In high-end industrial sectors such as aerospace and energy equipment there is an increasingly urgent demand for ceramic fiber materials with excellent thermal insulation properties and good flexibility under extreme high-temperature conditions. Traditional ceramic fibers have shown significant progress regarding high-temperature resistance and mechanical properties. Recently zirconia-based ceramic fibers have attracted considerable attention due to their ultra-high temperature limits extremely low thermal conductivity outstanding thermal stability and phase transformation strengthening effects. Collectively these characteristics demonstrate exceptional comprehensive performance and significant potential for engineering applications. This paper systematically reviews the progress of domestic and international research on the preparation of flexible zirconia-based fibers. It focuses on the principles and characteristics of mainstream spinning technologies including electrostatic spinning centrifugal spinning and dry spinning as well as their effects on the structural properties of the fibers. Electrostatic spinning technology is capable of producing continuous nanofibers with a uniform diameter distribution and a large specific surface area however it faces limitations in macroscale production efficiency and fiber strength. In contrast centrifugal spinning offers high preparation efficiency and is suitable for large-scale production of micrometer-scale fibers although there is still room for improvement in controlling fiber orientation. Dry spinning is compatible with certain polymer precursor systems and allows for good control of fiber morphology. However it does not enhance fiber orientation control during high-temperature firing and is susceptible to structural defects during high temperature sintering. In this paper the flexibility mechanism is elucidated as originating from microscale regulation achieved via doping. At the microscopic level doping regulates crystalline phases and alleviates stress through optimization. At the mesoscopic level it controls grain size and suppresses intergranular cracking. Ultimately at the macroscopic level it achieves collaborative energy dissipation through synergistic interactions between the fibers and their network structure. By regulating the spinning process it is possible to optimize the internal grain size pore distribution and phase composition of the fibers thus balancing their thermal insulation and flexibility. Under extremely high temperatures strong thermal shocks and complex stress environments these materials demonstrate good structural integrity and thermal stability indicating broad application prospects in aerospace thermal protection systems high-thrust-to-weight-ratio engine insulation high-temperature pipeline insulation for energy equipment and key components of next-generation nuclear energy systems. Despite significant advancements in the research of flexible zirconia-based fiber materials several challenges remain in their practical engineering applications including insufficient long-term thermal stability loss of flexibility in high-temperature environments immaturity of continuous preparation technology and high production costs. Future research should prioritize the optimization of fiber formation and the exploration of multiscale structural control strategies to enhance the overall performance and durability of these fibers. Additionally efforts should aim to the advance the preparation process towards environmentally friendly cost-effective and large-scale production. Promoting the integrated design of material structure and function will further accelerate the application of flexible zirconia-based ceramic fibers in high-end equipment.

Fiber‑reinforced polymer composites are increasingly critical in sectors like aerospace wind energy and transportation with excellent specific strength and specific modulus. As components evolve toward larger sizes and greater complexity manufacturing processes face stringent demands for efficiency cost‑effectiveness and quality stability. Vacuum‑assisted resin infusion VARI as a mainstream low‑cost liquid composite molding technique has become the preferred solution for the production of large‑scale components. However the quality of these components is intrinsically governed by the resin' s impregnation efficiency into the fibrous preform and improper flow control often leads to defects such as dry spots and microscopic voids thereby limiting the improvement of component performance. Therefore precisely adjusting the rheological characteristics of the resin and deeply understanding its permeation mechanism are key to overcoming the quality bottlenecks of this process. This review examines the physical correlations between viscosity evolution and multi‑scale impregnation quality. Macroscopically resin flow is described by Darcy' s law with corrections for non‑Newtonian behaviour in nano‑modified systems. Microscopically the competition between viscous and capillary forces defined by the modified capillary number criterion establishes an optimal processing window to minimise defects. Chemo‑rheological models provide the theoretical basis for predicting flow fronts and gelation. To achieve a low initial viscosity and a long processing window the paper systematically summarizes chemical and physical regulation strategies. Chemically molecular design and reactive diluents reduce intrinsic viscosity while latent curing agents maintain a low‑viscosity state before triggered cross‑linking. Physically the review compares heating methods highlighting the limitations of traditional oven curing and the advantages of field‑assisted techniques like microwave and induction heating. Special emphasis is placed on "Out‑of‑Oven" technologies such as self‑regulating Joule heating and Frontal Polymerization which enable energy‑efficient in‑situ curing. Beyond rheology synergistic enhancements are discussed including optimised pressure fields to improve compaction and permeability and the development of sustainable bio‑based flow media. The trend towards structural‑functional integration is also noted where consumables like conductive meshes are transformed into permanent functional layers of the component. At the digital level process numerical simulation has evolved into a multiphysics coupling model encompassing flow heat transfer and curing which can be accelerated through integration with machine learning. Meanwhile various in‑situ monitoring techniques provide data support for closed‑loop control. Looking ahead the VARI process is expected to follow three major development trends green manufacturing centered on oven‑free curing and eco‑friendly consumables intelligent manufacturing based on digital twins and integrated manufacturing that deeply combines process and functionality. This comprehensive review aims to provide theoretical guidance and technical pathways for the high‑quality sustainable and cost‑effective manufacturing of advanced composite structures.

