Improved photoluminescence properties of europium complex/polyacrylonitrile composite fibers prepared by electrospinning

Novel fluorescent composite nanofibers of the europium complexes Eu(DBM)3(Bath) (DBM = dibenzoylmethanato, Bath = bathophenanthroline) or Eu(DBM)3(Phen) (Phen = 1,10-phenanthroline) and polyacrylonitrile (PAN) are prepared by electrospinning. The thermal-stability, photo-stability and photoluminescence properties of these composite nanofibers are studied in comparison to that of the pure europium complexes in detail. The results indicate that, after incorporating europium complexes into the polymer matrix, the site symmetry of the coordination sphere for the Eu3+ ions decreases, which makes the excitation bands of the composite nanofibers split into two different components. But the PAN can provide a rigid environment for the europium complexes, so the thermal-stability and photo-stability of composite nanofibers are considerably improved. Most importantly, the luminescent quantum efficiency and luminescence lifetime of the composite nanofibers are of great improvement. In addition, compared Eu(DBM)3(Bath)/PAN with Eu(DBM)3(Phen)/PAN composite nanofibers, the former exhibit superior properties.