Search Results (1,925)

The development of lightweight multifunctional materials integrating electromagnetic interference (EMI) shielding, Joule heating and flame retardancy is highly demanded for advanced electronics and aerospace systems. Herein, we fabricate graphene/Fe₃O₄@hollow glass microsphere (G/Fe₃O₄@HGM) composite foam with an ultralow density of 0.36 g/cm⁻³. The porous structure synergizes graphene’s conductivity, Fe₃O₄’s magnetism and HGM’s low thermal conductivity to optimize impedance matching. The foam delivers absorption-dominated EMI shielding with a maximum X-band shielding effectiveness (SE) of 60.1 dB and an average absorption coefficient of 0.56, which effectively suppresses secondary electromagnetic reflection pollution. The composite exhibits stable voltage-controllable Joule heating: the 25 wt% Fe₃O₄@HGM sample reaches 91.3 °C at 16 V, enabling rapid de-icing within 200 s and stable thermal maintenance at −20 °C. Flame tests confirm no combustion or structural collapse under open flame. This work provides a simple fabrication strategy for lightweight multifunctional materials applicable to aerospace stealth, electronic thermal management and anti-icing systems. Full article

The fastest growing waste stream worldwide is represented by Waste from Electrical and Electronic Equipment (WEEE). One of the main critical issues related to the recovery of such waste is the mixed plastic fraction, which is difficult to sort and can contain flame retardants and additives that pose a risk to human health and the environment. This study aims to validate the possibility of using tribo-electrostatic separator technologies to sort plastic polymers (e.g., PP, PA6, PS and PVC) obtained after a size-reduction operation of WEEE. The experimental study was conducted on a 10 kg/h laboratory-scale pilot plant. Several parameters were analysed during the tribo-charging and electrostatic separation processes, including the rotation speed and residence time of the particles in the tribo-charging device as well as electrode voltage, and the distance between the deflectors and the electrodes in the electrostatic separator. The results show that the tribo-electrostatic separation technologies are promising and efficient for plastic waste recycling. In fact, under specific conditions, it is possible to achieve high recovery rates (>70%) and purity levels (>76%) that allow the reintegration of plastic polymers into the economic cycle as a secondary raw material. Full article

Dry eye disease (DED) is a complex ocular surface disorder characterized by tear film instability, discomfort, hyperosmolarity, inflammation, and neurosensory dysfunction. Since individuals spend a significant amount of time inside buildings, exposure to indoor environments has emerged as a noteworthy and adjustable factor influencing ocular surface disorders. This analysis consolidates recent findings connecting indoor air contaminants, such as particulate pollutants, volatile organic substances, formaldehyde, and other gaseous irritants, as well as tobacco and cooking fumes, heavy metals, organophosphate flame retardants, and liquid crystal compounds, with the mechanisms and symptoms associated with DED. Research suggests that indoor environmental factors can exacerbate DED by triggering interconnected mechanisms such as oxidative damage, inflammation, lipid degradation, meibomian gland issues, decreased tear production, impairment of goblet cells and the mucin layer, disruption of tight junctions, and damage to the corneal or conjunctival epithelium. The most robust clinical evidence currently pertains to tobacco smoke, particulate matter, indoor air pollution, low humidity, and poor ventilation. In contrast, although biological plausibility exists for heavy metals, flame retardants, and liquid crystal monomers, the supporting data remain relatively sparse, indirect, and less comprehensive. Harmonized exposure assessments, prospective cohort studies, analyses of pollutant mixtures, and experimental intervention trials are needed to better characterize dose–response relationships and to establish effective preventive measures. Assessment of environmental history and improvement of indoor air quality should be regarded as integral and interrelated components in the prevention and management of DED. Full article

