Water adsorption on planar interfaces: Classical density functional study

Abstract

• A new cDFT based on SAFT with an explicit account for dipole-dipole interactions was formulated. • Our model provides a good description of binodal, liquid-vapor surface tension, latent heat of vaporization, and wetting contact angles. • The energy distribution functions for non-porous silica and alumina were calculated. Theoretical modeling of water adsorption in micro- and mesoporous materials remains a challenging problem for physical chemistry and chemical engineering despite its great importance for industrial applications. Here, we present the theoretical study of bulk and inhomogeneous water within the classical density functional theory. Our model includes all important intermolecular interactions, such as dispersion, association, and dipole-dipole. We validated the model via comparison with existing literature experimental and computer simulation data. Among the others, the following water properties were compared: liquid-vapor binodal (T - ρ ), surface tension, latent heat of vaporization, wetting contact angle, and adsorption isotherms on nonporous silica and alumina. Our computational results demonstrate good agreement with the experimental literature data and show similar trends compared to the several commonly used water models (SPC/E, TIP4P, TIP4P/2005). Because the presented model can accurately describe the thermodynamic and interfacial properties of water then it can be of interest to the adsorption community. Also, the model may serve as a starting point for further works regarding porous adsorbents characterization employing classical density functional theory.