Preparation and characterization of magnetic carbon aerogel from pyrolysis of sodium carboxymethyl cellulose aerogel crosslinked by iron trichloride

Multifunctional carbon aerogel was prepared by pyrolysis of sodium carboxymethyl cellulose aerogel after sol-gel processing and freeze-drying. Ferric iron and D-(+)-gluconic acid-lactone were used as cross-linker and releasing agent, respectively. The as-prepared carbon aerogel was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffractometry, thermogravimetric analysis, nitrogen adsorption measurements, vibrating sample magnetometry and water contact angle tests. The carbon aerogel had a high specific surface area of 742.34 m(2)/g and contained mostly mesopores. Its density was as low as 0.062 g/cm(3). The carbon aerogel morphology has an uneven three-dimensional structure and presented a type-IV adsorption isotherm. Carbonization resulted in the destruction of the carboxymethyl cellulose crystalline structure, damage to the oxygen-containing functional groups and provided the carbon aerogel with good magnetic properties. The carbon aerogel displayed good hydrophobicity and flame retardance, which has potential application in adsorption, hydrophobic materials and fireproofing.