Electron paramagnetic resonance investigations of electrospun polyaniline fibers

A comparative study of the EPR magnetic susceptibility behavior of the camphorsulfonic acid-doped polyaniline (PANCSA) blends with polyethylene oxide (PEO) is reported. Compared to films, the fibers are found to exhibit increased Pauli susceptibility, more Lorentzian character in the EPR lineshape, and smaller EPR linewidth. These changes are interpreted as due to increased chain alignment in the fibers compared with the cast films. Electron localization effects in true nanofibers (diameter <100 nm) of organic polymers can therefore be studied using the technique of electron paramagnetic resonance.