Krypton, thermodynamic properties

Inverse gas chromatography (IGC) is another technique that can be used to measure the specific surface area of a particulate material, as well as to measure a number of surface thermodynamic properties of powders. Such instrumentation operates on a different principle than traditional nitrogen/krypton adsorption using the BET isotherm. 

V. A. Rabinovich, A. A. Vasserman, V. I. Nedostup, and I. S. Veksler, Thermodynamic Properties of Neon, Argon, Krypton and Xenon, Springer, Berlin, 1988. 

L. V. Gurvich, I. V. Veyts, and C. B. Alcock, Thermodynamic Properties of Individual Substances, Vol. 1 Elements Oxygen, Hydrogen (Deuterium, Tritium), Fluorine, Chlorine, Bromine, Iodine, Helium, Neon, Argon, Krypton, Xenon, Radon, Sulfur, Nitrogen, Phosphorus, and Their Compounds, Pt. 1 Methods and Computation, Hemisphere, New York, 1989. 

It is well known that even for the simplest substances such as argon or krypton there is no satisfactory theory of the liquid state at the present time. The theories of Mayer (24), Kirkwood (25), and Born and Green (41) may for practical purposes be considered rigorous and would presumably give excellent agreement with experimentally observed thermodynamic properties of classical (i.e., nondegenerate) liquids with spherically or effectively spherically symmetrical molecules—but the equations which can be written down are so complicated that they cannot be solved for useful numerical results. The best that can be done along these lines at present is to use Kirkwood s superposition approximation. There are also a number of approximate theories of liquids, but none of these is really very adequate. 

Values extracted and in some cases rounded off from those cited in Rabinovich (ed.), Thermophysical Properties of Neon, At on, Krypton and Xenon, Standards Press, Moscow, 1976. v = specific volume, mVkg h = specific enthalpy, kj/kg s = specific entropy, kJ/(kg-K). This source contains an exhaustive tabulation of values. The notation 7.420.-4 signifies 7.420 x 10". This book was published in English translation by Hemisphere, New York, 1988 (604 pp.). The 1993 ASHRAE Handbook—Fundamentals (SI ed.) has a thermodynamic chart for pressures from 1 to 2000 bar, temperatures from 90 to 700 K. Saturation and superheat tables and a chart to 50,000 psia, 1220 R appear in Stewart, R. B., R. T. Jacobsen, et al.. Thermodynamic Properties of Refrigerants, ASHRAE, Atlanta, GA, 1986 (521 pp.). For specific heat, thermal conductivity, and viscosity see Thermophysical Properties of Refrigerants, ASHRAE, 1993. 

Fischer et al, [122] proposed a model to predict the adsorption isotherm of krypton in porous material at supercritical temperature. In their study, a model pore of infinite length is formed by concentric cylindrical surfaces on which the centers of solid atoms are located. The interaction between an adsorbate and an individual center on the pore wall is described by the LJ 12-6 theory, and the overall potential is the integral of this interaction over the entire pore surface. With thermodynamic relations, Fischer et al. obtained the functional dependence of the saturation adsorption excess and the Henry s law constant on the pore structure. The isotherm was then produced by the interpolation between Henry s law range and saturation range. They tested their theory with the adsorption of krypton on activated carbon. It was shown that, with information on the surface area of the adsorbent and thermodynamic properties of the adso bate, their model gives more than quantitative agreement with experimental data. If a few experimental data such as the Henry s law constant at one temperature are available, the isotherms for all temperatures and pressures can be predicted with good quality. 

Juza, J. Sifner, O. (1976). Modified equation of state and formulation of thermodynamic properties of krypton in a canonical form in the range from 120 to 423 K and 0 to 300 MPa. Acta Tech. CSAV, 2,1-32. 

Polt, A. Maurer, G. (1992). The Bender equation of state for describing thermodynamic properties of krypton, neon, fluorine, sulfur dioxide and water over a wide range of state. Fluid Phase Equil, 73,27-38. 

Holder, G.D. Corbin, G. Papadopoulos, K.D. Thermodynamic and molecular properties of gas hydrates containing methane, argon and krypton. Ind. Eng. Chem. Fund. 1980, 19, 282-289. 

While a monomolecular film of krypton on graphite has an incipient triple point and a commensurate-incommensurate 2D solid transition, this phenomenon does not appear on a-BN. The differences in the Kr-film properties probably originate in the particular size of the Kr atom with respect to the distances of potential wells on the substrate. For relevant compilation of thermodynamic data and diagrams of the adsorption isotherms, see [51 ]. Long-range interactions between rare gas atoms on the surface of a-BN (in context with other... 

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