ABSTRACT
The interaction of two surfaces is usually dictated by the balance between the fundamental forces such as the van der Waals and the electrostatic forces (including ion-electrostatic and dispersion forces) as described by the DerjaguinLandau-Verwey-Overbeek (DLVO) theory [1, 2]. In most cases, the interaction is not limited to these forces, alone and may include specific forces such as solvation, hydration, structural and hydrophobic forces, sometimes termed nonDLVO forces. Additionally, steric, hydrodynamic and frictional forces may also need to be considered in specific systems. The understanding of most industrially relevant phenomena such as particle adhesion and dispersion are based on the DLVO theory and other contact mechanics models such as the Hertz model [3], the Johnson-Kendall-Roberts (JKR) model [4] and the Derjaguin-Muller-Toporov (DMT) model [5]. The first systematic attempt at understanding the role of roughness in the interaction forces was made in terms of the Rumpf model [6]. The introduction of the A F M provided the capability of verifying the applicability of these theories to different length scales and revealed their limitations, thus necessitating the development of better models.
