Flexible wearable sensors based on conductive hydrogels demonstrate immense potential in health monitoring and medical diagnostics. However, it remains challenging to balance high strength, conductivity, and environmental stability. Inspired by honeycomb networks, a tough and multifunctional cellulose nanofibers reinforced hydrogel was engineered via regional crystallization and multiple crosslinking strategy. Specifically, cellulose nanofibers and cyclic freeze-thaw treatment were used to modulate the pore structure of hydrogels, and zinc sulfate and ethylene glycol were introduced to endow with multifunctionality. The resulting hydrogel-based strain sensor exhibits remarkable tensile strength (4.32 MPa), fracture strain (868.2%), and toughness (20.2 MJ/m3). The electron-conduction arose from CNTs complements the dominant ion-conduction in hydrogel, compensating for the electrical performance degradation caused by environment. It demonstrates excellent antifreezing property with a low freezing point of -39.7 degrees C, and maintains a high conductivity of 2.61 S/m even at -20 degrees C. The hydrogel sensor can sensitively detect human motion and health signals in real time. An identification accuracy of 99.6% in electrical signals was achieved by optimizing a deep learning algorithm. This work provides a promising strategy to develop high-performance flexible wearable sensors in training and health monitoring applications.

The key challenge in developing sustainable lignocellulosic materials lies in the simultaneous enhancement of mechanical performance and environmental friendliness without synthetic adhesives. Herein, inspired by the microstructure of bee tarsal setae, we propose a novel strategy integrating in-situ nanofiber liberation with lignin retention as a biomacromolecule binder to fabricate self-bonded bamboo fiber material (S-BFM). Unlike conventional delignification approaches, our method preserves native lignin, which undergoes hydrothermal softening during hot pressing to reinforce inter-fiber bonding, while water-induced swelling promotes robust micro/nanofiber interlocking. Molecular dynamics simulations revealed that retained lignin strengthened intermolecular interactions. The S-BFM achieved excellent mechanical strength of 59.4 MPa, exhibiting a 748.6% increase compared to untreated controls. Furthermore, after silane coupling modification, the material exhibited exceptional dimensional stability with a thickness swelling of only 7.3% (24 h), far superior to unmodified S-BFM (55.4%). The material also demonstrated high thermal stability (decomposition temperature up to 376.9 °C) and a favorable life-cycle environmental profile. This bioinspired design resolves the long-standing trade-off between mechanical robustness and ecological sustainability, offering a promising alternative to conventional plastics for high-performance applications such as smart card substrates.

Traditional indoor heating materials, such as metals and their oxides, are non-renewable and energy-intensive. Lignocellulosic fiber composites represent a sustainable alternative, yet a key challenge lies in simultaneously achieving high electrical conductivity, robust mechanical performance, and adhesive-free processing for indoor heating applications. Here, lignocellulosic binder-free composites (LBCs) with good electrothermal properties is constructed through self-bonding technology. Through mechanical refining, nanofibers were generated and exposed on the fiber surface, enabling effective anchoring of inorganic nanoparticles. The LBCs demonstrated exceptional mechanical properties with a tensile strength of 56.1 MPa. Importantly, it exhibited an electrical conductivity of 557.1 & times; 10- 3 S/m, significantly surpassing that of lignocellulosic fibers (LF) and LF/GO (3.1 & times;10- 3 S/m). This superior performance was attributed to the in-situ growth of iron oxide nanoparticles (IONPs) and the impregnation of graphene oxide (GO). They were anchored on fibrillated fibers via H-bond mediated interactions. Molecular dynamics (MD) analysis verified the enhancement of intermolecular interaction between inorganic nanoparticles and fibers. The temperature of LBCs could be rapidly increased by 9.3 degrees C in 10 min by Joule heating under low voltage. The enhanced electrothermal performance was due to the conductive pathways formed by anchoring inorganic nanoparticles. The introduction of inorganic nanoparticles also improved the thermal conductivity, which paves the way for the application of LBCs in indoor heating.

