Measurements of surface forces between reactive mineral surfaces

Abstract

Minerals growing under confinement may significantly affect the mechanical strength of a porous medium, and depending on the setting, they can provide cohesion or induce damage. The estimation of the disjoining pressures associated with these growth and recrystallization reactions is challenging. In this work, we present direct measurements of nm and μm-range surface forces acting between reactive mineral surfaces across aqueous media using the surface forces apparatus (SFA) technique. In SFA, the forces are measured between two macroscopic surfaces in a symmetrical surface configuration with a spherical nominal interaction area of ~150 μm in diameter. The information about mineral growth and dissolution can be simultaneously accessed from white light interferometry measurements coupled to the SFA. We will discuss forces measured in two setups: one with recrystallizing calcite surfaces and the second with one calcium silicate hydrate film replacing a calcium silicate surface.