As a typical metal‑organic framework MOF material cobalt‑based zeolitic imidazolate framework‑67 ZIF‑67 possesses a high specific surface area abundant active sites and excellent PMS activation capability which enables it to efficiently promote the degradation of dyes such as methylene blue MB . However ZIF‑67 usually exists in powder form and tends to agglomerate and is difficult to settle in practical water treatment systems. This leads to difficulties in catalyst recovery which not only causes resource waste but also may introduce secondary pollution due to cobalt ion leaching severely limiting its engineering application. Therefore the development of ZIF‑67‑based composite support materials with high catalytic performance good dispersibility and easy recoverability has become a critical direction to overcome the aforementioned bottlenecks. In this study sugarcane—an abundant environmentally friendly raw material with a natural highly oriented and hierarchical porous structure—was used as the starting material. Sugarcane cellulose was subjected to selective oxidation using a 2 2 6 6‑tetramethylpiperidin‑1‑oxyl TEMPO oxidation system converting the hydroxyl groups on the cellulose surface into carboxyl groups. Subsequently sugarcane nanocellulose aerogels SNCA with a three‑dimensional porous network structure were prepared via a freeze‑drying process. On this basis ZIF‑67 was introduced into the porous channels of SNCA by an in‑situ growth method. The loading amount and dispersibility of ZIF‑67 in SNCA were regulated by controlling the number of ZIF‑67 assembly cycles 1‑4 cycles and a series of ZIF‑67@SNCA composite aerogels were finally constructed. The microstructure chemical composition and surface properties of the materials were characterized by means of scanning electron microscopy SEM X‑ray photoelectron spectroscopy XPS specific surface area analysis and other techniques. Moreover in the PMS activation system MB was used as the target pollutant to systematically investigate the adsorption performance catalytic degradation efficiency and cyclic stability of the composite aerogels. The results indicate that TEMPO oxidation treatment significantly increases the carboxyl content on the surface of SNCA. The carboxyl groups can form a coordination interaction with Co²⁺ in ZIF‑67 which effectively inhibits the agglomeration of ZIF‑67 nanoparticles and enables the uniform dispersion of ZIF‑67 within the porous network of SNCA. The loading rate of ZIF‑67 in ZIF‑67@ SNCA‑4 reaches as high as 32. 47%. BET tests show that the prepared ZIF‑67@SNCA‑1 composite aerogel has a high specific surface area of 217 m²/ g. Its three‑dimensional porous structure not only provides sufficient adsorption sites for MB molecules with an adsorption capacity of 8. 15 mg / g but also accelerates the mass transfer efficiency of PMS and active free radicals. In a high‑concentration MB solution 50 mg / L the catalytic degradation rate of ZIF‑67@ SNCA‑4 in the PMS activation system remains at 92. 15% and deep degradation of MB can be achieved within 60 min of reaction. Within a wide pH range of 4‑9 there is no significant change in catalytic degradation performance which overcomes the defect of activity attenuation of traditional cobalt‑based catalysts under extreme pH conditions. In addition after 5 adsorption‑desorption cycles the catalytic degradation rate of ZIF‑67@SNCA remains above 90%.

