Accidental spills of hazardous and flammable liquids, such as aviation kerosene and industrial lubricants, pose severe environmental and safety risks, especially under extreme temperature conditions where conventional cleanup materials fail. Existing adsorbents are plagued by a performance trilemma, lacking the combined mechanical resilience, high adsorption capacity, and thermal stability required for effective remediation. Here, inspired by the human capillary system, we developed a biomimetic polyimide/polybenzoxazine (PI/PBOZ) aerogel with a layered "fiber-node-pore" structure. Among them, flexible PI nanofibers constitute the continuous scaffold (fibers, mimicking the compliant vascular walls), while rigid crosslinked PBOZ domains selectively localize at fiber junctions to function as "chemical rivets" (nodes, formed via strong intermolecular hydrogen bonding between phenolic hydroxyl groups on cured PBOZ and carbonyl groups on PI). The large interconnected voids between these riveted fibers form open macropores (pores, emulating the luminal channels for fluid transport). The optimized aerogel demonstrates an unprecedented combination of ultralow density (5.2 mg cm- 3), super-resilience (98% recovery after 90% strain), and massive oil uptake (up to 276 g/g for high-viscosity oils). Crucially, it maintains functionality after direct flame exposure and in cryogenic environments (-140 degrees C), with a low thermal conductivity of 0.0248 W m- 1 K-1. The material's reusability is demonstrated through combustion-based regeneration, enabling complete oil removal without generating secondary liquid waste. This strategy establishes a robust and generalizable route to high-performance porous materials for mitigating hazardous oil spills and managing thermal risks in extreme industrial and aviation environments.

Polymer aerogels for oil-water separation often need to combine high pore interconnectivity with stable elastic recovery under cyclic compression, yet these requirements are rarely compatible in conventional polyimide (PI) networks. A room-/high-temperature sequential interpenetrating polymer network (IPN) strategy is introduced to decouple pore formation from mechanical locking. Poly(hexahydrotriazine) (PHT) forms in situ at room temperature, acting as a flexible bridging network that disrupts PI lamellar stacking and induces three-dimensional pore interconnectivity. Subsequent high-temperature curing of benzoxazine (BOZ) generates rigid polybenzoxazine (PBOZ) nodes that stabilize stress distribution and enhance elastic recovery without sealing pore throats. Pure PI aerogels exhibit poor connectivity and limited resilience, while PI/PBOZ/PHT aerogels show hierarchical interconnected pores (3-15 mu m) with reduced shrinkage. Mechanistically, PHT promotes interfacial coupling and suppresses interlayer slippage, while PBOZ nodes on pore walls dominate elastic recovery and mechanical stability. The optimized aerogel exhibits superhydrophobicity (water contact angle 159.1 degrees), oil uptake of 36-70 g/g, emulsion flux up to 6971 L m(-2) h(-1) (>98% efficiency), only 3% stress decay after 30 cycles at 80% strain, low thermal conductivity (0.0333 W m(-1) K-1), and high char yield (42% at 800 degrees C). These results demonstrate that stage-specific network formation allows for the decoupling of pore connectivity and mechanical resilience, leading to enhanced transport and mechanical properties without trade-offs.

The requirement for good flame retardancy is urgent for polymers. In this work, a boron-containing spiro bisphenol (PHB) was synthesized and used to modify a typical diamine-type benzoxazine (Db). The effects of PHB with different ratios on the curing behavior, heat resistance, and thermal stability of the modified polybenzoxazines (PDb-PHBs) were studied by differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). Additionally, the flame retardancy of PDb-PHBs was investigated by the UL-94 test, limiting oxygen index (LOI), and microcalorimetry (MCC), and the degradation and flame retardancy mechanisms were investigated by scanning electron microscopy (SEM), Raman spectra, and thermogravimetric analysis-infrared (TGA-FTIR) spectra. When the addition amount of PHB was 13 wt %, the flame retardancy rating of PDb-PHB reached V-0 and the LOI value was as high as 35.2%. In addition, the ablation resistance of PDb-PHBs after carbonization was tested. This work suggests that the incorporation of this boron-containing compound is a proficient approach to enhance the flame retardancy and ablation resistance of polymers.

