Molecular dynamics study of cyclohexane in a cylindrical pore of amorphous silica

Abstract

A series of molecular dynamics simulations of cyclohexane in a cylindrical pore was performed at 293·3 K, for increasing numbers of molecules. The new configuration is generated from the previous simulation by introducing new molecules into the pore. The maximum number of the cyclohexane molecules corresponds to about 50% of the liquid density. Thermodynamic, structural and dynamic properties of the molecules confined in the pore were studied and are discussed in terms of the surface density of cyclohexane. The molecules are adsorbed on the pore surface and, for higher densities, a second layer is formed. The adsorption has a non-localized nature; however, the mobility of the molecules in the contact layer diminishes with surface density. Translations of cyclohexane moving within the contact layer are described by the diffusion equation of a particle on a cylindrical surface.