Development of Glass Nanofiber and Lanthanide Phosphor–Embedded Natural Polymer Nanocomposite Coating for Ultraviolet Filtering Smart Windows and Optical Data Encryption

Glass nanofibers were prepared by using the electrospinning technology, demonstrating diameters of 50-150 nm. A smart polymer adhesive that has the ability to glow in the dark and resist water was developed from a hybrid of electrospun glass nanofibers (EGN; a reinforcement fibers), rare-earth aluminate (REA; a photochromic agent), and gum Arabic (GA; a hosting matrix). After an excitation source is turned off, the produced luminescent glue can continue to produce light for up to 100 min. The EGN@GA adhesive was used to immobilize nanoparticles of REA ranging in size from 6 to 12 nm. The produced adhesives exhibited an excitation band at 365 nm and an emission intensity at 518 nm. Both fluorescence and afterglow emissions were tracked depending on the REA concentration. The presence of photochromism was confirmed when the colorless film switched to green upon exposure to UV light and yellowish-green in a dark place. The scratch resistance and hydrophobicity of nanocomposites were observed to improve with increasing the REA content. The photostability and durability of the REA/EGN@GA nanocomposite were explored. The current photoluminescent adhesives have several potential smart applications, including smart packaging, safety signs, and security encoding.