Organic Phase Change Materials (oPCMs) are functional and effective materials in regulating temperature changes, with broad applications such as electronic device cooling, building energy conservation, and solar thermal utilization. However, their practical deployment is hindered by issues including leakage, poor thermal conductivity, and flammability. In the current work, synthesized flame-retardant PCMs are synthesized by chemically modifying polyethyleneglycol (PEG) with a phosphorus-containing molecule. To enhance structural stability and performance, composite aerogels are fabricated using poly (vinyl alcohol) (PVA) and modified carbon nanotubes (CNT@TA) as the supporting framework materials via freeze-drying, which can effectively assimilate and translate visible sunlight energy into thermal energy. Additionally, the strong capillary force of aerogels compounded with PCMs can ameliorate the shortcoming of leakage, which can endow PCMs a large thermal conductivity (0.352 W center dot m-1 center dot K-1) and lead to a high P-PEG loading of 3613 wt% in the aerogel system. The incorporation of CNT@TA significantly enhances the photothermal conversion efficiency, achieving a remarkable value of 81.3 %. Moreover, this material exhibits excellent thermal stability to retain their original shape and structural integrity after heating at 90 degrees C for 40 min and maintain a robust thermal cycling endurance after thermally cycled for 500 times. Furthermore, the mixture of phosphorus and PVA/CNT@TA aerogel significantly reinforces the flame retardancy of PCMs, e.g., the peak heat release rate and total heat release are declined by 55.2 % and 11.9 %, respectively. This work provides a promising strategy for customizing flame-retardant PCMs to achieve efficient solar thermal energy collection and storage/release.

Oil spills have caused serious environmental problems, making oil absorbing materials highly important. Creating polymeric aerogels with compressive resilience, superhydrophobicity, high absorption capacity, and excellent regeneration capability remains challenging. In this study, polyacrylonitrile (PAN) nanofibers prepared by electrospinning were used as the aerogel skeleton, with carbon nanofiber (CNF) serving as flame retardants and conductive agents, and benzoxazine (BOZ) as a crosslinking agent. The composite nanofiber aerogels (PAN/PBOZ/CNF-x) were prepared through freeze-drying, followed by thermal curing of ring-opening of oxazine. The low-density aerogel (0.0113g/cm(3)) exhibited remarkable properties, including over 96% compressive recovery after 30 cycles at 60% strain, superhydrophobicity (WCA = 150.6 degrees), and low thermal conductivity (0.0346W/mK at 25 degrees C). Furthermore, they demonstrated high absorption capacities between 51.4 and 104.8 g/g for various organic solvents and realized rapid separation of oil-in-water emulsion, such as dichloromethane, with a maximum separation flux of 3022.59 L m(-2)h(-1). Additionally, the aerogels showed excellent thermal stability (with a char yield of 83.6 % at 800 degrees C for PAN/PBOZ/CNF-0.1 aerogel) and outstanding flame retardancy, endowing the aerogels with combustion regeneration capability, and providing a fast (similar to 1s) and durable (similar to 400s) hazard alarm response after fire removal, retaining 81.8% of their initial absorption capacity after ten combustion-absorption cycles. The multifunctionality of PAN/PBOZ/CNF-x aerogels offers a new strategy for designing advanced multifunctional aerogels.

