A computer simulation study of extended DLVO interactions between calcite nanoparticles and real rough surfaces

Abstract

The interaction energy between calcite nanoparticles and real rough surfaces in calcium carbonate supersaturated solutions was numerically calculated according to the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory and the surface element integration method. Three different surfaces, namely polished stainless steel, plasma-treated stainless steel, and fluorine-doped diamond-like carbon film, were prepared by mechanical polishing, plasma sputtering and film deposition, and characterized by atomic force microscopy. These images were then used as inputs in numerical simulations, where particle radius, solution concentration, surface electric potential, and surface tension components were varied. A total of 4052 simulations were performed. It was obtained that smaller particles interact more strongly with the surface and therefore are more attracted or repelled by the surface than larger ones. The effect of surface roughness on the particle interaction, however, depends on the physicochemical properties of the system and, therefore, a given surface may change its fouling behavior when the set of experimental conditions is changed. The effect of particle size on particle-surface interaction was found to be dependent on the relative sizes of the particle and the typical roughness features of the surface. A new local roughness metric – the minimum distance between the south pole of the particle and the rough substrate – can be used to predict the contact energy. These results may be important to engineer better antifouling surfaces for a wide range of applications, such as oil and gas exploitation and water treatment and desalination.