Reliable and flexible early fire warning sensors play a crucial role in fire detection, yet remain a major challenge. Herein, we combined poly (p-phenylene benzobisoxazole) (PBO) nanofibers with thermoelectric and thermochromic (PTT) nano-functional particles to construct a dual-mode early fire warning sensing fiber, which realizes accurate temperature detection through visual and digital signal cooperative sensing. The resulting core-sheath structured nanoscale PTT sensing fiber features PBO nanofibers as sheath, with perovskite crystals assembled on the outermost layer, while the core is composed of poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)@tellurium nanowires (Te NWs)/polyurethane composite thermoelectric nanomaterial. Incorporating PEDOT:PSS@Te NWs into the core facilitates a millisecond-level response to fire (threshold voltage: 1.0 mV, response time: <= 0.9 s) and wide temperature range (50-300 degrees C) fire warning performance. This rapid response is attributed to the optimization of the Te NWs nanointerface heterojunction structure, as well as the formation of a nanowire permeable conductive network, which synergistically enhances the Seebeck coefficient and conductivity (S = 46.5 mu V K--(1), sigma = 2.05 & times; 10(4) S m(-)(1)). Moreover, the sensing fiber has achieved an independent power-free visual warning capability by utilizing colorimetric monitors and the thermochromic properties of perovskite crystals over a wide temperature range of 100-300 degrees C. This work offers a novel approach to develop a reliable real-time monitoring strategy with an impressive temperature sensing accuracy of up to 97.25% to early fire warning detection in precombustion. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & ( http://creativecommons.org/licenses/by/4.0/ )

Bio-based wood aerogel is one of the most promising materials to replace traditional petrochemical-based insulation materials. However, the flammability and poor mechanical strength of bio-based wood aerogels limit their applications in emerging fields. Inspired by a truss-supporting system, this study prepared a multifunctional bio-based cross-linked wood aerogel (TSP@Ca) by a dual hydrogen-ionic bonding strategy involving an oxidized wood cellulose framework, sodium alginate, phytic acid (PA), and Ca2 +. Finite element simulation and mechanical analysis indicated that the multi-point support structure, resembling a truss framework, formed in the oxidized wood template significantly improved the strength of TSP@Ca aerogel (9.99 MPa), with a 154.84 % enhancement relative to that of oxidized delignified wood (TODW). The limiting oxygen index of TSP@Ca3 aerogel was as high as 43.3 %, and it can extinguish immediately when the fire was removed. The introduction of PA and Ca2+promoted the dehydration, cross-linking, and charring of TSP@Ca aerogel, while the produced phosphorus-containing free radicals played an inhibitory role in the gas phase. Therefore, the peak of heat release rate of TSP@Ca aerogel was 80.66 % lower than that of TODW, showing excellent fire safety. Benefiting from the complex heat conduction path and enhanced interface resistance, the thermal conductivity of TSP@Ca was 46.4 % lower than that of TODW. The resulting aerogel combines ultra-high mechanical strength, excellent fire resistance, and thermal insulation, aligning with "green" development goals and offering broad application potential in construction, rail transport, and new energy sectors. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Although widely applied in diverse industries, conventional fire-retardant coatings generally suffer from poor adhesion and fire protection. These coatings are typically phosphorus-containing and non-recyclable, making their waste prone to causing environmental issues, e.g., bioaccumulation and (micro)plastic pollution. Inspired by the multi-non-covalent adhesion mechanism of ticks, we designed a strongly adhesive and self-healing coating (DCNC/40PEN) with superior fire protection by incorporating hydrogen bonding, π-π stacking, and cation-π interactions. Incorporating these interactions into a dynamic covalent network further imparts closed-loop recyclability and biodegradability to the coating. DCNC/40PEN can adhere to diverse substrates and self-heal at room temperature due to the non-covalent and covalent interactions within its structure. DCNC/40PEN features closed-loop recyclability and biodegradation because of its dynamic covalent network. Owing to the catalytic and crosslinking carbonization of sulfonate and Schiff base groups, phosphorus-free DCNC/40PEN delivers exceptional fire protection for various materials, e.g., wood, polymer foams, and steel. At a coating thickness of 100 μm, DCNC/40PEN significantly increased the limiting oxygen index and vertical combustion (UL-94) rating of wood to 35.0 % and V-0. The multifunctionality and sustainability of DCNC/40PEN enable it to outperform commercial and reported fire-retardant coatings and adhesives. This work presents an innovative design strategy for the next generation of sustainable, versatile fire-retardant coatings, accelerating “green” development.

