UV-shielding Properties Research Articles

Innovative coating of cotton textile fabrics for integrating outstanding flame hazard safety, UV protection, tensile strength strengthening and antibacterial properties

A rational green synthesis method was developed to produce sustainable nanocoatings for cotton fabrics that are flame retardant, strengthened, antibacterial, and UV protective. The nanocoatings were created using silica nanoparticles with an average size of 73.2 nm derived from rice husk (RH-SNP). These nanoparticles were adorned with ZnONPs with an average size of 7.6 nm, which were reduced and capped with molokhia extract made from molokhia stems by-products. The ultimate nanocomposite was evenly distributed in a chitosan solution using ultrasonication. The mass ratio of RH-SNP in the nanocoating was adjusted and fine-tuned for optimization. The coated cotton fabrics were analyzed using spectroscopic and microscopic techniques. The flammability of cotton fabrics treated with sustainable coatings was assessed. The coated fabrics exhibited significantly greater flame retardancy, achieving a zero burning rate compared to 110 mm/min for the untreated one. The enhanced flame-retardant properties were a result of the combined flame-retardant effects of RH-SNP and molokhia stem extract, along with decorated ZnONPs, which created a more robust protective char layer. The coated cotton's antibacterial characteristics showed significant inhibition of bacterial growth, resulting in a 10 mm distinct inhibition zone, while pure cotton had no inhibition zone. Additionally, the coated cotton fabrics had exceptional UV shielding properties with a UPF rating of 167.8, which was more than fourth the value of the uncoated fabric. The tensile strength and elongation of the cotton fabrics were enhanced after applying a sustainable nanocoating, indicating a beneficial effect on tensile strength. Furthermore, the coated fabrics exhibited exceptional durability characteristics.

A Comparative Study of Cerium(III) and Cerium(IV) Phosphates for Sunscreens.

Crystalline cerium(III) phosphate (CePO4), cerium(IV) phosphates, and nanocrystalline ceria are considered to be promising components of sunscreen cosmetics. This paper reports on a study in which, for the first time, a quantitative comparative analysis was performed of the UV-shielding properties of CePO4, Ce(PO4)(HPO4)0.5(H2O)0.5, and CePO4/CeO2 composites. Both the sun protection factor and protection factor against UV-A radiation of the materials were determined. Ce(PO4)(HPO4)0.5(H2O)0.5 was shown to have a sun protection factor of 2.9, which is comparable with that of nanocrystalline ceria and three times higher than the sun protection factor of CePO4. Composites containing both cerium dioxide and CePO4 demonstrated higher sun protection factors (up to 1.8) than individual CePO4. When compared with the TiO2 Aeroxide P25 reference sample, cerium(III) and cerium(IV) phosphates demonstrated negligible photocatalytic activity. A cytotoxicity analysis performed using two mammalian cell lines, hMSc and NCTC L929, showed that CePO4, Ce(PO4)(HPO4)0.5(H2O)0.5, and nanocrystalline ceria were all non-toxic. The results of this comparative study indicate that cerium(IV) phosphate Ce(PO4)(HPO4)0.5(H2O)0.5 is more advantageous for use in sunscreens than either cerium(III) phosphate or CePO4/CeO2 composites, due to its improved UV-shielding properties and low photocatalytic activity.

A multifunctional biogenic films and coatings from synergistic aqueous dispersion of wood-derived suberin and cellulose nanofibers

Here, biogenic and multifunctional active food coatings and packaging with UV shielding and antimicrobial properties were structured from the aqueous dispersion of an industrial byproduct, suberin, which was stabilized with amphiphilic cellulose nanofibers (CNF). The dual-functioning CNF, synthesized in a deep eutectic solvent, functioned as an efficient suberin dispersant and reinforcing agent in the packaging design. The nanofibrillar percolation network of CNF provided a steric hindrance against the coalescence of the suberin particles. The low CNF dosage of 0.5 wt% resulted in dispersion with optimal viscosity (208.70 Pa.s), enhanced stability (instability index of <0.001), and reduced particle size (9.37 ± 2.43 μm). The dispersion of suberin and CNF was further converted into self-standing films with superior UV-blocking capability, good thermal stability, improved hydrophobicity (increase in water contact angle from 61° ± 0.15 to 83° ± 5.11), and antimicrobial properties against gram-negative bacteria. Finally, the synergistic bicomponent dispersions were demonstrated as fruit coatings for bananas and packaging for strawberries to promote their self-life. The coatings and packaging considerably mitigated fruit deterioration and improved their freshness by preventing moisture loss and microbial attack. This sustainable approach is expected to pave the way toward advanced, biogenic, and active food packaging based on widely available bioresources.

