Carbon nanofibers prepared from electrospun polyimide, polysulfone and polyacrylonitrile nanofibers by ion-beam irradiation

Abstract

Novel electrical conductive carbon nanofibers were prepared by a combination of electrospinning and ion-beam irradiation techniques. Four types of polymer nanofibers, including polyimides (2,2′-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA)-2,2′-bis(4-aminophenyl) hexafluoropropane (6FAP) and 6FDA-Bis(4-(4-aminophenoxy)phenyl) sulfone (APPS)), polysulfone (PSF) and polyacrylonitrile, were prepared by the electrospinning method, which yielded fine nanofibers with diameters of ∼150 nm (except PSF) under optimized conditions. The obtained polymer nanofibrous membranes were irradiated with Kr+ using an ion implanter at various ion fluences to give carbonized nanofibers. The electrical conductivities of the carbon nanofibers increased with an increase in the ion fluence; the conductivity of the electrospun 6FDA-6FAP nanofibrous membrane reached up to ca. 10−1 S cm−1 with 1016 ion cm−2 of Kr+. The influence of the starting polymers on the electrical conductivity of the carbon nanofibers was studied by Raman and X-ray photoelectron spectroscopy analyses.