Polyacrylonitrile-Derived 1D Carbon Structures via Template Wetting and Electrospinning

In-situ polymerisation of acrylonitrile as well as a DMF solution-phase impregnation of polyacrylonitrile, PAN, in porous aluminium oxide templates (PAOX) to synthesise 2D arranged carbon nanotubes with diameters in the range of 40-200 nm were studied. The preparation of graphitised carbon tubes from polyacrylonitrile consists of two steps, first a low-temperature crosslinking of aromatic ring units at 250 degrees C, which is followed by a stepwise high-temperature pyrolysis (carbonisation) in an inert atmosphere in the temperature range between 600-1100 degrees C. Finally, a graphitisation step was carried out at high temperature above 1500 degrees C, which however leads to a complete collapse of the structure due to a solid-state reaction between the template and the PAN infiltrated in the template pores. X-ray diffraction of the carbonised PAN tubes in PAOX indicates no graphitisation up to curing temperatures of 750 degrees C. The process of PAN loading and subsequent polymerisation by thermal curing within PAOX was followed by IR and UV/Vis spectroscopy, thermogravimetric analysis coupled with mass spectrometry (TGA/MS), XPS spectroscopy as well as combustion analysis. The presence of nitrogen in the final carbonised product was determined.