Slip velocity during wetting of solids

Abstract A slip velocity at the contact line of a liquid drop on a solid surface originates because of the force induced by the gradient of the chemical potential in the liquid along the solid-liquid interface. Einstein's equation is used to relate the slip velocity and the force. The gradient occurs because (a) the interaction potential at the liquid-solid interface near the contact line due to the neighboring molecules differs from that of a semi-infinite liquid and depends upon the distance from the contact line and (b) the chemical potential is pressure dependent.