Composites of CaAl2O4: Eu2+, Nd3+/Ca0.25Sr0.75S: Eu2+in Polyacrylonitrile Fibers with Tri-Stimuli-Responsive Persistent Luminescence

In this study, ultraviolet(UV) light-excited CaAl2O4: Eu2+, Nd3+ and visible light-excited Ca0.25Sr0.75S: Eu2+ were incorporated in the polyacrylonitrile (PAN) fibers by wet-spinning. Scanning electron microscopy, X-ray diffraction, photoluminescence, and decay analysis were used to characterize the morphology, inner structure, photoluminescence and afterglow behavior of the composite fibers, respectively. The results indicated random distribution of the two inorganic phosphors into the PAN fiber. To investigate the stimuli-responsive properties of the composite fiber, experiments were performed under UV light, visible light and D65 lamp. The results revealed that, the obtained composite fibers featured a blue emission of CaAl2O4: Eu2+, Nd3+ at 450 nm and a red emission of Ca0.25Sr0.75S: Eu2+ at 620 nm. Furthermore, decay curves indicated the decrease of luminescence intensity of the composite fiber when the two phosphors were simultaneously excited, which are attributed to the different irradiation source. It is expected that this multicolor fiber could be used in high-level information anti-counterfeiting label in clothes and smart clothing.