Swan-feathers inspired smart-responsive sustainable carboxymethyl cellulose/polyvinyl alcohol based food packaging film for robustly integrated Intelligent and Active Packaging

The integration of advanced packaging technology with innovative multifunctional bio-based materials emerges as a promising next-generation strategy to tackle two enduring challenges in food storage technology: food spoilage and counterfeiting. Inspired by the superhydrophobic properties of swan feathers, this study developed a smart-responsive, sustainable food packaging film called C-CPQ using carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA). The as-prepared C-CPQ film exhibited remarkable hydrophobicity and water-vapor barrier properties owing to its novel design featuring an asymmetric bionic feather-like barbed texture, representing significant advancements in CMC/PVA-based packaging materials. Additionally, C-CPQ exhibited satisfactory mechanical strength, biodegradability, and film-forming capabilities. Notably, incorporating quercetin（QR） endowed C-CPQ with exceptional pH-sensing, fluorescence, antioxidant, UV-shielding, and antibacterial properties, enabling intelligent and active food packaging. Consequently, C-CPQ exhibited UV-stimulated photochromic characteristics and fatigue-resistant food anti-counterfeiting capabilities while extending food shelf life to 5 days, surpassing conventional PE packaging by 2 days. Moreover, the integration of smartphones enabled highly sensitive, rapid, and real-time visual monitoring of food degradation under natural light. The findings of this study present promising outcomes under real-world conditions, serving as a framework for the development of sustainable, high-performance modern food packaging with comprehensive real-time visual freshness monitoring, anti-counterfeiting, and preservation functionalities.

A facile cellulose finishing strategy through in-situ growth of sliver-doped manganese dioxide assisted by amine-quinone for improving indoor living quality

Nowadays, various harmful indoor pollutants especially including bacteria and residual formaldehyde (HCHO) seriously threaten human health and reduce the quality of public life. Herein, a universal substrate-independence finishing approach for efficiently solving these hybrid indoor threats is demonstrated, in which amine-quinone network (AQN) was employed as reduction agent to guide in-situ growth of Ag@MnO2 particles, and also acted as an adhesion interlayer to firmly anchor nanoparticles onto diverse textiles, especially for cotton fabrics. In contrast with traditional hydrothermal or calcine methods, the highly reactive AQN ensures the efficient generation of functional nanoparticles under mild conditions without any additional catalysts. During the AQN-guided reduction, the doping of Ag atoms onto cellulose fiber surface optimized the crystallinity and oxygen vacancy of MnO2, providing cotton efficient antibacterial efficiency over 90 % after 30 min of contact, companying with encouraging UV-shielding and indoor HCHO purification properties. Besides, even after 30 cycles of standard washing, the Ag@MnO2-decorated textiles can effectively degrade HCHO while well-maintaining their inherent properties. In summary, the presented AQN-mediated strategy of efficiently guiding the deposition of functional particles on fibers has broad application prospects in the green and sustainable functionalization of textiles.

UV photo-degradation of the secondary lichen substance parietin: A multi-spectroscopic analysis in astrobiology perspective

The cortical anthraquinone yellow-orange pigment parietin is a secondary lichen substance providing UV-shielding properties that is produced by several lichen species. In our work, the secondary metabolite has been extracted from air-dried thalli of Xanthoria parietina. The aims of this study were to characterize parietin absorbance through UV–VIS spectrophotometry and with IR spectroscopy and to evaluate its photodegradability under UV radiation through in situ reflectance IR spectroscopy to understand to what extent the substance may have a photoprotective role. This allows us to relate parietin photo-degradability to the lichen UV tolerance in its natural terrestrial habitat and in extreme environments relevant for astrobiology such as Mars. Extracted crystals were UV irradiated for 5.59 h under N2 flux. After the UV irradiation, we assessed relevant degradations in the 1614, 1227, 1202, 1160 and 755 cm−1 bands. However, in light of Xanthoria parietina survivability in extreme conditions such as space- and Mars-simulated ones, we highlight parietin UV photo-resistance and its relevance for astrobiology as photo-protective substance and possible bio-hint.

