Fabrication-properties relationships in polymeric nanofibers

The mechanics of nanoscale polymeric fibers under quasi-static and intermediate loading rates and as a function of fabrication conditions is largely unexplored. In this work the mechanical behavior of polyacrylonitrile (PAN) nanofibers, fabricated by systematically varying the acceleration voltage and distance of electrospinning, were investigated. The mechanical strength of the PAN nanofibers was as high as 300 MPa while their ductility was larger than 200%. The mechanical properties of PAN nanofibers changed significantly with the electrospinning distance: the elastic modulus and the tensile strength of nanofibers with diameters between 200-800 nm were highly dependent on the electrospinning distance while spectroscopic analyses showed that nanofibers with improved mechanical strength were characterized by significant molecular alignment.