Effect of FeCl3 on the morphology, wetting behavior, and stabilization/carbonization of polyacrylonitrile nanofibers prepared by electrospinning

Abstract

Herein we report that the neat polyacrylonitrile (PAN) nanofibers and PAN/FeCl3 composite nanofibers were prepared by the materials-processing technique of electrospinning. The effect of FeCl 3 amount on the morphology and wetting behavior of the resulting composite nanofibers were studied by scanning electron microscopy (SEM) and drop shape analysis (DSA), respectively. The SEM images indicated that the diameters of composite nanofibers decreased with increase of FeCl3 amount, and this was probably due to the conductivity increase of spinning solutions. The results acquired from DSA measurement showed that the addition of FeCl 3 increased the surface contact angle of water deposited on composite nanofibers, suggesting the higher hydrophobicity and the lower wetting behavior. Additionally, the effect of FeCl3 on stabilization and carbonization of the PAN composite nanofibers were investigated. The structural and morphological evolutions of the stabilized and carbonized nanofibers were studied by Fourier transfer infrared (FTIR) spectra and SEM. The FTIR spectra showed that the presence of FeCl3 in composite nanofibers considerably varied the mechanisms of thermo-chemical reactions during the heat treatments. The SEM images revealed that there were conglutinations of nanofibers after carbonization, while the degree of conglutination for the carbonized PAN composite nanofibers with FeCl3 was higher than that for the carbonized neat PAN nanofibers.