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Author Clarke, J. T.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CHEMISTRY ♦ ADSORPTION ♦ GAMMA RADIATION ♦ GRAIN SIZE ♦ GRAPHITE ♦ HALF-LIFE ♦ KRYPTON ♦ KRYPTON 85 ♦ MEASURED VALUES ♦ PERFORMANCE ♦ SURFACES
Abstract BS>A method was developed to measure the surface area of small samples of low surface area materials using the gamma radiation of /sup 85/Kr-traced Kr to determine the amount of Kr adsorbed. Since the count rate observed is directly proportional to the Kr adsorbed, the method is much more rapid and the calculations much less time-consuming than other methods of surface area measurement. The method is applicable over a wide range of surface areas (0.001 to 10 m/sub 2//g) and to sample sizes of 0.5 g or less. The long half life of / sup 85/Kr (10.5 years) minimizes the corrections necessary for radioactive decay. The usual advantages of Kr over nitrogen (inertness, low vapor phase corrections, and spherical shape) are utilized in this method. Using this new method, it was found that the surface area of TSX nuclear graphite increased by a factor of four as the particle size was reduced from 3-mm cubes to 80-mesh. This is interpreted as indicating that the increased surface area results primarily from the opening of closed pores; this allows the surface area of graphite samples having different sizes and shapes to be estimated. (auth)
ISSN 00223654
Educational Use Research
Learning Resource Type Article
Publisher Date 1964-04-01
Publisher Department Brookhaven National Lab., Upton, N.Y.
Publisher Place United States
Journal Journal of Physical Chemistry
Volume Number 68
Technical Publication No. BNL-7566
Organization Brookhaven National Lab., Upton, N.Y.


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