Enhancement in antimicrobial efficacy and biodegradation of natural rubber latex through graphene oxide/nickel oxide nanoparticles

This work aims to fabricate antibacterial natural rubber latex composites by introducing different ratios of graphene oxide (GO) and nickel oxide (NiO) nanoparticles. The nanocomposites were prepared using latex mixing and a two-roll mill process, followed by molding with a heating hydraulic press. Detailed analyses were conducted to evaluate the rheological, chemical, physical, thermal, mechanical, and electrical performance of the composites. Fourier transform infrared spectroscopy (FTIR) was employed to analyze the interaction among different components, while the surface morphology was examined through the field emission scanning electron microscopy (FESEM) technique. The composites with a loading ratio of 1:2 of GO to NiO (optimized concentration) exhibited the highest tensile strength (24.9 MPa) and tear strength (47.4 N/ mm) among all the tested samples. In addition, the composites demonstrated notable antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. The thermal stability of the composites was observed up to 315 °C, and their electrical resistivity lies in the insulating range across a temperature span of 25 °C to 50 °C. The research uncovers critical insights into advancing composite materials suitable for diverse applications, featuring inherent antibacterial attributes, robust mechanical properties, resilience to solvent, UV shielding properties, and controlled electrical resistivity capabilities.

Preparation of strong, UV-blocking and sustainable glucose-cross-linked cellulose plastics via hydroxyl-yne click reaction

The construction of functional cellulose plastics possessing strong UV-blocking, hydrophilicity, and biodegradability is challenging. Therefore, we provide a novel strategy to successfully prepare sustainable and hydrophilic glucose-cross-linked cellulose (GC) plastics showing effective UV-blocking and excellent mechanical properties via hydroxyl-yne click reaction at room temperature. The results demonstrated that hydroxyl-yne click chemistry enabled efficient crosslinking of cellulose with glucose using 4-dimethylamino pyridine (DMAP) as a catalyst. Moreover, the DMAP residue imparted good UV-shielding properties to GC films exhibiting nearly 100 % UVC (200–275 nm) and 100 % UVB (320–275 nm) shielding ratios. The introduction of glucose imparted superior hydrophilicity (water contact angle of 40.3–43.2°) and improved water adsorption. Additionally, the mechanical properties of the GC films increased with the increasing crosslinking density, and the highest tensile stress was 94 MPa. The water-induced breaking and hydrogen bond reforming strategy led to a stress of 127 MPa and a strain of 25.6 % for the final GC2 film, which were excellent compared to those of the most reported cellulose films. Additionally, GC films were biosafe, exhibited improved oxygen barrier, and good biodegradability. Hence, this study provides a promising and efficient approach for preparing high-performance cellulose plastics.

Konjac glucomannan-based nanocomposite spray coating with antimicrobial, gas barrier, UV blocking, and antioxidation for bananas preservation

Fruit is prone to rot and deterioration due to oxidative browning and microbial infection during storage, which can cause serious economic losses and food safety problems. It is urgent to develop a multifunctional composite coating to extend the shelf life of fruits. In this work, multifunctional quaternized chitosan nanoparticles (QCs/TA NPs) with excellent antibacterial and antioxidant properties were prepared based on electrostatic interaction using tannic acid instead of conventional cross-linking agents. Meanwhile, konjac glucomannan (KGM) with high viscosity, edible and biodegradable properties was used as a dispersant to disperse and stabilize the nanoparticles, and as a film-forming agent to form a multifunctional composite coating. The composite coating exhibited excellent oxygen and water vapor barrier properties, antioxidant, antibacterial, mechanical properties, hydrophobicity, and UV shielding properties. Surprisingly, the oxygen permeability of the K-NPs-15 composite film was as low as 1.93 × 10−13 (cm3·cm)/(cm2·s·Pa). The banana spray preservation experiments proved that the K-NPs-15 composite coating could effectively prolong the shelf life of bananas. Therefore, this study provides a new idea for designing multifunctional freshness preservation coatings, which has a broad application prospect.