With the widespread application of carbon fiber, glass fiber and natural fiber‑reinforced composites in aerospace, civil engineering and high‑end equipment manufacturing, fracture and failure issues induced by surface defects have received increasing attention. These composites typically exhibit quasi‑brittle fracture characteristics, with crack propagation behavior influenced by material heterogeneity, anisotropy and size effects. In engineering practice, the fracture performance of large‑scale components is often evaluated based on small‑scale specimen tests; however, conventional fracture mechanics methods cannot effectively eliminate the influence of size effects on fracture parameter identification, thereby limiting the applicability of experimental results to engineering structures. Therefore, developing a theoretical model capable of stably predicting intrinsic fracture parameters from small‑scale specimens holds significant engineering relevance.The boundary effect model provides an effective theoretical framework to address the size effect problem in quasi‑brittle material fracture. The model posits that the essence of size effects originates from the interaction between the fracture process zone at the crack tip and the specimen boundary conditions, and it quantitatively characterizes this effect by introducing the equivalent crack \(a_\text{e}\). Building on this concept, the boundary effect model further incorporates the characteristic composite unit \(C_\text{ch}\), introducing material microstructural features into the fracture analysis. This approach allows a unified description of crack propagation behavior and actual failure modes while reducing computational complexity. Within this framework, the fracture behavior of composites can be classified into three regimes: strength‑controlled, toughness‑controlled and transitional ones. This classification facilitates the elucidation of the intrinsic relationship between crack propagation mechanisms and the governing fracture parameters.Based on the boundary effect model framework, this review systematically summarizes its application progress in the fracture analysis of quasi‑brittle composites, including carbon fiber, glass fiber, bamboo fiber and ceramic‑reinforced materials. The focus is placed on its application to predicting crack propagation behavior, ultimate load capacity and damage modes. Relevant studies indicate that the model can stably identify intrinsic tensile strength \(f_\text{t}\) and fracture toughness \(K_\text{IC}\) using small‑scale three‑point bending test data, effectively mitigating the influence of size effects on fracture parameter determination and significantly improving prediction accuracy. By introducing the characteristic composite unit \(C_\text{ch}\), the boundary effect model demonstrates good applicability and engineering potential for quantitatively describing fracture behavior in multiphase composites, providing important theoretical support for the safe design, damage assessment and reliability evaluation of composite structures.

Carbon nanotube (CNT)‑reinforced silk fibroin (SF) composites are limited by weak interfacial bonding, which restricts their application in impact‑resistant protective systems. This study aims to address interfacial incompatibility through chlorosulfonic acid (CSA)‑assisted densification combined with surface modification strategies, so as to construct a reliable design system for bio‑inspired nanocomposites under extreme dynamic loads. Three interfacial engineering strategies‑oxygen plasma etching, nitric acid oxidation and polydopamine (PDA) coating‑were applied to CSA‑densified CNT films pre‑treated with CSA for structural alignment before hot‑pressing impregnation with SF solution. CSA densification ensured uniform CNT alignment prior to surface modification, which is critical for enhancing interfacial bonding. PDA‑coated densified CNT / SF films exhibited optimal performance, achieving a dynamic fracture strength of 2138.74 MPa and a specific energy absorption of 104.01 MJ/m³, representing 150.14% and 128.26% improvements over CNT/SF films respectively. Plasma‑treated densified CNT/SF films showed corresponding values of 1491.56 MPa and 94.75 MJ/m³. XPS analysis revealed that PDA‑treated CNTs achieved a nitrogen content of 3.52%, compared to 2.11% for plasma‑treated samples, confirming selective functionalization. Dynamic tensile fracture morphology indicated that PDA composites maintained smooth surfaces with tightly aligned CNT bundles. Strain‑rate sensitivity analysis showed that the strength of PDA composites increased by 43.4% from quasi‑static to dynamic loading (1491.56 MPa to 2138.74 MPa), while that of plasma‑treated composites only increased by 12.7%. PDA coating uniquely enables simultaneous CNT surface functionalization (13.61% O‑content and 3.52% N‑content) and SF matrix infiltration without fiber damage, outperforming plasma‑induced fragmentation and acid‑mediated purification. Moreover, PDA composites exhibit a 43.4% strength enhancement at 1900 s⁻¹ compared to quasi‑static conditions, demonstrating interfacial activation under dynamic loading. The optimized composite achieves a specific energy absorption of 104.01 MJ/m³ that surpasses commercial polycarbonate (35‑50 MJ/m³) while maintaining biocompatibility.