In this study, the polyurethane materials with polyethylene glycol (PEG) segments were designed and prepared as the base material for phase change composite materials, and by incorporating paraffin and boron nitride (BN) into the materials, a series of high-enthalpy, high-thermal-conductivity phase change composite materials (PCCMs) were obtained, achieving efficient utilization of thermal energy. The thermal stability of PCCMs was analyzed through thermogravimetric analysis (TGA). X-ray diffraction (XRD), differential scanning calorimetry (DSC), accelerated thermal cycling tests, and scanning electron microscopy (SEM) were employed to study the microstructure, crystallinity, and energy storage properties of the prepared samples. The results indicated that the PAPI-PEG-PW-BN was successfully synthesized. The thermal conductivity of PAPI-PEG-PW-BN was improved by 155

Among the chemical methods of solid-solid PCMs (SSPCMs) copolymerization which are employed to overcome the brittleness and leakage of organic phase-change materials (o-PCMs), the usage of crosslinking is broad. However, the heat latent decreases with the increasing crosslink density due to the limitations of cross-linked networks on segment motion. Herein, we controlled the crosslink density of network and introduced dynamic bonds to tune phase separation and study the effects of crosslink density on different properties. In this work, pbenzoquionone dixoime (BQDO) was selected as intrinsic photothermal agent with dynamic bonds, polyethylene glycol (PEG) as phase-change ingredient, triethanolamine (TEA) as crosslinks to fabricate crosslinking polyurethane-based photothermal PCMs (PTPCMs). With the increasing crosslink density, the toughness of PTPCMs were104.3 MJ/m3, 166.4 MJ/m3 and 144.6 MJ/m3 which suggest the advantage of medium crosslinking density. The advantage of medium crosslinking density is also reflected in energy storage and photothermal transformation properties. With the increasing crosslink density, the temperature difference between two glass transition peaks of PTPCM-R1.2, PTPCM-R1.6 and PTPCM-R2.0 are 33.2 degrees C, 52.2 degrees C and 67.1 degrees C in DMA testing, which suggested the increasing phase separation. The incomplete crosslinking networks can keep excellent solvent resistance and anti-leakage properties to PTPCM-R1.6 after soaking in THF for 30 days.

Self-healing materials possess the ability to autonomously repair damaged regions, holding tremendous potential in smart devices, aerospace, material protection, and other fields. This article summarizes and organizes the research on light-triggered self-healing materials from the perspectives of light-responsive mechanisms and application domains. It introduces the distinct healing principles and effects of systems based on direct light interaction and those utilizing photothermal effects, with a focus on the various types of healing driven by photothermal mechanisms. The applications of light-controlled self-healing materials in electronics and coating protection are discussed. Insights into the challenges and future directions in the field of light-controlled self-healing materials are provided. This review aims to advance the development of self-healing materials, offering valuable references and guidance for scientific research and engineering applications, and providing new ideas for the preparation of intelligent, green, and efficient materials.

Fruits constitute a vital component of a nutritious diet but are highly perishable, contributing substantially to food waste. Consequently, identifying safe and edible biological agents to enhance product quality and extend shelf life is of critical importance. In this study, we demonstrate that exogenous pre-harvest foliar application with nanoselenium (nano-Se) in tomato enhances fruit quality, prolongs fruit shelf life, and enhances the resistance of tomato fruit to Botrytis cinerea infection. Transcriptomic analysis revealed coordinated upregulation of genes associated with quality maintenance and modulation of phytohormone-related pathways. Notably, nano-Se treatment induced expression patterns of ripening-related genes that resembled those triggered by ethylene (ET) but were antagonistic to the effects of 1-MCP. We further demonstrated that although SlMYC2 knockout increased susceptibility to B. cinerea, nano-Se application restored resistance in a manner independent of the SlMYC2-associated jasmonic acid signaling pathway, implicating ET as the primary regulatory mechanism. Collectively, these findings support nano-Se as a promising biostimulant for reducing post-harvest losses while preserving the nutritional and sensory quality of tomato fruits.

