Development of photoluminescent, superhydrophobic, and electrically conductive cotton fibres

Electrospun glass nanofibers to strengthen polycarbonate plastic glass toward photoluminescent smart materials

Electrospun glass nanofibers (GNFs) were used to strengthen polycarbonate (PC) to create long-persistent photoluminescent and fluorescent smart materials such as afterglow concrete and smart window. Physical integration of lanthanide-activated aluminate (LA) nanoparticles (NPs) yielded transparent GNFs@PC smart sheets. Spectral investigations utilizing photoluminescence and CIE Lab parameters were performed to confirm that the translucent appearance of GNFs@PC changed to green when exposed to UV light. This fluorescence activity was quickly reversible for the GNFs@PC hybrids with low concentrations of LANPs, which indicate fluorescence emission. Higher phosphor concentrations in GNFs@PC led to longer-lasting afterglow photoluminescence and slower reversibility. The GNFs@PC hybrids showed an emission band detected at 518 nm upon excitation at 368 nm. The morphological characteristics of LANPs and GNFs were analyzed by transmission electron microscopy (TEM), which revealed sizes of 11-26 nm and 250-300 nm, respectively. GNFs were prepared using electrospinning technology and then used as a roughening agent into PC sheets. Morphological characteristics of GNFs and GNFs@PC smart sheets were examined using energy-dispersive X-ray spectroscopy (EDXA), X-ray fluorescence (XRF) and scanning electron microscopy (SEM). The GNFs@PC smart sheets were shown to have enhanced scratch resistance in comparison to LANPs-free PC control sample. Increases in LANPs concentration enhanced both hydrophobicity and UV protection.

Green preparation of electrically conductive solution blow spun nanofibers from recycled polyethylene terephthalate via plasma-assisted oxidation-reduction

Simple and green strategy was described for the development of multifunctional polyester nanofibers (PNFs). Solution blow spinning (SBS) technology was applied to in situ immobilize nanocomposites of polyaniline (PANi) and silver nanoparticles (AgNPs) into plasma-treated polyester nanoscaled fibers prepared. The polyester nanofibers were prepared from recycled polyethylene terephthalate waste, which was exposed plasma-curing and a REDOX reaction in the presence of AgNO₃, aniline, and CH₃COONH₄. Plasma-catalyzed oxidative polymerization of aniline to polyaniline together with a reductive process of Ag⁺ to silver nanoparticles led to their enduring insoluble dispersion into the surface of polyester nanofibers. By taking the advantage of the PANi oxidation, AgNPs were precipitated from an aqueous medium of AgNPs. The morphological properties were investigated by various analytical techniques. The polyester fiber diameter was determined in the range of 450-650 nm. In addition, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were utilized to examine AgNPs, demonstrating diameters of 4-20 nm. The plasma-uncured AgNPs/PANi immobilized nanofibrous film displayed weak absorption bands at 399 nm and 403 nm upon increasing the concentration of AgNPs. On the other hand, the plasma-cured AgNPs/PANi immobilized nanofibers displayed strong absorption bands at 526 nm and 568 nm upon increasing the concentration of AgNPs. The AgNP-induced antimicrobial performance and the PANi-induced electrically conductivity were explored. The prepared PNFs showed high UV protection.

Preparation of photoluminescent and anticorrosive epoxy paints immobilized with nanoscale graphene from sugarcane bagasse agricultural waste

