Surface area measurements, column

The mass of the packing material in the column is a largely underestimated parameter. As it was discussed in the theory chapter, the retention is proportional to the total surface area of the adsorbent in the column. External methods of the surface area measurement determine the specihc surface area (in square meters per gram of the material), and the total surface in the column is a product of the specific surface area of base material and the mass of the adsorbent in the column. 

In elutriation methods, particles are classified in a column by a rising fluid stream. A series of cyclones are used to separate particles into different size ranges. Gas adsorption of a gas on a powder is another method for determining surface area. Measurements are usually interpreted by using the Braunauer, Emmett, and Teller (BET) theory. 

In order to characterize our membrane structures as completely as possible, we determined their total surface areas by nitrogen adsorption. The surface areas measured in this way are shown in the last column of Table IV, and include not only the... 

The major gaseous components were analyzed by a gas chromatograph equipped with a TCD and a molecular sieve 13X column. The specific surface areas of carbon produced were measured by the BET method(ASAP 2010, Micromeritics). The morphology and particle size of the formed carbon were investigated by the scanning electron microscopy(S-4200, Hitachi... 

The conversion of butane is based on the difference in the moles between the feed and the products. Intrinsic rate constants, shown in the third column of Table II, are based on BET surface areas (m2/g) measurements (101). 

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