To improve the flame resistance of a standard diamine-based polybenzoxazine [poly(PH-ddm)], a trialdehyde compound (TPBA) with a triazine ring was synthesized and added with different contents as a distinctive flame retardant. The curing behaviors of the resulting resins (PH-ddm/TPBA) were analyzed using differential scanning calorimetry (DSC). Concurrently, the thermal properties of the polymers were investigated by dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA). The incorporation of TPBA facilitated additional cross-linking reactions due to the presence of aldehyde groups, which led to a higher cross-linking density within the material. The glass transition temperature (Tg) and char yield (Yc) of poly(PH-ddm/TPBA-6) were increased to 243 degrees C and 46.2%, respectively. Moreover, the flame retardancy of the modified polybenzoxazines was characterized by the UL-94 test, limiting oxygen index (LOI) test, and Micro combustion calorimetry (MCC). The addition of only 2 wt% of TPBA enabled the polybenzoxazine to achieve a V-0 rating. In addition, the mechanical property of these polybenzoxazines was studied, and the flexural strength of 120 MPa can be obtained. In this work, the polybenzoxazine with excellent flame retardancy obtained by adding a low-loading trialdehyde compound can be used in aviation and electronics fields.

Environmental and human health are significantly threatened by oily wastewater emission and oil spills. Polymeric porous aerogels are ideal materials to absorb oils or organic solvents selectively, thereby mitigating environmental pollution and protecting human health. In this study, a shapeable, super-hydrophobic, polyacrylonitrile fiber/polybenzoxazine (PAN/PBOZ) aerogel with high oil-water separation ability were successful designed. The preparation process of PAN/PBOZ aerogel is as follows: Firstly, PAN micro-nanofibers were prepared by electrospinning, and then benzoxazine was uniformly dispersed into PAN fibers. After freeze-drying and thermal curing, the aerogel was obtained. For comparative analysis, a pure polyacrylonitrile (PAN) fiber aerogel is also presented. The resulting PAN/PBOZ aerogel exhibits ultralight (0.017 g/cm3), remarkable hydrophobicity, as evidenced by a water contact angle of 156 degrees, high adsorption capacity up to 157.7 g/g for oil or organic solvents, and a high water-in-oil emulsion separation flux (9718 +/- 45 L m- 2 h-1) efficiently. Notably, the rigid cross-linking structure of PBOZ and the toughness structure of PAN make the aerogel exhibit synergistic strengthening and toughening effects. When the PAN/PBOZ fiber aerogel is compressed to 60 %, an outstanding recovery stability of its original size is displayed. While the springback of pure PAN fiber aerogel is poor under the same compression test condition. In conclusion, this study provides a preparation method and design concept of aerogel that can meet the requirements of low density, high toughness and high oil adsorption capacity. The rationally designed PAN/PBOZ aerogel shows significant potential for practical applications in treating oily and organic wastewater.

The phenomenon of high-temperature oxidation in magnesium alloys constitutes a significant obstacle to their application in the aerospace field. However, the incorporation of active elements such as alloys and rare earth elements into magnesium alloys alters the organization and properties of the oxide film, resulting in an enhancement of their antioxidation capabilities. This paper comprehensively reviews the impact of alloying elements, solubility, intermetallic compounds (second phase), and multiple rare earth elements on the antioxidation and flame-retardant effects of magnesium alloys. The research progress of flame-retardant magnesium alloys containing multiple rare earth elements is summarized from two aspects: the oxide film and the matrix structure. Additionally, the existing flame-retardancy models for magnesium alloys and the flame-retardant mechanisms of various flame-retardant elements are discussed. The results indicate that the oxidation of rare earth magnesium alloys is a complex process determined by internal properties such as the structure and properties of the oxide film, the type and amount of rare earth elements added, the proportion of multiple rare earth elements, synergistic element effects, as well as external properties like heat treatment, oxygen concentration, and partial pressure. Finally, some issues in the development of multi-rare earth magnesium alloys are raised and the potential directions for the future development of rare earth flame-retardant magnesium alloys are discussed. This paper aims to promote an understanding of the oxidation behavior of flame-retardant magnesium alloys and provide references for the development of rare earth flame-retardant magnesium alloys with excellent comprehensive performance.

