Physical adsorption of gases on graphitized carbon black

Thermodynamics of Adsorption Phenomena: Theory and Experiment

“…The dimensionless quantity ΠΑ/nRTis equal to unity at zero coverage. For physical adsorption of gases on heterogeneous surfaces the value of this quantity increases with coverage, but on energetically homogeneous surfaces like graphitized carbon black it decreases at first and then increases with coverage [9] in a manner similar to the variation of PV/nRTwith density for bulk vapors.…”

Monolayer Adsorption of Ar and Kr on Graphite: Theoretical Isotherms and Spreading Pressures

“…For example, that in the previously cited work of Glandt et al (4,17); that is, the adsorption isotherms measured by Constabaris et al (9) for Ar adsorbed on highly graphitized carbon black P33(2700ЊC) with A Å 12.5 m 2 /g, and by Putnam and Fort (10) for Kr adsorbed on Sterling FT-D5 with A Å 11.5 m 2 /g, respectively (Figs. 2-5).…”

“…These equations plied to 2D Lennard-Jones (LJ) fluids. Subsequently Glandt are based on models of completely localized, partially local-et al (4) used values of the equation of state of 2D-LJ fluids ized or partially mobile films of gases on solid surfaces (1, obtained from Percus-Yevick theory. Later, Monson et al 2).…”

“…K H is the Henry's constant exsimulation results have been published, the important theo-pressed in (atm 01 mol/g), which depends on temperature retical problem of modelling adsorption of fluids on solid and on the nature of the adsorbed fluid, and it is related with surfaces has not yet been fully solved. The prediction of the second adsorption virial coefficient (4). adsorption isotherms is generally made through empirical or…”

Isotherms for Monolayer Adsorption of Lennard-Jones Fluids onto Flat Surfaces

“…Steele's theory was a first approach to make a molecular description of a well-defined but oversimplified representation of monolayer films of simple fluids physically adsorbed onto perfectly flat surfaces. Steele used statistical mechanics and introduced the so-called “two-dimensional” approximation: the surface is sufficiently uniform and the temperature sufficiently high for the adsorbed fluid molecules to be completely mobile in two dimensions; i.e., the vibrational motion (perpendicular to the surface) of the adsorbed molecules is negligible. By neglecting the second and higher terms of the periodicity of the fluid−solid interactions, Steele obtained the theoretical perfectly-mobile-adsorption isotherm equation where T , ρ, and μ are the temperature, density, and excess (over the ideal gas) of chemical potential per molecule of the two-dimensional (2D) adsorbed system, expressed in reduced Lennard-Jones unit, and P red is the equilibrium pressure of the bulk gas, expressed in particular reduced units as a function of the real pressure, the temperature, and the Henry's law constant or the second adsorption virial coefficient. − …”