Effect of Diameter on the Structural Evolution and Tensile Properties of Electrospun PAN-Based Carbon Nanofiber Mats

The mechanical properties of carbon nanofiber mats (CNFMs) were closely correlated with the fiber diameter due to their brittle nature. In this work, CNFMs with different fiber diameters were prepared by electrospinning with different spinning parameters, followed by stabilization in air and carbonization in nitrogen. Structural characterizations revealed that PAN nanofibers with smaller diameters tended to form larger cross-linking structures during stabilization. Meanwhile, the degree of graphitization of CNFMs was higher when the diameter was reduced. However, the tensile properties of CNFM were not solely determined by the fiber diameter but were the general reflection of structural regularity and defects. The highest tensile strength of 125.2 MPa was achieved when the fiber diameter was around 500 nm.