Epoxy resins (EPs) are widely used in structural and functional applications due to their excellent mechanical properties, chemical resistance, and dimensional stability. However, their inherent flammability and non-recyclability pose significant fire safety and environmental challenges. The emergence of dynamic covalent chemistry and advanced flame-retardant strategies has enabled the design of EP systems with both recyclability and intrinsic flame retardancy. Nevertheless, the introduction of reversible dynamic covalent bonds to facilitate network adaptability often compromises structural integrity, resulting in increased susceptibility to creep and deteriorated in-service performance (e.g., mechanical properties, thermal stability, and durability). This review outlines the state-of-the-art research on flame-retardant, recyclable EPs in recent years and highlights feasible and potential strategies to improve the creep resistance and in-service performance of flame-retardant, recyclable EPs. Finally, potential future development directions for the development of flame-retardant, recyclable and high-stability EPs are proposed.

Vinyl ester resins (VERs) are widely used in various industries owing to their excellent mechanical properties and chemical resistance. However, their inherent flammability severely restricts further application, and conventional flame retardants often enhance fire safety at the cost of mechanical and thermal performance. Herein, a reactive ammonium polyphosphate (APP) derivative (MDO) with abundant C--C bonds was synthesized by grafting maleic anhydride onto the surface of an amine-modified APP (DO). The resulting MDO not only acts as an efficient flame retardant but also participates in the curing of VER through radical copolymerization. With the addition of only 22 wt% MDO, the 22% MDO/VER composite achieves a vertical burning (UL-94) V-0 rating and a high limiting oxygen index (LOI) of 28.5%, accompanied by remarkable reductions in peak heat release rate (PHRR), total heat release (THR), peak smoke production rate (PSPR) and total smoke production (TSP) compared to the neat VER. More importantly, introducing MDO enhances the tensile strength (49% improvement), flexural strength (56% improvement), and impact strength (19% improvement) of VER while effectively maintaining the glass transition temperature (Tg, 115 degrees C). The dual enhancement originates from the reactive crosslink sites of MDO that improve the interfacial compatibility and promote condensed-phase charring. This work provides a rational strategy to fabricate high-performance VER composites with superior fire retardancy, outstanding mechanical properties and well-preserved thermal performance.

To mitigate the environmental impact of plastic pollution and paper waste, developing bioplastics from wastepaper as alternatives to non-degradable petroleum-based plastics is of great importance. However, current wastepaper recycling faces challenges such as complex preparation processes, low efficiency, suboptimal performance, and limited scalability. In this work, we present a facile and scalable direct hot-press transformation approach to directly convert wastepaper into thermally processable, transparent, and high-performance bioplastics. This approach involves the cleavage of the cellulose ring structure in wastepaper, followed by hot-pressing under mild conditions. The resultant bioplastics demonstrate excellent thermal processability and tunable mechanical properties (with tensile strengths ranging from 85.7 to 103.2 MPa) and thus can be converted into rigid containers or flexible packaging bags without the need for adhesives. They also exhibit high optical transparency, good water resistance, repairability and biodegradability. This work provides a streamlined direct transformation strategy to produce thermally processible, transparent and mechanically robust bioplastics, offering a scalable avenue to transform waste papers into bioplastics for sustainable packaging.

