Preparation of Photochromic and Photoluminescent Nonwoven Fibrous Mat from Recycled Polyester Waste

Abstract

Photochromic and photoluminescent clothes can be described as smart textiles that alter their color and emission spectra upon exposure to a light stimulus. Recycled nonwoven polyester fabrics screen-printed with rare-earth strontium aluminate nanoparticles were developed to introduce photochromic and photoluminescent properties. Both spinning and preparation of nonwoven fibrous mat was performed industrially starting from recycled polyester waste. Aqueous-based phosphor-binder nanocomposites containing different concentrations of inorganic phosphor with excellent thermal and photostability were applied directly onto nonwoven polyester fabrics. The screen-printing process produced a uniform photochromic and photoluminescent film onto the nonwoven polyester surface that showed strong green emission color (440 nm) under UV light even at lower phosphor concentrations (0.5 wt%) in the printing paste. The excitation wavelength of the printed nonwoven polyester samples was monitored at 382 nm. Long-persistent greenish-yellow phosphorescence was detected in the dark at higher phosphor concentrations. The morphological microscopic data of phosphor nanoparticles and printed nonwoven polyester fabrics were collected using various analytical methods. TEM analysis of phosphor nanoparticles designated diameters of 4–11 nm, whereas XRD analysis indicated a crystal size of 9 nm. The printed cloth exhibited a quick and reversible photochromic emission when exposed to ultraviolet light. The ultraviolet protection, antimicrobial and superhydrophobic properties were improved with increasing the pigment concentration in the printing paste. The static contact and slide angles improved in the ranges of 108.6°–132.6°, and 12°–7°, respectively. The effects of increasing the phosphor concentration in the printing paste on the comfort features and colorfastness were examined.