Enhancing security authentication and mapping of fingermarks using dual-mode emission of phosphor-immobilized glass nanofiber-reinforced carboxymethyl cellulose nanocomposite.

Photochromic inks have been employed as a certification measure to increase the efficiency of document anti-counterfeiting. However, they have shown several critical drawbacks, such as weak photostability and poor durability. Herein, a self-healable photochromic hydrogel was developed for advanced anti-counterfeiting applications. Carboxymethyl cellulose (CMC) was used to immobilize nanoparticles (2–4 nm) of lanthanide-activated strontium aluminate (LaSA) as a photochromic agent, and electrospun glass nanofibers (80–140 nm) as a reinforcement agent. Photostability and durability can be guaranteed by efficiently immobilizing a hosting hydrogel with an inorganic photochromic agent. As a result, the LaSA-encapsulated carboxymethyl cellulose (LaSA@CMC) nanocomposite showed excellent reversibility and photostability in response to ultraviolet light. When various ratios of LaSA nanoparticles were applied, a wide variety of carboxymethyl cellulose hydrogels with distinct emission properties were produced. Under visible daylight, the LaSA@CMC nanocomposite showed transparency; however, a green emission was observed under UV irradiation. The excitation intensity was recorded at 365 nm to specify transparency, whereas the released emission was detected at wavelength 517 nm to indicate a green color. Numerous techniques were employed to determine the morphologies and chemical components of the glass nanofiber-reinforced carboxymethyl cellulose nanocomposite hydrogel films. We investigated the mechanical performance of sheets stamped with the LaSA@CMC nanocomposite hydrogel. [ABSTRACT FROM AUTHOR]