High‑quality goose down is widely used in thermal insulation products due to its excellent loft, thermal insulation performance and softness, and its market value is significantly higher than that of duck down. However, in actual production, different types and qualities of down materials are often mixed, which seriously affects product quality and consumer trust. At present, the identification of goose down and duck down mainly relies on manual visual inspection, which is highly subjective and inefficient, and is prone to misjudgment and missed detection when dealing with down barbule clusters with small scales and complex structures. Although previous studies have attempted to apply traditional machine learning and deep learning methods to down classification, achieving high‑precision and real‑time automatic recognition remains challenging due to the weak visual features of barbules and the high proportion of small targets. To address these issues, this paper proposed a lightweight detection model named FCA‑YOLO based on feature fusion and attention mechanisms for automatic down type identification. First, a dedicated down image acquisition system was designed and constructed to collect high‑resolution grayscale images at a magnification of 914×, and a specialized dataset containing goose and duck down barbule clusters was established with manual annotation. Second, based on the YOLOv4‑tiny architecture, a large‑scale shallow feature layer Feat3 was introduced to preserve more spatial detail of small targets at the early stages of the network, thereby enhancing the detection capability for fine structures such as down barbules. Meanwhile, a convolutional block attention module (CBAM) was embedded to adaptively optimize feature representations from both channel and spatial dimensions, enabling the network to focus more effectively on discriminative regions. Furthermore, an attentional feature pyramid network (AFPN) was incorporated to fuse multi‑scale features, effectively alleviating information loss and semantic inconsistency commonly encountered in traditional feature pyramids during non‑adjacent layer fusion. Extensive experiments were conducted to systematically evaluate the proposed model in terms of detection accuracy, robustness and computational efficiency. Ablation studies demonstrate that each introduced module contributes positively to performance improvement. The complete FCA‑YOLO model achieves a mean average precision (mAP) of 76.14% on the test set, representing an improvement of 8.24% over YOLOv4‑tiny. Comparative experiments with YOLOv4, YOLOv4‑tiny, Faster R‑CNN, YOLOv4‑MobileNetV3, RTDETR‑ResNet50, YOLOv8n and YOLO12n further verify that FCA‑YOLO achieves a favorable balance between detection accuracy and computational complexity, particularly excelling in small‑scale goose down barbule cluster detection tasks. In single‑image recognition, the model attains an overall classification accuracy of 98.4% for goose down, duck down and unknown down, with an average inference time of only 0.01 s per image. The experimental results indicate that FCA‑YOLO significantly enhances fine‑grained down recognition performance while maintaining a compact architecture and low computational cost, demonstrating strong potential for real‑time detection and embedded deployment applications.

