Effect of Na⁺, Ca²⁺ on the hydration properties of quartz surface: a molecular dynamics simulation study

Abstract

Effects of metal ions on the surface hydration of fine quartz are investigated by the theoretical methodologies. The hydration layer on the quartz surface consists of three layers of water molecules, about 8-10 Å. The interaction energy of ions changes from -1.071 eV in water to -1.821 eV (Na + ) and -1.896 eV (Ca 2+ ) when ions are present. Metal ions improve the interaction of water molecules with the quartz surface, allowing more water molecules to enter the second and third hydration layers. In the presence of Na + , the diffusivity of water molecules is greater than in Ca 2+ solutions. Increased interaction between water molecules and surfaces in the order Ca 2+ > Na + is consistent with metal ions' propensity to hydrate.

Experimental study on the effect of ions on the surface hydration characteristics of fine quartz

“…And the interaction mechanism revealed from the atomic level (Luo et al 2022;Peng et al 2016). Water molecules interact with the α-quartz (001) surface via two hydrogen bonds between the surface active atoms and water molecules, generating the hydration layer, which is consist of three monolayers of water molecules (Liu et al 2019;Liu et al 2022). Reagent interactions with quartz surfaces are also described, for example, the effects of various nitrogen-containing compounds on the hydroxylated α-quartz (001) and (100) surfaces.…”