Sugarcane bagasse agricultural waste has been one of the most common solid pollutants worldwide. Thus, introducing a simple method to convert sugarcane bagasse into value-added materials has been highly significant. Herein, we develop a simple and green strategy to reprocess sugarcane bagasse as a starting material for the preparation of graphene oxide nanosheets toward the preparation of novel photoluminescent, hydrophobic, and anticorrosive epoxy nanocomposite coatings integrated with lanthanide-doped aluminate nanoparticles. Environmentally friendly graphene oxide (GO) nanostructures were provided by a single-step preparation procedure from sugarcane bagasse (SCB) agricultural waste using ferrocene-based oxidation under muffled conditions. The oxidized SCB nanostructures were applied as a drier, anticorrosion, and crosslinking agent for epoxy coatings. Different concentrations of pigment phosphor were applied onto the epoxy coating. The generated epoxy-graphene-aluminate (EGA) paints were then coated onto mild steel. The hydrophobic properties and hardness as well as resistance to scratch of the EGA paints were examined. The transparency and colorimetric screening of the EGA nanocomposite paints were determined by the absorption spectral analysis and CIE Lab parameters. The luminescent translucent paints demonstrated a bright green emission at 520 nm when excited at 372 nm. The anticorrosion properties of the painted steel submerged in NaCl_(aq) were inspected by the electrochemical impedance spectral (EIS) method. The EGA paints with phosphor (11% w/w) exhibited the most distinct anti-corrosion properties and long-persistent luminescence. The produced paints displayed high durability and photostability.

Universal Preparation Strategy for Ultradurable Antibacterial Fabrics through Coating an Adhesive Nanosilver Glue

Microbiological protection textile materials played an important role in the battle against the epidemic. However, the traditional active antimicrobial treatment of textiles suffers from narrow textile applicability, low chemical stability, and poor washability. Here, a high-strength adhesive nanosilver glue was synthesized by introducing nontoxic water-soluble polyurethane glue as a protectant. The as-prepared nanosilver glue could adhere firmly to the fiber surfaces by forming a flexible polymer film and could encapsulate nanosilver inside the glue. The as-prepared nanosilver had a torispherical structure with diameter of ~22 nm, zeta potential of −42.7 mV, and good dispersibility in water, and it could be stored for one year. Further studies indicated that the nanosilver glue had wide applicability to the main fabric species, such as cotton and polyester fabric, surgical mask, latex paint, and wood paint. The antimicrobial cotton and polyester fabrics were prepared by a simple impregnation–padding–baking process. The corresponding antimicrobial activity was positively correlated with nanosilver content. The treated fabrics (500 mg/kg) exhibited ultrahigh washing resistance (maintained over 99% antibacterial rates for 100 times of standard washing) and wear resistance (99% antibacterial rates for 8000 times of standard wearing), equivalent breathability to untreated fabric, improved mechanical properties, and good flexibility, demonstrating a potential in cleanable and reusable microbiological protection textiles.

Simple Preparation of Multifunctional Luminescent Textile for Smart Packaging

Linen has been a significant material for textile packaging. Thus, the application of the simple spray-coating method to coat linen fibers with a flame-retardant, antimicrobial, hydrophobic, and anticounterfeiting luminescent nanocomposite is an innovative technique. In this new approach, the ecologically benign room-temperature vulcanizing (RTV) silicone rubber was employed to immobilize the environmentally friendly Exolit AP 422 (Ex) and lanthanide-doped strontium aluminum oxide (RESAO) nanoscale particles onto the linen fibrous surface. Both morphological properties and elemental compositions of RESAO and treated fabrics were examined by transmission electron microscopy (TEM), scanning electron microscopy (SEM), wavelength-dispersive X-ray fluorescence (WD-XRF), Fourier transform infrared (FTIR) spectroscopy, and energy-dispersive X-ray spectroscopy (EDX). In the fire resistance test, the treated linen fabrics produced a char layer, giving them the property of self-extinguishing. Furthermore, the coated linen samples' fire-retardant efficacy remained intact after 35 washing cycles. As the concentration of RESAO increased, so did the treated linen superhydrophobicity. Upon excitation at 366 nm, an emission band of 519 nm was generated from a colorless luminescent film deposited onto the linen surface. The coated linen displayed a luminescent activity by changing color from off-white beneath daylight to green beneath UV source, which was proved by CIE Lab parameters and photoluminescence spectral analysis. The photoluminescence effect was identified in the treated linen as reported by emission, excitation, and decay time spectral analysis. The comfort properties of coated linen fabrics were measured to assess their mechanical and comfort features. The treated linen exhibited excellent UV shielding and improved antimicrobial performance. The current simple strategy could be useful for large-scale production of multifunctional smart textiles such as packaging textiles.

