(260h) Evaporation Induced Nucleation of NaCl in Clay Minerals: Mechanism and Potential Sites

Salt crystallization and nucleation in confined media occur in Earth's crust, damaging physical properties of porous media. It also occurs in other solid materials of high practical importance, such as asphalt and concrete. Clays are a main component of sedimentary geological formations and, thus, salt crystallization and precipitation in clays is the prototype of the more general phenomenon. Despite numerous efforts to understand the mechanisms of nucleation of salt crystals, the effect of the chemical composition of nanopores of geological formations and their fluid content on the growth, distribution and properties of salt crystals has not been studied. To address this shortcoming, we have carried out extensive molecular dynamics simulation using models of two types of clay minerals: Na-montmorillonite (Na-MMT) and Kaolinite. The simulations provide new and deep insight into the mechanism of nucleation and crystal growth in clay minerals. We have investigated the effect of the evaporation rate of brine and the clay mineral type on the spatial distribution of the precipitated NaCl crystals from supersaturated brine.