COARSE-GRAINED POTENTIAL FOR INTERACTION WITH A SPHERICAL COLLOIDAL PARTICLE AND PLANAR WALL

An effective coarse-grained interaction potential between a point particle and a spherical colloidal particle with continuously distributed inverse power-law interaction sites is derived. The potential covers all ranges of spherical particle size, from a point particle up to an infinitely large particle forming a planar surface. In the small size limit, the point-to-point interaction is recovered, while in the limit of an infinitely large sphere the potential comes over to the known particle-wall potentials as, e.g., the 9-3 potential in the case of the Lennard-Jones interaction. Correctness and usefulness of the derived potential is exemplified by its application to SPC/E water at a graphite sphere and wall.