First Adsorbed Layer of Nitrogen on Pyrex at 77.4° K

A measure of the nitrogen adsorption isotherm on pyrex (Corning 7740) at 77.4° K has been made for pressures above the adsorbed layer ranging from 10 −3 to 10 −9 mm Hg. Ultrahigh-vacuum techniques were used. Geometric adsorbing areas were 60 and 32 cm 2 . Coverages ranged approximately from 0.001 to 0.3 monolayer. Full equilibrium was probably not achieved but the data could be represented by the Dubinin–Radushkevich equation,[Formula: see text]for P/P 0 from 10 −6 to 10 −11 , where σ is the amount adsorbed.