Polybenzoxazines are a type of thermosetting resin with good thermal resistance. A flame-retardant and degradable polybenzoxazine (ERY-a) was synthesized by a special bisphenol containing a bridging diacetal structure (ERY) and aniline. A systematic comparative study was conducted between ERY-a and bisphenol A/aniline-type benzoxazine (BA-a). Their chemical structures were confirmed by Fourier transform infrared (FTIR) spectra and nuclear magnetic resonance (NMR) spectra. The curing behaviors and polymerization reactions were analyzed by differential scanning calorimetry (DSC) and FTIR spectra. Dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) were used to investigate their thermal properties, and the results showed that the cured ERY-a, referred to as P(ERY-a), exhibited a notable glass transition temperature T-g of 297 degrees C and a char yield of 51% under N-2 at 800 degrees C, both of which were significantly higher than those of cured BA-a. Furthermore, the flame retardancy of P(ERY-a) and ERY-a-based composites was assessed through microcalorimetry (MCC) and vertical combustion testing. The findings highlighted that the superior flame retardancy and low heat release capacity (HRC) of P(ERY-a) were due to the presence of the diacetal structure. More importantly, the cross-linked P(ERY-a) can be degraded in a solvent via the cleavage of the diacetal structure, and optimal degradation conditions were systematically studied. Moreover, the carbon fiber from the ERY-a-based composite can be easily recycled through the degradation of ERY-a.

Enhancing fire safety performance in resin-based composites is critical for mitigating fire hazards. Composites that provide early warnings during initial fire stages and maintain prolonged alarm capabilities under flame exposure are essential for minimizing injuries and property damage. This study employs chitosan (CS) as a cross-linking and char-forming agent, while carbon nanofiber (CNF) acts as a flame retardant and conductive component. Cotton fiber-reinforced chitosan/carbon nanofiber composites with varying epoxy and CNF contents (CS/CNF/EP) were prepared through a straightforward low-temperature curing process (40 degrees C, 4 h). Crosslinking polymerization between chitosan and epoxy was confirmed via Fourier Transform Infrared Spectroscopy (FTIR). The presence of the tough structure of CS and the rigid structure of EP results in a synergistic toughening and reinforcement effect in the CS/CNF/EP composites. Additionally, due to the carbon facilitating properties of CS and the enhanced conductivity of CNF, the composites exhibit a sensitive fire alarm functionality. At 35 % epoxy content, the CS/CNF/EP composites demonstrated exceptional properties, including mechanical flexibility (tensile strength of 7.09 MPa and breaking elongation of 129.05 %) and outstanding flame retardancy (LOI of 32.3 % and UL-94 V-0 rating). These composites provided a rapid alarm (similar to 1 s), sustaining a 263 s warning under flame exposure and over 35 min post-flame removal. These findings indicate that CS/CNF/EP composites, integrating mechanical flexibility, flame retardancy, and superior fire warning properties, present significant potential applications in fire safety engineering.

Near-infrared (NIR) phosphors as crucial components of NIR light sources have multifunctional and smart spectroscopy applications, prompting an increasing research interest in developing efficient and stable NIR materials. Focusing on this issue, the present study explored the luminescent properties of Cr3+-doped Ca3ZnMGe3O12 (M = Zr, Hf, Sn and Ti) garnet family. These materials exhibit an emission peak falls within the range of 785-805 nm with a full width at half maximum (FWHM) varying from 114 to 123 nm. Among them, the Ca3ZnZrGe3O12:Cr3+ phosphor shows the highest photoluminescence quantum yield (PLQY = 60.3 %) and an excellent thermal stability (I423K/I298K = 77.51 %). Moreover, the performance of a prototype Ca3ZnZrGe3O12: Cr3+-containing NIR pc-LED device was estimated, which achieves an NIR output of 23.46 mW and a photonic efficiency of 14.09% under 100 mA driving current. Non-destructive examination can be realized using this light source, demonstrating the good potential of the material in NIR spectroscopy applications.

