Structure and Morphological Evolvement of Electrospun Polyacrylonitrile/Organic-Modified Fe-Montmorillonite Composite Carbon Nanofibers

In the present work, a facile compounding and electrospinning method was used to prepare PAN/Fe-OMT composite nanofibers. Electrospinning solution properties including viscosity, surface tension, and conductivity were measured and combined with the results of Fourier transform-infrared (FT-IR) spectra, high-resolution transmission electron microscopy (HRTEM), and scanning electron microscopy (SEM) to investigate the effects of Fe-OMT on the structure and morphology of electrospun PAN nanofibers, respectively. It was found from FT-IR and HRTEM that the silicate clay layers were well dispersed within the composite nanofibers and were oriented along the fiber axis. The SEM images indicated that the loading of Fe-OMT decreased the average diameters of composite nanofibers due to the increased conductivity of composite solutions. Then, the prepared PAN nanofibers and PAN/Fe-OMT composite nanofibers were further pre-oxidized and carbonized. The effects of Fe-OMT on the structure and morphology of PAN-based carbon nanofibers were also investigated by FT-IR and SEM. The FT-IR spectra indicated that there were different characteristic absorption peaks for pure PAN nanofibers and PAN/Fe-OMT composite nanofibers during the pre-oxidation and carbonization processes. The SEM images revealed that the morphology of nanofibers underwent marked changes before and after carbonization. The Fe-OMT loadings might promote the dehydrogenation, cyclization, and cross-linking reactions of the PAN composite nanofibers during carbonization.