Ultraviolet shielding composites of different cellulose/aramid nanofibers

In order to improve the UV shielding properties of cellulose nanofibers (CNF), aramid nanofibers (ANF) are used as additives. For composite preparation, three distinct CNFs are used in this work: ionic liquid mediated hydrolyzed (ILCNF), high-speed mechanically sheared (MCNF), and TEMPO-mediated oxidized (TCNF) to identify the effect of surface functionality and morphology on the composite properties. The performance of the prepared composites is compared by evaluating their UV shielding and mechanical properties. Due to the maximum (7.9 nm) and minimum (3.5 nm) average fibre diameters, respectively, pristine MCNF had minimum transparency and TCNF had maximum transparency. 5 wt% ANF - TCNF composite had maximum UV-250 and UV-300 nm shielding ratios of 74.6 and 93.7%, respectively. For the same composite, an enhancement in tensile strength of 117% is also noted. According to these findings, TCNF composite with 5% ANF has excellent UV shielding, superior transparency in the visible light region, and outstanding mechanical strength.

Flexible cellulose nanofibers/MXene composite films for UV-shielding packaging

Cellulose nanofibers (CNF) based films are promising packaging materials, but the lack of special functions (especially UV-shielding property) usually restrict their further applications. In this work, MXene was incorporated into the CNF film by a direct solvent volatilization induced film forming method to study its UV-shielding property for the first time, which avoided the using of a vacuum filtration equipment. The composite films containing glycerin could be folded repeatedly without breaking, showing good flexibility. The structure and properties of MXene/CNF composite films (CMF) were characterized systematically. The results showed that MXene distributed uniformly in the CNF film matrix and there was strong hydrogen bonding interaction between CNF and MXene. The tensile strength and Young's modulus of the composite films could reach 117.5 MPa and 2.23 GPa, which was 54.1 % and 59.2 % higher than those of pure CNF film, respectively. With the increase of MXene content, both the UVA and UVB shielding percentages increased significantly from 17.2 % and 25.5 % to 100.0 %, showing excellent UV-shielding property. Moreover, CMF exhibited a low oxygen permeability (OP) value of 0.39 cc μm d−1 m−2 kPa−1, a low water vapor permeability (WVP) value of 5.13 × 10−11 g−1s−1Pa−1 and a high antibacterial rate against E. coli (94.1 % at 24 h), showing potential application in the packaging field.

Konjac glucomannan/polyvinyl alcohol/citric acid–based active food-packaging films containing Polygonatum sibiricum polysaccharide

Biodegradable active packaging has recently attracted attention owing to its ability to solve environmental and food safety problems associated with traditional petroleum-based packaging. Herein, novel active food-packaging films were prepared using konjac glucomannan (KGM)/polyvinyl alcohol (PVA)/citric acid (CA) composites containing Polygonatum sibiricum polysaccharide (PSP) as the active agent. The effects of various PSP contents on the structure, physical properties and functionality of the composite films were investigated. Fourier transform infrared spectroscopy and scanning electron microscopy results revealed that hydrogen bonding within the films strengthened with increasing PSP content. X-ray diffraction results revealed that the addition of PSP improved the crystallinity of the composite films, and the tensile strength of the composite films reached the optimum when the PSP content is 0.2 %. Furthermore, at low contents (≤0.2 %), PSP was uniformly distributed in the composite films and exhibited good barrier, UV-shielding and antimicrobial properties. All composite films exhibited good antioxidant performance.The best sample (the composite film containing 0.2 % PSP) was successfully used for packaging strawberries; this film reduced the weight loss and extended the shelf life of strawberries. Thus, the fabricated films containing PSP have broad application prospects in food packaging.

