No abstract

Smart window can be defined as switchable material whose light transmission is altered upon exposure to light, voltage, or heat. However, smart windows are usually produced from expensive and breakable glass materials. Herein, transparent smart window with long-persistent phosphorescence, high optical transmittance, ultraviolet (UV) protection, rigid, high photostability and durability, an d superhydrophobicity was developed from recycled polyester (PET). Recycled polyester waste (RBW) was simply immobilized with different ratios of lanthanide-doped aluminate nanoparticles (LdAN) to provide a long-persistent phosphorescent polyester smart window (LdAN@PET) with an abili ty to persist emitting light for extended time periods. The solid-state high temperature technique was used to prepare lanthanide-doped aluminate (LdA) micro-scale powder. Then, the top-down technique was applied to afford the corresponding LdAN. Recycled shredded recycled polyester bottles were charged into a hot bath to provide a clear plastic shred bulk, which was then well-mixed with LdAN and drop-casted to provide long-persistent luminescent smart window. In order to improve the phosphor dispersion in the PET bulk, LdAN was synthesized in the nanoparticle form which was characterized utilizing transmission electron microscopy (TEM). For better preparation of translucent smart window of long-persistent phosphorescent polyester, LdAN must be homogeneously dispersed in the PET matrix without agglomeration. The morphology and chemical composition were studied by Fourier-transform infrared (FTIR) spectra), X-ray fluorescence (XRF) analysis, scanning electron microscopy (SEM), and energy-dispersion X-ray spectroscopy (EDX). In addition, spectral profiles of excitation and emission, and decay and lifetime were used to better understand the photoluminescence properties. The hardness properties were also investigated. The developed phosphorescent transparent polyester smart window demonstrated a color switch to intense green underneath UV irradiation and greenish-yellow under darkness as verified by CIELab color parameters. The afterglow polyester smart window showed an absorption wavelength at 365 nm and two phosphorescence intensities at 442 and 512 nm. An enhanced UV protection, photostability and hydrophobic activity were detected. The luminescent polyester substrates with lower LdAN ratios demonstrated rapid and reversible

Magnetic nanocomposites have attracted great attention as adsorbents for the removal of water pollutants, which respond to an external magnet that is used to remove both pollutants and composite nanomaterial traces from water. They are environmentally friendly and effective adsorbents for water treatment. In this respect, a simple in situ preparation method was used to prepare cryogel powder composite based on Fe 3 O 4 .Cu 2 O.Fe 3 O 4 nanomaterials. The ionic cryogel based on 2-acrylamido-2-methylpropane sulfonate sodium salt and styrene sulfonate sodium salt was prepared by crosslinking polymerization at low temperature. The new magnetic nanoparticles based on Fe 3 O 4 .Cu 2 O.Fe 3 O 4 were successfully prepared inside the cryogel networks by a simple reduction-coprecipitation method based on reaction of Fe 3+ with sodium sulfite and Cu 2+ in the presence of hydroxylamine and ammonia solution. The thermal stability, accurate Fe 3 O 4 .Cu 2 O.Fe 3 O 4 content, magnetic properties, crystal lattice structure, particle sizes and morphology of the prepared cryogel composite were evaluated. The optimum conditions such as pH, contact time, adsorbate concentrations, adsorption equilibrium and adsorption kinetics were investigated to determine the efficiency of the prepared composite as an adsorbent to remove toxic methylene blue (MB) pollutant from aqueous solution. The data for MB adsorption confirmed the high ability of the prepared composite to remove more than 4.696 mmol L −1 of MB from water during 6 min. The regeneration and reuse experiments showed excellent data for the synthesized new dye as an effective adsorbent for water treatment.

In situ techniques have attracted great attention for the formation of nanomaterials with controlled sizes, shapes and dispersion within supramolecular hydrogels. In the present work, the doping of copper oxides onto magnetite nanoparticles into hydrogels based on sodium 2-acylamido-2-methylpropanesulfonate (AMPS) and N-isopropylacrylamide NIPAm copolymers was investigated. The contents, morphology and thermal stability of magnetite, cupreous oxide and doped copper oxides onto the magnetite nanoparticles were evaluated. The optimum conditions for removal the cationic dye methylene blue (MB), such as solution pH, concentration of adsorbents, contact time and stirring time, were determined to investigate the effect of MB concentrations on the removal efficiencies of the prepared adsorbents. The recyclability of the prepared AMPS/NIPAm composites for the removal of MB was examined for up to six cycles without changes in removal effectiveness.