Bamboo powder (BP) is an abundant and renewable resource with established industrial applications, its shortcomings, such as low fire safety, poor water stability, and restricted multifunctionality, hinder its broader use in functional composites. This work reports a fabrication method for a high-performance bamboo powder-based composite (BPC), employing a targeted pre-treatment and a BP-chitosan (CS)-borax (BX) cross-linking strategy to stabilize the network during low-energy ambient drying. The synergistic effects of hydrogen bonding, electrostatic interactions, and chemical bonding within the structure significantly enhance the material's mechanical and fireproof performance. The optimized BPC sample, with a BP-to-CS mass ratio of 7:3, exhibits superior performance, including a low density, excellent compressive mechanical properties, and outstanding thermal insulation, surpassing many existing bio-based materials. Notably, it demonstrates superior fire resistance and thermal stability compared to commercial rigid polyurethane foam (RPUF) of similar density. Moreover, it also shows excellent water resistance and recyclability. Importantly, the combined pre-treatment and network stabilization enable efficient ambient drying without high-temperature steps, reducing energy input and improving scalability. This work emphasizes the vast potential of this bamboo powder-based composite for fire-resistant insulation applications, offering an innovative pathway for the development of sustainable and high-performance materials in the quest for greener solutions.

To improve the flame retardancy and mechanical properties of unsaturated polyester resin (UPR), this study reports a nano-hybrid filler designed through interface engineering to mimic the "bone marrow-bone tissueperiosteum" structure. Using vacuum-assisted methods to fill the halloysite nanotube (HNT) interior with aminomethylenephosphonic acid (ATMP), while the outer surface was also coated with ATMP through hydrogen bonding. Subsequently, zinc hydroxylstannate (ZHS)-modified chitosan (CS) was in situ grafted onto the surface via electrostatic attraction and coordination, forming an ATMP-CS-ZHS polyelectrolyte layer, resulting in a biobased nano-hybrid filler with a "core-tube-shell" structure: CS-ZHS@HNT@ATMP (CZHA). This biomimetic strategy enables the additional loading of more flame retardants within the interior cavity of the rigid HNT, while the outer flame-retardant polyelectrolyte layer enhances interfacial compatibility. This results in excellent dispersion and strong interfacial adhesion within the UPR matrix, forming a bridging network that improves flame retardancy and mechanical properties. The addition of 6 wt% CZHA increased the limiting oxygen index to 24%, representing a 21.2% improvement, while the peak rates of heat, smoke, COQ, and CO generation were reduced by 19.7%, 20.5%, 25.8%, and 32.0%, respectively. Concurrently, tensile strength, elongation at break, and impact strength were enhanced to 38.63 MPa, 8.08%, and 4.94 kJ/m2, respectively. This study provides a new approach for developing polymer composites with excellent comprehensive properties and offers insights for research on eco-friendly biomass additives, biomimetic strategies, and multi-functional coordination.

The limited number of active sites and rapid saturation of single-metal catalysts hinder the sustained adsorption and efficient conversion of lithium polysulfides (LiPSs) in lithium-sulfur batteries (LSBs). Here, we report a bimetallic catalyst (Bi-CoP@G) with a core-shell adsorptive-conductive-catalytic network to address the above challenges. In this structure, Bi sites strongly adsorb LiPSs via Bi-S bonds, effectively immobilizing LiPSs and suppressing the shuttle effect. Complementarily, Co sites accelerate the redox kinetics of solid Li2S nucleation and dissolution. Interfacial charge redistribution and orbital coupling between the metals enhance electron transfer, establishing a synergistic "adsorption-catalysis" cycle. Using Bi-CoP@G/PP separators, the LSBs exhibit 82.9% capacity retention after 500 cycles at 1 C and an ultra-low decay rate of 0.02% per cycle over 1000 cycles at 2 C. Moreover, the LSBs demonstrate stable cycling at a wide temperature range (-20 to 50 degrees C) and at the pouch-LSB scale with a capacity of 124 mA h. Additionally, Bi-CoP@G significantly enhances the fire safety of LBSs by simultaneously scavenging gas-phase free radicals and promoting condensed-phase carbonization during combustion. In summary, this work demonstrates a strategy for highly active bimetallic synergistic catalysts, offering a novel approach for the large-scale production of advanced safe, and stable LSBs.