Developing flame-retardant epoxy resin (EP) with high performance has drawn extensive attention recently due to the growing public concern for fire safety. However, the simultaneous enhancement of flame retardancy and toughness without the sacrifice of mechanical strength and thermal stability is still a challenge for EP. Herein, a novel kind of imidazole-based reactive flame retardant MD containing P/N/Si was synthesized and applied into EP. The results demonstrated that due to the presence of P/N/Si multiple flame-retardant elements, incorporating 4 wt% MD could make EP/MD pass UL-94 V-0 grade and have a limiting oxygen index (LOI) of 29.7%. Meanwhile, compared with pure EP, the peak heat release rate (PHRR), total heat release rate (THR), peak smoke production rate (PSPR), and total smoke production (TSP) of EP composite containing 4 wt% MD exhibited an obvious reduction of 41.5%, 11.4%, 24.2%, and 12.9%, respectively. Moreover, thanks to the high reactivity of imidazole groups, the MD could participate in the cross-linking reactions of EP and form strong interfacial interaction between the matrix and flame retardant. Therefore, the mechanical strength and toughness as well as the glass transition temperature of EP/MD composites could be simultaneously and greatly enhanced (tensile strength +30%, flexural strength +35%, impact strength +22%, and T g + 7 degrees C). This work provided a feasible methodology for the fabrication of highly efficient flame-retardant EP with prominent mechanical and thermal properties.

Artificial intelligence (AI) has demonstrated great potential for discovering new flame retardants (FRs) for polymers. While existing AI can describe flame retardancy of FRs, it has been unable either to generate new FR molecules with desired performances or predict their impacts on mechanical strength and glass transition temperature ( Tg ) of polymer matrices. To fill this knowledge gap, we, herein, propose a generative artificial intelligence (GAI)-based de novo molecular design approach (GAI4FR) to generate new FR molecules for commercially important epoxy (EP) resins. Also, a descriptive AI model is trained using existing works to predict impacts of AI-generated FR molecules on flame retardancy, tensile strength ( sigma t ), and Tg of EP, enabling the identification of three FR molecules with better overall performances. The as-identified FR molecules are then synthesized, and their predicted performances are well-validated. We further demonstrate the application of as-prepared flame-retardant EP-coated wood sheets as heat shields for preventing thermal runaway of lithium-ion battery (LIB) packs. The coated wood shows equally desirable thermal protection for LIB packs to commercial counterparts. This work offers a groundbreaking GAI4FR framework for creating next-generation high-performance flame retardants for various flammable polymers and opens the door to discovering many other functional materials. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & ( http://creativecommons.org/licenses/by/4.0/ )

Biopolymer-based temperature-sensing fibers are increasingly employed to realize the eco-friendly concept of wearable electronics. However, keeping their long-term development remains challenging due to limited mechanical robustness and poor environmental tolerance. Herein, a bionic autonomous selfhealing thermoelectric (TE) aerogel fiber with visual damage warning function (STDF) inspired by biological skin was prepared via a coaxial wet spinning strategy, which yielded a core-shell heterogeneous structure with a protective sheath with an intrinsic self-healing ability and a temperature-sensing core layer. The core layer of STDF, composed of flexible thermoplastic polyurethane embedded with rigid Ti3 C2 Tx MXene, effectively minimizes disruptions in continuous conductive pathways during repeated extreme bending. Featuring a synergistic network of reversible hydrogen bonds and dynamic Schiff-base linkages constructed among oxidized alginate, sericin, and tannic acid, the fractured STDF aerogel fiber exhibits exceptional water-responsive self-healing efficiency (97.51 % stress recovery). Moreover, the visual damage location in STDF fiber is enabled through a coloration reaction at the damaged interface between the Fe2 + ions and 1,10-phenanthroline incorporated into the core and sheath layers, respectively. Furthermore, the resultant STDF demonstrates a wide-range temperature-sensing performance at 10 0-50 0 degrees C and an ultrasensitive alarm response time (within 2 s) when encountering fires. This work sheds new light on the design of bionic temperature sensing fibers with environment-adaptive self-healing and damage warning abilities for improved reliability and durability in real-world wearable application scenarios. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & ( http://creativecommons.org/licenses/by/4.0/ )

