Studies on preparation of carbon aerogels

A new method for preparing carbon aerogels by using starch as a starting ma terial through sol-gel process, followed by supercritical drying and pyroly sis is described. The resulting aerogels which consist of irregular carbon particles with sizes about 20 nm were of uniform sizes, low density, porous monolithic materials with a bulk density of 108 kg . m(-3) and an electric al conductivity of 1. 6 S . cm(-1) The regular arranging crystal structure in manometer dimensions was observed by using high-resolution transmission electron microscopy and electron diffraction, The results of DTA-TG studies indicated that when starch aerogels were heated, the carbon aerogels with graphite structure formed through dehydration, pyrolysis and subsequent pha se transition.