Surface tension of hard sphere fluid near a wall

Abstract

Two equivalent expressions for the surface tension of a hard sphere fluid near a rigid wall are deduced. The effect of an attractive potential between the wall and the fluid is included. Percus-Yevick and superposition approximations are used to calculate the surface tension, for densities η ⪅ 0·4, numerically. The superposition approximation describes the problem more accurately than the Percus-Yevick approximation. New inconsistencies are found in both of them. An equivalent but simpler integral equation for the density profile in the superposition approximation is proposed.