Modelling short-range interaction of clay particles to improve erodibility prediction

Abstract

Introduction: Erosion has become an urgent problem to society due to the increasing intensity and frequency of disturbances, e.g. storms, wave energy and rainfall. Yet, a universal model to predict erosion thresholds for cohesive sediment is still missing. Short range interaction of clays is recognized as the source of cohesion and adhesion of cohesive sediment. The interaction of negatively charged (i.e., montmorillonite (MMT) and beidellite (BD)) and neutral clay particles (i.e., kaolinite (KL)) are traditionally simulated through DLVO theory and van der Waals interaction[1]. However, the applicability of DLVO theory at short range (i.e., at distance less than 3 nm) has been increasingly challenged in molecular dynamics simulations[2]. A suitable description of short-range clay particle interaction is crucial for the prediction of cohesive sediment erodibility. The aim of this study was to determine how clay mineralogy and water chemistry influence clay particle interactions at short range to affect inter-particle attraction and stability under imposed forces.