Near interface diffusion of various kinds of colloidal particles

Whensuspended colloidal particles move in the ultimate vicinity of a flat solid interface, their mobility is smaller than in the bulksuspension due to a drag force caused by hydrodynamic interaction between the particle and the wall. Further, the friction acting on aparticle depends on the direction of motion. Leading to different diffusion coefficients parallel, ∥,and normal, to the interface. Toexpand the catalogue of particles being studied at interfaces [1-5], we are now investigating colloidal particles with controlled surfaceroughness and hollow shells. In this work, we show the anisotropic diffusion of these particles when they are close to a glass/dispersioninterface by means of evanescent wave dynamic light scattering (EWDLS). By comparing the results from various kinds of particles withdata from smooth spherical particles and with theoretical predictions for hard sphere colloids [4], we assess the influence of particlemorphology on the particle interface hydrodynamic interactio