Dual-mode security authentication of SrAl2 O4 :Eu,Dy phosphor encapsulated in electrospun cellulose acetate nanofibrous films.

Abstract

Photochromic inks have been an attractive authentication strategy to improve the anti-counterfeiting efficiency of commercial products. However, recent reports have showed significant disadvantages with photochromic inks, including poor durability and high cost. In this context, we develop novel photochromic nanofibers for advanced anti-counterfeiting applications. Lanthanide-doped strontium aluminate (LdSA) nanoparticles (NPs) were prepared and immobilized into electrospun cellulose acetate nanofibers (CANF). Authentication materials immobilized with inorganic photochromic agent can warranty durability and photostability. Therefore, the ultraviolet-stimulated photochromism of LdSA-encapsulated cellulose acetate nanofibers (LdSA@CANF) demonstrated high reversibility and photostability. A broad range of cellulose acetate nanofibers with unique emission characteristics were developed when applying different ratios of LdSA NPs. LdSA@CANF appeared colorless under visible daylight, whereas a green emission was monitored under UV-illumination. The shape and chemical content of the photochromic fibrous films were examined by various analytical techniques. The mechanical characteristics of LdSA@CANF-coated paper were investigated. The emission wavelength was detected at 514 nm to designate green color, whereas the excitation wavelength was detected at 369 nm to indicate transparency. The prepared cellulose acetate nanofibrous film can be described as an efficient strategy for anti-counterfeiting of commercialized items.