To address the long‑standing issues of high impact, high wear and the difficulty in achieving both high energy transfer efficiency and high impact strength in the weft insertion mechanism of shuttle looms, this study innovatively proposed a dimensionless parameter—the cosine coupling coefficient C of the shuttle insertion pressure angle.This study first established a dynamic analytical model with coefficient C as the core variable based on the classical impact theory by equating the oblique impact between the shuttle rotor and the shuttle nose to a two‑mass collision model concentrated at the contact point. Through theoretical derivation, explicit expressions for the impact impulse \(\int P\mathrm{d}t\), post‑impact velocities \(u_1\) and \(u_2\), effective impact force component \(P_\mathrm{e}\) and kinetic energy transfer efficiency \(\eta\) were obtained. The model parameters were derived from the precise measurement of a 1515K‑135 type shuttle loom weft insertion mechanism used for denim weaving, with the measurement conducted using a RoyalArm RA325 portable three‑coordinate measuring arm to ensure the geometric accuracy of the model. Based on the derived explicit expressions, the regulation law of coefficient C on the performance of the weft insertion mechanism was revealed through numerical analysis: ① in terms of impact load, the effective impact force component \(P_\mathrm{e}\) monotonically increases with the increase of C value, indicating that a higher C value intensifies the impact; ② as for motion performance, the velocity \(u_2\) transferred to the shuttle nose shows good kinetic energy transfer efficiency around \(C=0.889\), while the rebound velocity \(u_1\) of the shuttle rotor decreases with the increase of C, which is beneficial for smooth operation; ③ with regard to energy efficiency, the kinetic energy transfer efficiency \(\eta\) monotonically decreases with the increase of C value, indicating that high impact load and high transfer efficiency cannot be achieved simultaneously.To verify the correctness of the theoretical model, a rigid‑flexible coupling multi‑body dynamics simulation model was established in the ADAMS software. Simulations were conducted under three center shaft rotation speeds of 125, 150 and 175 r/min, and the impact impulse and shuttle rod angular velocity response data were extracted from the simulation results for quantitative comparison with theoretical predictions. The results showed that the relative error between the theoretical value of the impact impulse and the average value of the simulation was within 15%, the error between the theoretical prediction of the peak angular velocity of the shuttle rod and the simulation result was less than 7%. These results verified the reliability and engineering applicability of the theoretical model from the perspectives of momentum transfer and motion response.Through theoretical modeling and simulation verification, this study for the first time integrated the geometric effects of the two independent pressure angles of the shuttle rotor and the shuttle nose into a unified parameter C, and quantitatively revealed its regulation mechanism on the impact dynamics of the weft insertion mechanism. The research conclusion indicates that coefficient C is an important design parameter. In practical engineering optimization, there is no need to precisely pursue the extreme value of C, but rather to make trade‑offs within the range of C less than a certain extreme value point (in this model \(C<0.889\)) based on different emphases on low impact, high efficiency or low rebound. This provides theoretical guidance and parameterized design paths for achieving multi‑objective optimization of the performance of the weft insertion mechanism in shuttle looms.

Driven by the dual demands of wearable hyperthermia and real‑time information interaction, a one‑step embroidery‑only strategy that simultaneously achieves low‑voltage Joule heating and pixel‑level thermochromic display is proposed to overcome the uneven heating, poor breathability and easy delamination of conventional electrothermal films or coated fabrics. With 210 D silver‑plated polyester conductive yarn as both top and bottom threads, subsequently replaced by 31 ℃ pink‑to‑white thermochromic yarn for the display top thread, 5×5, 6×6 and 7×7 arrays of three‑dimensional spherical bulges were embroidered on a 40 mm×40 mm non‑woven substrate via computerized embroidery. A 0.065 mm copper foil was adhered to the sample's back to establish a row‑column addressing circuit and electrothermal‑chromic performance was evaluated under 3‑7 V DC using an infrared thermal imager. The 7×7 array exhibited a resistance of 44.7 Ω and reached a steady‑state temperature of 59.6±0.5 ℃ after 480 s at 7 V with a power density of 687 W/m². The 5×5 array with a resistance of 33.2 Ω achieved a peak temperature of 92.6±0.5 ℃ at 7 V and a power density of 923 W/m². The 6×6 array with a resistance of 39.4 Ω stabilized at 70.7±0.5 ℃ with a power density of 778 W/m². Throughout the test, temperature increased linearly with the square of the applied voltage, showing no hysteresis or drift. During 4 V heating/cooling cycles, all samples reached their maximum temperature within 60 s and cooled to 23 ℃ within 70 s. Stepwise heating from 3‑7 V showed monotonically increasing plateau temperatures at each voltage level with clear thermal gradients among samples of different densities. The 7×7 sample underwent five on‑off cycles at 4 V, 5 V and 6 V with the first and fifth cycles overlapping perfectly. Bending the sample along either the transverse or longitudinal direction causes only negligible resistance fluctuation, remaining close to the initial value. Infrared thermal images revealed that heat initially concentrated at the three‑dimensional spherical bulges and then spread uniformly across the substrate. For display samples with copper foil attached to the back, activating single points, multiple points or entire rows/columns caused only the intersecting protrusions to heat. At 31 ℃, the pink front surface instantly turned white, enabling controllable color switching in a 7×7 pixel matrix. The three‑dimensional embroidery structure integrates conductive paths and thermochromic pixels into one, delivering uniform cyclic electrothermal output and a visual dot‑matrix display at safe voltages ≤7 V. The process is fully compatible with existing computerized embroidery production lines, offering a low‑cost scalable route for smart thermotherapy garments, rehabilitation patches and wearable dynamic signage.

