Excellent Ultraviolet Research Articles

Reducing Oxidative Stress Levels and Inhibiting Aging by l-Cysteine-Derived Carbon Dots with Highly Efficient Broad-Spectrum UV Absorption.

Ultraviolet (UV) exposure causes damage to human skin and mucous membranes, resulting in oxidative stress, and can also lead to inflammation of human skin, skin aging, and even diseases such as squamous cell carcinoma and melanoma of the skin. The main means of protection against UV radiation is physical shielding and the use of sunscreen products. Carbon dots as a novel nanomaterial provide a new option for UV protection. In this article, we introduced sulfhydryl groups to synthesize l-cysteine-derived carbon dots (GLCDs) with UV resistance. GLCDs exhibit high-efficiency and excellent UV absorption, achieving 200-400 nm UV absorption (99% UVC, 97% UVB, and 86% UVA) at a low concentration of 0.5 mg/mL. Meanwhile, GLCDs can reduce apoptosis and UVB-induced oxidative damage, increase collagen type I gene expression, and inhibit skin aging in zebrafish. It also inhibits senescence caused by the senescence inducer 2,2'-azobis(2-methylpropionamidine) dihydrochloride and reduces oxidative damage. The above studies show that GLCDs possess efficient broad-spectrum UV absorption, antiphotoaging, and antiaging capabilities, which will have a broad application prospect in UV protection.

Conductive and superhydrophobic lignin/carbon nanotube coating with nest-like structure for deicing, oil absorption and wearable piezoresistive sensor

The development of multifunctional coatings is a trend. Here, a conductive and superhydrophobic coating with nest-like structure was prepared on the wood or polyurethane (PU) sponge by spraying or soaking methods. The coating contains lignin and carboxylated multi-wall carbon nanotubes (MWCNT) as the main materials, both methyl trimethoxysilane (MTMS) and polydimethylsiloxane (PDMS) as the modifiers. And benefiting from the protective effect of the nest-like structure, the coating exhibits excellent abrasion resistance (withstanding 43 abrasion cycles), stability, and UV resistance (little change in water contact angle after 240 h of ultraviolet (UV) irradiation) by optimizing the proportions. Additionally, the coating provides eminent deicing (complete removal after 142.7 s) and self-cleaning on the wood, as well as the superior sensing performance and oil absorption (15.0–49.6 g/g for various oils) on the PU sponge. When assembled into compressible piezoresistive sensor, it could clearly sense the signals of rapid, short, circulation, different speed and deformation, possessing a prosperous wearable device prospect. It is envisaged that the coating supplies a new platform for superhydrophobicity, wearable electronics and oil absorption.

A comparative analysis of crustacean exoskeletons: structural, microstructural, morphological, and UV absorption studies

This study aims to investigate the structural, thermal, and spectral characteristics, along with the ultra-violet (UV) absorption of various marine benthos exoskeletons, such as various species of crabs (Portunus sanguinolentus, Portunus pelagicus, Charybdis feriata) and mantis shrimp (Oratosquilla oratoria). Their unique properties and ability to survive in harsh oceanic environments make them interesting research subjects. This research utilized powder x-ray diffraction (XRD) analysis to determine the crystal structure of the benthic varieties. The sample surface was analyzed using high-resolution micrographs obtained from field-emission scanning electron microscopy (FESEM), which identified the presence of chitin and calcite in the marine benthos. This was further confirmed by differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). The optical characteristics were investigated using UV-visible spectroscopy. The proximate analysis revealed high protein content in the mantis shrimp exoskeleton compared to other crab species, highlighting its excellent UV absorption characteristics. Overall, this research has the potential to broaden our understanding of marine organisms, which can have potential applications in biotechnology and materials science to develop nature-inspired innovative materials sustainably.

