Formation of carbon micro-sphere chains by defluorination of PTFE in a magnesium and supercritical carbon dioxide system

Well-crystallized carbon micro-spheres at the sub-micrometer scale were prepared by defluorination of polytetrafluoroethylene ( PTFE) with metallic magnesium in supercritical carbon dioxide at 650 degrees C for 6 h. The products were characterized by X-ray diffraction, transmission electron microscopy, field-emission scanning electron microscopy and micro-Raman spectroscopy. FT-IR spectroscopy was used to monitor the extent of defluorination of PTFE. The produced carbon spheres tend to agglomerate to form chains and the possible mechanism of forming these carbon sphere chains in this system is tentatively discussed.