Polyphenylene sulfide (PPS) is a high-performance thermoplastic engineering material known for its excellent chemical resistance, thermal stability, and flame retardancy. In this work, the interfacial mechanical behavior of short-cut Kevlar fiber-reinforced PPS composites was systematically investigated by all-atom molecular dynamics (MD) simulations. By constructing a full-atom interface model between an amorphous PPS matrix and a Kevlar crystal, interfacial normal tension and tangential shear simulations were performed to reveal the mechanisms of load transfer, damage initiation, and damage evolution at the molecular scale. The results show that the interfacial normal tensile strength (approximately 245 MPa) is lower than the bulk tensile strength of pure PPS (approximately 270 MPa), which is attributed to the stiffness mismatch at the interface induced by the high modulus of Kevlar fibers, promoting the preferential initiation and propagation of voids near the geometrical interface. The tangential shear process exhibits pronounced stick-slip characteristics, with the interfacial binding energy fluctuating periodically with shear displacement, corresponding to the alternating establishment and rupture of non-bonded interactions between molecular chains. This study provides a theoretical basis for the micromechanical design of high-performance thermoplastic composite interfaces and identifies molecular-level optimization directions for future interfacial modification strategies of Kevlar/PPS systems. Full article

Li-ion batteries (LIBs) are seeing increasingly widespread adoption across consumer electronics, electric vehicles, and grid-scale energy storage systems, yet their susceptibility to thermal runaway remains a concern. This study evaluates ethoxy (pentafluoro) cyclotriphosphazene (PFPN) as an electrolyte additive to reduce electrolyte flammability and thermal stability without significantly compromising electrochemical performance. Electrolyte flammability was quantified using self-extinguishing time (SET) measurements, which revealed that PFPN significantly suppresses combustion. At 4 wt% PFPN, 60% of electrolyte samples failed to ignite despite extended ignition exposure, and the average SET decreased from 51.15 s g⁻¹ to 34.60 s g⁻¹. Differential scanning calorimetry (DSC) further demonstrated improved thermal stability, with the onset of solvent decomposition delayed by ~30 °C at 4 wt% PFPN. Ionic conductivity modestly decreases (14%, from 8.13 to 6.97 mS cm⁻¹ at 4 wt% PFPN). Electrochemical testing showed negligible impact on battery performance. Graphite||Li and NMC811||Li half-cells containing PFPN exhibited comparable capacity retention to baseline cells. NMC811||graphite pouch cells were used to further evaluate extended cycling and rate capability; PFPN-containing cells demonstrated similar capacities even after prolonged cycling and high-rate operation. Overall, PFPN provides effective flame retardance at 4 wt% while maintaining electrochemical compatibility, making it a promising additive for enhancing thermal stability of LIB electrolytes. Full article

Phenolic panels are widely used in applications requiring stringent fire resistance due to their advantages of flame retardancy, heat resistance, low smoke emission, and low toxicity. However, traditional products are prone to powdering and slagging under high temperatures or open flames, leading to structural failure and limiting their use in high-end applications. Currently, there is a lack of comprehensive research summaries and recommendations addressing the critical failure mode known as “carbonization.” This is a review of research progress in this field: first, it analyzes the thermal degradation mechanisms underlying powdering; then, it summarizes key strategies for enhancing anti-powdering performance from two broad categories: chemical strategies (resin modification and flame retardant systems) and physical strategies (interface design and process optimization); next, it outlines relevant characterization methods; finally, it discusses future development trends, aiming to provide a concise reference for related research and development efforts. Full article

Improving the flame-retardant performance of asphalt is particularly important for tunnel pavements, where confined environments can intensify fire hazards and smoke accumulation. This study prepared different modified asphalt binders to investigate their flame-retardant performance and rheological properties. The limiting oxygen index and smoke density rating were first used to evaluate the flame-retardant and smoke-suppression performance. Frequency sweep tests were then conducted to analyze the rheological behavior, aging characteristics, and low-temperature cracking resistance of the binders. Finally, microscopic tests were performed to reveal the thermal decomposition behavior and modification mechanism. Results showed that the incorporation of FR02 increased the limiting oxygen index of the warm-mix modified binders by more than 47%. Among the investigated binders, 13% fast-melting warm-mix flame-retardant composite modifier (SBS-WZ) exhibited the highest limiting oxygen index of 30.95% and the lowest smoke density rating of 57.73, indicating the best experimentally measured flame-retardant and smoke-suppression performance. At a reduced frequency of approximately 10⁻² rad/s, the unaged 13%SBS-WZ binder exhibited a complex modulus of approximately 2.0 × 10⁵ Pa, nearly one order of magnitude higher than those of the conventional 4%SBS- and 4%fast-melting SBS modifier (SBS-T), while its phase angle was approximately 6–10° lower. At −24 °C, the creep stiffness and creep rate of the unaged 13%SBS-WZ binder were approximately 654 MPa and 0.246, respectively. After Pressure Aging Vessel (PAV) ageing, these values changed to approximately 720 MPa and 0.237. Moreover, the onset decomposition temperature of 13%SBS-WZ was 392.1 °C, which was 17.2 °C higher than that of 4%SBS-T. Together with its higher residual mass, this result suggests enhanced thermal stability and residue-forming potential, which may partly explain the measured improvements in flame-retardant and smoke-suppression performance. However, the increased complex modulus and reduced creep rate indicate a concurrent loss of low-temperature flexibility. The findings can provide theoretical guidance and technical support for the application of this material in tunnel asphalt pavements. Full article

