Search Results (195)

Rosin- and castor-oil-derived resins provide a renewable platform for rapidly curable protective coatings, but the effects of formulation and curing route remain insufficiently resolved. Four composite formulations containing modified rosin glycerol ester (MRGE) and modified castor oil anhydride (MCOA) were cured thermally using ultraviolet irradiation or electron beam (EB) irradiation. Surface C=C conversion, thermal behavior, morphology, mechanical properties, neutral salt spray resistance, electrochemical barrier performance, and AC dielectric breakdown strength were evaluated. Among the formulations tested, F2 (MRGE/MCOA = 3:1) showed the best overall property balance under each curing route. For F2, EB curing produced a surface C=C conversion of 92 ± 2%, a glass transition temperature of 88 ± 1 °C, an 800 °C residue of 12.5 ± 0.3%, and an atomic force microscope (AFM) roughness Ra of 5.8 ± 0.5 nm. F2-EB exhibited 9H pencil hardness, 5B adhesion, an impact resistance of 55 ± 2 cm·kg, and a flexibility value of 1.0 ± 0.1 mm. After 500 h of neutral salt spray, both F2-EB and F2-UV achieved a protection rating of 10 with no measurable corrosion creep at the scribe; time-resolved photographs at 100, 300, and 500 h confirmed that F2-EB showed the least visible damage evolution among the three curing routes. After 1 day of immersion in 3.5 wt% NaCl, F2-EB exhibited the largest low-frequency impedance and the lowest fitted corrosion current density among the EB-cured formulations, indicating the strongest short-term electrolyte barrier behavior. The AC dielectric breakdown strength of F2-EB reached 21.5 ± 0.3 kV mm⁻¹. The combined results are consistent with more extensive EB-induced network formation, although direct measurements of through-thickness conversion and crosslink density are still required. These findings demonstrate the potential of EB curing for rapidly preparing rosin/castor-oil-derived protective coatings for electrical insulation applications. Full article

Developing durable multifunctional clothing with enhanced mechanical and comfort properties utilizing eco-friendly, cost-effective hybrid nano finishes is highly challenging. The reason behind the nondurable functionality is the lack of bonding ability of nanoparticles (NPs) with cotton fabric, and this additional coating has a great impact on the mechanical, thermo-physiological, and sensorial comfort properties of cotton fabric. Focusing on these issues, this paper attempts to develop biogenic chitosan-loaded CuO-SiO₂ hybrid nano finishes with three distinct formulations, namely Chi-CuO-SiO_2(5g/L), Chi-CuO-SiO_2(10g/L), and Chi-CuO-SiO_2(20g/L) hybrid nanofluids, to incorporate on cotton fabric by pad-dry-cure method. These hybrid nanofluids from biogenic Chi-CuO and rice husk SiO₂ NPs have been newly introduced for textile application. The NPs CuO and SiO₂ are synthesized from lemon peel zest extract and rice husk, respectively. Characterization of CuO NPs by Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDX), and X-ray diffractometers (XRD) evidences that spherical-shaped, amorphous, and 60–80 nm sized NPs are synthesized. The hydrodynamic performance of hybrid nanofluids measured by Zeta Sizer shows that the chitosan-loaded CuO-SiO_2(5g/L) hybrid nanofluid is the most stable among the three, and the value is +29.4 mV. The presence of CuO NPs, SiO₂ NPs, and chitosan on cotton fabric was confirmed by FTIR, FESEM, and EDX spectra of the hybrid nanofluid-deposited fabric. The cotton fabric coated with chitosan-loaded CuO-SiO₂ hybrid nanofluids exhibits better durable antimicrobial efficacy, UV-protective properties, and thermo-physiological comfort properties than that of the uncoated fabric. More specifically, CuO-SiO_2(20g/L)-coated fabric demonstrates approximately 99.99% bacterial efficacy against both gram-positive and gram-negative bacteria even after 15 washing cycles, and excellent UV-protective properties. In addition, CuO-SiO_2(5g/L)-coated fabric displays around 75% enhancement of overall moisture management properties and 1.22% and 0.53% enhancement of tensile strength in warp and weft directions with excellent elongation compared to the pristine one. Moreover, assessment of the mechanical sensorial comfort properties of this fabric depicts that it is smoother, and has better thermal conductivity than that of the control one. In addition, CuO-SiO_2(5g/L) hybrid nanofluid-treated cotton fabric exhibited cell viability above 95%, which confirms its non-cytotoxicity. The outcomes of this study suggest that chitosan-loaded CuO-SiO_2(5g/L) hybrid nanofluid-treated cotton fabric can be considered as optimum and employed as biomedical textiles with better mechanical and comfort properties. Full article

