Influence of temperature on water adsorption / desorption hysteresis loop in disordered mesoporous silica glass by Grand Canonical Monte Carlo simulation method

摘要

The water adsorption / desorption properties in a mesoporous silica glass are investigated by way of Grand Canonical Monte Carlo simulations. The SPC and PN-TrAZ potential are used to describe water-water and water-silica interactions. The numerical sample of mesoporous silica glass (pore size: 3.6 nm) was obtained by off-lattice reconstruction, known to reproduce in a realistic way the geometrical complexity of high specific surface Vycor. The ability of the PN-TrAZ potential to describe the hydrophilic properties of silica surfaces is shown through the calculation of the adsorption isotherm and isosteric heat of adsorption at 300 K, which compare well to experimental data for Vycor. This study is extended to several temperatures, and the evolution of the hysteresis loop is examined.