THE ELECTROSTATIC INTERACTION BETWEEN A SMALL COLLOIDAL PARTICLE AND A CHARGED INTERFACE

The electrostatic interaction between a small particle and a charged i nterface is considered, using an exact solution of the linearised Pois son-Boltzmann equation, yielding an integral form for the potential. S imple approximate expressions are given for common systems such as int erfaces between water and glass, air or conductors. Qualitative compar isons are made with the analogous Derjaguin approximation results for a large particle. Although the small and large particle interactions d iffer in origin they display many qualitative similarities. However, u nder some circumstances differences exist.