Triboelectric nanofiber‑based pressure‑sensing yarns demonstrate broad application prospects in healthcare monitoring, human motion capture and smart home interaction systems due to their efficient biomechanical energy collection, sensitive posture perception and excellent flexibility. However, current triboelectric sensing systems are prone to interference from tensile strain and environmental factors e. g. temperature/humidity during practical pressure detection, causing significant signal distortion. This critical bottleneck severely restricts their large‑scale deployment in wearable scenarios. An ideal flexible pressure sensor must combine superior stretchability, biocompatibility and mechanical stability to accommodate dynamic human contact, while crucially maintaining pressure signal independence and accuracy under high‑strain conditions. Nevertheless, existing sensors often exhibit signal crosstalk induced by multi‑physics coupling effects e. g. triboelectric‑mechanical interplay during stretching, further exacerbating application constraints and demanding targeted breakthroughs. To effectively address the aforementioned technical challenges, this paper innovatively proposes a design scheme for triboelectric nanofiber sensing yarns that integrates a core‑sheath separation structure and an embedded helical configuration. During the preparation process, firstly conjugate electrospinning technology is employed to coat polyvinylidene fluoride (PVDF) and nylon 11 (PA‑11) nanofiber layers with outstanding triboelectric properties onto the surface of highly conductive silver‑plated nylon filaments, constructing core‑sheath structured single yarns; subsequently a precision twisting process is adopted to fabricate twisted yarns for enhanced structural stability and triboelectric response efficiency; differential wet spinning technology is utilized to uniformly encapsulate the twisted yarns in a highly elastic polyurethane matrix, forming one‑dimensional sensing units with a self‑assembled helical configuration. This core design efficiently activates the triboelectric effect under compression via the twisted structure while the embedded helical configuration buffers mechanical stress and maintains structural integrity under tensile deformation, thereby achieving effective decoupled transmission of pressure and strain signals. Experimental test results show that the as‑prepared triboelectric nanofiber sensing yarns exhibit excellent comprehensive performance, their breaking elongation exceeds 400%, within the tensile strain range of 0‑100%, the strain interference suppression rate remains stably above 98%, which can effectively shield the interference of tensile conditions on pressure detection, presenting outstanding anti‑tensile‑interference performance and stable reliable pressure‑response characteristics. This study not only provides an efficient material platform and key technical route for the next generation of highly robust wearable sensing systems but also offers important technical insights and theoretical support for the development of anti‑interference sensing systems in smart wearable devices.

Regarding the fixing method of the filling of down products, quilting or hot rolling is generally adopted to combine the inner and outer layers of high‑density fabrics to form a flocculent filling cavity. After filling with down, there will be a small amount of down filling near the quilting line or hot rolling point and the thickness difference with other filling parts is big, or even only the inner and outer layers of fabric without down, which will have an impact on the overall warmth of the down products. In the vicinity of the quilting line or hot rolling point of a down product where the filling density is small, the thickness difference with other filling parts is large and there exists a warmth‑retaining weak link. To address the above defects, a multi‑chamber quilting‑free three‑dimensional filling base fabric was developed using multi‑layer weaving. The filling cavities arranged alternately along the warp direction can enhance filling uniformity and eliminate thermal weaknesses. The filling cavity width and filling density were selected as the influencing factors of filling thermal insulation performance. Down filling samples were made with different filling cavity widths and different filling densities. A three‑dimensional model of “skin‑down‑filling base fabric” was constructed using SolidWorks. The finite element thermal analysis module of ANSYS Workbench was utilized to simulate and analyze heat transfer for models with varying cavity widths and filling densities. The results obtained from simulation were analyzed and compared with experimental data to validate the model’s accuracy. The results show that the staggered arrangement of filling cavities of this multi‑chambered non‑quilted filling base fabric can improve the filling uniformity and warmth retention. The down‑filled samples have uniform heat transfer in the X‑axis direction, the direction of the staggered arrangement of cavities, without the uneven heat transfer phenomenon caused by the filling defects of conventional quilting or hot‑rolled structures. At the same filling density, thermal insulation performance improves as the width of the filling cavity increases since a greater volume of stationary air is retained within the cavity. The simulation solution results of the finite element heat transfer model are in good agreement with the experimental results with an error of 3.53%, which has high prediction accuracy and important guiding significance. The model can be used for the subsequent improvement research of quilt‑free multi‑chamber three‑dimensional filling base fabric, which can greatly shorten the experimental time, improve the efficiency, reduce the cost and simplify the production process. By presetting the base fabric material parameters, the thermal insulation properties of products with varying cavity sizes and down fill quantities can be rapidly predicted. This provides reference for the development and optimized design of down products, particularly those intended for use in extreme cold conditions.

