DLVO interaction energy between a sphere and a nano-patterned plate

The potential energy of interaction between a microsphere and regular nano-topographies of varying shape and dimensions in 1:1 aqueous electrolyte is determined using the surface element integration (SEI) technique. The height and diameter of a square-lattice of cylindrical protruding and hollow asperities are varied to show the influence of these geometric parameters on the interaction energy. The simulation predicts that the nano-protrusions would decrease the energy barrier towards adhesion, which in turn would yield much larger deposition rates than predicted by the DLVO (Derjaguin-Landau-Verwey-Overbeek) theory for particles on smooth surfaces. In qualitative agreement with experimental observations, decreasing the radius of curvature of the protrusions results in lower energy barriers. Inversely, at 100 mM the presence of nano-pits on a surface would increase the height of the energy barrier, thus hampering particle deposition. (C) 2007 Elsevier B.V. All rights reserved.