Lithium-sulfur batteries (LSBs) have attracted increasing attention due to their ultrahigh theoretical energy density (2600 Wh kg-1). However, their application is still hindered by several critical issues, such as the slow reaction kinetics induced by the shuttle of lithium polysulfides (LiPSs), lithium dendrite growth, and fire safety concerns. In this work, by in situ growth of hexachlorocyclotriphosphazene (HCCP) and bisphenol S (BPS) on the surface of carbonized ZIF-67 (Co-N-C), a multifunctional polyphosphazene/Co-N-C (Co-N-C@HCPS) particle is constructed to cope with LiPSs shuttle, Li-dendrite growth, and fire danger. The Co-N-C@HCPS is coated on one side of the PP separator toward the anode, which will anchor LiPSs by the formation of covalent bonding. Meanwhile, a three-dimensional conductive carbon framework is constructed by the Co-N-C rich in Co-Nx catalytic sites, which will effectively adsorb and catalyze the rapid conversion of LiPSs. The LSBs equipped with the Co-N-C@HCPS/PP separator deliver an initial capacity of 1423.2 mAh g-1 at 0.2 C, with a capacity retention of 77.2 % after 100 cycles. At 1 C, an ultralow capacity decay rate of only 0.049 % per cycle is maintained over 800 cycles. Under heating or ignition, Co-N-C@HCPS promotes charring of the PP separator, improving the fire safety of the LSBs. Overall, this work provides a novel strategy for the design of high-safety and long-cycle-life LSBs by coating of carbonized ZIF-67 rich on the PP separator.

Poly(ethylene oxide) (PEO) is a promising solid polymer electrolyte, yet its application in all-solid-state lithium metal batteries is limited by low ionic conductivity, a narrow electrochemical window, and flammability. Herein, a triple-functional molecular engineering strategy integrating anion anchoring, radical quenching, and flame retardancy is realized by incorporating HCCP-EA (HE), synthesized via one-step precipitation of hexachlorocyclotriphosphazene (HCCP) and ellagic acid (EA). With only 3 wt.% HE, the crystallinity of 3%HE-PEO/PE (HE-PEO/PE) is effectively reduced, delivering an ionic conductivity of 4.80 & times; 10-4 S cm-1 and a Li+ transference number of 0.40 at 60 degrees C. Owing to radical quenching capability, HE scavenges R & horbar;O & centerdot; and H & centerdot; generated under high-voltage, improving the stability of PEO and extending the electrochemical window to 5.02 V. Meanwhile, HE's anion anchoring effect promotes lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) dissociation, increases free Li+ concentration, and lowers TFSI- redox barrier, inducing in situ formation of P/N/F-rich interface layers. Consequently, the Li//HE-PEO/PE//Li symmetric cells operate stably for 3000 h (250 & micro;A cm-2 at 60 degrees C), while NCM811//HE-PEO/PE//Li cells retain 83.6% capacity after 300 cycles at 0.5 C and cycle stably at 4.5 V. This work presents an effective molecular-engineering strategy for safe, high-voltage solid-state lithium batteries.

To address the issue of excessive addition amount when using the expansive intumescent flame retardant (IFR, PAPP:MPP = 7:3) alone, a combination of high flame retardant efficiency and low toxicity coated red phosphorus ((w)RP) and IFR was added to polypropylene (PP) to improve the flame retardant performance of the PP composite. When the total addition amount of flame retardant decreases to 13 wt.%, it still could reach the UL-94 V-0 rating, with a limit oxygen index (LOI) value of 27.2%. Subsequently, in order to synergistically enhance its flame retardant performance, mechanical properties, and water resistance, the IFR needed to be modified. Zinc oleate (ZnOA) has good compatibility with PP and hydrophobicity, so it was selected to modify IFR to synthesis ZnOPM. Compared to PP/10%IFR/3%(w)RP, the PP/10%ZnOPM/3%(w)RP composite showed increased LOI to 28.8% while maintaining UL-94 V-0 rating, with peak heat release rate (pHRR) and total smoke production (TSP) reduced by 23.1% and 71.5% respectively. Additionally, compared with PP/10%IFR/3%(w)RP, the tensile strength and elongation at break of PP/10%ZnOPM/3%(w)RP increased by 25.1% and 98.1%. After water immersion tests, water absorption and flame retardant leaching rate of PP/10%ZnOPM/3%(w)RP decreased to 0.6% and 0.38%, with the composite maintaining excellent flame retardancy and mechanical properties. This study proposes a highly promising strategy for manufacturing PP composites with excellent flame retardant, smoke suppression, water resistance, and mechanical properties.