The flame-retardant modification of polypropylene (PP) often deteriorates its resistance to ultraviolet (UV) radiation, leading to severe degradation in both flame retardancy and mechanical properties during long-term service. To address this issue, cerium oxide (CeO2) was incorporated into an intumescent flame retardant (IFR) system to achieve synergistic flame retardancy and enhance anti-UV performance. The resultant PP/IFR/ CeO2 achieved a UL-94 V-0 rating with a limiting oxygen index (LOI) of 32.7 % at a total loading of only 20 wt% IFR and CeO2. After UV irradiation for 120 h, the surface of PP/IFR/CeO2 remained smooth, with only shallow cracks, and its water contact angle was maintained at 64.5 degrees. The carbonyl index increased merely to 1.45, indicating a markedly low degree of photo-oxidative aging. In addition, the tensile strength and elongation at break decreased by 9.4 % and 28.5%, respectively, which were significantly smaller reductions than those of PP/ IFR. The results indicate that CeO2 can effectively improve the anti-UV performance and flame retardancy of PP/ IFR, providing a valuable foundation for developing durable, flame-retardant PP composites with improved anti-UV performance.

The development of sustainable thermal insulation materials that combine light weight, high strength, and fire retardancy is essential to support global carbon neutrality goals. Herein, fully bio-based polyvinyl alcohol/phytic acid (PVA/PA) composite aerogels were fabricated through an environmentally benign refrigerator-assisted freezing process without the use of toxic solvents. The strong reactivity of bio-based phytic acid enabled the formation of a robust micro-nano three-dimensional (3D) network, yielding an aerogel with low density (0.075 g cm-3), high porosity (94.21%), and ultralow thermal conductivity (33.1 mW & sdot;m-1 & sdot;K-1). Benefiting from its micro-nano 3D network, the aerogel exhibited excellent mechanical robustness, with compressive strength and specific modulus increasing by 125.7% and 194.5%, respectively. Due to the formation of intrinsic intumescent flame retardant (IFR) system, the aerogel achieved an extremely high limiting oxygen index (LOI) of 41.9% and a UL 94 V-0 rating (self-extinguishing time of only 1.8 s) with significantly reduced heat and smoke release during combustion. Furthermore, a solvent-free thermal chemical vapor deposition (CVD) treatment imparted durable hydrophobicity (water contact angle = 145.6 degrees). This work provides a green and scalable strategy for producing multifunctional bio-based aerogels with great potential for high-performance and sustainable thermal insulation applications.

Large-scale forest fires have caused severe and irreversible environmental damage, making the rapid and effective prevention and control of forest fires an urgent global challenge. Currently, conventional water-based fire-extinguishing agents used for forest fire suppression exhibit poor adhesion, wetting ability, spreading performance, and environmental compatibility. In this study, a rapidly thermoresponsive bio-based hydrogel forest fire extinguishing agent (MCT) was successfully prepared by the hydration and intermolecular entanglement of cellulose derivatives and integration of trihydroxymethyl phosphorus oxide (THPO). At room temperature, MCT exhibits excellent fluidity and sprayability. When exposed to elevated temperatures, it undergoes a sol-gel phase transition, enabling strong adhesion to vegetation surfaces. MCT demonstrates good fire extinguishing performance and effectively suppresses heat and smoke release from natural pine wood (NW) during combustion. In the burning process, PO & sdot;and inert gases released from the decomposition of MCT suppress flame propagation in the gas phase, and the phosphoric acid compounds generated simultaneously promotes dehydration and charring in the condensed phase. Furthermore, MCT shows excellent biodegradability, storage stability (up to 30 days) and long-term fire-resistant effectiveness. This environmentally friendly and highly efficient bio-based thermoresponsive hydrogel provides a promising pathway for next-generation forest fire prevention and control technologies.

