Crystallographic characteristics of carbons derived from cellulose and hemi‐cellulose

Abstract

AbstractThe crystallographic characteristics of carbons derived from both cellulose and hemi‐cellulose are reported. It is shown that, although such carbons normally exhibit little crystal development, the presence of impurities at the calcining stage catalyses the graphitisation process.X‐ray examination indicated that the high degree of directional orientation present in the untreated fibres is not carried over into the carbon material produced by heat‐treatment.Results of electron microscope and X‐ray small‐angle scattering studies are used to demonstrate the existence of a complex pore structure which changes with temperature of heat‐treatment.Crystal thermal expansion results indicate a large coefficient perpendicular to the layer planes, comparable in magnitude with those observed in graphitic carbons. This fact, together with helium density measurements, indicates that the crystallites in cellulose carbons consist essentially of graphite‐like layers in a ‘turbo‐stratic’ stack.