ABSTRACTAn oxidation method has been applied to functionalize multiwalled carbon nanotubes with carboxylic acid (-COOH) group. Functionalized carbon nanotubes (f-MWNT) were used for the fabrication of conducting nanocomposite fibers by electrospinning, in comparison with the composite nanofibers made of un-functionalized carbon nanotubes (u-MWNT). Our results showed that the addition of f-MWNTs into polymer solution could increase the compatibility of MWNTs with the polymer matrix, and thus result in composite nanofibers with uniform diameters. Alignment of the composite nanofibers was achieved by using a rotating drum as the collector. F-MWNTs were found to align parallel to the axis direction of the nanofibers. Temperature-dependent DC electrical properties of a single composite fiber were investigated by a two-probe method. It was shown that the conductivity of the material could be significantly improved above a percolation threshold. The conductivity could be of ten orders of magnitude higher than the pure PVAc.
A supramolecular approach towards strong and tough polymer nanocomposite fibers