HIGH-RESOLUTION ADSORPTION-ISOTHERMS OF MICROPOROUS SOLIDS

High-resolution static adsorption of nitrogen and argon at 77 K was de termined on six microporous carbons and two synthetic zeolites. The ad sorption behavior at very low relative pressures such as 10(-6) was ex amined in close detail. An S-shaped feature was observed in the low-pr essure region of most of the nitrogen and argon isotherms on microporo us carbons. A novel mechanism for the physical processes involved in t he filling of micropores designated as monolayer-induced micropore fil ling is proposed to account for this behavior. Examination of the low- pressure region of these high-resolution adsorption isotherms also rev ealed that the ultramicropores are filled in the region of 10(-5) rela tive pressure.