Preparation of Lighting in the Dark and Photochromic Electrospun Glass Nanofiber-Reinforced Epoxy Nanocomposites Immobilized with Alkaline Earth Aluminates

Abstract

Alkaline earth aluminates (AEAs) as photoluminescent agents and silicon dioxide-based electrospun glass nanofibers with an average diameter of 150−450 nm as a roughening agent were prepared and applied to reinforce an epoxy resin toward the development of long-persistent photoluminescent and photochromic smart materials, such as smart windows and anticounterfeiting barcodes. With the physical immobilization of lanthanide-doped aluminate nanoparticles (NPs), a light-induced luminescent transparent glass@epoxy film was developed. The glass@epoxy samples were able to alter their color to green beneath ultraviolet rays and greenish-yellow in the dark, as explored by CIE Lab and luminescence spectral analyses. The morphology of the lanthanidedoped aluminate nanoparticles (43−98 nm) was examined by transmission electron microscopy (TEM). The morphologies and chemical composition of the luminescent glass@epoxy substrates were determined by different analytical techniques. The mechanical properties of the developed photoluminescent glass@epoxy substrates were inspected to show improved scratch resistance as compared to the AEA-free substrate. The photoluminescence spectra were measured to indicate the detection of two emission bands at 494 and 525 nm when excited at 365 nm. The photoluminescent glass@epoxy hybrids with lower AEA contents have showed fast reversibility of photochromism. On the other hand, the glass@epoxy substrates with higher phosphor contents underwent persistent luminescence. Results showed that the luminescent colorless glass@epoxy hybrids have enhanced superhydrophobicity and ultraviolet blocking.

Photoluminescent polymer‐based smart window reinforced with electrospun glass nanofibres

“…EGN@PVC was made using a range of LANP concentrations. Electrospinning was utilized to prepare EGN [31]. Both EGN and PVC were admixed with various quantities of LANP.…”

“…Blue (shorter wavelength at 435 nm) and green (longer wavelength at 519 nm) emission bands are often provided by LANP, with these colours coming from two distinct strontium sites inside the SrAl 2 O 4 crystal. However, the blue peak strength is significantly dampened by ambient thermal quenching [31, 32]. Therefore, all emissions are green at the various concentrations of LANP.…”

“…According to a prior procedure [31], EGN were produced by dissolving TEOS (15% concentration) and PVP (15% concentration) in a combination of DMSO/DMF (1/2) and then pyrolyzing the mixture at 800°C. The provided glass fibres were sonicated for 10 min while suspended in distilled water (5%).…”

“…According to the standard procedure [31, 32], the photoluminescent EGN@PVC sample was illuminated with UV light for 5 min. The EGN@PVC sample was restored to its initial condition after being stored for 1 h in a dark box.…”

“…There has been much interest in nanofibre‐reinforced polymer nanocomposites as a potential material for a broad range of applications. The manufacturing of satellites, automobiles, and aeroplanes are just a few examples of the many fields that benefit from fibre‐reinforced polymeric composites [31]. This can be ascribed to the enhanced surface area provided by the incorporated nanofibres, which greatly improves the strength of interfacial binding between matrix and filler [32].…”