The effect of solvation and temperature on the adsorption of small organic molecules on calcite.

Abstract

We performed density functional theory calculations to investigate the effect of solvation and temperature on the adsorption of small organic molecules on calcite. The Conductor like Screening Model for Real Solvents (COSMO-RS) solvation model was used to describe a multicomponent mixture consisting of both hydrophobic and hydrophilic phases. The results demonstrate that the combination of solvation and temperature significantly influences adsorption, with the effect of temperature dominating over the effect of solvation. At 25 °C, carboxylic acids and methanol are stable on calcite with free energy of adsorption <0 in the hydrophobic phase. None of the molecules considered in this study remain on the surface in the hydrophilic phase.