Study on the construction of durable superhydrophobic coatings using simple spray coating method and their underwater drag reduction performance

Superhydrophobic surfaces have significant applications in industrial and chemical fields. However, their current mechanical stability and underwater durability are insufficient, limiting their widespread application. This study successfully developed a durable superhydrophobic coating suitable for various substrates using a simple one-step spraying technique. By thoroughly investigating the effects of SiO2 concentration and curing temperature on the coating's wettability, underwater durability and mechanical stability, the preparation process was optimized. The prepared superhydrophobic coating achieved a contact angle (CA) of 159.6° and a sliding angle (SA) of less than 1°. In tests of underwater immersion, sandpaper abrasion, repeated water impact, corrosion resistance and ultraviolet (UV) resistance, the coating demonstrated excellent underwater durability, mechanical stability, chemical stability and UV stability. Furthermore, when applied to the steel sphere, the superhydrophobic coating exhibited significant drag reduction effects underwater, reducing the drag coefficient by approximately an order of magnitude and achieving a drag reduction efficiency of 79.1 %. Numerical simulations using STAR-CCM+ showed that the streamlined cavity formed by the superhydrophobic coating effectively suppressed fluid separation, reduced pressure-induced drag, and allowed the superhydrophobic steel sphere to attain a higher terminal velocity. Therefore, the superhydrophobic coating developed in this study has tremendous application potential in underwater drag reduction and is expected to provide effective solutions for energy-saving and drag reduction in fields such as maritime navigation.

NaK5La2(SO4)6: Enhanced Birefringence of Multiple-Alkali Metal Sulfate Systems via Rare Earth Metal-Centered Polyhedra.

Polarization modulation of ultraviolet (UV) birefringent crystals is crucial for various applications. Here, we introduce distorted La-O polyhedra into alkali metal sulfates to synthesize a novel birefringent material with excellent UV transmission and birefringence. The incorporation of distorted La-O polyhedra significantly increases the birefringence to 0.0255 at 550 nm, surpassing that of many alkali metal sulfates while maintaining excellent UV transparency. The material exhibits excellent thermal stability up to 450 °C. Theoretical calculations show the connection between the crystal structure and optical functionality, confirming that the incorporation of La-O polyhedra enhances birefringence. This research provides novel insights into the discovery and design of outstanding birefringence materials.

Polyphosphazene Microparticles with High Free Radical Scavenging Activity for Skin Photoprotection.

Ultraviolet (UV) filters are the core ingredients in sunscreens and protect against UV-induced skin damage. Nevertheless, their safety and effectiveness have been questioned in terms of their poor photostability, skin penetration, and UV-induced generation of deleterious reactive oxygen species (ROS). Herein, an organic UV filter self-framed microparticle sunblock was exploited, in which quercetin (QC) and hexachlorocyclotriphosphazene (HCCP) were self-constructed into microparticles (HCCP-QC MPs) by facile precipitation polymerization without any carriers. HCCP-QC MPs could not only significantly extend the UV shielding range to the whole UV region but also remarkably reduce UV-induced ROS while avoiding direct skin contact and the resulting epidermal penetration of small-molecule QC. Meanwhile, HCCP-QC MPs possess a high QC-loading ability (697 mg g-1) by QC itself as the microparticles' building blocks. In addition, there is no leakage issue with small molecules due to its covalently cross-linked structure. In vitro and vivo experiments also demonstrated that the HCCP-QC MPs have excellent UV protection properties and effective ROS scavenging ability without toxicity. In summary, effective UV-shielding and ROS scavenging ability coupled with excellent biocompatibility and nonpenetration of small molecules make it a broad prospect in skin protection.

