Nanostructured phosphorescent pigment and uses thereof

Abstract

The present invention relates to a nanostructured phosphorescent pigment comprising an Al2O3 substrate; MAl2O4:X nanocrystals, where M is a cation selected from Ca2+, Sr2+, Ba2+, Mg2+, Zn3+ and combinations thereof and where X is a cation selected from Eu3+, Dy3+, Nd3+, Er3+, La3+, Lu3+, Ce3+, Y3+, Gd3+, Tb3+, Tm3+, Yb3+ and combinations thereof, disposed on the Al2O3 substrate; and nanocrystals of molten salt disposed on the MAl2O4:X nanocrystals. Additionally, the invention relates to a method for preparing the nanostructured phosphorescent pigment of the invention comprising the steps of i) mixing starting materials comprising a cation M precursor, a cation X precursor, Al2O3 and a molten salt; ii) heating the mixture resulting from step (i) in reducing atmosphere. The invention also relates to the use of the nanostructured phosphorescent pigment of the invention for signaling, illumination, decoration or authentication and to a security article comprising the nanostructured phosphorescent pigment of the invention