Експериментальне і теоретичне дослідження окиснення природного та терморозширеного графіту

• Datum: 2015
• Hauptverfasser: Nasiedkin, D. B., Grebenyuk, A. G., Babich, I. V., Plyuto, Yu. V., Kartel, M. T.
• Format: Artikel
• Sprache: Ukrainisch
• Veröffentlicht: Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine 2015
• Online Zugang: https://surfacezbir.com.ua/index.php/surface/article/view/575
• Назва журналу: Surface

The process of air oxidation of natural and thermally expanded graphite samples with specific surface area of 1 and 32 m2/g, respectively, was investigated by thermogravimetric method. It has been proved that the increase of the surface area of expanded graphite occurs mainly due to exfoliation of natural graphite along the basal plane during thermal expansion. It has been found out that the temperature of maximum oxidation rate of the expanded graphite is 150 °C lower than that of the natural graphite due its dispersion increase because of the formation of graphene nanoblocks with thickness of about 30–35 nm as a result of thermal expansion. The quantum chemical calculations of graphite cluster models formed by three coronene C24H12 molecules have confirmed that air oxidation of graphite resulting in the formation of defect structures and CO2 is energetically favorable only by removing carbon atom from the lateral surface of graphite (the reaction energy of –325 kJ/mol).