Studies on preparation of carbon aerogels

A new method for preparing carbon aerogels by using starch as a starting material through solgel process, followed by supercritical drying and pyrolysis 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 electrical 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 phase transition.