Analysis of adsorption isotherms: Lattice theory predictions, classification of isotherms for gas-solid equilibria, and similarities in gas and liquid adsorption behavior

Journal Article · Wed Apr 15 04:00:00 EDT 1998 · Journal of Colloid and Interface Science

DOI:https://doi.org/10.1006/jcis.1997.5398· OSTI ID:616333

Aranovich, G; Donohue, M ^[1]

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1. Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Chemical Engineering

Adsorption at fluid-solid interfaces is considered in the framework of a lattice with boundaries. Using ideas proposed by S. Ono and S. Kondo (in ``Molecular Theory of Surface Tension in Liquids`` (S. Fluegge, Ed.), Encyclopedia of Physics, Vol. 10, P. 134, Springer-Verlag, Berlin, 1960), a lattice model is derived both rigorously and phenomenologically, and applied to macro-, meso, and microporous adsorbents by imposing different boundary conditions. It is shown that this lattice theory can predict the entire spectrum of behavior observed when gases, liquids, or supercritical fluids adsorb on solid surfaces. In particular, it is able to predict steps in the isotherms, scaling behavior near saturation conditions, supercritical behavior, and adsorption hysteresis. It is shown that there is a profound analogy in the adsorption behavior of a one-component gas to that of a binary liquid mixture. This analysis leads to a new classification of physisorption isotherms for fluid/solid equilibria.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG02-87ER13777
• OSTI ID: 616333
• Journal Information: Journal of Colloid and Interface Science, Journal Name: Journal of Colloid and Interface Science Journal Issue: 2 Vol. 200; ISSN 0021-9797; ISSN JCISA5
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
ADSORBENTS
ADSORPTION
ADSORPTION ISOTHERMS
GASES
LIQUIDS
MATHEMATICAL MODELS
POROUS MATERIALS
SOLIDS