Deep-eutectic-solvent modulation of self-assembled multi-responsive films based on polyvinyl alcohol/cellulose nanocrystal and grape skin red for highly sensitive food monitoring

To enhance the mechanics performance, sensitivity and response range of multi-responsive photonic films, herein, a facile method for fabricating multi-responsive films is demonstrated using the evaporative self-assembly of a mixture of grape skin red (GSR), cellulose nanocrystal (CNC), polyvinyl alcohol (PVA) and deep eutectic solvent (DES). The prepared materials exhibited excellent thermal stability, strain properties, solvent resistance, ultraviolet (UV) resistance and antioxidant activity. Compared to a pure PVA film, the presence of GSR strengthened the antioxidant property of the film by 240.1 % and provided excellent UV barrier capability. The additional cross-linking of DES and CNC promoted more efficient phase fusion, yielding a film strain of 41.5 %. The addition of hydrophilic compound GSR, wetting and swelling due to the DES and the surface inhomogeneity of the films rendered the multi-responsive films high sensitivity, wide response range and multi-cyclic stability in environments with varying pH and humidity. A sample application showed that a PVA/CNC/DES film has the potential to differentiate between fresh, sub-fresh and fully spoiled shrimps. The above results help in designing intelligent thin film materials that integrate antioxidant properties, which help in monitoring the changes in food freshness and food packaging.

Effective photoabsorption and band-structural engineering in CuxO/NiO interfacial photosensor for improved ultraviolet response

Energy bands modulations in thin films heterostructure has offered exceptional leads towards the development of photosensing material. In this work, nanostructured metal oxides interfacial electrode structure has been employed to fabricate a highly sensitive ultraviolet (UV) sensor with high responsivity and detectivity. A unique, simple and cost-effective electrodeposition approach was adopted for the growth of the film samples. The interfacial structural effect and optical energy band modulations on the photo-electronic structure and UV detector performance of the structure have been examined. The films had fair transmissions of the visible light spectrum with CuxO dominance in the resulting bilayer structure and a high absorption peak in the ultraviolet (UV) region. The energy band gap redshifted towards the bilayer structure from 3.74 to 2.67 eV. Charge carriers trapping through surface recombination has been found to reduce from the assistance of ohmic contact formation of the heterostructure. The bilayer film-based photodetector demonstrated enhanced performance with photodetectivity (1.6⨯1011 Jones at 0.068 mWcm−2 power density), attributable to the existence of lower recombination state in the structure, according to the UV sensing study. The study showed that tailoring dissimilar metal oxide semiconducting films to the bilayer (CuxO/NiO) structure can provide excellent UV photodetector performance over single-layer of NiO and CuxO.

Facile fabrication of multifunctional aramid fibers for excellent UV resistance in extreme environments

Aramid fibers (AFs) are widely applied as structural material, cordage, and versatile protection in many harsh environments, including space and deep sea. However, intense ultraviolet (UV)/ irradiation, high/low temperatures, and/or chemical solvent with strong acid/alkali/corrosion feature seriously affect their mechanical properties, thus severely shorten the life cycle of AF-based products. Inspiration by the principle of multiple refractions and partly reflections, an innovative strategy by depositing of laminated Al2O3/TiO2 composite onto the surface of poly(m-phenylene isophthalamide) (PMIA) via atomic layer deposition (ALD) technique was presented. The tenacity of ALD-coated PMIA only decreases by ∼ 8 %, and the yellowness index (YI) only increasing to 129.24 %, far lower than 321.63 % of pristine PMIA fabric under the combination of intense UV irradiation (4260 W/m2) and high temperature (200 °C + ) for 6 h, which equals to continuous strong sunlight exposure for approximately 7.5 years. Meanwhile, ultraviolet protection factor (UPF) value increased to 126.4, which is double that of the pristine PMIA fabric, exhibiting an impressive UV-resistance property. Furthermore, the ALD-coated PMIAs also shows a significant enhancement in both chemical and thermal stabilities. In all, this work not only forge a new route for the functionalization of fibrous materials, but also exhibits great promise for next generation advanced composite material and cutting-edge equipment in harsh environment.

