Advances in the preparation of uncopyable photoluminescent security inks from long-persistent phosphors for secure documents
Marwa M. Abdelhameed, Yasser A. Attia, Meram S. Abdelrahman, Tawfik A. Khattab · Egyptian Journal of Chemistry · 2022
Luminescent security inks have great commercial importance in anti-counterfeiting applications. There are many methods and strategies for making luminescent ink and the improvement for these methods and designing strategies is the major challenge. Luminescent inks are usually characterized with high stability, low cost of ink medium, availability of ink medium, high-quality distribution of luminescent nanomaterials, strong luminescence intensity, the suitability of the print on different surfaces, high surface tension, and viscous nature of ink medium. Luminescent security inks may be hydrophilic or hydrophobic in nature so studying chemistry for this kind of ink is very important before using it to print security encodings and patterns on various kinds of surfaces. There are principles to synthesize luminescence-based security inks with desired characteristics, such as the selection of photoluminescent ink medium. Thus, we must take into consideration some conditions for the ink medium, including homogeneous dispersion of the luminescent nanomaterials, viscous medium appropriate to print onto various types of printable surfaces, and appropriate boiling point of the ink medium. In this review, we discuss the recent developments on hybrid photochromic inks for anticounterfeiting applications.