Here we demonstrated the ability to fabricate ultra-fine carbon fibers through electrospinnig of the polymer blends of the polyacrylonitrile (PAN) and polyamic acid (PAA) and the subsequnt thermal treatment. The good spinnability of the polymer blends was achieved by reducing the solution viscosity with the addition of PAN. There was a close correlation between the fiber diameter developed in the spinning process and the physical properties of the carbonized fibers; the smaller in fiber diameter gave rise to the higher crystallinity of the single carbonized fiber and, furthermore, the higher electrical conductivity and mechanical strength of the carbonized fiber web. High anisotropy in mechanical strength of the carbonized fiber webs was ascribed to the partial alignment of fibers along the winding direction in the electrospinning process.

In this study, two-phase activated carbon nanofibers are fabricated by electrospinning the bicomponent solution of the polyacrylonitrile (PAN) and pitch, then oxidatively stabilization, carbonization and/or activation. The use of PAN decreases the solution viscosity, then enhance the spinnability of the polymer blends. In addition, the crystallinity and electrical conductivity of the carbonized carbon fiber increased according to the reduced diameter of as-electrospun fibers. The morphology and electrical properties of two-phase carbon nanofibers were investigated using field-emission scanning electron microscopy (FE-SEM), XRD, X-ray photo electron spectroscopy (XPS), and electrochemical measurement.