Fabrication of ultra thin and aligned carbon nanofibres from electrospun polyacrylonitrile nanofibres

Abstract

Ultra thin and aligned carbon nanofibres (CNFs) have been fabricated by heat treatment from aligned polyacrylonitrile (PAN) nanofibre precursors prepared by electrospinning. The alignment of the precursor nanofibres was achieved by using a modified electrospinning set up developed recently, where a tip collector was used to collect and align the nanofibres. The average diameter of the aligned CNFs is about 80 nm. The stabilization and carbonization behaviour were studied mainly based on the randomly oriented PAN nanofibres. The effects of stabilization and carbonization temperatures, temperature-increasing rates, and with and without substrates on the morphology and structure of the CNFs were investigated. Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, transmission electron microscopy and Raman spectroscopy were used to characterize the structure of the CNFs and thermogravimetric/ differential temperature analysis was used to evaluate the thermal behaviour of PAN nanofibres.

Improved Graphitic Structure of Continuous Carbon Nanofibers via Graphene Oxide Templating

“…The integrated intensities I D and I G and the width of the G band were calculated by fitting the D and G peaks using Lorentzian curve shapes. The ratio R = I D / I G was originally linked by Tuinstra and Koenig38 to the in‐plane crystallite size L a ( R proportional to L a −1 ) and was subsequently widely used for this purpose,20, 24, 39–42 although there have been reports of this relationship breaking down for crystals smaller than 2 nm 43, 44. The width of the G band is also often used as an indicator of the level of graphitization (narrower G band indicates better graphitic structure).…”

Carbon nanowalls grown by microwave plasma enhanced chemical vapor deposition during the carbonization of polyacrylonitrile fibers

“…crystallinity). 12,17,22 As shown in Fig. 4(b) and summarized in Table I, the R-value calculated for the present stabilized PAN fibers is 1.6 (sample b).…”

“…3 Such disorder could be resulted from the low crystallinity of carbonized PAN fibers (i.e., sample d), due to the relatively low carbonization temperature. 12,17,22,23 As we discussed before, sample d was carbonized at $750 C, which is significantly lower than the carbonization temperature (at 1000 C) for sample c when using conventional furnace method. Therefore, sample d shows the presence of D 0 band representing the higher level of disorder than sample c.…”

“…It can been seen that there is a strong peak located at 2242 cm À1 which corresponds to nitrile group (C N). 16,17 Other peaks located at 2938 cm À1 , 1453 cm À1 , 1357 cm À1 , and 1249 cm À1 are corresponding to the vibrations of the aliphatic CH groups (CH, CH 2 , and CH 3 ). 18 A weak peak located at 1623 cm À1 was assigned to amide group.…”

An ultralight, elastic carbon nanofiber aerogel with efficient energy storage and sorption properties

“…For PAN/PVPh foam, it can be seen that there is a strong peak located at 2242 cm −1 which corresponds to the nitrile group (CN). 23,24 Compared with the FTIR peaks of neat PAN in which the cyano band peak is at 2243 cm −1 , there is a low-frequency shift in the cyano band, indicating complexation via the π-orbital of the CN bond and suggesting the presence of interactions between the electrophilic hydrogens of PVPh and the CN bond of PAN. 19,25 Other peaks located at 2923 cm −1 and 1453 cm −1 are ascribed to CH and CH 2 functional groups, while a peak located at 1612 cm −1 corresponds to the amide group.…”