ABSTRACT Ionic thermoelectric hydrogels show great potential for wearable electronics and low‐power energy harvesting. Achieving high ionic conductivity, large Seebeck effect, mechanical robustness, and environmental stability simultaneously remains challenging. Inspired by natural wood mass transport, we fabricated a wood‐based ionic thermoelectric hydrogel (WPCH) retaining its skeleton structure. The vertically aligned anisotropic wood channels offer mechanical stability and oriented ion transport pathways. The rigid skeleton overcomes the low compression resistance of cellulose‐based counterparts, well balancing thermoelectric performance, mechanics, and environmental stability. Benefiting from oriented, continuous ion transport channels formed by the wood–poly(vinyl alcohol) network, WPCH exhibits a high ionic conductivity of 39.94 mS cm −1 . Strong solvation/coordination interactions between Li + ions and the hydroxyl‐rich cellulose/PVA network retard cation thermodiffusion relative to Cl − , as revealed by molecular dynamics simulations, producing a high n‐type ionic Seebeck coefficient of −2.06 mV K −1 . WPCH also delivers a compressive strength of 890 kPa, enabling applications that require rigid, compressive‐supporting materials. High‐concentration electrolyte impregnation further improves water retention and environmental stability, ensuring durability under practical conditions. Demonstrations in LED powering, fire‐warning systems, and ambient thermal energy harvesting highlight wood‐skeleton engineering as a sustainable route to mechanically robust and environmentally stable ionic thermoelectric devices.

Traditional cell lumens in cellulose fibers induce severe light scattering. Though polymer impregnation boosts transparency, it drastically lowers fiber content and composite sustainability. Herein, we propose a chameleon skin-inspired selective cell lumen densification strategy that converts intrinsic scattering defects into a tunable optical asset. By mechanically closing the lumens, selectively reopening inter-fiber gaps via alkaline swelling, and infiltrating a refractive-index-matched polymer, we fabricate cellulosic fiber-reinforced composites (CFRC) that can achieve ultrahigh fiber content of 91% and optical transmittance of up to 89.7%. The material delivers a tensile strength of 71.8 MPa, superior to most plastics and glass. We establish quantitative relationships between scattering/transmission behavior and lumen width (0-20 nm) by combining optical measurements with COMSOL simulations, revealing a transition from Rayleigh- to Mie-type scattering as the dominant mechanism. The developed CFRC possesses outstanding thermal insulation, favorable water resistance and low environmental footprint validated by life-cycle assessment. We verify its practical potential as light-diffusing greenhouse screens for shade-sensitive plants and laser-scattering windows to eliminate laser hazards. This biomimetic structural regulation provides a facile strategy for high-performance sustainable polysaccharide optical composites.

Efficient extraction of lignin from lignocellulose by low-cost and eco-friendly way has been a key focus in the lignin-first biorefinery strategy. The bamboo lignocellulose consists of three major components, in which the complex crosslinking structure greatly hindering the rapid and large-scale extraction of lignin. To address this issue, an innovative method of microwave-assisted deep eutectic solvent (MA-DES) was developed to extract lignin from bamboo. The DES emerging as promising alternatives to conventional solvents, offers outstanding selective extraction capabilities. The effect of DES types on the lignin yield was investigated. The DES containing choline chloride-formic acid (1:6 Molar ratio), and the 1:40 solid-liquid ratio of bamboo powder to solution were selected as optimal conditions for the high lignin yield. Under the microwave radiation, the optimum lignin yield (89.5 %) was achieved in 10 min. The bamboo fibers and extracted lignin were analyzed by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and thermos gravimetric (TG) techniques. The extracted lignin was granular and irregular cluster morphology. The crystallinity index of bamboo fibers increased by 20.4 % after treatment, thus offering a new strategy for optimizing extraction procedures for producing lignin.