Preparing strong, tough, and high-barrier biobased polyester composites by regulating interfaces of carbon nanotubes

Carbon nanotubes (CNTs) have been regarded as ideal functional fillers for enhancing superior mechanical properties of polymer composites. However, the performances of CNTs-based composites are well below the theoretical values, due to the poor dispersion of inert CNTs and weak interfacial interaction with the polymer matrix. Herein, “hydrothermal and in-situ growth” approach is induced to synthesize multiscale TiO2@CNTs functional fillers. Such the TiO2@CNTs show excellent dispersibility and strong interfacial bonding with matrix. The biobased TiO2@CNTs/poly (ethylene furandicarboxylate) (TCP) composite films are prepared via loading a small amount (0.05–0.2 wt%) of TiO2@CNTs. When the mass content of fillers is 0.2 wt%, TCP composite film exhibits the optimal of strength (80 MPa), Young's modulus (4.12 GPa), and toughness (1.2 MJ/m3). Moreover, the presence of TiO2 nanoparticles endow the films with excellent oxygen barrier and UV-shielding properties. We believe these composite films promise a spread application potential in high-performance food packing materials.

Photoluminescent Transparent Wood with Excellent UV-Shielding Function.

At present, light transmission, energy saving, environmental protection, and UV-shielding materials are very important for optimizing indoor living environment. Here, a fluorescent transparent wood (FTW) with UV-shielding function was prepared by encapsulating a carbon quantum dot and epoxy resin into a delignification wood template. FTW exhibits excellent optical transmittance (about 91%), water absorption stability (weight gain rate less than 9%), longitudinal tensile strength (139 MPa), and UV-shielding properties. Due to the photoluminescence characteristics of the carbon quantum dot and the natural cellulose skeleton of wood, FTW can show uniform luminescence under ultraviolet lamps. At the same time, it has remarkable UV-shielding performance. This kind of photoluminescent transparent wood with a UV-shielding function also has the potential to be applied to fields such as electromagnetic shielding and harmful gas detection.

Modified cellulose nanocrystals enhanced polycaprolactone multifunctional films with barrier, UV-blocking and antimicrobial properties for food packaging

The packaging industry demands improved eco-friendly materials with new and enhanced properties. In this context, bio-nanocomposite films with antimicrobial and UV-shielding properties based on modified cellulose nanocrystals/polycaprolactone (MCNC/PCL) were fabricated via solution casting method, and then food packaging simulation was carried out. CNCs were obtained by acid hydrolysis followed by successful functionalization with Quaternary ammonium surfactant, confirmed by FTIR, XPS, XRD, TEM, and DLS analyses. Furthermore, the morphological, physical, antibacterial, and food packaging properties of all prepared films were investigated. Results showed that the mechanical, UV blocking, barrier properties, and antibacterial activity of all composite films were remarkably improved. Particularly, the addition of 3 wt% MCNC increased the tensile strength and elongation at break by 27.5 % and 20.0 %, respectively. Moreover, the permeability of O2, CO2, and water vapor dramatically reduced by 97.6 %, 96.7 %, and 49.8% compared to the Neat PCL. Further, the UV-blocking properties of the composite films were significantly improved. The antimicrobial properties of MCNC/PCL films showed good antimicrobial properties against S. aureus. Finally, cherry packaged with 1 and 3 wt% MCNC films exhibited satisfactory freshness after 22 days of preservation. Overall, the fabricated PCL nanocomposite films can be utilized in the food packaging industry.

Environment-friendly, high-performance cellulose nanofiber-vanillin epoxy nanocomposite with excellent mechanical, thermal insulation and UV shielding properties