The global textile industry is facing the challenges of resource consumption, environmental pollution and low recycling rate of waste fibers. The research and development of green and sustainable textile materials has become an urgent need. As a natural nanofiber material synthesized by microorganisms, bacterial cellulose has great application potential in the textile field due to its high purity, high crystallinity, excellent biocompatibility and controllable three‑dimensional nanonetwork structure. However, its original form has defects such as insufficient mechanical properties and lack of functional characteristics, which restricts the practical textile application. In recent years, the research on modified bacterial cellulose film materials has become more and more extensive, and its modification mechanism and strategy have gradually become clear, which provides important support for breaking through the performance bottleneck and promoting its innovative application in the textile field. At present, researchers have developed a variety of modification strategies, which are mainly divided into two major technical routes: in‑situ and ex‑situ. Substantial research focuses on in‑situ modification, optimizing intrinsic structure and properties through intervention during synthesis. These studies reveal three primary reinforcement mechanisms: fiber‑scale filling and defect repair, enhanced intermolecular interactions, and fiber assembly and orientation regulation. Conversely, ex‑situ modification research fully exploits the loading and reaction potential of bacterial cellulose networks post‑synthesis. This is achieved primarily through physical impregnation with antimicrobial nanoparticles or conductive polymers, chemical grafting to introduce stable functional groups, or nanomorphological restructuring to transform the material into nanofibers/nanocrystals serving as high‑performance functional carriers. These approaches successfully endow the material with diversified functions such as antimicrobial properties, electrical conductivity and UV protection. The current research has gone beyond simple form imitation and single performance improvement and entered a new stage of multi‑strategy coordination and fine regulation of "structure‑function" correlation. The focus is on the integration of high strength, high toughness and specific functions, overcoming the problem of performance trade‑off and providing innovative possibilities for high‑end medical textiles, smart wearable textiles and other fields. Systematic modification strategies are pivotal to unlocking the textile application potential of bacterial cellulose. In‑situ modification fundamentally optimizes its structure and mechanical properties by regulating the biosynthetic process, while ex‑situ modification leverages its nanoscale network to precisely introduce and expand functionalities. Together these form a complementary technological framework of "strengthening fundamentals" and "expanding capabilities". Future research needs to focus on the core challenges of industrialization, achieving breakthroughs in multifunctional synergistic optimization and long‑term performance stability, developing green low‑cost scalable production processes to reduce environmental impact, and ultimately propelling bacterial cellulose‑based materials from promising laboratory outcomes into large‑scale high‑value commercial textile products.

