Synthesis and characterization of graphene oxide–polyimide nanofiber composites

Graphene oxide–polyimide (GO–PI) nanofiber composites were made by electrospinning poly(amic acid) (PAA) containing up to 2 wt% graphene oxide (GO), followed by thermal imidization of PAA. The resulting GO–PI nanofiber composites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, transmission electron microscopy (TEM) and high resolution scanning electron microscopy (HRSEM). The formation of GO was confirmed by X-ray diffraction, infrared and Raman spectroscopy. Morphological analysis of the nanocomposites done with HRSEM indicates that the GO is bunched up into bead or spindle-like structures within the nanofibers. Dynamic mechanical analysis indicates that adding up to 2 wt% GO to PI leads to an improvement in the storage modulus from 1.4 × 108 to 3.8 × 108 Pa and an improvement in the glass transition temperature from 317 to 323 °C over neat PI. Thermogravimetric analysis also shows increasing thermal stability with increasing GO content.