Browsing by Author "Partyka, Stanislas"

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    Calorimetric Evidence for a Bidimensional Phase Change in the Monolayer of Nitrogen or Argon Adsorbed on Graphite at 77 K
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1977, 73 (2), 1977) Rouquerol, Jean Rouquerol; Partyka, Stanislas; Rouquerol, Franchise
    Nitrogen adsorption on a Sterling MT 3100 graphitized carbon black is followed by isothermal microcalorimetry at 77 K. A special feature of the curve of isosteric heats is a distinct peak recorded for a coverage close to 1. Simultaneously, a sub-step is detected on the adsorption isotherm. Both effects are assigned to a bidimensional phase transition of the monolayer, changing from an hypercritical fluid state to a localized state. A similar phenomenon is observed in the case of argon adsorption: here again, a peak on the calorimetric curve and an inflexion on the isotherm are interpreted by a bidimensional fluid -> solid transition; nevertheless, in the latter state, argon is not localized at graphite lattice sites.