Carbon having unique properties prepared from microcrystalline cellulose

Abstract

Carbons possessing unique properties somewhat like those of glassy carbon have been prepared from structural microcrystalline cellulose precursors by prolonged pyrolysis up to 800°C in a nitrogen atmosphere. Samples of the dry microcrystalline cellulose powders were fabricated into various shapes in a high pressure mold or by slow drying of an aqueous suspensoid gel in a mold under ambient conditions. Pyrolysis gave objects of amorphous carbon about one-third the original size. Some of the carbons are about as hard as glass and have a density (helium pycnometer) of 2.01 g/cm³ (cf. graphite 2.265). As expected, the carbon resulting from the pressed microcrystalline cellulose dry powders had a lower density and more pores than carbons produced from structural forms, prepared from air dried, aqueous gels. Pore size and pore size distribution data and scanning electron photomicrographs are shown.