TY - JOUR T1 - Numerical Studies for an Interface Problem Involving Fourth- and Second-Order Poisson-Fermi Electrostatic Equations AU - Liu , Mengjie AU - He , Mingyan AU - Sun , Pengtao JO - International Journal of Numerical Analysis and Modeling VL - 2 SP - 226 EP - 245 PY - 2025 DA - 2025/02 SN - 22 DO - http://doi.org/10.4208/ijnam2025-1011 UR - https://global-sci.org/intro/article_detail/ijnam/23822.html KW - Fourth-/second-order Poisson-Fermi interface problem, nonhomogeneous interface condition, interface-fitted finite element method, optimal convergence, electrostatic correlation, charge reversal. AB -

A class of particular interface problems, which is derived from Bazant-Storey-Kornyshev (BSK) theory to account for the electrostatic correlation in concentrated electrolytes, is studied in this paper. It involves a modified fourth-order Poisson-Fermi equation in solvents and a second-order Poisson equation in solutes with high-contrast coefficients, where nonhomogeneous interface conditions are introduced over the interface that divides solutes from solvents. A type of interface-fitted finite element method is developed and analyzed for this interface problem, and optimal error estimates are obtained for all variables in both $H^1$ and $L^2$ norms. Numerical experiments validate all attained theoretical results through two mathematical examples, as well as the electrostatic correlation phenomenon in concentrated electrolytes through a physical example, practically, where the electrostatic stress and interactional forces in the concentrated electrolyte are computed to reveal the charge reversal phenomenon that is governed by the BSK theory.