A direct method for studying particle deposition onto solid surfaces

摘要: An experimental technique has been developed to study the deposition of colloidal particles under well controlled hydrodynamic conditions. The process is observed a microscope and recorded on video tape for further analysis. Fluid flow conditions in set-up were determined by numerical solution Navier-Stokes equations. Mass transfer equations solved numerically (taking into account hydrodynamic, gravitational, electric double layer, dispersion forces) stagnation point region. Also, some analytical solutions are presented. Deposition studied 0.5μm polystyrene latex cover glass slides used as collectors. From an analysis shape coating density vs. time curves independently from distribution collector surfaces, it was found that one particle able block area about 20 30 times its geometrical cross-section. initial flux given salt concentration depend strongly method cleaning surface. In general escape surface sensitive interaction energy at small separations. direct observing detachment could lead important insights nature particle-wall interactions near contact.