A series of diamine-based polybenzoxazine (PDMB)/polyhexahydrotriazine (PHT) interpenetrating polymer networks (IPNs) were successfully prepared by sequential polymerization. For the IPN structures, the mechanical and thermal properties were explored. Fourier transform infrared spectrometric studies provide evidence of intermolecular hydrogen bonding (OH horizontal ellipsis O) between PDMB and PHT, and the compatibility of these two polymers was enhanced by this hydrogen bonding. The homogeneous structures in the PDMB/PHT IPNs with a micro-level phase separation were observed from scanning electron microscope analysis. PDMB, however, is too fragile to form a film. Compared to pure PHT, PDMB/PHT IPNs exhibit 190% higher tensile strength and 284% higher elongation. PDMB/PHT-0.8 reaches an elongation at break of 12.40% and tensile strength of 118.67 MPa, showing better mechanical properties than the other PDMB/PHT IPNs. Results of dynamic thermomechanical analysis indicate a higher heat resistance for PDMB/PHT-0.8, and its glass transition temperature reached 238 degrees C. (c) 2022 Society of Chemical Industry.

Oily wastewater and light crude spills are great threats to the environment and human health, polymeric porous materials for oil/water separation is a very effective method to reduce environmental pollution and protect human health. Herein, we design recycle, super-hydrophobic, and mechanically flexible silicone-based polyhexahydrotriazine (Si-PHT) aerogel for efficient oil/water separation, hexanediamine-based polyhexahydrotriazine (HDA-PHT) is also designed for parallel comparison. The Si-PHT and HDA-PHT aerogels are obtained via the cross-linking reaction between diamine and formaldehyde, followed by the atmospheric drying without any additional post-processing. The as-prepared Si-PHT aerogel shows excellent hydrophobicity (water contact angle of 154.19°). Moreover, the adsorption capacity of Si-PHT aerogel for oil or organic solvent is 22.6–40.5 times of its own weight. More importantly, the Si-PHT aerogel could be compressed to 50% of its original size with outstanding high compress strain (554.3 kPa). The major raw material for synthesis of Si-PHT and HDA-PHT aerogels are readily recoverable and further recycle. This work provides a simple prepared and recyclable porous material for oil/water separation, and a rationally designed Si-PHT aerogel shows great potential for practical applications in the treatment of oily wastewater.

Thermosetting resin matrix composites are difficult to degrade due to their irreversible cross-linking structures, which makes carbon fiber composites difficult to recycle and imposes a huge burden on environment. Here we propose a series of recycle rigid-flexible polybenzoxaizne/silicon-based polyhexahydrotriazine interpenetrating network (IPN) resins through sequential controllable curing reaction, among them, polybenzoxazine and poly-hexahydrotriazine are hard segments and soft segments, respectively, and these two crosslinked networks are interspersed with each other. The results showed char yields of these resins at 800 degrees C under N2 are up to 47.6 %. These IPN resins are used as matrix to prepare carbon fiber-reinforced composites, mechanical test results show that these composites exhibit impressive increases in tensile strength, flexural strength and shearing strength, with minimums of 2393.98 MPa, 1204.90 MPa and 111.07 MPa respectively, which are higher than those of carbon fiber reinforced composites reported. Meanwhile, due to the intermolecular hydrogen bonding, the IPN composites showed maximum water drop angle reached 129.1 degrees, which was nearly 15 degrees higher than that of polybenzoxazine composites. Additionally, these IPN matrix and fibers can be easily recycled from the com-posites by degradation without damage.

Oily wastewater and oil spills pose a threat to the environment and human health, and absorbing these harmful organics through porous aerogel materials is an efficient method for oil/water separation.