SYNTHESIS OF NOVEL NANOCARBONS FROM CARBON PRECURSORS PRERARED BY DEFLUORINATION

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The purpose of this study is to synthesis novel nanocarbons such as nanofibers and nanospheres by use of defluroination of perfluoroorganic compounds with alkali metals. This procedure has an advantage in which the reaction can progress at low temperatures less than 200℃. The as-prepared products(carbon precursors) were heat-treated up to higher temperatures in order to obtain stable carbons from the precursors. As a result we succeeded in synthesis of nanoporous carbons with characteristic morphology and unique porosity by using various kinds of perfluorocompounds. These carbons are consisted basically of amorphous structure, but the treatment at higher temperatures than 2000℃ brought about not only the non-graphitic constituents, but also the graphitic components. In addition, when pentafluorooctane with an aliphatic C-C chain, hexafluorobenzene and octafluorotoluene containing an aromatic ring and also pentafluoropyridine having a nitrogen atom in a ring were defluorinated under vacuum with sodium or potassium, nanoporous carbons and nanofibers were obtained. It was found that they have different mesopores volume and pore size distributions. In order to control the pore size distribution and to obtain nano-composites made up of sp and sp^2 carbons, octafluorotoluene and pentafluorooctane were used as starting reagents. These compounds have nearly same boiling point. The mixture of both components with various ratios was defluorinated and treated as the same manner. As a result it was elucidated that the mixing of both perfluorocompounds is very effective for the control of the pore size distribution. Now we are continuing accumulation of the data on this experiment.