Development of photoluminescent artificial nacre-like nanocomposite from polyester resin and graphene oxide

Long-lasting phosphorescent nacre-like material was simply prepared from a nanocomposite of inorganic and organic materials. Low molecular weight unsaturated polyester (PET), graphene oxide (GO), and nanoparticles of rare-earth activated aluminate pigment were used in the preparation process of an organic/inorganic hybrid nanocomposite. Using methylethylketone peroxide (MEKP) as a hardener, we were able to develop a fluid solution that hardens within minutes at room temperature. Covalent and hydrogen bonds were introduced between the polyester resin and graphene oxide nanosheets. The interface interactions of those bonds resulted in toughness, excellent tensile strength, and high durability. The produced nacre substrates demonstrated long-persistent and reversible luminescence. The excitation of the produced nacre substrates at 365 nm resulted in a 524 nm emission. After being exposed to UV light, the photoluminescent nacre substrates became green. The increased superhydrophobic activity of the produced nacre substrates was achieved without affecting their physico-mechanical properties.

Simple Preparation of Photoluminescent and Color-Tunable Polyester Resin Blended with Alkaline-Earth-Activated Aluminate Nanoparticles

A simple inorganic/organic nanocomposite was used to generate long-lasting phosphorescent pebbles for easy commercial manufacturing of smart products. An organic/inorganic nanocomposite was made from low-molecular-weight unsaturated polyester and rare-earth-activated strontium aluminum oxide nanoparticles doped with europium and dysprosium. The polyester resin was mixed with phosphorescent strontium aluminate oxide nanoparticles and methylethyl ketone peroxide as a cross-linking agent to create a viscous mixture that can be hardened in a few minutes at room temperature. Before adding the hardener catalyst, the phosphorescent strontium aluminate nanoparticles were dispersed throughout the polyester resin in a homogeneous manner to ensure that the pigment did not accumulate. Long-lasting, reversible luminescence was shown by the photoluminescent substrates. The emission was reported at 515 nm upon exciting the pebble at 365 nm. In normal visible light, both blank and luminescent pebbles had a translucent appearance. As a result of UV irradiation, the photoluminescent pebbles produced an intense green color. The three-dimensional CIE Lab (International Commission on Illumination) color coordinates and luminescence spectra were used to investigate the color changing characteristics. Photophysical characteristics, including excitation, emission, and lifetime, were also investigated. Scanning electron microscopy, wavelength-dispersive X-ray fluorescence spectroscopy, and energy-dispersive X-ray analysis were employed to report the surface morphologies and elemental content. Without impairing the pebbles' original physico-mechanical characteristics, the pebbles showed improved superhydrophobic activity. The current simple colorless long-lasting phosphorescent nanocomposite can be applied to a variety of surfaces, like ceramics, glassware, tiles, and metals.

Development of silica-coated rare-earth doped strontium aluminate toward superhydrophobic, anti-corrosive and long-persistent photoluminescent epoxy coating

Long-persistent phosphorescent smart paints have the ability to continue glowing in the dark for a prolonged time period to function as energy-saving products. Herein, new epoxy/silica nanocomposite paints were prepared with different concentrations of lanthanide-doped aluminate nanoparticles (LAN; SrAl₂ O₄ : Eu²⁺ , Dy³⁺ ). The LAN pigment was firstly coated with SiO₂ utilizing the heterogeneous precipitation technique to provide LAN-encapsulated between SiO₂ nanoparticles (LAN@SiO₂ ). The epoxy/silica/lanthanide-doped aluminate nanoparticles (ESLAN) nanocomposite paints were coated on steel. The prepared ESLAN paints were studied by transmission electron microscope (TEM), infrared spectra (FTIR), scanning electron microscope (SEM), X-ray fluorescence analysis (XRF), and energy-dispersive X-ray spectra (EDS). The transparency and coloration properties of the nanocomposite coated films were explored by CIE Lab parameters and photoluminescence spectra. The ultraviolet-induced luminescence properties of the transparent coated films demonstrated greenish phosphorescence at 518 nm upon excitation at 368 nm. Both hardness and hydrophobic activities were investigated. The anticorrosion activity of the nanocomposite films coated onto mild steel substrates immersed in NaCl_(aq) (3.5%) was studied by the electrochemical impedance spectral (EIS) analysis. The silica-containing coatings were monitored to exhibit anticorrosion properties. Additionally, the nanocomposite films with LAN@SiO₂ (25%) exhibited the optimized long-lasting luminescence properties in the dark for 90 minutes. The nanocomposite films showed highly reversible and durable long-lived phosphorescence.

