ISSN:
1573-4854
Keywords:
clinoptilolite zeolite
;
micropore constrictions
;
low-pressure hysteresis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The micropore-filling characteristics of a series of natural and modified microporous clinoptilolite-type zeolites with N2 at 76 K are measured and analysed. The adsorption behaviour of these substrata is examined in the range of relative pressures between 10−5–1. Several methods such as: Sing's αs-plots, de Boer's t-plots, Lee and Newnham's direct comparison plots, Dubinin's classical methods and a difference isotherm procedure proposed here, are used to assess the microporosity of the samples. Natural samples are used as reference materials to perform these sorption analyses of the modified samples. The effect of narrow micropore constrictions on the adsorption behaviour of clinoptilolites is explored experimentally. The occurrence of a low-pressure hysteresis loop along the sorption isotherm of a modified sample is frequently found and may be due to the strong adsorption of adsorbate molecules at the entrance of necked micropores that interfere with the diffusion of adsorbate molecules inside the porous structure of these zeolites.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009662408173
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