Luminescent cellulose fibers activated by Eu3+-doped nanoparticles

UV-active cellulose fibers were obtained by dry-wet method spinning an 8 % by weight alpha-cellulose solution in N-methylomorpholine-N-oxide (NMMO) modified by europium-doped gadolinium oxyfluoride Gd4O3F6:Eu3+ containing 5 mol (%) of the dopant. Photoluminescent nanoparticles were introduced in the in powder form into a polymer matrix during the process of cellulose dissolution in NMMO. The dependencies of emission intensity on excitation energy and the concentration of Gd4O3F6:Eu3+ nanoparticles in the final cellulosic products were examined by photoluminescence spectroscopy (excitation and emission). The fiber structure was studied by X-ray powder diffraction analysis. The size and dispersity of the nanoparticles in the polymer matrix were evaluated using scanning electron microscopy and X-ray microanalysis. The influence of different concentration particles (in the range from 0.5 to 5 % by weight) on the mechanical properties of the fibers, such as tenacity and elongation at break, were determined.