Flexible electronics have garnered significant attention in recent years. The emergence of membrane electronics addresses several limitations of rigid counterparts, such as high Young's modulus, poor biocompatibility, and poor responsiveness. Nevertheless, the development of traditional polymer and semiconductor membranes faces serious limitations. Nanocellulose (NC), known for its multifunctionality, biocompatibility, biodegradability, high mechanical strength, structural flexibility, and reinforcing capabilities, presents an excellent possibility to develop flexible electronics depending on the self-assembly behavior. Meanwhile, the combination of NC and functional fillers enables the fabrication of high-performance membranes with amplification capabilities, making them suitable for application in conductive materials for sensing and energy storage applications. The creation includes preparation strategies and potential applications. Moreover, the interface reaction mechanism and micro/nano scale morphology structure of carbon-based materials, polymers, and metal oxides combined with NC hybrid membranes are summarized from a molecular perspective. We discuss the design strategies and performance trends for improving mechanical properties, thermal conductivity, heat resistance, optical performance, and electrical conductivity of NC hybrid membranes. The recent advancements in nanocellulose for flexible sensors, thermal management, supercapacitors, and solar cells are evaluated along with perspectives on the current challenges and future directions in the development of NC membrane-based multifunctional flexible electronics. It will help improve the development of green flexible electronics, thereby advancing future investigations of this field.

Plant protein-based adhesives are favored for their cost-effectiveness and environmental friendliness. However, the low reactivity of plant protein and inherent water sensitivity of its adhesive significantly limits their scalability and broader application. Drawing inspiration from mussels, we developed a robust and waterproof bio-based adhesive reinforcing soybean protein (SP) with lignosulfonate. Specifically, the lignosulfonate was modified with phenol and epoxidated to synthesize phenolated lignin epoxy resin (PLEP), which was then added into SP matrix. The resulting adhesive demonstrated excellent bonding performance, with a dry shear strength of 3.59 MPa and a wet shear strength of 2.07 MPa. Finite Element Method (FEM) simulation confirmed a decreased stress concentration due to energy dissipation for the SP/PLEP. Furthermore, the adhesive exhibited an 81.22 % residual rate after water immersion. The adhesion strength was enhanced due to the π-π/cation-π interactions, hydrogen bonds, metal coordination of calcium ions, and covalent bonds formed by amino groups in proteins. Molecular dynamics (MD) analysis verified the enhancement of intermolecular interaction after phenolic modification. Life cycle assessment (LCA) revealed that the environmental impact of SP/PLEP adhesive was lower than that of urea-formaldehyde resin. This study presents a soybean-based adhesive inspired by mussel, offering a straightforward strategy for developing biomimetic adhesives.

To alleviate the environmental pressure, it is of great significance to develop the green and sustainable structural materials by utilization of waste biomass. In this work, an eco-friendly, high-strength, superhydrophobic, and thermally stable material was fabricated through a scalable binder-free lamination method using waste biomass (e.g., wood residues, crop straw, and waste paperboard). The waste biomass was separated and molded into fiber mats by a clean pulping process, and then laminated without adhesives. The finite element method (FEM) was adopted to visually observe fracture behaviors and detect the weakest zones. The utilization of FEM to enhance the mechanical strength is unique in productions of traditional biomass composites. The weakest zones were reinforced by the H2O2 spraying approach, and the flexural strength (FS) was improved from 80.12 to 120.35 MPa. The moisture content (MC) in the mat was used for regulating the softening of cellulosic fibers. In virtue of the water-induced plasticization, the laminated materials showed a high internal bonding strength (IBS) of 2.24 MPa and excellent FS of 134.81 MPa. Being benefitted from the silica modification, the materials exhibited a superhydrophobic surface with the high water contact angle (154.1 degrees), good dimensional stability (a thickness swelling of 14.8%), and superior mechanical stability (remained 94.3% FS after two months of ultraviolet radiation). This work provides a new strategy to develop green and sustainable structural materials for buildings, furniture, and related applications.

