Nanostructured Synthetic Carbons Obtained by Pyrolysis of Spherical Acrylonitrile-Divinylbenzene CopolymersReportar como inadecuado




Nanostructured Synthetic Carbons Obtained by Pyrolysis of Spherical Acrylonitrile-Divinylbenzene Copolymers - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Novel carbon materials have been prepared by the carbonization of acrylonitrile AN-divinylbenzene DVB suspension porous copolymers having nominal crosslinking degrees in the range of 30–70% and obtained in the presence of various amounts of porogens. The carbons were obtained by pre-oxidation of AN-DVB copolymers at 250−350°C in air followed by pyrolysis at 850°C in an N2 atmosphere. Both processes were carried out in one furnace and the resulting material needed no further activation. Resulting materials were characterized by XPS and low temperature nitrogen adsorption-desorption. It was found that maximum pyrolysis yield was ca. 50% depending on the oxidation conditions but almost independent of the crosslinking degree of the polymers. Porous structure of the carbons was characterized for the presence of micropores and macropores, when obtained from highly crosslinked polymers or polymers oxidized at 350°C and meso- and macropores in all other cases. The latter pores are prevailing in the structure of carbons obtained from less porous AN-DVB resins. Specific surface area BET of polymer derived carbons can vary between 440 m2-g and 250 m2-g depending on the amount of porogen used in the synthesis of the AN-DVB polymeric precursors.



Autor: Danish J. Malik , Andrzej W. Trochimczuk, Sylwia Ronka

Fuente: http://plos.srce.hr/



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