Urushiol, the main active compound in raw lacquer, is a catechol derivative with long alkyl side chains. Its use in traditional coatings has long been held back by slow enzymatic curing, UV sensitivity, and its own allergenicity. Over the past decade, greener ways to extract it have emerged—ultrasound- and microwave-assisted methods, plus vortex-assisted matrix solid-phase dispersion and ball-milling-enhanced microextraction. These approaches have been shown to recover urushiol efficiently, using less solvent and lowering operator risk. The catechol structure explains its many uses: fast-curing UV coatings that resist corrosion, antibacterial materials (both plain and metal-coordinated), superwetting surfaces for oil–water separation, and selective uptake of heavy metals and rare-earth ions. Early biomedical work also hints at its potential as a bioactive scaffold, drug carrier, or low-toxicity starting point. To balance performance and safety, multiple strategies have been proposed to reduce allergenicity: protecting the hydroxyl groups, modifying specific sites on the ring, and designing synthetic mimics. Still, a few bottlenecks are holding back industrial scale-up. These include large-scale green extraction, long-term material stability, and the lack of solid biocompatibility data. Future work needs to integrate three core research directions: high-throughput structure–activity–toxicity screening, cross-disciplinary molecular design, and life-cycle assessment. The integrated development of these three directions will facilitate the industrial transformation of urushiol-based materials from laboratory prototypes to high-value commercial products. This review summarizes and outlines a roadmap for green extraction, functional polymer applications, and the safe use of urushiol. Full article

Natural lacquer, a bio-based polymer derived from Toxicodendron vernicifluum, has attracted renewed scientific interest as a sustainable coating material with exceptional mechanical durability, chemical resistance, and aesthetic qualities. This review synthesizes current knowledge on the chemical composition, enzymatic curing mechanisms, and structure–property relationships of lacquer-based polymer systems, with particular focus on recent advances in functional modification and processing technology. Key findings indicate that laccase-catalyzed oxidative polymerization, operating optimally at pH 6.0–7.5 and 20–30 °C, governs the formation of a highly cross-linked urushiol network whose properties are fundamentally determined by side-chain unsaturation and emulsion stability. Mechanistic analysis reveals that polyurethane hybridization improves weathering resistance by introducing flexible aliphatic segments and additional hydrogen-bonding cross-links, while graphene oxide incorporation enhances anticorrosion performance through a physical barrier mechanism that prolongs ionic diffusion pathways. UV-curable LPEA derivatives achieve an 83% reduction in curing time relative to ambient-cured lacquer, enabling integration with industrial spray-coating lines. Despite these advances, several critical limitations remain inadequately resolved. Allergen reduction strategies have not yet achieved sufficient quantitative efficiency for large-scale commercial deployment, and the long-term stability of nanocomposite lacquer films under sustained UV exposure and hydrothermal conditions is not well established. Furthermore, most high-performance modification systems reported in the literature are demonstrated only on laboratory scale, with scalability, substrate compatibility, and lifecycle performance remaining largely unvalidated. The review identifies the absence of standardized performance evaluation protocols and the fragmentation of structure–property data across studies as key barriers to systematic progress, and proposes that future work prioritize the development of integrated processing–modification–performance frameworks to guide the rational design of next-generation lacquer-based functional materials. Full article

Driven by the high-end furniture industry’s demand for skin-tactile decorative boards, UV inkjet printing shows potential for wood-based surface finishing. Using primer-treated inkjet-printed melamine-faced panels, this study compared traditional UV varnish coatings with different thicknesses and UV curing intensities and 254 nm UV excimer-cured coatings with different radiant energies. Varnish thickness significantly affected surface roughness, 20° gloss, 85° gloss, and color difference, indicating a trade-off between matte tactile appearance and color fidelity. Thinner varnish coatings exhibited higher roughness and lower gloss but larger color differences, whereas thicker coatings better preserved color fidelity but resulted in higher gloss. For the UV excimer-cured system, one-way ANOVA showed significant treatment effects on acrylate conversion, water contact angle, 85° gloss, surface roughness, and abrasion mass loss. The coating prepared at an excimer radiant energy of 827.9 mJ/cm² showed the lowest 85° gloss of 5.28 GU and a pencil hardness of 3H, but also exhibited the highest abrasion mass loss in the short-cycle abrasion screening test. For both coating systems, three independently prepared specimens were tested for each processing condition. The UV varnish system was analyzed using two-way ANOVA, whereas the UV excimer-cured system was analyzed using one-way ANOVA. Friedman tests of sensory evaluation data showed significant differences among the eight selected samples for fineness, smoothness, and elasticity, with the excimer-cured coatings generally receiving higher fineness and smoothness scores than the UV varnish coatings. These results indicate that 254 nm UV excimer curing is a promising route for producing low-gloss, micro-wrinkle-induced skin-tactile surfaces on inkjet-printed melamine-faced panels, although optimization should balance tactile quality, gloss reduction, and abrasion resistance. Full article

