Water in nanopores in equilibrium with a bulk reservoir - Gibbs ensemble Monte Carlo simulations

Water confined in cylindrical and spherical nanopores in equilibrium with a bulk reservoir at atmospheric pressure was simulated in the Gibbs ensemble. Capillary condensation or capillary evaporation is observed depending on the strength of the water-pore interaction, Liquid water exists in the pore by forming two prominent orientationally ordered layers near the pore wall, whereas the properties of the rest of the water are close to the bulk. Water oxygens in the outermost layer show ordering in hydrogen-bonded quasi-planar polygons, which improves with strengthening water-pore interaction, decreasing temperature and decreasing pore size.