Poly-(lactic acid) composite films comprising carvacrol and cellulose nanocrystal–zinc oxide with synergistic antibacterial effects

Herein, carvacrol (CRV) and modified cellulose nanocrystal–zinc oxide (CNC–ZnO) were incorporated into a poly (lactic acid) (PLA) matrix to prepare a PLA-based composite film using a simple solution casting method to achieve antimicrobial effects for application in antimicrobial food packaging. Compared with films obtained from neat PLA, the PLA@CRV20%@CNC–ZnO3% composite film shows better performance in terms of mechanical properties, ultraviolet (UV) blocking, and antimicrobial effects. The PLA composites containing CRV and 3 wt% CNC–ZnO blends exhibit improved tensile strength (21.8 MPa) and elongation at break (403.1 %) as well as excellent UV resistance. In particular, CRV and the CNC–ZnO hybrid endow the obtained PLA composite films with a synergistic antibacterial effect, resulting in good antibacterial properties for microbes, such as Escherichia coli, Staphylococcus aureus and Aspergillus niger. The diameters of the inhibition zone of the PLA@CRV20%@CNC–ZnO3% composite films against E. coli, S. aureus, and A. niger were 4.9, 5.0, and 3.4 cm, respectively. Appling the PLA@CRV20%@CNC–ZnO3% composite film as an antibacterial food packaging material, the storage period for strawberries was considerably extended. This study provides a theoretical basis for developing new organic/inorganic composite antimicrobial film materials from PLA.

Enhancing polyamide fabric performance through green reduction of graphene oxide for superior ultraviolet protection and electrical conductivity

AbstractIn this study, a polyamide warp‐knitted fabric was treated with a graphene oxide (GO) aqueous dispersion using a laboratory‐type Jigger dyeing machine. Subsequently, the GO underwent a chemical reduction process, employing rosehip extract powder as a nature‐based reducing agent. The effect of reduction time (12 and 24 h) was investigated. The study involved an examination of the surface morphology, colour coordinates, and colour difference of both the GO coated and reduced graphene oxide (RGO) coated fabrics. Additionally, the colour fastness against rubbing was assessed. Furthermore, electrical resistivity measurements were conducted on the GO‐coated polyamide‐6,6 fabric both before and after the reduction process. The ultraviolet (UV) transmittance and ultraviolet protection factor (UPF) of both GO‐coated and reduced fabrics were determined. The study also explored the effect of the washing process on colour properties, electrical resistivity, and UPF. Notably, the lowest electrical surface resistivity and the highest UPF rating were obtained as 1.20 × 102 kΩ/sq and 50+ after the reduction process. Additionally, after the washing process, the electrical surface resistivity increased, while the UPF rating remained 50+, indicating excellent UV protection.

Full‐Spectral Response Perovskite Solar Cells Through Integration of MXene Modified Near‐Infrared Organic Heterojunction and Waveguide‐Structure Quantum‐Cutting Down‐Converter

AbstractTo date, lead‐based perovskite solar cells (PSCs) are optimized to the extreme and achieved an efficiency of as much as 26.1%. Expanding the spectral response is one of the most effective methods for achieving further efficiency breakthroughs. In this study, integrated PSCs are constructed by combining near‐infrared (NIR) organic bulk heterojunctions (BHJs) with perovskite layers to broaden the NIR spectral response range. Ultraviolet (UV)‐plasma‐treated MXene Nb2CTx ‐ quantum dots (QDs) are introduced to promote exciton dissociation inside the BHJ and to solve the problems of severe nonradiative exciton recombination and open‐circuit voltage (Voc) loss in IPSCs. In addition, CsPbCl3:Yb(7%),Li(2%) QDs with quantum‐cutting emission and photoluminescence quantum yield of up to 170% act as down‐converters to enhance the utilization of UV light. MgF2 is deposited on the quantum‐cutting layer to construct a waveguide‐structured anti‐reflection layer and further increase UV photon utilization. The champion device achieves superior photoelectric performance with a photoelectric conversion efficiency of 24.3%, Voc of 1.17 V, a short circuit current of 26.65 mA cm−2, and a fill factor of 77.95%. Champion devices exhibit excellent UV and long‐term stability. This study provides an instructive strategy for fabricating high‐performance full‐spectral‐response PSCs.

Carbon Quantum Dots for Long-Term Protection against UV Degradation and Acidification in Paper-Based Relics.