With the increased demand for biobased epoxy thermosets as an alternative to petroleum-based materials in various fields, developing environment-friendly and high-performance natural fiber-biobased epoxy nanocomposites is crucial for industrial applications. Herein, an environment-friendly nanocomposite is reported by introducing cellulose nanofiber (CNF) in situ interaction with lignin-derived vanillin epoxy (VE) monomer and 4, 4´-diaminodiphenyl methane (DDM) hardener that serves as a multifunctional platform. The CNF-VE nanocomposite is fabricated by simply dispersing the CNF suspension to the VE and DDM hardener solution through the in-situ reaction, and its mechanical properties and thermal insulation behavior, wettability, chemical resistance, and optical properties are evaluated with the CNF weight percent variation. The well-dispersed CNF-VE nanocomposite exhibited high tensile strength (∼127.78 ± 3.99 MPa) and strain-at-break (∼16.49 ± 0.61 %), haziness (∼50 %) and UV-shielding properties. The in situ loading of CNF forms covalent crosslinking with the VE and favors improving the mechanical properties along with the homogeneous dispersion of CNF. The CNF-VE nanocomposite also shows lower thermal conductivity (0.26 Wm−1K−1) than glass. The environment-friendly and high-performance nanocomposite provides multiple platforms and can be used for building materials.

Quaternized chitosan-based organic-inorganic nanohybrid nanoparticles loaded with prothioconazole for efficient management of fungal diseases with minimal environmental impact

Poor foliar deposition and retention of pesticides results in serious pesticide residues and environmental pollution. Organic-inorganic hybridized nanoparticles (OIHN), combining the advantages of organic and inorganic materials, can be used as carriers to load pesticides for efficient and safe application. Herein, a novel multifunctional OIHN composed of mesoporous silica nanoparticles (MSNs) and cationic chitosan quaternary ammonium salt (HACC) was constructed and used as a delivery system for prothioconazole (PTC). The resultant PTC@MSNs-HACC exhibited a remarkable loading capacity of 39.07 wt% and demonstrated enhanced PTC release (31.47 %) under alkaline conditions. The UV-shielding properties of MSNs efficiently shielded PTC from photodegradation, increasing its photostability by over threefold. The strong positive charge of HACC conferred excellent adhesion of PTC@MSNs-HACC to fungal cell membranes, leading to high deposition on wheat leaves with improved rain-wash resistance (increased by 30 %). Consequently, PTC@MSNs-HACC (EC50: 12.48 mg/L) exhibited superior wheat scab control compared to PTC emulsifiable concentrate (EC50: 28.49 mg/L). Additionally, PTC@MSNs-HACC displayed excellent uptake and transport in plants, ensuring plant safety and reducing toxicity to zebrafish by >1-fold. The potential application of the developed PTC@MSNs-HACC in agricultural production holds significant promise and is anticipated to find widespread use in the future.

Exploring g-C3N4 as a green additive for biodegradable poly(butylene adipate-co-terephthalate) film with enhanced UV shielding and mechanical properties.

Typical small organic dyes exhibit excellent UV absorption capabilities and are commonly used as additives to shield plastic films from photoaging. However, their tendency to decompose easily and migrate rapidly within a polymer matrix limits their service life. Herein we prepared g-C3N4 nanosheets and fabricated g-C3N4/PBAT films to investigate the effects of g-C3N4 on UV shielding and plasticizing of a biodegradable PBAT film. Photophysical characterizations revealed that an improved UV light barrier performance was achieved on g-C3N4/PBAT films compared to pure PBAT. Furthermore, the photoaging results show that g-C3N4 can stably exist in the PBAT matrix, enabling the aged g-C3N4/PBAT films to maintain their effective UV shielding ability, whereas the aged benzophenone (UV-0)/PBAT film shows a substantial decrease in UV light absorption due to the photodecomposition of UV-0. Additionally, g-C3N4 acted as a reinforcing material for PBAT, as evidenced by the approximately 1.5-fold increase in longitudinal tear strength and 1.6-fold increase in tensile strength of g-C3N4/PBAT films compared to pure PBAT. Remarkably, even after 100 hours of photoaging, the aged g-C3N4/PBAT films retained their favorable mechanical properties. This study highlights the potential of g-C3N4 as a new type of UV shield additive for future practical applications in protecting biodegradable plastic from photoaging.

High UV shielding and mechanical properties of shellac composite film for fruit packaging

We developed simple methods to prepare shellac composite films/coating with practical application value.

Thin multifunctional coatings for textiles based on the layer-by-layer application of polyaromatic hybrid nanoparticles

Multifunctional textile coatings were developed using biobased nanoparticles from lignin and fatty acids, achieving significant water repellency, breathability, UV-shielding, and antibacterial properties, while remaining eco-friendly and durable.