The widespread use of modern steel structures is challenged by a significant loss of load-bearing capacity at elevated temperatures, particularly above 550–600 °C. Intumescent fireproof coatings (IFCs) are an effective protection method. While inorganic coatings such as sodium silicate (SS) offer advantages of non-combustibility and thermal stability, their application is limited by high water solubility and fragile char. This study addresses these limitations by constructing an organic–inorganic hybrid system through in-situ modification of SS with a synthesized polyurethane (PU) prepolymer, facilitated by hydrogen bonding. A flame retardant system comprising melamine (MEL) and piperazine pyrophosphate (PAPP) was incorporated to synergistically enhance performance. The resulting coatings were systematically evaluated for their flame retardancy, water resistance, and formed char structure. It achieved a protection time of 58.6 min, exhibited a micron-scale synaptic surface after curing and showed a mass loss of only 12

Passive cooling thermal management is crucial for addressing inevitable heating and inefficient heat dissipation in photovoltaic (PV) devices. Designing cooling systems with high transparency, solar conversion, and interfacial properties for diverse PV technologies remains challenging. This work develops a photoluminescent passive cooling film as a "front-surface" solution for silicon (Si) based solar cells, integrating passive evaporative cooling with spectral conversion. This environmentally friendly film is fabricated through simple self-cross-linking of polyvinyl alcohol (PVA), calcium chloride (CaCl2), and 3-acrylamidophenylboronic acid (ABA). The film exhibits adaptive moisture sorption-desorption dynamics across wide humidity ranges, enabling efficient cooling. Additionally, PVA-ABA film possesses unique UV-activated fluorescence and room-temperature phosphorescence (RTP) in ambient conditions. Its spectral conversion capability enhances photon utilization in solar cells, increasing short-circuit current density (Jsc) by 2.2%. Under dual functionality, solar cells coated with a PVA-ABA3 film achieve an average temperature reduction of 10.7 °C and a relatively 7.9% improvement in power conversion efficiency (PCE) compared to uncoated cells under simulated sunlight. Outdoor evaluations demonstrate PVA-ABA3 coated solar cells sustain temperature stabilization and achieve a peak enhancement in PCE of 15.4%. This work develops a multifunctional coating that simultaneously addresses thermal management and spectral conversion challenges in PV applications.

Polyamide 66 (PA66) is a widely used engineering plastic, but its inherent flame retardancy cannot meet the high requirements of many application scenarios. Various flame retardants have been used in PA66. However, the compatibility between most of these flame retardants and PA66 is not good, resulting in obvious mechanical loss. In this study, a new flame retardant (DOPO-MMEL) was synthesized from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), melamine (MEL), and maleic anhydride (MA). Only 2.0 wt% incorporation of DOPO-MMEL in PA66 increased the limiting oxygen index (LOI) from 22.7 % to 25.2 % and enabled a UL-94 V0 rating, while the tensile strength was maintained at 72.0 MPa, corresponding to 93.4 % of the original values. Cone calorimetry test (CCT) revealed that the total heat release (THR) and peak heat release rate (PHRR) of PA66/2.0 %DOPO-MMEL decreased by 9.8 % and 18.5 % compared with the control PA66. This study demonstrates an effective strategy to enhance flame retardancy without significantly sacrificing mechanical performance.

