolytes between two parallel dielectric surfaces. In comparison to other modified models, the new model is shown more accurate in agreement with particle-based simulations and capturing the physical properties of ionic structures near interfaces.