Polyacrylonitrile-derived ID 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 °C, which is followed by a stepwise high-temperature pyrolysis (carbonisation) in an inert atmosphere in the temperature range between 600-1100 °C. Finally, a graphitisation step was carried out at high temperature above 1500 °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 °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.