OXYGEN DIFFUSION AND RADIAL-STRUCTURE TRANSFORMATION OF ELECTROSPUN POLYACRYLONITRILE COPOLYMER NANOFIBERS DURING OXIDATIVE STABDLIZATION PROCESS

摘要

Continuous nanoscale carbon nanofibers can be developed by stabilization and carbonization of highly aligned and extensively stretched electrospun polyacrylonitrile copolymer nanofiber precursor under optimal tension. These carbon nanofibers, with diameters of tens of nanometers, are expected to possess superior mechanical strength that is unlikely to be achieved through conventional approaches. This is because i) the innovative precursor, with a fiber diameter approximately 100 times smaller than that of conventional counterparts, possesses an extremely high degree of macromolecular orientation and a significantly reduced amount of structural imperfections, and ii) the ultra-small fiber diameter also effectively prevents the formation of structural inhomogeneity, particularly sheath/core structures during stabilization and carbonization [1].