Pharmaceuticals in water are a growing environmental concern, as they can harm aquatic life and human health. To address this issue, an adsorbent made from coffee waste that effectively removes ibuprofen (a common pharmaceutical pollutant) from wastewater was developed. The experimental adsorption phase was planned using a Design of Experiments approach with Box-Behnken strategy. The relation between the ibuprofen removal efficiency and various independent variables, including adsorbent weight (0.01-0.1 g) and pH (3-9), was evaluated via a regression model with 3-level and 4-factors using the Response surface methodology (RSM) . The optimal ibuprofen removal was achieved after 15 min using 0.1 g adsorbent at 32.4 °C and pH = 6.9. Moreover, the process was optimized using two powerful bio-inspired metaheuristics (Bacterial Foraging Optimization and Virus Optimization Algorithm). The adsorption kinetics, equilibrium, and thermodynamics of ibuprofen onto waste coffee-derived activated carbon were modeled at the identified optimal conditions. The Langmuir and Freundlich adsorption isotherms were implemented to investigate adsorption equilibrium, and thermodynamic parameters were also calculated. According to the Langmuir isotherm model, the adsorbent's maximum adsorption capacity was 350.00 mg g-1 at 35 °C. The findings revealed that the ibuprofen adsorption was well-matched with the Freundlich isotherm model, indicating multilayer adsorption on heterogeneous sites. The computed positive enthalpy value showed the endothermic nature of ibuprofen adsorption at the adsorbate interface.

To achieve the goal of carbon neutrality, it is great significance to develop the high-performance and sustainable structural material. In this work, an eco-friendly, high-strength, super-hydrophobic, and thermally stable structural material based on low-value waste biomass (e.g., wood residues, crop straw and waste paperboard) was fabricated through a scalable binder-free lamination process. The waste biomass was first separated into cellulosic fibers by the simple pulping technology, which were further molded into mat and laminated into structural material without commercial adhesives. The moisture content in mat was used for regulating fiber plasticity during lamination process. In virtue of the water-induced cell wall plasticization, the laminated material showed high internal bonding strength of 2.24 MPa (e.g., 0.7 MPa required for plywood) and excellent flexural strength of 134.81 MPa (e.g., 83.13 MPa for wooden composites). Benefitting to the silica modification, the laminated materials exhibited a super-hydrophobic surface with the water contact angle as high as 154.1°, and superior mechanical stability with 94.3% flexural strength remained even after two months of ultraviolet radiation, which were much better than those of commonly used polypropylene and wooden composites. The finite element model demonstrated the mechanically enhanced laminated materials possess stress delamination advantages, favoring to the buffering improvement. Moreover, the dynamic mechanical analysis revealed that the glass transition temperature was reduced after water swelling fiber cell wall. This work provides a new strategy to develop co-friendly structural materials with high strength, super-hydrophobic and thermally stable performance having huge potential in furniture applications.

Effective separation of cellulose and hemicellulose from lignocellulosic biomass is an essential step for creating high-value products. In this study, a modified treatment process was proposed for cellulose purification via microwave-assisted formic acid catalytic hydrolysis followed by cold caustic extraction. The sugar content in the extract was determined using UV spectrophotometer and dual-wavelength visible spectrophotometry. Combined microwave-assisted formic acid (M-FA) with cold caustic extraction (CCE) treatments achieved rapid separation and removal of hemicelluloses from waste hardwood pulp fibers. The hemicelluloses content decreased from 28.6% to 2.3%, and the lignin content changed from 27.8% to 6.1%, which resulted in a maximal cellulose content of 91.5% under the optimal M-FA/CCE treatment conditions. In addition, the crystallinity index of pulp fibers increased from 54.3% to 67.1%, and the initial decomposition temperature decreased from 335.4 to 270.2 °C with the decrease of hemicellulose and lignin content. The modified process provided a sustainable and effective method for hemicellulose separation and lignin removal from cellulosic fibers.