As a commonly present organophosphorus flame retardant and persistent organic pollutant, 2-ethylhexyl diphenyl phosphate (EHDPP) has been observed to be genotoxic in cultured human hepatoma (HepG2) cells which depends on CYP activities. Yet, its impacts on hepatic Cyp expression, hepatotoxicity and genotoxicity in intact mammalians remain unidentified. In this study, adult male C57BL/6J mice received EHDPP by gastric gavage at doses of 50, 100, and 150 mg/kg (b.w.)/d for 7 d, then the hepatic expression of several Cyp proteins, aryl hydrocarbon receptor (AhR) and pregnane X receptor (PXR) was analyzed by Western blotting; hepatoxicity was determined by serum ALT/AST activities and hepatic histological examination, while genotoxicity by comet assay, phosphorylated histone (γ-H2AX) protein, micronucleus test, and Pig-a assay. A micronucleus test in mouse hepatoma (Hepa1-6) cells in vitro was employed to observe the modulating effect of PCB 126 (100 nM)/BAY-218 (700 nM) (Ahr-Cyp1a1 activator/inhibitor). The results indicated that EHDPP induced hepatic Cyp1a1, 2e1, AhR, Cyp1a2, Cyp3a4 and PXR proteins and histologic liver damage at 50 mg/kg/d and/or higher doses, while at the highest dose (150 mg/kg/d) with hepatic DNA damage and micronucleus formation in bone marrow polychromatic erythrocytes. The result of Pig-a assay (at 14 and 28 d) was negative. In Hepa1-6 cells EHDPP induced micronucleus marginally; however, this effect was enhanced by PCB 126, while abolished by BAY-218. This study suggests that EHDPP may enhance protein expression of hepatic Cyp1a1, Cyp2e1, AhR and PXR and induce liver damage and DNA/chromosome damage in mice; Cyp1a1 might be a major activating enzyme. Full article

This study investigates the reaction of charred wood cladding systems to fire, focusing on the influence of wood species, charred surface treatment, flame retardant treatment, surface coating and board orientation. Nine different configurations of larch and spruce cladding samples with 20 mm thickness were investigated, which were installed into the system according to standard requirements. The samples differed by wood type, charred surface treatment, board orientation, covering with flame retardant agents and additional surface coverings. Two commercial flame retardant treatments and three commercial surface coatings were included in the experimental matrix. Fire behaviour was evaluated according to the EN 13823 Single Burning Item (SBI) method, analysing the ignition time, fire growth rate index, total heat release from the specimen in the first 600 s of exposure to the main burner flames, smoke growth rate index and total smoke production from the specimen in the first 600 s of exposure to the main burner flames as indicators. Although it was determined that the ignition time fluctuated in a relatively narrow range (from 5 min 12 s to 5 min 36 s), analyses of the additional SBI indicators revealed much clearer differences between the systems. The best results were obtained for the charred notched spruce system treated with the phosphate-, urea- and biocide-based flame retardant, which had the longest ignition time and lowest values for the investigated indicators. Meanwhile, the least favourable behaviour was observed in the notched untreated spruce system and in the horizontally oriented system, marked by higher fire spreading and smoke formation values. The obtained results show that the reaction of a wood cladding system to fire is not determined only by the type or application rate of flame retardant, but also the whole system’s structure, including the wood type, surface processing, covering combination and installation configuration. Full article

