Immobilization of rare-earth phosphor in electrospun nanofibrous label of cellulose acetate and polylactic acid biocomposite for information encryption

Photoresponsive inks have been an attractive security coding technique to increase the authentication efficiency of commercialized materials. However, photoresponsive inks have shown low durability. Herein, we reported the development of photoresponsive anti-counterfeiting nanofibers for information encryption. The nanoparticles of lanthanide-doped aluminate (NLdA), which range in size from 5 nm to 7 nm, were encapsulated into electrospun nanofibrous label made of a combination of polylactic acid and cellulose acetate biocomposite (PLCA). The produced nanofibers showed diameters of 50 -80 nm. NLdA-immobilized nanofibrous label ensured remarkable reversibility, durability and photostability. A range of photoresponsive and afterglow PLCA nanofibrous label with unique emission characteristics were synthesized by adjusting the NLdA concentrations. When irradiated with ultraviolet light, NLdA@PLCA emitted a green light that was undetectable under daylight. Various microscopic and spectroscopic methods were employed to determine the structure and chemical content of the prepared nanofibrous labels. The mechanical performance of the NLdA@PLCA-coated papers was explored. Transparency was indicated by an excitation band of 365 nm, whereas a green color was indicated by an emission wavelength of 518 nm. This nanofibrous material made of polylactic acid and cellulose acetate can assist prevent counterfeiting of commercially available products.