Dynamical properties of wall-confined colloids

We report on a Stokesian Dynamics simulation study of monolayers of spherical colloidal particles diffusing in the midplane between two parallel walls. The method accounts for many-body hydrodynamic interactions (HI) between particles and particles and walls. Two cases are studied: hard spheres between neutral walls and charged particles interacting by a Yukawa-type potential. Various properties are calculated: mean-squared displacement, self-diffusion coefficient, van Hove functions and hydrodynamic functions. The importance of HI is assessed by treating particle-particle and particle-wall HI separately. Striking features are discussed like the hydrodynamic enhancement of self-diffusion for strongly charged particles and the unbounded increase of the hydrodynamic function at small wave numbers.