Paper-based cultural relics constitute a significant and invaluable part of human civilization and cultural heritage. However, they are highly vulnerable to environmental factors such as ultraviolet (UV) photodegradation and acidification degradation, posing substantial threats to their long-term preservation. Carbon quantum dots (CQDs), known for their outstanding optical properties, high water solubility, and good safety, offer a promising solution for slowing down UV damage and acidification of paper-based relics during storage and transportation. Herein, we propose a feasible strategy for the simple preparation of CQDs with high dispersion stability, excellent UV absorption, room-temperature phosphorescence, and photostability for the safety protection of paper. Accelerated aging experiments were conducted using UV and dry-heat aging methods on both CQD-protected paper and unprotected paper, respectively, to evaluate the effectiveness of CQD protection. The results demonstrate a slowdown in both the oxidation and acid degradation processes of the protected paper under both UV-aging and dry-heat aging conditions. Notably, CQDs with complex luminescence patterns of both fluorescence and room-temperature phosphorescence also endue them as enhanced optical anticounterfeiting materials for multifunctional paper protection. This research provides a new direction for the protection of paper-based relics with emerging carbon nanomaterials.

Silver nanoparticles coated cellulose-based flexible membrane with excellent UV resistance, high infrared reflection and water resistance for personal thermal management

Designing of a green and multifunctionally integrated cellulose-based flexible wearable material with personal thermoregulation, water and ultraviolet (UV) resistance is essential for the development of personal thermal management and smart textiles. Herein, a hydrophobic silver nanoparticles cellulose-based membrane (H-AgNPs/CEPCM) was prepared through simple solution blending, spin-coating process and chemical vapor modification. The prepared membrane exhibited excellent UV resistance due to the synergistic effect of carbon quantum dots (CQDs) as well as UV-absorbing functional groups. The spin-coated AgNPs layer with high infrared reflectivity has great radiant insulation, and temperature was reduced by 3.4 °C compared with H-CEPCM in indoor environment. Furthermore, the mechanical properties of H-AgNPs/CEPCM were significantly improved by the introduction of amide and ether bonds, as well as a large number of hydrogen bonds. This led to a tensile strength of 23.21 MPa and an elongation at break of 16.57 %, while also providing water resistance. Additionally, the H-AgNPs/CEPCM exhibited outstanding thermal stability and hydrophobicity. This work may provide a feasible and promising strategy for the construction of multifunctional integrated cellulose membrane materials for radiant insulation, outdoor textiles and novel UV protection applications.

Enhanced far infrared emissivity, UV protection and near-infrared shielding of polypropylene composites via incorporation of natural mineral for functional fabric development

Far infrared radiation in the range of 4–20 µm has been showed to have biological and health benefits to the human body. Therefore, incorporating far-infrared emissivity additives into polymers and/or fabrics hold promise for the development of functional textiles. In this study, we incorporated nine types of natural minerals into polypropylene (PP) film and examined their properties to identify potential candidates for functional textiles and apparels. The addition of 2% mineral powders into PP film increased the far-infrared emissivity (5–14 µm) by 7.65%-14.48%. The improvement in far-infrared emissivity within the range of 5–14 µm, which overlaps with the peak range of human skin radiation at 8–14 µm, results in increased absorption efficiency, and have the potential to enhance thermal and biological effects. Moreover, the incorporation of mineral powders in PP films exhibited favorable ultraviolet (UV) protection and near-infrared (NIR) shielding properties. Two films, specifically those containing red ochre and hematite, demonstrated excellent UV protection with a UPF rating of 50+ and blocked 99.92% and 98.73% of UV radiation, respectively. Additionally, they showed 95.2% and 93.2% NIR shielding properties, compared to 54.1% NIR shielding properties of PP blank films. The UV protection and NIR shielding properties offered additional advantages for the utilization of polymer composite with additives in the development of sportswear and other outdoor garments. The incorporation of minerals could absorb near-IR radiation and re-emit them at longer wavelength in the mid-IR region. Furthermore, the incorporation of minerals significantly improved the heat retention of PP films under same heat radiation treatment. Notably, films with red ochre and hematite exhibited a dramatic temperature increase, reaching 2.5 and 3.2 times the temperature increase of PP films under same heat radiation treatment, respectively (46.8 °C and 59.9 °C higher than the temperature increase of 20.9 °C in the PP film). Films with additives also demonstrated lower thermal effusivity than PP blank films, indicating superior heat insulation properties. Therefore, polypropylene films with mineral additives, particularly those containing red ochre and hematite, showed remarkable heat capacity, UV-protection, NIR-shielding properties and enhanced far infrared emissivity, making them promising candidates for the development of functional textiles.

