An overlapped electrical double layer model for aqueous electrolyte lubrication with asymmetric surface electric potentials

Abstract

We developed an aqueous electrolyte lubrication model with asymmetric surface electric potentials using the Poisson equation with no simplification to determine electric field and using the Nernst equation to determine ionic concentrations. The site-dissociation of water was considered and modeled using equilibrium dissociation equations. Electric field strength was modeled by assuming that the streaming current balances the conduction current. An electro viscosity term was obtained in our modified Reynolds equation. Our model was validated by comparing with data from literatures and with the Debye-Hückel model and Poisson-Boltzmann model. The effects κh (κ is Debye length and h is film thickness) and surface electric potential on the electro viscosity are explored using our overlapped EDL model.