As a derivative of agriculture crops and forestry cultivated plants, cellulosic fiber product (CFP) is of much industrial interest deemed a promising alternative to wooden composites and plastics owing to the low environmental impact. The high-performance CFP was fabricated via a facile molding and hot-pressing process without using adhesives. The UV aging test was carried out to evaluate the physical and mechanical stability before and after delignification. The tensile strength was increased from 41.3 MPa to 53.7 MPa, and the flexural strength was increased from 72.3 MPa to 85.4 MPa as the lignin was removed from 11.7% to 3.0%. The holocellulose content and crystallinity of fibers were increased, and the fiber dimensions were correspondingly decreased after delignification. However, the delignified specimens exhibited a faster reduction in mechanical strength than that of lignin-rich products (e.g., 0.074 vs 0.041 in the slope rate of fitting curves) throughout the UV irradiation, and the thermal stability was also decreased from 317.2 & DEG;C to 311.3 & DEG;C in onset decomposition temperature due to the delignification. Moreover, the lignin-rich CFP was superior to that of typical plastics (e.g., PP and epoxy resin) and wooden composites (e.g., WF/PP) in mechanical and thermal stability under UV irradiation through the comparison.

为研究木质生物炭对厌氧发酵产甲烷性能的影响,以玉米秸秆、牛粪作为发酵底物,以灌木生物炭、杨木生物炭、混合木屑生物炭作为添加剂,通过控制生物炭的种类、粒径以及灰分含量等关键因素,进行了批式厌氧发酵强化试验.结果表明:生物炭对厌氧发酵系统有重要影响,且粒径越小,产气能力越强.其中,杨木生物炭对厌氧发酵系统影响最大,不仅提升了厌氧发酵系统的甲烷累积产量(4.9％)、最大甲烷日产率(15.0％)以及水解速率(15.6％),也缩短了发酵延滞期.此外,杨木生物炭的灰分含量对厌氧发酵也有重要影响.当灰分含量为2.6 g·L-1时,对厌氧发酵系统影响最大,在提升厌氧发酵系统的缓冲能力、最大甲烷日产率(14.4％)的同时,也缩短了延滞期(11.8％),灰分含量过高或过低均不利于系统产甲烷.

利用AMPTS全自动甲烷潜力测试系统、First-Order水解模型、修正的Gompertz 和logistic模型,在了解生物炭各理化特性的基础上,通过对厌氧发酵的水解速率、产甲烷潜力及最大甲烷产率等进行拟合和对比分析,研究木屑生物炭对序批式湿法厌氧发酵的影响规律.结果表明:木屑生物炭对序批式厌氧发酵前期的底物水解速率、甲烷产率及累积甲烷产量均有着显著的影响,其中木屑生物炭对水解速率的影响强于果木生物炭和活性炭,较椰壳生物炭弱,且提升厌氧发酵系统的缓冲能力较椰壳生物炭和活性炭强.木屑生物炭对厌氧发酵的强化作用与生物炭粒径成负相关,当粒径＜0.5 mm 时强化效果最好,提高水解速率33.93％,提升最大产甲烷速率约19.32％,缩短延滞期约51.28％.

A novel natural fiber-metallic composite (NMC) with remarkable gradient structure is presented in this paper. Natural fibers generated from poplar wood, preformed into mat, are pre-treated through an in-situ impregnation process with Fe2+ and Fe3+ solutions. After the incorporation of ammonia, the iron oxide particles are formed inside the porous structures of fiber mat. The treated natural fiber mat with a certain moisture content, is then densified into composites through a compression molding process under a certain temperature, that a high-strength NMC is created without using binders. The resulted composites exhibited high iron oxide loading of 34.9 %, and presented a remarkable gradient structure with porous scale-like metallic surface and well-distributed uniform-sized nanoparticles for the core. The NMC also demonstrated a high flexural strength of 92.5 MPa, which was 2.2 times higher than that of poplar wood (42.6 MPa), and showed a strong magnetic response of 11.1 emu g−1 in saturation magnetization. The gradient structures of NMC can be controlled through changing the fiber mat density, impregnation process, mat moisture content, and compression molding parameters.

