Adhesion of Iron Oxide to Silica Studied by Atomic Force Microscopy

摘要: The interaction of an iron oxide sphere with a silica flat immersed in dilute electrolyte solution has been studied atomic force microscope using the colloid probe technique. adhesion energy obtained from measurement pull-off force, as function ionic strength and pH, particular focus. pH range over which occurred correlated strongly electrokinetic data, suggesting that electrostatic mechanism was dominant. However, magnitude significantly less than anticipated on basis attractive van der Waals forces decreased increasing strength. These results may be qualitatively explained terms roughness component surfaces, increases effective separation at asperity contact. In addition not found to single-valued but dependent loading prior surfaces. presence hydration or gel layer, giving rise strong short-range repulsion neighborhood contact points is implicated. observations highlight deficiencies currently accepted models for description nonideal, particularly rough,