Photoluminescent and photochromic smart window from recycled polyester reinforced with cellulose nanocrystals.

Smart windows with long-persistent phosphorescence, ultraviolet (UV) light protection, high transparency, and high rigidity were developed by easily immobilizing varying ratios of lanthanide-activated aluminate phosphor nanoscale particles within a composite of recycled polyester/cellulose nanocrystals (RPET/CNC). Cellulose nanocrystals were prepared from rice straw waste. Cellulose nanocrystals were used at low concentration as both crosslinker and drier to improve both transparency and hardness. The phosphor nanoscale particles must be distributed into the recycled polyester/cellulose nanocrystals composite bulk without agglomeration to produce transparent RPET/CNC substrates. Photoluminescence characteristics were also studied using spectroscopic profiles of excitation/emission and decay/lifetime. The hardness efficiency was also examined. This transparent recycled polyester waste/cellulose nanocrystals nanocomposite smart window has been shown to change colour under UV light to strong green and to greenish-yellow when it is dark, as proved by Commission Internationale de l'éclairage (CIE) laboratory colour parameters. It was found that the afterglow RPET/CNC smart window had phosphorescence intensities of 428, 493, and 523 nm upon excitation at 368 nm. There was evidence of improved UV shielding, photostability, and hydrophobic activity. In the presence of a low phosphor ratio, the luminescent RPET/CNC substrates showed quick and reversible fluorescence photochromic activity when exposed to UV radiation.

Circular economy reinforcement through molecular fabrication of textile wastes with microbial synthesized ZnO nanoparticles to have multifunctional properties.

The fibrous wastes generated from the mills of textile production can be recycled and converted into high add-values products to be implemented in several applications. The current study aimed to employ commercial free cellulase enzyme to partially hydrolyze (activate) the polyester cotton blended (PET/C) fibrous wastes by creation functional groups such as OH and COOH on their surfaces. The activated fibrous wastes were then modified by coating with ZnO nanoparticles (ZnO-NPs) biosynthesized by actinobacterial cultures free supernatant. The isolate was identified as Streptomyces pseudogriseolus with accession number of OR574241. The conditions that influence the actino-synthesis of ZnO-NPs were optimized and the product was characterized using spectroscopic vision, FTIR, XRD, TEM and SEM. The characteristic ZnO peaks were obviously observed by EDX analysis with 0.38 and 0.75% (wt%), respectively. TEM analyses proved the nanoscale of ZnO-NPs (5-15 nm) which was followed by cytotoxic evaluation for the produced NPs. Fortunately, the tested actino-ZnO-NPs didn't have any cytotoxicity against human normal fibroblast cell line (BJ1), which means that the product can be safely used in a direct-contact with human skin. The treated PET/C blended waste fabrics coated with ZnO-NPs showed high antimicrobial activity and ultraviolet protection values after functionalization by cellulase. EDX analysis demonstrates the presence of Zn peaks on the coated fabrics compared with their absence in blank and control samples, while SEM images showed the formation of a thin layer of ZnO-NPs on the fabric surface. The obtained smart textile can be applied several needed sectors.

Vapochromic wool fibers for hazardous ammonia detection using xanthohumol biomolecule from natural extract of common hop (Humulus lupulus L.).

Ammonia is a colorless gas, yet it can be fatal if inhaled or ingested in high enough concentrations. Herein, a solid-state colorimetric smart wool (WL) sensor for ammonia was developed. Common hop (Humulus lupulus L.) is a natural resource of spectroscopical dyestuff known as xanthohumol (XN). Wool fabrics were dyed with different concentrations of xanthohumol extract using the high-temperature high-pressure method in the presence of a mordant. The coloration parameters and absorption spectra were employed to explore the yellow-to-white colorimetric shift of the wool fabric after it was exposed to aqueous ammonia. The wool fabric showed an excellent detection limit of 5 to 125 ppm. When the ammonia concentration was increased, the absorbance spectra demonstrated a hypsochromic shift from 498 nm to 367 nm. This could be attributed to changes in the molecular structure of xanthohumol that happen owing to intramolecular charge delocalization. Using transmission electron microscopy (TEM), the mordant/xanthohumol nanoparticles were measured to have diameters of 15-40 nm. The xanthohumol-finished wool fabrics showed good colorfastness properties. The incorporation of mordant/xanthohumol nanoparticles into wool fabrics showed no negative effects on their stiffness or air-permeability.

Correction to: Biosynthesis and characterization of silver nanoparticles induced by fungal proteins and its application in different biological activities.

In the publication of this article [1], the title of Figure 6 was missing. The original article has been corrected.

Biosynthesis and characterization of silver nanoparticles induced by fungal proteins and its application in different biological activities.

BACKGROUND: The present study aims to apply an efficient eco-friendly and inexpensive process for green synthesis of silver nanoparticles (AgNPs) through the mediation of fungal proteins from Aspergillus fumigatus DSM819, characterization, and its application as antimicrobial finishing agent in textile fabrics against some infectious microorganisms. RESULTS: Optimum conditions for AgNP biosynthesis could be achieved by means of using 60% (v/v) of cell-free filtrate (CFF) and 1.5 mM of AgNO3 at pH 10.0 after 90 min. The obtained AgNPs were of spherical shape with 90% of distribution below than 84.4 nm. The biosynthesized AgNPs exerted an antimicrobial activity against the studied pathogenic microorganisms (E. coli, B. mycoides, and C. albicans). In addition, IC50 values against in vitro tumor cell lines were found to be 31.1, 45.4, 40.9, and 33.5 µg/ml for HCT116, A549, MCF7, and PC3, respectively. Even with a very low concentration (0.25%), the treated PET/C fabrics by AgNPs exerted an antimicrobial activity against E. coli, B. mycoides, and C. albicans to give inhibition zone diameter of 15, 15, and 16 mm, respectively. CONCLUSIONS: The green biosynthesis approach applied in this study is a non-toxic alternative to the traditional chemical and physical methods, and would be appropriate for biological large-scale production and prospective treatments.