Production of photoluminescent transparent poly(methyl methacrylate) for smart windows

Photochromic and long-lasting photoluminescent transparent, rigid, ultraviolet (UV) protective and superhydrophobic poly(methyl methacrylate) (PMMA) plastic able to switch colour beneath UV irradiation was developed. Photoluminescent transparent PMMA plastic was prepared by the simple polymerization process of methyl methacrylate immobilized with alkaline earth aluminate (AEA) nanoparticles. These colourless PMMA plastic substrates showed a colour switch to greenish underneath UV light as proved using CIELAB screening. The morphology of AEA was evaluated using transmission electron microscopy. Conversely, transparent PMMA samples were evaluated using energy-dispersive X-ray spectra, scanning electron microscope, X-ray fluorescence spectroscopy and for hardness properties. Additionally, the photoluminescence properties were explored by studying excitation and emission spectra. The produced luminescence colourless PMMA plastic substrates displayed excitation band at 370 nm, and three emission peaks at 433, 494 and 513 nm. Photoluminescent PMMA with lower contents of AEA showed fast and reversible photochromism under UV light, while PMMA samples with higher contents of AEA showed long-lasting luminescence such as a flashlight with the ability to replace electric power. The findings showed that the produced photoluminescence colourless PMMA plastic substrates exhibited enhanced UV shielding and superhydrophobicity.

Development of Mechanically Reliable and Transparent Photochromic Film Using Solution Blowing Spinning Technology for Anti-Counterfeiting Applications

Photochromic materials have attracted broad interest to enhance the anti-counterfeiting of commercial products. In order to develop anti-counterfeiting mechanically reliable composite materials, it is urgent to improve the engineering process of both the material and matrix. Herein, we report on the development of anti-counterfeiting mechanically reliable nanocomposites composed of rare-earth doped aluminate strontium oxide phosphor (RESA) nanoparticles (NPs) immobilized into the thermoplastic polyurethane-based nanofibrous film successfully fabricated via the simple solution blowing spinning technology. The generated photochromic film exhibits an ultraviolet-stimulated anti-counterfeiting property. Different films of different emissive properties were generated using different total contents of RESA. Transmission electron microscopy was utilized to investigate the morphological properties of RESA NPs to display a particle diameter of 3-17 nm. The morphologies, compositions, optical transmittance, and mechanical performance of the produced photochromic nanofibrous films were investigated. Several analytical methods were employed, including energy-dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier-transform infrared spectrometry. The fibrous diameter of RESA-TPU was in the range of 200-250 nm. In order to ensure the development of transparent RESA-TPU film, RESA must be prepared in the nanosized form to allow better dispersion without agglomeration in the TPU matrix. The luminescent RESA-TPU film displayed an absorbance intensity at 367 nm and two emission intensities at 431 and 517 nm. The generated RESA-TPU films showed an enhanced hydrophobicity without negatively influencing their original appearance and mechanical properties. Upon irradiation with ultraviolet light, the transparent nanofibrous films displayed rapid and reversible photochromism to greenish-yellow without fatigue. The produced anti-counterfeiting films demonstrated stretchable, flexible, and translucent properties. As a simple sort of anti-counterfeiting substrates, the current novel photochromic film provides excellent anti-counterfeiting strength at low-cost as an efficient method to develop versatile materials with high mechanical strength to create an excellent market as well as adding economic and social values.

