ISSN:
1572-8757
Keywords:
He adsorption
;
micropore
;
ultramicroporosity
;
N2 adsorption
;
zeolite
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Physics
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
Abstract The density of He adsorbed in the cylindrical micropores of zeolites NaY and KL has been determined by He adsorption at 4.2K. He adsorption isotherms were then compared with N2 adsorption isotherms at 77K. Crystallographic considerations of the micropore volumes gave the density of the He adsorbed layer, which is necessary for assessment of ultramicroporosity of less-crystalline microporous solids, such as activated carbons. The determined density of He adsorbed in the cylindrical micropores of the zeolite was in the range 0.22 to 0.26 gml−1, greater than that of He adsorbed on a flat surface (0.202 gml−1). A value for the density of He between 0.20 to 0.22 gml−1 is recommended for evaluation of ultramicroporosity of a slit-shaped microporous system such as activated carbon.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00705003
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