Ti3C2Tx MXene-based textiles are gaining rapid attention for next-generation wearable technologies. However, drawbacks of MXene, such as susceptibility to oxidative degradation, poor adhesion to fabrics, and low flameretardant efficiency, hinder its applications. Herein, we proposed a collaborative interfacial strategy to fabricate a durable, antioxidant Mxene-based cotton fabric (C-E-FR-cotton) that exhibited flame retardancy, sensing, and thermal management. MXene was surface-modified with Ag NPs and potassium sodium tartrate, and then firmly adhered to the fabric by covalent bonds. Flammability test results demonstrated that the C-E-FR-cotton fabric had excellent flame retardancy, with a limiting oxygen index value (LOI) of 36.8% and a reduction of 42.8% in total heat release. The fabric retained its electrical stability, exhibiting only 1.2 times its original resistance value even after 20 soaking cycles. Besides, the signal output of the fabric remained stable during 4000 s of compression-release cycles testing, demonstrating durable sensing capability. Furthermore, the C-E-FRcotton achieved thermal regulation, including electrothermal heating (76 degrees C at 10 V), photothermal warming (53.5 degrees C under 1000 W & sdot;m-2), and radiative insulation equivalent to four cotton layers. This work presents a practical strategy to develop MXene-based textiles with enhanced antioxidant capacity, flame retardancy, and capabilities for sensing and personal thermal management.

Epoxy resins (EP) suffer from high flammability and poor corrosion resistance, which restrict their application in harsh environments. Herein, a novel phosphorus- and nitrogen-containing additive (MMPADA) was synthesized through the reaction of 3,5-diamino-1,2,4-triazole (DATA) with dimethyl methylphosphonate (DMMP). Remarkably, with only 2 wt.% MMPADA incorporation, the EP coating kept high transparency and exhibited outstanding flame retardancy. The latter was evidenced by a limiting oxygen index of 31.9 % and a UL-94 V-0 rating, and significant reductions in heat and smoke release. Meanwhile, electrochemical impedance spectroscopy (EIS) confirmed that the EP/2%MMPADA coating maintained much higher charge transfer resistance than the control EP, even after 40 days of immersion in 3.5 wt.% NaCl solution, demonstrating superior long-term anticorrosion performance. These results highlighted that incorporating merely 2 wt.% MMPADA endowed EP coatings with excellent transparency, flame retardancy, and corrosion resistance, thereby offering a feasible strategy to extend their service life in demanding environments.

Commercial intumescent flame retardants (IFRs) effectively reduce the flammability of polypropylene (PP) but significantly deteriorate its weather resistance. Although hindered amine light stabilizers (HALS) can improve UV-aging resistance, their intrinsic acid-base antagonism with IFRs limits their combined application. In this study, a bio-based supramolecular approach is proposed by employing chitosan (CS) as a functional shell to encapsulate HALS116, forming a core-shell structured light stabilizer (CS@HALS116). The resulting PP/IFR/CS@HALS116 composites exhibit excellent flame retardancy, achieving a limiting oxygen index (LOI) of 30.0% and a UL-94 V-0 rating. Thermal analysis shows that the chitosan shell broadens the effective thermal action range of HALS116 to above 600 °C, preventing its premature degradation from interfering with char formation while enabling gas-phase radical scavenging. Meanwhile, the composites demonstrate outstanding UV-aging resistance, retaining 95.1% of tensile strength after 120 h of UV exposure and maintaining the V-0 rating. The carbonyl index (CI) is reduced to 0.37, much lower than that of neat PP (0.72). Mechanistic analysis reveals a dual anti-UV effect: the chitosan shell physically shields the NOR structure from acidic attack, while the hydrogen-bond network facilitates proton transfer and enhances nitroxide radical (NO·) regeneration. This work highlights a bio-based supramolecular design strategy for overcoming incompatibility in multifunctional polymer systems, offering a promising route toward durable and sustainable polyolefin materials.