Solution blowing spinning technology and plasma-assisted oxidation-reduction process toward green development of electrically conductive cellulose nanofibers

Cellulose fibers have been one of the most common fibers due to their biodegradability, excellent mechanical properties, biocompatibility, high absorption ability, cheapness and renewability. In this study, novel, simple and green method is concerned with the production of multifunctional cellulose nanofibers (CNFs). Nanocomposites consisting of silver nanoparticles (AgNPs) and polyaniline (PANi) were in situ synthesized into plasma-pretreated cellulosic nanofibers fabricated by solution blowing spinning technique. The produced cellulose acetate nanofibers were then subjected to deacetylation followed by plasma-activation followed by a treatment with aniline and silver nitrate (AgNO₃) in the presence of ammonium acetate. Plasma-assisted oxidation polymerization process of aniline into PANi associated with a reduction of Ag⁺ into AgNPs results in their permanent insolubility into the surface of the cellulose nanofibers. The morphologies and elemental contents were determined by polarizing optical microscope (POM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray patterns and scanning electron microscopy (SEM). Additionally, transmission electron microscope (TEM) was applied to explore the morphologies of silver nanoparticles and PANi showing particle diameter between 12 and 25 nm. The antimicrobial Ag NPs were formed from an aqueous medium of silver nitrate by taking the reduction ability advantage of the electrically active PANi. The immobilization of polyaniline and silver nanoparticles into the surface of the cellulose nanofibers enhanced its electrical conductivity. The produced CNFs demonstrated a high UV protection as well as antibacterial activity.

Preparation of cellulose-based electrospun fluorescent nanofibres doped with perylene encapsulated in silica nanoparticles for potential flexible electronics

Novel fluorescent nanofibres were developed via the electrospinning of chromophore-doped cellulose. Two different perylene-doped cellulose fluorescent fibres were fabricated using cellulose as a host material and perylene dye derivatives as active dopants. Fluorescent cellulose nanofibres were prepared via the electrospinning technique using two different perylene dyes, including perylene diimide and perylene mono-imide sodium/potassium salts. The generated fluorescent silica nanoparticles exhibited diameters varying in the range 80-180 nm. The generated electrospun fluorescent nanofibrous structures displayed smooth surfaces with average diameters of 200-300 nm for cellulose comprising perylene diimide and sodium/potassium salts of perylene mono-imide dyes, respectively, dispersed uniformly in the cellulose matrix. The generated fluorescent nanoparticles and nanofibres were characterized by different standard methods, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), fluorescent optical microscope (FOM) and Fourier-transform infrared spectra (FT-IR). The fluorescence properties of the fabricated cellulose nanofibres were explored. Those fluorescent nanofibres pave the way for the development of promising textile fluorescence materials, such as flexible displays, photonics, and optical devices.

Facile production of smart superhydrophobic nanocomposite for wood coating towards long-lasting glow-in-the-dark photoluminescence

A smart photoluminescent nanocomposite surface coating was prepared for simple industrial production of long-persisting phosphorescence and superhydrophobic wood. The photoluminescent nanocomposite coatings were capable of continuing to emit light in the dark for prolonged time periods that could reach 1.5 h. Lanthanide-doped aluminium strontium oxide (LASO) nanoparticles at different ratios were immobilized in polystyrene (PS) and developed as a nanocomposite coating for wood substrates. To produce transparency in the prepared nanocomposite coating, LASO was efficiently dispersed in the form of nanoscaled particles to ensure homogeneous dispersion without agglomeration in the PS matrix. The coated wood showed an absorption band at 374 nm and two emission bands at 434 nm and 518 nm. The luminescence spectra showed both long-persisting phosphorescence as well as photochromic fluorescence relying on the LASO ratio. The improved superhydrophobicity and resistance to scratching of the coated wood could be attributed to the LASO NPs incorporated in the polystyrene matrix. Compared with the uncoated wood substrate, the coated LASO-PS nanocomposite film also displayed photostability and high durability. The current study demonstrated the potential high-scale manufacturing of smart wood for some applications such as safety directional signs in buildings, household products, and smart windows.

