Sorptive properties and small angle neutron scattering from porous carbon

✍ Scribed by Peter G. Hall; Shirley A. Müller; Ruth T. Williams

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 483 KB
• Volume: 27
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(89)90162-0

✦ Synopsis

The investigated carbons included eight graphitized carbon blacks (A to H), ball milled to give specific surface areas ranging from 5 to 540 mz g -I, a Koch-Light graphite (nonporous), graphitized (g-FT) and ungraphitized (u-IT) carbons, activated charcoal, and charcoal cloth. Small-angle neutron scattering (SANS) Porod plots (In I versus In Q) showed normal Porod behavior (negative slope = 4.0) with the Koch-Light and u-FT carbons but marked deviations (<3) were evident for activated charcoal and charcoal cloth. The Porod slopes (-3.6 to -2.8) for the samples A to H reflected the extent of ball milling. These deviations from Porod behavior may also reflect the fractal nature of the solids. Lamond n-N' type plots constructed from nitrogen isotherms at 78 K indicated the presence of ultramicropores (d < 0.7 nm) only in the cases of activated charcoal and charcoal cloth.

Water isotherms (303 K) on graphite H and g-FT showed the hydrophobic nature of these surfaces. With sample H. the sorption of 2,2-dimethyl-propane (spherical) was quite similar to that of n-butane (linear).