结合汽车灯罩实际注射情况,对待成型塑件进行CAE模拟仿真分析,确定了最佳浇口位置及工艺参数,熔体流动和冷却分析预测了塑件成型质量和冷却系统的合理性,翘曲分析获得了塑件翘曲受冷却不均、取向效应和材料收缩不均3个因素的影响,其中材料收缩不均是引起翘曲变形的主要因素,并在此基础上对分型面和模具结构进行了合理设计.研究表明,通过模流分析技术的应用可提高模具设计的效率,优化工艺参数,提高塑件成型质量.

以汽车灯罩为研究对象,利用Moldflow软件对模型进行翘曲分析,确定了导致翘曲变形的主要因素.通过正交试验,对注塑件的翘曲变形参数进行优化,得到最佳注塑工艺.采用最优工艺参数进行注塑模拟,结果表明,在所有因素影响下的最大总变形量为3.386 mm,由冷却不均导致的最大翘曲变形量为0. 205 3 mm,收缩不均引起的最大翘曲变形量为2.733 mm,角效应引起的最大翘曲变形量为0. 498 8 mm;与初始成型方案翘曲变形量相比,在所有因素影响下的最大总变形量下降了19. 15％,由冷却不均导致的最大翘曲变形量下降了37. 33％,收缩不均引起的最大翘曲变形量下降了16.75％,角效应引起的最大翘曲变形下降了23.84％.因此,优化后的工艺参数能够显著降低产品的翘曲变形量,为类似产品性能预测、结构设计及优化提供有效分析方法,并推动塑料制造业的快速发展.

A sandwich-structured natural fiber-based magnetic composite, without the use of a binder, was developed in this study. It was fabricated via in situ synthesis, densification, and magnetron sputtering processes. The chemical composition, crystal structure, microstructure, and thermal stability were characterized via X-ray photoelectron spectroscopy, energy-dispersive spectroscopy, X-ray diffraction, scanning electron microscope, and thermogravimetric analysis. The hydrophobic, magnetic, and electromagnetic interference shielding properties were investigated by measuring the static water contact angle, the magnetic hysteresis loops, and the shielding effectiveness. The resulted composites exhibited a unique inner structure with a larger iron oxide size and content (492 nm and 26.1 wt%) on the interlayer surface in comparison to the core layer (135 nm and 18.7 wt%). The magnetic response can be controlled by the loaded iron oxide content and the copper film deposition. Sputtering copper film changed the surface free energy, and created rough micro-/nanostructures, which yielded a highly hydrophobic nature (133° in water contact angle), and approximately 99.2% of the electromagnetic energy was shielded by the 0.8 mm thick composite.

目的 研究温度、湿度和紫外老化对脱木素和未脱木素纸浆模塑材料性能的影响,定量地对比不同因素作用下2种材料的力学性能差异.方法 以废纸浆为原料,经打浆、脱木素、湿成型、热压等工艺制得脱木素和未脱木素等2种纸浆模塑材料;模拟不同的温湿度和紫外老化环境,测试2种纸浆模塑材料物理力学性能的变化.结果 在同等条件下,脱木素材料的拉伸强度与弯曲强度均高于未脱木素材料;2种材料的拉伸强度、弹性模量和弯曲强度随着含水率升高而大幅降低;当温度为20℃、含水率为0～40％时,脱木素材料的拉伸强度下降了45 MPa,未脱木素材料的拉伸强度下降了35 MPa.当温度为0℃、含水率为0～40％时,脱木素材料的弯曲强度下降了70 MPa,未脱木素材料的弯曲强度降低了62MPa;当含水率低于20％时,脱木素材料的拉伸性能和弯曲性能更易受到温度影响;虽然2种材料的拉伸性能和弯曲性能均随着紫外老化时间的延长而不断降低,但其影响程度远小于温湿度.结论 湿度对材料的力学性能影响最大,其次是温度和紫外老化;脱去木素有利于提高纸浆模塑材料的力学性能和抗紫外老化性能.