Mg(C3 O4 H2 )(H2 O)2 : A New Ultraviolet Nonlinear Optical Material Derived from KBe2 BO3 F2 with High Performance and Excellent Water-Resistance.

Acquiring high-performance ultraviolet (UV) nonlinear optical (NLO) materials that simultaneously exhibit a strong second harmonic generation (SHG) coefficients, as short as possible SHG phase-matching (PM) wavelength and non-hygroscopic properties has consistently posed a significant challenge. Herein, through multicomponent modification of KBe2 BO3 F2 (KBBF), an excellent UV NLO crystal, Mg(C3 O4 H2 )(H2 O)2 , was successfully synthesized in malonic system. This material possesses a unique 2D NLO-favorable electroneutral [Mg(C3 O4 H2 )3 (H2 O)2 ]∞ layer, resulting in the rare coexistence of a strong SHG response of 3×KDP (@1064 nm) and short PM wavelength of 200 nm. More importantly, it exhibits exceptional water resistance, which is rare among ionic organic NLO crystals. Theoretical calculations revealed that its excellent water-resistant may be originated from its small available cavity volumes, which is similar to the famous LiB3 O5 (LBO). Therefore, excellent NLO properties and stability against air and moisture indicate it should be a promising UV NLO crystal.

Mg(C3O4H2)(H2O)2: A New Ultraviolet Nonlinear Optical Material Derived from KBe2BO3F2 with High Performance and Excellent Water‐Resistance

AbstractAcquiring high‐performance ultraviolet (UV) nonlinear optical (NLO) materials that simultaneously exhibit a strong second harmonic generation (SHG) coefficients, as short as possible SHG phase‐matching (PM) wavelength and non‐hygroscopic properties has consistently posed a significant challenge. Herein, through multicomponent modification of KBe2BO3F2 (KBBF), an excellent UV NLO crystal, Mg(C3O4H2)(H2O)2, was successfully synthesized in malonic system. This material possesses a unique 2D NLO‐favorable electroneutral [Mg(C3O4H2)3(H2O)2]∞ layer, resulting in the rare coexistence of a strong SHG response of 3×KDP (@1064 nm) and short PM wavelength of 200 nm. More importantly, it exhibits exceptional water resistance, which is rare among ionic organic NLO crystals. Theoretical calculations revealed that its excellent water‐resistant may be originated from its small available cavity volumes, which is similar to the famous LiB3O5 (LBO). Therefore, excellent NLO properties and stability against air and moisture indicate it should be a promising UV NLO crystal.

Photocrosslinkable and hydroplasicable UV-shielding nanocellulose films facilitated by hydroxyl-yne click reaction

