2-DIMENSIONAL CRITICAL BEHAVIOR OF RARE GASES ADSORBED ON GRAPHITIZED CARBON BLACK

Heat capacities of one half layer of neon, argon, and kryptou adsorbed on graphitized carbon black have been measured as a function of temperature. Anomalies were found which are ascribed to changes in the adsorbed phases in their critical regions. The shapes of the anomalies were determined and the temperatures of the maxima in the heat capacity curves were identified with the two-dimensional critical temperatures. These results are compared with each other and with similar measurements made using a xenon-covered adsorbent; it is concluded that such data are quite sensitive to the nature of the mutual interactions of the adsorbed atoms and to the potential barriers to translation across the surface which modify the configurational properties of the interacting adsorbed atoms. © 1968.