Liquid electrolytes in conventional lithium-ion batteries pose safety risks associated with flammability, leakage, and explosion, whereas solid polymer electrolytes are generally limited by insufficient ionic conductivity at ambient temperature, restricting the development of high-energy lithium batteries. To address these issues, flexible poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based gel polymer electrolyte membranes (GPEs) were prepared via a slit-coating process combined with UV curing. NASICON-type lithium aluminum titanium phosphate (Li_1.3Al_0.3Ti_1.7P₃O₁₂, LATP) and garnet-type tantalum-doped lithium lanthanum zirconate (Li_6.4La₃Zr_1.4Ta_0.6O₁₂, LLZTO) were introduced as inorganic ceramic fillers to improve the ion-transport and interfacial properties of the GPE. Among the investigated samples, the PVDF-HFP-based GPE containing 10 wt% LLZTO exhibited the best overall performance, with an ionic conductivity of 3.40 × 10⁻⁴ S·cm⁻¹ at ambient temperature and a Li⁺ transference number of 0.77. Cyclic voltammetry results showed that the LLZTO-modified electrolyte membrane exhibited sharper and more symmetric redox peaks, higher peak current response, and better curve overlap during repeated cycles, indicating improved electrochemical reversibility and interfacial stability. In addition, LLZTO incorporation enhanced the mechanical strength, broadened the electrochemical stability window, and improved the flame-retardant behavior of the membrane. The LiFePO₄/GPE/Li cell assembled with the optimized membrane delivered an initial discharge capacity of 160 mAh·g⁻¹ at 0.1 C and maintained 80 mAh·g⁻¹ at 1 C, demonstrating good rate capability. Moreover, a capacity retention of 96% was maintained after 100 cycles at 0.1 C, confirming excellent cycling stability. Therefore, this work provides an effective strategy for the structural optimization and scalable preparation of high-performance gel polymer electrolyte membranes for lithium battery applications. Full article

Raw lacquer, a natural polymer derived from the bast of lacquer trees (Toxicodendron vernicifluum), is renowned as the “King of Coatings” due to its exceptional film-forming properties, abrasion resistance, corrosion resistance, and biocompatibility. However, its inherent limitations—including stringent drying conditions, slow curing rates, deep coloration, and difficult application—have severely restricted its modernization and widespread adoption. This review systematically summarizes recent research advances in the modification and application of raw lacquer, focusing on four major modification strategies: (1) Nanocomposite modification—incorporating functional nanofillers such as Al₂O₃, cellulose nanofibrils (CNF), polydopamine (PDA) melanin-like nanoparticles, and SiO₂ to significantly enhance film hardness, compactness, UV-aging resistance, and drying kinetics. (2) Chemical structure modification—employing molecular design strategies including aminoanthraquinone grafting, tung oil blending, water-based emulsification, and terpene/allyl group functionalization to improve hydrophobicity, flexibility, fast-drying properties, and achieve dual photo/oxygen curing. (3) Biomass synergistic composites—utilizing natural polymers such as chitosan and lignin, along with bio-inspired adhesion mechanisms (e.g., PDA), to confer advanced functionalities including antibacterial and antifouling properties. (4) Curing behavior regulation—precisely controlling drying kinetics through inorganic salt ion microenvironment engineering, nonionic surfactants, and salicylaldehyde Schiff base-based driers. Building upon these foundations, this review further expands on the emerging high-value applications of modified lacquer in preventive conservation of cultural heritage, advanced functional coatings (anti-corrosion, super-hydrophobicity, flame retardancy), biomedical materials (hemostasis, antibacterial activity, drug-controlled release, water treatment adsorption), and intelligent responsive flexible electronics. Finally, addressing challenges including weak fundamental research, bottlenecks in green industrialization, and lack of standardization, future development directions are proposed encompassing interdisciplinary innovation, sustainable modification strategies, integration of multifunctional intelligent systems, and big data-driven research paradigms, aiming to provide theoretical guidance and technical references for the high-value utilization and modernization of lacquer resources. Full article

