Undulation Theory and Analysis of Capillary Condensation in Cylindrical and Spherical Pores

摘要: The undulation theory, recently developed to explain the mechanism of onset condensation in an open end slit pore, is extended investigate effects pore diameter, wall curvature, temperature, and surface strength on argon cylindrical spherical pores. Using concept undulating interface separating adsorbed phase gas-like core, we can determine mean thickness adsorbate thus radius core just before condensation. curvature used Cohan–Kelvin equation, modified account for contribution from solid–fluid interaction (better known as Derjaguin–Broekhoff–de Boer equation), derive interfacial energy parameter. For cylinders spheres, this parameter always greater than bulk value, which unmodified equation but converges value diameter increased. smaller same still higher diameters less 6 nm. This difference attributed packing 3D-confined geometry. shows interesting interplay between 3D-spherical confinement cohesiveness enhanced by interaction.