In the present study, electrospun PAN precursor webs and the stabilized and carbonized nanofiber webs processed under different heat-treatment conditions were characterized by means of weight loss measurement, elemental analysis, scanning electron microscopy (SEM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), thermogravimentric analysis (TGA), and X-ray diffraction (XRD) analysis. The result indicated that stabilization and carbonization processes with different temperatures and heating rates significantly influenced the chemical and morphological characteristics as well as the thermal properties of the stabilized and then subsequently carbonized nanofiber webs from PAN precursor webs. It was noted that the filament diameter and the carbon content of a carbonized nanofiber web as well as its weight change may be effectively monitored by controlling both stabilization and carbonization processes.

Recently, membrane can be prepared by two methods, phase inversion and electrospinning techniques. Phase inversion technique is a conventional but commercially preparation membrane. The most versatile of preparation in this technique is immersion of the cast film into nonsolvent bath, causing dense top layer with a finger-like pattern in the sub layer membrane. The membrane pore size getting from phase inversion is in the range of micro or submicrometer. As a result, it can be used as microfiltration and ultrafiltration applications. A new technique, electrospinning, is introduced for membrane preparation. Nonwoven nanofibrous mat or nanofibrous membrane is obtained. In this technique, electrostatic charge is introduced to the solution jet, causing a thin fiber with high surface area; hence it can be used in the applications where high surface area-to-volume or length-to-diameter ratios are required. Moreover, the pore size can be controlled by controlling the time of electrospinning. Hence, it can be used as a filter for filtering microparticles as well as nanoparticles.