MOLECULAR CALCULATION OF THE SOLID-LIQUID INTERFACIAL SHEAR STRENGTH FOR LOW LIQUID PRESSURES BY USING THE COULOMB INTERACTION MODEL

摘要

The solid-liquid interfacial shear strength under low liquid pressures was calculated on the molecular scale by using the Coulomb interaction potential model. The solid wall had a cubic lattice structure with normal parameters. Both the molecules of the solid wall and the liquid were taken as consisted of charged atoms. The long-rang and short-range interactions simultaneously occur between the molecules of the solid wall and the liquid, and are respectively characterised by the Coulomb interaction potential model and the Lennard-Jones potential model. Following the former study on the interfacial shear strength using the Lennard-Jones potential model, the present paper presents the molecular calculation results of the solid-liquid interfacial shear strength for low liquid pressures using the Coulomb interaction model by considering the elementary interaction between unit electric charge within the solid wall and unit opposite electric charge within the liquid. The actual shear strength of the solid-liquid interface may be the summation of the components, respectively contributed by the Lennard-Jones type interaction and the Coulomb interaction. The results in the present study showed that under low liquid pressures, the solid-liquid interfacial shear strength can normally be taken as constant independent on the liquid pressure, and a high liquid temperature usually results in a low solid-liquid interfacial shear strength.