Multi-mode luminescent ceramic glaze for advanced anti-counterfeiting

This work explores a novel ceramic glaze formulation, which incorporates unique anti-counterfeiting features and demonstrates versatile luminescence characteristics that vary with time and excitation conditions. Departing from conventional fluorescent materials employed in anti-counterfeiting measures, the phosphors utilized in this investigation showcase a remarkable ability to emit multiple colors under diverse excitation wavelengths, offering enhanced security and complexity. The key components of the multimode fluorescent glazes are three primary color phosphors: red phosphor (Y2O3: 0.05Eu(3+)), green phosphor (SrAl2O4: 0.01Eu(2+), 0.02Dy(3+)), and blue phosphor (CaAl2O4: 0.012Eu(2+), 0.06Nd(3+), 0.036Gd(3+)). Employing the high-temperature solid-state approach, the synthesis of these luminescent materials was successfully achieved. The phosphors, glazes, and xanthan gum were mixed and ground together. The multimode ceramic fluorescent glazes were obtained by adjusting the ratios of red (R), green (G), and blue (B) phosphors, adding the mixed powders into n-butanol, thoroughly mixing them, and then applying the glazes onto skeleton boards. The glazes were then placed in muffle furnaces at high temperatures after static drying to achieve the desired multimode ceramic fluorescent glazes. This simple process results in low production costs, making it feasible to produce advanced anticounterfeiting fluorescent glazes at a low cost. The glaze paste was applied to the ceramic sheet using a skeleton plate and watercolor chalk, and an anti-counterfeiting logo in the form of a "butterfly" was created. The logo exhibited dynamic luminescence, with the luminescent effect varying depending on the excitation wavelength and duration. The anti-counterfeiting effect of the pattern demonstrates the promising potential for further development and practical application of the multimode fluorescent glaze.