Adhesive technologies have expanded rapidly and are now widely employed across diverse industrial sectors. However, conventional wood adhesives emit substantial amounts of formaldehyde and rely on fossil-derived feedstocks, posing risks to human health and the environment. Developing sustainable, multi-functional bio-based adhesives has therefore become increasingly important. As a renewable, environmentally friendly, bio-based material, soy protein shows strong potential to replace formaldehyde-based adhesives in plywood. This review summarizes the molecular structure, bonding mechanisms, and recent advances in functional soy protein adhesives. Topics include bonding strength, water resistance, anti-mold and antibacterial performance, flame retardancy, and electromagnetic shielding. The review discusses theoretical foundations and application prospects for green adhesives and outlines opportunities to design and fabricate high-value, multi-functional bio-based composites. Full article

Numerous previous investigations have exploited single-component aluminum hydroxide, silica, or phosphorus-containing organic agents to improve the fire resistance of epoxy resin. Existing literature confirms that ATH relies on endothermic dehydration and inorganic barrier layers to suppress combustion, while phosphorus organics exert radical quenching effects in the gas phase. However, separate use of these fillers generally requires high loading to achieve satisfactory flame retardancy, which inevitably weakens the mechanical properties of the epoxy matrix; few studies integrate N, P, and Si elements into ATH via chemical grafting to realize synergistic flame retardancy at low filler dosage, and the dual heat-transfer regulation effect of formed SiO₂-Al₂O₃ inorganic residues has rarely been systematically discussed in prior reports. This study presents an organic–inorganic hybrid flame retardant, SPDP-PTMS@ATH, synthesized by grafting N,P,Si-containing organic groups onto Al(OH)₃. The modified ATH retained its layered structure, as confirmed by FTIR, XPS, SEM, and XRD. At only 5 wt.% loading in epoxy, the additive significantly enhanced flame retardancy and smoke suppression: LOI increased to 33.5% (34% higher than pure EP), UL-94 reached V-0 rating, and peak HRR, THR, COPR, TSR, CO2PR, and SPR are reduced by 30.2%, 30.8%, 33.1%, 26.9%, 25.86%, and 15%, respectively. Char analysis revealed a denser, more graphitized structure with fewer defects. Moreover, tensile strength and elongation at break improved by 22.0% and 47.5%, respectively. This work demonstrates that low-loading SPDP-PTMS@ATH simultaneously boosts fire safety, smoke suppression, and mechanical performance, offering a cost-effective and sustainable route to high-performance epoxy composites. Full article

Vinyl acetate–ethylene copolymer emulsion (VAE) adhesives are widely used in formaldehyde-free wood-based panels and coating systems, but their inherent flammability limits broader application in fire-safety-demanding fields. In this work, fly ash (FA), an industrial solid waste rich in Si- and Al-containing inorganic components, was introduced into a conventional ammonium polyphosphate/melamine/pentaerythritol (APP/MEL/PER) intumescent flame-retardant (IFR) system to prepare flame-retardant VAE emulsion adhesives. The results showed that the incorporation of IFR effectively improved the flame retardancy of VAE, while FA further enhanced the condensed-phase protective effect. The limiting oxygen index (LOI) of VAE/IFR/FA increased to 28.5% from 18.3% for neat VAE, and the sample achieved a UL-94 V-0 rating. Cone calorimetry results showed that the peak heat release rate and total heat release were significantly reduced after flame-retardant modification, accompanied by an increase in residual char. The VAE/IFR/FA sample exhibited the highest char residue and the lowest total smoke production, indicating the positive role of FA in promoting char formation and smoke suppression. The addition of KH403 further regulated the combustion behavior, mainly improving early-stage heat release suppression and fire performance index rather than increasing the final char yield. The KH403-containing formulation also showed improved tensile properties and plywood bonding strength, indicating its potential as a flame-retardant adhesive for wood-based panels. The KH403-containing formulation also showed improved tensile properties and plywood bonding strength, indicating its potential as a flame-retardant adhesive for wood-based panels. SEM-EDS, XPS, Raman, and TG-FTIR analyses confirmed that FA and KH403 contributed to the formation of a phosphorus-rich organic–inorganic hybrid char layer containing Si/Al inorganic structures. This reinforced char layer effectively inhibited heat transfer, oxygen diffusion, and the release of combustible volatiles. This study provides a feasible strategy for developing low-cost flame-retardant VAE adhesives while promoting the high-value utilization of fly ash. Full article