The clinical reliability of swabs is affected by their ability to collect and elute biological samples for further detection. Since elution is particularly critical for swab functionality, the goal of this work was to develop a nasopharyngeal swab prototype that could potentially facilitate the release of biological specimens through controlled elastic deformation. To this end, a helical swab-head geometry was designed and 3D-printed by means of stereolithography (SLA). A dual post-curing process combining UV and thermal treatment was employed to maximize the mechanical stiffness of the resin—up to about 750 MPa. Microtomography of the 3D-printed prototypes demonstrated the accuracy of SLA printing, with only 0.12% closed porosity due to printing defects. The mechanical deformation of the prototype under compression was then investigated through numerical modeling and experimental analysis. The results of Finite Element (FE) simulations revealed stress localization in the upper coils, with global mechanical integrity. Experimental compression tests validated the predicted deformation behavior, as supported by video tracking and displacement analysis at multiple nodes, showing good agreement between numerical and experimental displacement. Furthermore, preliminary functional tests with P. aeruginosa and S. aureus, both in saline solution and artificial mucus, demonstrated that the swab-tip prototype per se, without any coating or any applied compression, could perform comparably to commercial cotton and flocked swabs. About a 2-log reduction in bacterial load was detected for all swabs compared to the inoculum when used in saline solution, while a bacterial load roughly matching the inoculum was found when the swabs were used in artificial mucus. Overall, these findings demonstrate the feasibility and the potential of the designed swab prototypes. Full article

Zinc oxide nanoparticles (ZnO NPs) exhibit strong and broad-spectrum antibacterial properties, making them a promising agent for textile applications. However, their weak adhesion to fibers and poor washing durability have hindered practical use. In this work, we report zinc/catechol resin-based microspheres (Zn/CFRs) synthesized via a one-pot hydrothermal route and applied to cotton fabric through a pad-dry-cure process. The resulting Zn/CFRs exhibit a monodisperse spherical morphology, with zinc ions concentrated on the surface and ZnO NPs encapsulated within the resin matrix. The finished fabric demonstrates potent, non-leaching antibacterial activity, achieving over 99.99% inhibition against S. aureus, E. coli, and C. albicans, with excellent performance retention even after 50 laundering cycles. Furthermore, we observed that catechol oxidation in the Zn/CFRs proceeds slowly under UV light, which may contribute to the durable adhesion of the coating. Moreover, the functional finishing does not compromise the fabric’s tensile strength, hand feel, or breathability, which positions it favorably for scalable adoption in functional textile manufacturing. Full article

In this study, a non-typical luminescent organosilicone was synthesized through a click reaction and used as a cross-linker to cure hydroxyl-terminated dimethylsilicone oil at room temperature via the sol–gel process, followed by application as a coating on a glass surface. This organosilicone film functions effectively as a luminescent down-shifting (LDS) material. Additionally, the presence of methyl groups and voids in the structure imparts a low refractive index, allowing it to serve as an anti-reflective (AR) layer. Optical and structural analyses on organosilicone-coated glass samples were conducted, and the dual-functional layer was applied to the glass cover of a perovskite solar panel to evaluate its performance. The coating not only enhanced light transmission as an AR layer but also converted UV light into blue light, which was absorbed by the solar cell. The results indicated improved solar panel performance, particularly in short-circuit current (Isc), external quantum efficiency (EQE) in the UV wavelength range, and overall efficiency. Overall, this material is a promising candidate for solar panel applications owing to maximized UV absorption for LDS, preserved transparency of the top cover glass, and room-temperature gelation, which facilitates repair of the dual-functional coating. Full article

Developing materials that simultaneously exhibit bulk elasticity and a durable, self-renewing surface is a persistent challenge, as traditional fillers often impair flexibility and sacrificial coatings fail under repeated strain. This paper presents an innovative thiol–ene/polyurethane hybrid system, fabricated via a sequential thermal–UV curing process, which decouples the properties of the highly elastic bulk from those of the robust surface layer. The resulting bulk elastomer achieves an outstanding combination of high strength (20.9 MPa) and exceptional extensibility (990% elongation at break). Crucially, the UV-crosslinked surface forms a dense, abrasion-resistant shield that reduces friction-induced mass loss by 81% compared to the bulk material. This surface layer also exhibits a unique self-renewing capability, effectively restoring its protective function over at least three abrasion cycles and reducing mass loss by 57% after the first recovery cycle relative to an unprotected control. Dynamic mechanical analysis validates the distinct dual-network structure, evidenced by two well-separated glass transition temperatures, which underpin the material’s pronounced shape memory effect. This work provides a design paradigm for creating flexible and durable polymer systems with independently tailored bulk and surface properties, offering significant potential for applications in artificial skin and demanding flexible components. Full article