Polyamide 6 is an important engineering thermoplastic; however, its practical use is often constrained by its high flammability. Although aluminum diethylphosphinate is widely employed as a flame retardant for polyamide 6, its relatively slow char-forming kinetics hinders the attainment of the stringent 750 °C glow-wire ignition temperature required for electrical applications at moderate loadings. To address this limitation, a synergist was fabricated via the self-assembly of phytic acid, benzoguanamine, and ZnSO4·7H2O and subsequently incorporated to enhance the char-forming capability and flame retardancy of polyamide 6/aluminum diethylphosphinate composites. The results revealed that the synergist acted as an efficient charring promoter, improving flame retardancy. At a total loading of 15 wt%, the composite reached a UL-94 V-0 rating and high limiting oxygen index of 30.7%. Cone calorimetry data indicate that the peak heat release rate decreased by 34.0%, and the smoke production rate decreased by 33.3% compared with the polyamide 6/aluminum diethylphosphinate composites. Mechanistic analysis indicated that the synergist catalyzed the carbonization of the polyamide 6, enabling the formation of a dense thermally insulating char barrier in the condensed phase. Notably, the optimized formulation achieved a glow-wire ignition temperature of 750 °C, demonstrating its strong potential for high-safety electrical applications.

Solid-liquid phase change materials (PCMs) offer considerable potential for thermal energy storage; however, leakage and flammability continue to restrict their engineering applications. To address these limitations, a side-chain modified epoxy resin (DGEDBA(C12)) was developed to construct form-stable PCMs (FSPCMs) with improved compatibility toward paraffin (PW). The resulting composite achieved a high PW loading of 60 wt% with a latent heat of 102.5 J/g and good shape stability (leakage rate < 1% at 80 degrees C). To further enhance heat transfer efficiency and fire safety, a red phosphorus/expandable graphite hybrid filler (RG) was incorporated. RG addition enhanced thermal conductivity and reduced supercooling. It also promoted char formation in the condensed phase, leading to a significant reduction in the peak heat release rate from 1582 to 236 kW/m(2) in cone calorimetry. This study provided a design strategy for developing safe and efficient EP-based FSPCMs.

Under high-load and harsh conditions, power cables tend to accumulate heat, which puts higher demands on the reliability and durability of flame-retardant materials. Herein, magnesium hydroxide (MH) was surface-modified via an “anchoring-grafting” strategy to prepare the flame-retardant MBP, which was subsequently used synergistically with coated red phosphorus (mRP). Ethylene-vinyl acetate (EVA) composites were then prepared by melt blending, achieving a simultaneous enhancement of flame retardancy, UV resistance and humid-thermal aging. In terms of flame retardancy, the limiting oxygen index (LOI) of EVA/45MBP/5mRP increases to 37.9%, and the composite achieves a UL-94 V-0 rating. Compared with EVA, the peak heat release rate and peak smoke production rate of EVA/45MBP/5mRP decrease by 57.6% and 23.4%, respectively. Relative to the composite containing unmodified MH, the tensile strength and elongation at break of EVA/45MBP/5mRP increase by 12.3% and 123.2%. After 100 h of aging treatment, EVA/45MBP/5mRP maintains excellent flame retardancy and satisfactory mechanical performance, with an LOI of 38.7%, a tensile strength of 4.7 MPa, and an elongation at break of 34.6%. This work provides an effective strategy for the fabrication of long-service-life flame-retardant EVA composites.

It remains a challenge to design and prepare polylactic acid (PLA) composites with a well-balanced combination of flame retardancy and mechanical performance. In this work, a nanohybrid flame retardant (HNTs-P@ZIF-67) was prepared by employing an interface-engineered strategy of nanocavity confined encapsulation and surface in-situ growth. Specifically, diphenylphosphinic acid (DPPA) was encapsulated inside the halloysite nanotubes (HNTs), and zeolitic imidazolate framework (ZIF-67) was in-situ grown on the outer surface. Benefiting from the reinforced phosphorus-containing crosslinked char layer contributed by HNTs, combined with the catalytic and adsorption effects of ZIF-67, PLA composites achieved a limiting oxygen index (LOI) of 27.2% and obtained a V-0 rating in the UL-94 test at an addition of 8%. Moreover, both the peak heat release rate (pHRR) and total heat release (THR) were reduced compared to those of control PLA. Owing to a pre-stretch strategy applied to PLA, together with the strong interfacial adhesion and excellent dispersion of HNTs-P@ZIF-67 within the PLA matrix, the PLA composites exhibited higher tensile strength and elongation at break than control PLA. This work provided a reference for developing PLA materials with high fire safety and enhanced mechanical performance, laying a foundation for their future widespread application as bio-based and biodegradable materials.