Argon Adsorbed on a Graphitic Surface. The Heat of Adsorption from Lattice Liquid Theory

Journal Article · Tue Jan 01 04:00:00 EST 1957 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.1744004· OSTI ID:4339063

Pace, E. L.

A model is proposed to account for the differential or isosteric heat of adsorption which has been observed for argon on graphite at concentratioms between 0.5 and 2.0 monolayers for temperatures in the neighborhood of the normal boiling point of argon. The energy of a molecule on the surface is considered to be the sum of the contributions of a site energy for the isolated molecule and an interaction energy with neighbors in the same layer. The site energy for a molecule is calculated assuming atoms and molecules in lower layers fixed with respect to both a configuration in a hexagonally packed planar lattice and the distance between layers. The interaction energy is calculated assuming the behavior in any layer is represented by a two dimensional lattice liquid model utilizing the so-called Ono approximation for the variation of the generalized free volume with vacancies in the lattice. The distribution of adsorbed molecules in any layer is considered to be completely random. On the basis of this model, an interpretation is made of the two maxima in the isosteric heat which have been observed experimentally.

• Research Organization: Western Reserve Univ., Cleveland
• Sponsoring Organization: USDOE
• NSA Number: NSA-12-011380
• OSTI ID: 4339063
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 6 Vol. 27; ISSN 0021-9606
• Publisher: American Institute of Physics (AIP)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ADSORPTION
ADSORPTION HEAT
ARGON
ATOMS
BOILING
CHEMISTRY
ENERGY
GRAPHITE
INTERACTIONS
LATTICES
LAYERS
LIQUIDS
MATHEMATICS
MOLECULES
QUANTITY RATIO
SURFACES
TEMPERATURE
THERMODYNAMICS
VACANCIES
VOLUME