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 electrodes. 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 structures. Comparisons were made between carbons derived from aerogel and xerogel polymer precursors, and the effects of carbonization temperature and activation were investigated to determine the effect of processing variables on microstructural ordering at internal near-surface regions. The materials were characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Raman spectroscopy and nitrogen physisorption techniques. Xerogel-derived carbons were found to have more microstructural order than carbons derived from aerogels. The degree of short-range order within the aerogel-derived carbons was observed to increase slowly with increasing pyrolysis temperature. Microporous bulk regions were found to be preferentially attacked during carbon dioxide activation.