Study on the silica-polymer hybrid coated SrAl2O4:Eu2+, Dy3+ phosphor as a photoluminescence pigment in a waterborne UV acrylic coating

In this paper, the preparation of SrAl2O4:Eu2+, Dy3+ (SAOED) phosphors coated with SiO2 and poly (methyl methacrylate-co-butyl acrylate) [P(MMA-BA)] was reported, the water resistance and afterglow performance of SAOED phosphors coated with different layers were compared. The photoluminescence behavior and dispersion stability of coated SAOED phosphor as a pigment used in waterborne UV acrylic coating (WUV) were also evaluated. The scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FTIR) analysis results showed continuous and uniform SiO2 and P(MMA-BA) layers on the coated phosphors, respectively. Based on X-Ray Diffraction and Excitation and emission spectra, the coating process did not cause damage to the phosphor crystal. The pH value of water solution versus time showed that the phosphors can obtain excellent water resistance with a 5wt.% SiO2 coating. Fluorescence performance test showed that when the mass fraction of coated phosphor in the WUV was 15%, and the light excitation time was beyond 180s, the afterglow performance of the WUV was the best with the excitation brightness exceeding 120 Lux. The dispersibility test results showed that the SiO2–P(MMA-BA) hybrid coating layer could maintain the uniform dispersion stability of SAOED phosphor in WUV for more than 72 h