SURFACE AND NEAR-SURFACE STRUCTURE IN CARBON MICROCELLULAR MATERIALS PRODUCED FROM ORGANIC AEROGELS AND XEROGELS

Carbons have been produced from organic aerogel and xerogel precursors for application in chemical separations and as electrochemical electr odes. An emulsion-derived macro-structure was imposed to maximize the mass transport within these high-surface-area materials. The presence of the interfacial region affects the order within the adjacent struct ures. Comparisons were made between carbons derived from aerogel and x erogel polymer precursors, and the effects of carbonization temperatur e and activation were investigated to determine the effect of processi ng variables on microstructural ordering at internal near-surface regi ons. The materials were characterized by transmission electron microsc opy, scanning electron microscopy, X-ray diffraction, Raman spectrosco py and nitrogen physisorption techniques. Xerogel-derived carbons were found to have more microstructural order than carbons derived from ae rogels. The degree of short-range order within the aerogel-derived car bons was observed to increase slowly with increasing pyrolysis tempera ture. Microporous bulk regions were found to be preferentially attacke d during carbon dioxide activation.