Influence of the PAN:PEO Ratio on the Morphology of Needleless Electrospun Nanofiber Mats Before and After Carbonization

Nanofiber mats with a high surface-to-volume ratio can be prepared by electrospinning. The Porosity is sometimes reported to be tunable by blending different materials, e.g., water-soluble poly(ethylene oxide) (PEO) with not water-soluble poly(acrylonitrile) (PAN). Here, nanofiber mats were electrospun from different PAN:PEO ratios, using a wire-based electrospinning machine “Nanospider Lab”. Investigations of the as-spun nanofiber mats as well as of membranes after washing off the water-soluble PEO by scanning electron microscopy (SEM) revealed severe differences in the nanofiber mat morphologies, such as varying fiber diameters and especially non-fibrous areas in the carbonized nanofiber mats, depending on the amount of PEO in the nanofiber mat as well as the molecular weight of the PEO. Similarly, the ratio and molecular weight of PEO influenced the results of stabilization and carbonization. This paper discusses the possibility of tailoring nanofiber porosity for the potential use of PAN nanofiber mats in tissue engineering, filtration, and other applications.