AREA OF NITROGEN MOLECULE ADSORBED ON CARBON

The surface area of a specially prepared nonporous very low structure carbon black was determined by two separate methods. Precise electron micrographic particle size measurements were carried out. Corrections were made for the influence of fused particles, while the actual particle density was determined in helium. Low-temperature nitrogen adsorption measurements using a volumetric as well as a gravimetric method were carried out. The results indicate that the area of the nitrogen molecule adsorbed on carbon black at - 196°C is clearly the area calculated for a solid state packing of 13.8 2 and not the previously supposed value of 16.27 2, corresponding to a liquid state packing. It appears, however, that on graphitized carbon black adsorbed nitrogen molecules at - 196°C are in the liquid state packing. © 1997 Elsevier Science Ltd. All rights reserved.