The rapid advancement of modern industries has placed higher demands on the comprehensive performance of nylon 6 (PA6) and addressing its flammability issue has also received significant attention. Therefore, developing flame-retardant PA6 with superior overall performance has become a key research objective. In this work, a novel and highly efficient triazine-based flame retardant, phthalimidoxy-1,3,5-triazine (TPT), was successfully synthesized, and it was found to have a radical quenching mechanism analogous to that of hindered amine light stabilizers (HALS). Incorporating only 1.5 wt% TPT significantly improved the limiting oxygen index (LOI) of PA6/1.5TPT to 28% and increased both tensile strength and flexural strength to 80.49 and 93.25 MPa, respectively. Compared to pure PA6, the time to ignition (TTI) of PA6/1.5TPT was extended by 46.7%, and the total smoke production (TSP) was reduced by 42%. The hygrothermal aging results demonstrated that the PA6 composites maintained outstanding flame-retardant performance and mechanical integrity even after aging. Moreover, density functional theory (DFT) calculations and gas-phase mechanism analysis indicated that TPT generated stable radicals during thermal decomposition, which effectively captured hydrogen (H & sdot;) and carbon (C & sdot;) radicals produced in the initial degradation stage of PA6, thereby suppressing the combustion. This work presents a promising strategy for creating high-efficiency, multifunctional flame retardants for PA6, thus broadening its application potential.

Polylactic acid (PLA) is considered one of the most promising bio-based plastics, but its inherent brittleness and high flammability hinder its broader industrial use. To advance its practical application, it is essential to simultaneously enhance its toughness and fire safety without compromising degradability. In this work, a fully bio-based, highly toughened, and flame-retardant PLA composite (PLA/E/A) was developed via a facile reactive blending process using epoxidized soybean oil (ESO), adenosine disodium triphosphate (ATP), and PLA. Covalent bonding formed during the reactive blending enhanced intermolecular interactions between chain segments, thereby significantly improving the toughness of PLA. The PLA/15E/2A composite (containing 15 wt% ESO and 2 wt% ATP) exhibited an elongation at break (epsilon) of 106 % and a tensile toughness (Ut) of 27.7 MJ/m3, which were 14 and 22 times higher, respectively, than those of neat PLA. Moreover, the heat-resistance index (THRI) of PLA/15E/2A was higher than that of PLA, indicative of enhanced thermal stability. PLA/15E/2A achieved a vertical burning (UL-94) V-0 rating, and its limiting oxygen index (LOI) increased from 19.2 % of PLA to 25.6 %, demonstrating satisfactory flame retardancy due to the highly effective char-forming action of phosphates within ATP. Specifically, the covalent interactions between ingredients did not adversely affect the rate of soil degradation of the PLA composites. Overall, this work provides a practical and eco-friendly strategy for fabricating fully bio-based, flame-retardant, and toughened PLA materials.

ABSTRACT Thermoelectric (TE) materials with high‐efficiency solid‐state cooling and low‐grade heat harvesting are crucial for sustainable energy technologies. Although Bi2Te3‐based compounds remain the only commercially viable near‐room‐temperature TE system, their deployment is still constrained by moderate conversion efficiency, limited mechanical robustness, and restricted multifunctionality. Here, we propose a dual‐regulation strategy that integrates intermetallic ZnSb and Se dopants to synergistically modulate carrier and phonon transport in Bi0.4Sb1.6Te3.01. ZnSb incorporation compensates for Sb vacancies, suppresses Te volatilization, and decreases carrier concentration, thereby enhancing the Seebeck coefficient and power factor. Concurrently, Se doping introduces hierarchical phonon‐scattering centers and induces swapped‐bilayer configurations near twin boundaries, strengthening interlayer coupling and improving mechanical integrity. The optimized Bi0.4Sb1.6Te2.97Se0.04 + 0.15% ZnSb achieves a peak zT of ∼1.51 at 353 K and an average zT of ∼1.47 below 403 K, together with high Vickers hardness (∼97 Hv) and compressive strength (∼188 MPa). A finite‐element‐optimized multifunctional device further delivers a maximum cooling temperature difference of ∼70 K at 303 K and a power‐generation efficiency of ∼7.1% under a 208 K temperature gradient, with exceptional stability under room‐temperature wearable conditions. This study establishes a scalable design framework linking atomic‐scale defect manipulation to device‐level performance for practical, multifunctional Bi2Te3‐based thermoelectrics.

