Churaev NV, Starke G, Adolphs J
Laboratory of Thin Liquid Layers, The Institute of Physical Chemistry of the Russian Academy of Sciences, Leninsky Prospect 31, Moscow, 117915, Russia
J Colloid Interface Sci. 2000 Jan 15;221(2):246-253. doi: 10.1006/jcis.1999.6592.
Isotherms of capillary condensation are often used to determine the vapor sorption capacity of porous adsorbents as well as the pore size distribution by radii. In this paper, for calculating the volume of capillary condensate and of adsorption films in a porous body, an approach based on the theory of surface forces is used. Adsorption isotherms and disjoining pressure isotherms of wetting films are presented here in an exponential form discussed earlier. The calculations were made for straight cylindrical capillaries of different radii and slit pores of different width. The mechanisms of capillary condensation differ in cylindrical and slit pores. In cylindrical pores capillary condensation occurs due to capillary instability of curved wetting films on a capillary surface, when film thickness grows. In the case of slit pores, coalescence of wetting films formed on opposite slit surfaces proceeds under the action of attractive dispersion forces. Partial volumes of liquid in the state of both capillary condensate and adsorbed films are calculated dependent on the relative vapor pressure in a surrounding media. Copyright 2000 Academic Press.
毛细管凝聚等温线常被用于确定多孔吸附剂的蒸汽吸附容量以及按半径计算的孔径分布。在本文中，为了计算多孔体中毛细管冷凝液和吸附膜的体积，采用了一种基于表面力理论的方法。这里以先前讨论的指数形式给出了湿润膜的吸附等温线和分离压力等温线。针对不同半径的直圆柱形毛细管和不同宽度的狭缝孔进行了计算。圆柱形孔和狭缝孔中毛细管凝聚的机制不同。在圆柱形孔中，当膜厚度增加时，由于毛细管表面弯曲湿润膜的毛细管不稳定性会发生毛细管凝聚。在狭缝孔的情况下，在相对的狭缝表面上形成的湿润膜在吸引力色散力的作用下合并。根据周围介质中的相对蒸汽压计算处于毛细管冷凝液和吸附膜状态的液体的部分体积。版权所有2000年学术出版社。
