Capillary condensation in templated nanoporous materials

Abstract

To elucidate the capillary condensation phenomena of vapor within mesoporous materials, we measured the adorption-desorption isotherms of nitrogen and other simple gases onto templated nanoporous materials (TNM) with well-defined porous structures over a wide temperature range. The temperature dependences of the chemical potential of different fluids, which were adsorbed in TNM at the condensation and evaporation pressures, indicate that the adsorption branch of the isotherm corresponds approximately to the true equilibrium, irrespective of the type of adsorbents. The results for KIT-6 and SBA-16 indicate that the interconnections among pores of almost the same size do not have a significant effect on the adsorption hysteresis and pore criticality, whereas interconnections among cagelike pores lead to the occurrence of cavitation on capillary evaporation.