Interactions between Confined Calcite Surfaces in Aqueous Solutions: A surface forces apparatus study

Abstract

The macroscopic mechanical strength of rocks and mineral-based materials is often controlled by micro- and nanoscale mechanisms occurring at solid-solid contacts. Such interfaces are critical to deformation processes as they confine fluids that facilitate chemical reactions, enable and govern mass transport, and allow the slip movement along the grain boundaries. Solid-solid contacts are also discrete regions in which adhesive or repulsive surface forces may operate. The surface forces are not only affected by the properties of solid phases but also by the chemistry of fluids confined between the surfaces. Both surface forces and mineral reactivity can render the solid-solid contacts stronger or weaker. Adhesive forces or cementing growth of minerals may strengthen the interfaces. Conversely, repulsive forces or displacive mineral growth can weaken the interfaces. The possible links between surface forces and reactivity of confined surfaces are not fully explored yet. In this thesis, I tackle the question of to what extent the nanoscale surface forces acting between reactive mineral surfaces may contribute to the macroscopic strength and cohesion of rocks and granular materials.