To prepare high‑viscosity bio‑based poly(ethylene 2,5‑furandicarboxylate) (PEF), three kinds of PEF samples were compared. The effects of liquid‑phase polycondensation conditions including reaction time, temperature, melt‑film thickness and vacuum degree on polycondensation rate, thermal properties and rheological properties were investigated. The results show that liquid‑phase polycondensation can effectively increase the intrinsic viscosity of PEF. For low‑viscosity PEF with intrinsic viscosity of 0.498‑0.680 dL/g, the intrinsic viscosity can reach 0.927‑1.20 dL/g after reaction at 230 ℃ for 4 h. Increasing reaction temperature and vacuum degree as well as reducing melt‑film thickness accelerates the reaction, while excessive temperature aggravates side‑reactions such as degradation. Under identical conditions, polycondensation rate depends not only on carboxyl end‑group concentration but also on catalytic system, and titanium‑based catalyst exhibits superior performance. PEF presents low crystallization rate and crystallinity, and its crystallization capacity is further weakened with the increase of viscosity. Liquid‑phase polycondensation remarkably improves thermal stability of PEF. As the intrinsic viscosity of PEF‑2 increases, the initial thermal decomposition temperature \(T_\text{id}\) rises from 368.0 ℃ (PEF‑2‑0.498) to 372.7 ℃ (PEF‑2‑0.925), and the temperature at maximum decomposition rate \(T_\text{max}\) increases from 386.9 ℃ (PEF‑2‑0.498) to 393.8 ℃ (PEF‑2‑0.925). PEF is a viscosity‑dominated viscoelastic complex fluid, whose complex viscosity decreases with oscillation frequency \(\omega\), showing shear‑thinning behavior. Both complex viscosity and shear‑thinning degree increase with intrinsic viscosity. At fixed frequency, complex viscosity and zero‑shear viscosity decrease with rising temperature. The viscous flow activation energy increases from 47.80 kJ/mol (0.1 rad/s) to 98.30 kJ/mol (100 rad/s), indicating that polymer viscosity is more sensitive to temperature at high frequency. This study systematically reveals the process‑structure‑property relationship during liquid‑phase polycondensation of PEF, and puts forward an efficient process window for PEF polycondensation, overcoming the limitations of traditional polycondensation routes. It provides theoretical insights and technical support for green and efficient preparation of high‑quality high‑molecular‑weight PEF, and possesses great engineering value and industrial potential for promoting the application of bio‑based polyesters in high‑end packaging, fibers and other fields.

As a natural cellulose fiber, pineapple fiber features eco‑friendliness, biodegradability and excellent mechanical potential, which makes it an important sustainable raw material for textile industry. Non‑cellulosic gums such as pectin, hemicellulose and lignin are tightly adhered inside and on fiber surface, resulting in stiff fiber bundles, rough hand‑feel and poor cohesion, which cannot satisfy spinning requirements. Therefore, degumming is essential to remove these gums and obtain fiber bundles with appropriate length and strength, which is the primary procedure for textile application of pineapple fibers. At present, industrial degumming mainly adopts strong‑alkali boiling chemical process. Although it can remove gums effectively, it has disadvantages including high energy consumption and long treatment time. Moreover, it may degrade cellulose molecular chains and cause fiber damage and strength loss. To solve the above problems, an NHPI‑assisted Na₂CO₃/H₂O₂ synergistic catalytic oxidation degumming system was established in this paper. Sodium carbonate provides mild alkaline environment to dissolve partial gums and activate H₂O₂ to produce hydroxyl radicals (·OH). The key innovation is introducing small‑molecule organic catalyst NHPI. Under alkaline conditions, NHPI is oxidized by H₂O₂ to generate highly reactive N‑oxyl radicals (PINO) and oxoammonium cations (PINO⁺). These active species selectively oxidize non‑cellulosic components and degrade them into water‑soluble small molecules for removal. They preferentially act on C6 primary hydroxyl groups of cellulose, with little damage to β‑1,4‑glycosidic bonds of cellulose backbone. Therefore, efficient degumming is realized while protecting cellulose skeleton. Taking residual gum content and breaking strength as core evaluation indexes, single‑factor experiments were carried out to investigate the effects of process parameters, and Box‑Behnken response surface methodology was used for process optimization. The optimal conditions are as follows: Na₂CO₃ 9 g/L, H₂O₂ 7.8 g/L, NHPI 0.8 g/L, temperature 90 ℃, time 120 min. Under the optimal conditions, residual gum content is 6.86%, breaking strength reaches 4.05 cN/dtex, and the error compared with predicted values is below 2.7%. Compared with single alkali degumming, breaking strength increases by 10.1% and whiteness increases by 26.3%. SEM shows smooth fiber surface without cracks. XRD verifies well‑preserved cellulose crystalline structure with crystallinity of 58.5%. This synergistic catalytic oxidation system achieves a good balance between degumming efficiency and fiber protection, showing broad application prospect for pineapple fiber degumming.