Preparation of flame-retardant, hydrophobic, ultraviolet protective, and luminescent transparent wood

Transparent wood with multifunctional properties has recently attracted more attention as an efficient building product. Here, we describe the development of transparent wood with long-persistent phosphorescence, tough surface, high durability, photostability, and reversibility without fatigue, and with ultraviolet shielding, superhydrophobicity, and flame-retardant activity. This long-persistent phosphorescent, or glow-in-the-dark, smart wood exhibited an ability to continue emitting light for prolonged periods of time. The photoluminescent translucent wooden substrate was prepared by immobilizing lignin-modulated wooden bulk with an admixture of methylmethacrylate (MMA), ammonium polyphosphate (APP), and lanthanide-doped strontium aluminate (LSA; SrAl₂ O₄ :Eu²⁺ ,Dy³⁺ ) phosphor nanoparticles. The photoluminescent transparent wood displayed a colour switch from colourless to bright white beneath ultraviolet (UV) light and greenish-yellow in the dark as reported by Commission Internationale de l'Éclairage laboratory colorimetric space coordinates. The generated phosphorescent wooden substrates demonstrated an absorbance band at 365 nm and an emission band at 516 nm. The phosphorescent transparent wood was improved flame-retardant properties, ultraviolet shielding, and superhydrophobic properties, as well as a reversible long-persistent phosphorescent responsiveness to UV light without fatigue. The current approach demonstrated a potential large-scale production strategy for multifunctional transparent wooden substrates for a range of applications such as smart windows, gentle indoor and outdoor lighting, and safety directional signs in buildings.

Production of photochromic nanocomposite film via spray-coating of rare-earth strontium aluminate for anti-counterfeit applications

New photochromic film was developed toward the preparation of anti-counterfeiting documents utilizing inorganic/organic nanocomposite enclosing a photoluminescent inorganic pigment and a polyacrylic binder polymer. To generate a translucent film from pigment/polyacrylic nanocomposite, the phosphorescent strontium aluminum oxide pigment should be well-dispersed in the solution of the polyacrylic-based binder without agglomeration. The photochromic nanocomposite was applied efficiently onto commercial cellulose paper documents utilizing the effective and economical spray-coating technology followed with thermofixation. A homogeneous photochromic film was immobilized onto cellulose paper surface to introduce a transparent film changing to greenish-yellow upon exposure to ultraviolet light as depicted by CIE coloration measurements. The photochromic effect was monitored at lowest pigment concentration (0.25 wt%). The spray-coated paper documents exhibit two absorbance bands at 256 and 358 nm, and two fluorescence peaks at 433 and 511 nm. The morphologies of the spray-coated documents were explored. The spray-coated paper sheets showed a reversible photochromic effect without fatigue under ultraviolet irradiation. The rheology of the produced photochromic composites as well as the mechanical properties and photostability of the spray-coated documents were studied.

Preparation of multifunctional long-persistent photoluminescence cellulose fibres

Simple preparation of flame-retardant, photoluminescent, and superhydrophobic smart nanocomposite coating was developed and applied onto cotton fibres using the simple pad-dry-cure technique. This novel strategy involved the immobilization of rare-earth-doped aluminium strontium oxide (ASO; SrAl₂ O₄ :Eu⁺² ,Dy⁺³ ) nanoparticles, environmentally friendly room temperature vulcanizing silicone rubber (RTV) and environmentally friendly Exolet AP422 (Ex). The fabrics were also able to produce a char film in the fire-resistant assessment, providing fibres with a self-extinguishing characteristic. Furthermore, the fire-retardant performance of the coated cotton samples remained resistant to washing over 35 laundry cycles. The superhydrophobicity of the treated fabrics was monitored to improve by increasing the photoluminescent phosphor nanoparticles. The produced transparent photoluminescent film displayed an absorption at 360 nm and an emission at 526 nm. The photoluminescent fabrics were observed to generate different colorimetric shades, including white, green-yellow and bright white as monitored by Commission Internationale de l'Éclairage laboratory colorimetric coordinates. Slow emissions were detected for the treated cotton fabrics as monitored by emission, ultraviolet-visible light absorption, lifetime, and decay time spectral profiles to indicate glow in the dark phosphorescence effect. Both comfort and mechanical properties of the coated fibres were evaluated by measuring their bending length and air permeability.