Sustainably-sourced functional nanocellulose materials are vitally important for the green and sustainable development. Herein, we reported photocrosslinkable and hydroplasticable TEMPO-oxidized cellulose nanofiber phenyl propylene ketone ethers (TOCNPPK) films with excellent ultraviolet (UV) shielding, highly reversible processability, and extended mechanical properties, which were facilitated by green hydroxyl-yne click reaction. The introduction of conjugated aromatic ring and vinyl bonds (-C=C-) had been demonstrated the key for the improved overall performance of resultant TOCNPPK, which not only endowed the TOCNPPK with nearly 100 % UV shielding, but also enabled it to be formed into diverse 3D shapes (helix, ring and letters “N, F, U”) via the facile hydrosetting method. The photocrosslinkable-enhanced mechanical performance of TOCNPPK films was also attributed to -C=C- which could crosslink via [2π + 2π] cycloaddition reactions under UV-irradiation. The ultimate stress of TOCNPPK films was as high as 210.0 ± 22.8 MPa and the Young's modulus was 11.5 ± 0.7 GPa, much superior to those of 128.6 ± 8.5 MPa and 9.2 ± 0.6 GPa for pristine TOCN films. Furthermore, the TOCNPPK had been demonstrated as efficient nanofillers for both hydrophilic polyvinyl alcohol and lipophilic polycaprolactone to develop advanced biodegradable composite films with the integration of good water-wetting resistance, excellent UV blocking, and photo-enhanced mechanical performance.

Transparent and anti-smudge ladder-like polysilsesquioxane coating with high wear resistance and UV aging resistance

With the rapid development of multi-function touch panels, more requirements are raised for touch screens including anti-smudge, anti-fingerprint, and high wear resistance, hardness, and UV resistance. Herein, ladder-like poly(2-(3,4-epoxycyclohexyl)ethyltrimethoxy-co-1H,1H,2H,2H-perfluorodecyltriethoxysilsesquioxane)s (LPEFSQs) were synthesized by the sol-gel reaction of 2-(3,4-Epoxycyclohexyl)ethyltrimethoxysilane (ECTMS) with 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (PFDTES) to reduce the surface energy of the coating. The incorporation of fluorine chains resulted in an improvement of water contact angle from 77.1° to 115.5°, and oil contact angle from 35.4° to 94.7°, respectively. The omniphobic property rendered the coating excellent anti-smudge and anti-fingerprint properties while maintaining an extraordinary visible light transparency of 90.1 %. A proper PFDTES fraction of 5 % and the curing agent of I-250 are desired for the coating to simultaneously realize excellent pencil hardness of 6H, anti-smudge, and wear resistance performance. The optimized LPEFSQ coating could withstand a steel wool abrasion for 500 cycles. In addition, the developed LPEFSQ coating maintained excellent omniphobicity when subjected to ultraviolet (UV) irradiation for 200 h demonstrating excellent UV resistance. Therefore, this work provides insights into the synthesis of multifunctional coatings integrated with high transparency, wear resistance, and hardness as well as anti-smudge, and anti-fingerprint properties for touch screens.

Mechanical and UV protection performances of polylactic acid spunlace nonwoven fabrics coated by eco-friendly lignin/water-borne polyurethane composite coatings

Lignin as a biopolymer, has drawn much attention owing to its renewable nature, biodegradability, easy availability, and excellent stability. Water-borne polyurethane (WPU)-based coatings have been contributing to sustainable and eco-friendly practices offer a straightforward avenue for the value-added utilization of lignin. With the alarming rise in death rates attributed to skin diseases due to ultraviolet (UV) radiation damage, researchers have been actively searching for sustainable coating processes that enhance the UV protective capabilities of fabrics. In this paper, a facile strategy was reported for fabricating an environment friendly, mechanically durable, and UV protective biodegradable polylactic acid (PLA) spunlace nonwoven fabrics (SNFs) using lignin/WPU composite coatings. Lignin/WPU coating pastes were prepared using five different recipes including different lignin concentrations (0.5, 1.0, 1.5, and 2.0 wt.%) and coated on PLA SNFs via an applicator and thermally cured. Mechanical properties (e.g. tensile strength and abrasion resistance) and UV protection factor (UPF) values of fabrics were investigated. The coating films were characterized by Fourier Transform-Infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) analysis. Lignin/WPU coated SNFs showed excellent UV protection performance and UPF values were obtained above 100 for all formulations. Lignin/WPU coatings provided an improving effect on the tensile strength and abrasion resistance performances of coated SNFs compared to uncoated SNFs. This work provides a simple and efficient strategy for preparing environmentally friendly lignin/WPU coatings, which are promising for application in the textile industry.