Sodium-ion batteries (NIBs) represent a promising alternative to lithium-ion technology due to the greater abundance and sustainability of sodium. However, the choice of suitable electrolytes is a major limiting factor for performance, safety, and operational life. Conventional organic electrolytes provide high ionic conductivity but suffer from flammability, volatility, and limited thermal stability. In this context, ionic liquids (ILs) emerge as promising alternatives due to their very or extremely high flame-retardant properties, very low vapor pressure, good to high power solvent, and wide electrochemical/thermal window. Despite these advantages, the use of ionic liquids in NIBs is hampered by their high intrinsic viscosity due to strong ion interactions. These characteristic limits the mobility of Na⁺ cations and reduces ionic conductivity, especially in low-temperature conditions, resulting in increased internal resistance and worsened performance at high current rates. To overcome these limitations, different strategies have been proposed based on the target selection of cation/anion pairs, the use of additives, and blending with low-content organic compounds, as well as the optimization of the electrolyte-electrode interface. Thus, the intent of authors in this review is to highlight the progress performed in the last decade, trying to realize a coherent and linear discussion on strategies in the use of ionic liquids for sodium-ion batteries. Full article

Conventional poly(vinyl alcohol) (PVA) hydrogels struggle to integrate the mechanical robustness, thermal management, and fire safety demanded by extreme environments. To overcome this, we fabricate a multifunctional hydrogel via a synergistic strategy combining freeze–thawing and citrate-driven Hofmeister salting-out. Kosmotropic citrate ions aggressively strip polymer hydration shells, driving intense intermolecular hydrogen bonding, elevated crystallinity, and severe network densification. Consequently, the optimized cit@PVA hydrogel exhibits a balanced mechanical performance, achieving a tensile strength of 1.31 MPa and an elongation at break of approximately 150%. The citrate-induced network densification not only reinforces the mechanical integrity of the hydrogel but also regulates its thermal transport characteristics. Benefiting from the dense polymer framework and intrinsic infrared-active chemical structures, the cit@PVA hydrogel demonstrates excellent thermal management capability, including effective high-temperature thermal insulation and high mid-infrared emissivity (~85%) for passive radiative cooling. Furthermore, the incorporated citrate shifts the degradation pathway toward catalytic charring, rapidly forming a dense carbonaceous shield to completely prevent burn-through during direct flame exposure. This scalable structural design overcomes traditional performance limitations, creating resilient soft materials for advanced flexible electronics and smart protective wearables. Full article

This work focuses on the combustion characteristics and kinetics of three building timber organic solid wastes (BTOSW)—China fir, Eucalyptus wood, and Pine wood—aiming to provide theoretical and data support for the thermal conversion and energy utilization of construction-derived woody biomass. Thermogravimetric analysis (TGA) reveals that all three materials exhibit two-stage combustion behavior: volatile combustion at low temperatures (<320 °C) and char combustion at high temperatures (320–500 °C). Increasing the heating rate shifts the decomposition peaks to higher temperature zones, reflecting the combined effects of thermal lag and shortened reaction time. Kinetic analysis shows that the correlation coefficients (R²) calculated by different models are all greater than 0.97, with the first-order chemical reaction model (O1) demonstrating the highest goodness-of-fit for Pine wood (R² = 1.000) and Eucalyptus wood (R² = 0.995), indicating that homogeneous chemical reactions dominate the combustion process. The initial combustion temperatures of China fir, Eucalyptus wood, and Pine wood are 256 °C, 262 °C, and 270.9 °C, respectively, with flammability indices of 1.08, 1.46, and 1.15 and comprehensive combustion characteristic indices of 2.71 × 10⁻², 1.26 × 10⁻², and 1.75 × 10⁻² °C⁻²min⁻¹, respectively. This work provides important theoretical support for both the energy utilization of timber-framed buildings waste and the fire protection design and flame retardancy of timber-framed buildings, contributing to the development of scientific fire prevention measures and the preservation of this architectural heritage. Full article