Polypropylene (PP) is highly flammable and prone to ultraviolet (UV) aging, limiting its durability. Conventional intumescent flame retardants (IFR) require high loadings (20-30 wt%), which deteriorate mechanical properties. Herein, a low-basicity N-alkoxyamine compound (CDMP) is designed as a multifunctional synergist for IFRmodified PP. With only 0.3 wt% CDMP and 19.7 wt% IFR, the composite achieves a limiting oxygen index (LOI) of 33.0% and a vertical burning (UL-94) V-0 rating, while reducing total heat release (THR) and total smoke production (TSP) by 22.2% and 37.6%, respectively. After 120 h UV exposure, the composite shows minimal surface damage and a lower carbonyl index growth rate (87.2% of neat PP), indicating enhanced UV resistance. Meanwhile, elongation at break and impact strength are significantly improved compared to PP/IFR. Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analysis reveals that CDMP generates nitroxyl radicals, which quench free radicals during both photo-oxidation and combustion. This synergy between IFR and CDMP enables simultaneous enhancement of flame retardancy, UV stability, and mechanical performance in PP.

Epoxy resin (EP) is widely used in electronic and electrical applications, but its inherent flammability significantly restricts further use in these fields. Phosphorus-based flame retardants, such as 9,10-dihydro-9-oxa-10phosphaphenanthrene-10-oxide (DOPO), provide efficient halogen-free flame retardancy and good compatibility with epoxy matrices, but their practical application is limited by high cost, reduced glass transition temperature, and increased smoke production. In this work, Australian red mud was upcycled to prepare high-purity Al2O3 fillers, which were subsequently surface-modified with a silane coupling agent and grafted with DOPO to fabricate multifunctional Al-Si-DOPO. Epoxy composites containing both 5 wt% Al-Si-DOPO and 5 wt% DOPO (EP/5Al-Si-DOPO/5DOPO) were successfully prepared, exhibiting significantly high glass transition temperature, enhanced flame retardancy, suppressed smoke generation, and well-maintained mechanical properties. The EP/5Al-Si-DOPO/5DOPO composite exhibited a limiting oxygen index (LOI) of 31.3% and achieved a UL-94 V0 rating, while its peak heat release rate (pHRR) and total hear release (THR) were reduced by 19.1% and 23.9%, respectively, compared with EP/DDM. Compared with the commercial DOPO price, the theoretically calculated price of Al-Si-DOPO decreased by 62.5%, indicative of superior cost-effectiveness. Thus, this strategy enables high-value utilization of industrial waste and offers a sustainable approach for designing environmentally friendly, cost-effective, high-performance epoxy composites.

The development of compatible p-type and n-type pairs within the same matrix is essential for high-efficiency thermoelectric devices. While substantial advancements have been achieved in the figure of merit for p-type GeSe, achieving high-performance n-type GeSe remains a formidable challenge due to the strong covalent bonding in the orthorhombic phase, which restricts dopant solubility, induces low cationic vacancy formation energy, and hence obstructs the critical p-to-n type transition. Here, we utilize AgBiTe2 alloying to facilitate the transition of GeSe from its covalently bonded orthorhombic phase to the metavalently bonded cubic phase, thus enhancing dopability and enabling precise manipulation of point defects. The superior solubility of Bi relative to Ag in the GeSe matrix generates a dominant donor effect from Bi3+, while the concentration of anionic vacancies, particularly Te vacancies, progressively outbalances that of cationic vacancies, both of which accelerate the successful p-to-n type conversion of GeSe. By introducing a slight Te deficiency to optimize electron concentration, we attain a record-breaking zT of 0.51 at 723 K in n-type cubic (GeSe)0.5(AgBiTe1.93)0.5. This work not only unveils a promising route for high-performance n-type GeSe but also provides valuable insights into the interplay of chemical bonding, phase structure, dopability, and point defects in chalcogenides.