Biofouling has a detrimental effect on marine infrastructure and poses a severe challenge to the global marine industry. Therefore, developing efficient and environmentally friendly anti-fouling coatings to protect those facilities has become extremely necessary nowadays. To address marine biofouling, a series of photocurable degradable waterborne boron-containing polyurethane acrylate (WPU-PTPBx) anti-fouling coatings were prepared by grafting pyridine-triphenylborane (PTPB) onto polyurethane side chains and UV curing. FTIR and ¹H NMR confirmed the successful grafting of PTPB. The WPU-PTPBx aqueous dispersions had a particle size of 30~75 nm with excellent thermal storage stability. DSC and XRD characterizations revealed the amorphous structure of the coatings, which favored biodegradation. All coatings exhibited adhesion strength over 2 MPa, meeting marine application requirements. Antibacterial and anti-algal tests showed that PTPB content positively correlated with anti-fouling performance: the coating achieved a 99.66% inhibition rate against Escherichia coli and reduced the adhesion density of Nitzschia closterium to only 36.9 cells/mm². With favorable degradability and outstanding anti-fouling performance, WPU-PTPBx coatings are promising green anti-fouling materials for marine applications. Full article

Optical plastics possess excellent optical and mechanical properties but are limited by poor surface hardness and scratch resistance. Herein, UV-curable organic–inorganic hybrid coatings were developed to enhance scratch resistance while maintaining high optical transparency. Nano-silica sols were prepared via tetraethoxysilane (TEOS) hydrolysis and surface modified with silane coupling agents (KH-560, KH-570, and KH-550) to improve their dispersion and interfacial reactivity in a polyurethane acrylate (PUA) matrix. The modified nano-silica was incorporated into a UV-curable PUA system to fabricate transparent composite coatings. The influences of nano-silica type and loading on hardness, flexibility, wettability, scratch resistance, and UV–visible transmittance were systematically evaluated. Modified nano-silica markedly improved pendulum hardness and scratch resistance, with hardness increasing by nearly 50%, while flexibility remained nearly unchanged. Although hydrophobicity and optical transmittance slightly decreased with increasing nano-silica content, the transmittance remained above 90% at 4 wt% loading. For KH-550 modified systems, strict pH control (pH 8.0) and ammonia removal were critical for sol stability. This work offers a feasible approach for fabricating scratch-resistant, transparent UV-curable coatings for optical plastics. Full article

Fluorine-free paper coatings with water- and oil-resistance properties have gained considerable attention for sustainable food packaging applications. In this study, a dual-layer coating based on chitosan (Chi) and acrylated epoxidized soybean oil (AESO), both derived from renewable and natural resources, was applied to kraft paper. The ultraviolet-cured AESO top layer formed a dense crosslinking network, while the Chi interlayer promoted strong interfacial adhesion with the kraft paper through hydrogen bonding, effectively restricting fluid penetration. The Chi/AESO₄₀/kraft paper showed markedly enhanced water repellency and oil resistance, with a reduced Cobb₆₀₀ value of 16 g m⁻² and kit rating of 12. Thermogravimetric analysis demonstrated improved thermal stability, and mechanical testing results revealed enhanced packaging-relevant strength, with the tensile strength increasing from 33 to 40 MPa and tensile index increasing from 45 to 60 kPa·m² g⁻¹; furthermore, the burst strength and index improved from 260 to 330 kPa and from 3.2 to 4.0 kPa·m² g⁻¹, respectively. Food contact tests conducted using French fries confirmed the effective barrier performance of the Chi/AESO/kraft paper, highlighting its potential for use in sustainable paper-based food packaging applications. Full article

Microcontact stamping is a promising microfabrication technique for producing functional patterned thin films on flexible substrates; however, systematic optimization of its process parameters for thermochromic applications remains limited. In this study, we present a comprehensive parametric optimization of the microcontact stamping process to fabricate thermochromic pigment-coated thin films with rapid and reversible color responses. The effects of liquid resin type, SU-8 mold thickness, polydimethylsiloxane (PDMS) mixing ratio, and pattern size on pattern fidelity and thermochromic performance were systematically investigated. The optimal conditions were identified as a UV-curable resin, a 600 µm-thick SU-8 mold, a PDMS base-to-curing-agent ratio of 5:1, and a pattern size of 125 × 125 µm². Under these conditions, the stamped thermochromic films exhibited uniform micro-patterns, rapid response and recovery behavior, and stable reversible color changes over 20 consecutive thermal cycles. This work provides practical guidelines for parameter-controlled microcontact stamping of functional thin films and demonstrates its potential for scalable fabrication of thermochromic micro-patterns. The proposed approach is expected to contribute to the development of flexible and wearable electronic devices, smart displays, and thermally responsive sensing platforms. Full article