SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low toxicity.However,the sluggish ...SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low toxicity.However,the sluggish reaction kinetics,low electronic conductivity,and large volume changes during charge and discharge hinder the practical applications of SnO_(2)-based electrodes for SIBs and PIBs.Engineering rational structures with fast charge/ion transfer and robust stability is important to overcoming these challenges.Herein,S-doped SnO_(2)(S-SnO_(2))quantum dots(QDs)(≈3 nm)encapsulated in an N,S codoped carbon fiber networks(S-SnO_(2)-CFN)are rationally fabricated using a sequential freeze-drying,calcination,and S-doping strategy.Experimental analysis and density functional theory calculations reveal that the integration of S-SnO_(2) QDs with N,S codoped carbon fiber network remarkably decreases the adsorption energies of Na/K atoms in the interlayer of SnO_(2)-CFN,and the S doping can increase the conductivity of SnO_(2),thereby enhancing the ion transfer kinetics.The synergistic interaction between S-SnO_(2) QDs and N,S codoped carbon fiber network results in a composite with fast Na+/K+storage and extraordinary long-term cyclability.Specifically,the S-SnO_(2)-CFN delivers high rate capacities of 141.0 mAh g^(−1) at 20 A g^(−1) in SIBs and 102.8 mAh g^(−1) at 10 A g^(−1) in PIBs.Impressively,it delivers ultra-stable sodium storage up to 10,000 cycles at 5 A g^(−1) and potassium storage up to 5000 cycles at 2 A g^(−1).This study provides insights into constructing metal oxide-based carbon fiber network structures for high-performance electrochemical energy storage and conversion devices.展开更多
Carbon fibers(CFs)are widely used in cutting-edge and civilian fields due to their excellent comprehensive properties such as high strength and high modulus,superior corrosion and friction resistances,excellent therma...Carbon fibers(CFs)are widely used in cutting-edge and civilian fields due to their excellent comprehensive properties such as high strength and high modulus,superior corrosion and friction resistances,excellent thermal stability,light weight,and high electrical conductivity.However,their natural ultra-black appearance is difficult to meet the aesthetic needs of today's civilian sector and the need for optical stealth in the military field.In addition,conventional coloring methods are difficult to effectively adhere to CF surfaces due to high crystallinity and highly inert surface caused by their graphite-like structure.In this work,inspired by the nacre structural color of pearls,colored CFs with 1D photonic crystal structure are prepared by cyclically depositing amorphous(Al_(2)O_(3)+TiO_(2))layers on the surface of carbon CFs through atomic layer deposition(ALD).The obtained CFs exhibit brilliant colors and excellent environmental durability in extreme environments.Moreover,the colored CFs also exhibit high EMI shielding effectiveness(45 dB)and optical stealth properties,which can be used in emerging optical devices and electromagnetic and optical stealth equipment.展开更多
Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are kn...Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are known for their unique compact structure;they are not only lightweight but also strong.In this study,an in-depth look at owl feathers was made and it found that owl feathers not only have the macro branches structure between feather shafts and branches but also have fine feather structures on the branches.The presence of these fine feather structures increases the specific surface area of the plume branches and allows neighboring plume branches to hook up with each other,forming an effective mechanical interlocking structure.These structures bring owl feathers excellent mechanical properties.Inspired by the natural structure of owl feathers,a weaving technique and a sizing process were combined to prepare bionic Carbon Fiber(CF)fabrics and then to fabricate the bionic CFRP with structural characteristics similar to owl feathers.To evaluate the effect of the fine feather structure on the mechanical properties of CFRP,a mechanical property study on CFRP with and without the fine feather imitation structure were conducted.The experimental results show that the introduction of the fine feather branch structure enhance the mechanical properties of CFRP significantly.Specifically,the tensile strength of the composites increased by 6.42%and 13.06%and the flexural strength increased by 8.02%and 16.87%in the 0°and 90°sample directions,respectively.These results provide a new design idea for the improvement of the mechanical properties of the CFRP,promoting the application of CFRP in engineering fields,such as automotive transportation,rail transit,aerospace,and construction.展开更多
Recycling of carbon fiber reinforced composites is important for sustainable development and the circular economy.Despite the use of dynamic chemistry,developing high-strength recyclable CFRPs remains a major challeng...Recycling of carbon fiber reinforced composites is important for sustainable development and the circular economy.Despite the use of dynamic chemistry,developing high-strength recyclable CFRPs remains a major challenge due to the mutual exclusivity between the dynamic and mechanical properties of materials.Here,we developed a high-strength recyclable epoxy resin(HREP)based on dynamic dithioacetal covalent adaptive network using diglycidyl ether bisphenol A(DGEBA),pentaerythritol tetra(3-mercapto-propionate)(PETMP),and vanillin epoxy resin(VEPR).At high temperatures,the exchange reaction of thermally activated dithioacetals accelerated the rearrangement of the network,giving it significant reprocessing ability.Moreover,HREP exhibited excellent solvent resistance due to the increased cross-linking density.Using this high-strength recyclable epoxy resin as the matrix and carbon fiber modified with hyperbranched ionic liquids(HBP-AMIM+PF6-)as the reinforcing agent,high performance CFRPs were successfully prepared.The tensile strength,interfacial shear strength(IFSS)and interlaminar shear strength(ILSS)of the optimized formulation(HREP20/CF-HBPPF6)were 1016.1,70.8 and 76.0 MPa,respectively.In addition,the CFRPs demonstrated excellent solvent and acid/alkali-resistance.The CFRPs could completely degrade within 24 h in DMSO at 140℃,and the recycled CF still maintained the same tensile strength and ILSS as the original after multiple degradation cycles.展开更多
Coal is a versatile energy resource and was a driver of the industrial revolution that transformed the economies of Europe and North America and the trajectory of civilization.In this work,a technoeconomic analysis wa...Coal is a versatile energy resource and was a driver of the industrial revolution that transformed the economies of Europe and North America and the trajectory of civilization.In this work,a technoeconomic analysis was performed for a coal-to-carbonfiber manufacture process developed at the University of Kentucky’s Center for Applied Energy Research.According to this process,coal,with decant oil as the solvent,was converted to mesophase pitch via solvent extraction,and the mesophase pitch was subsequently converted to carbon fiber.The total cost to produce carbon fibers from coal and decant oil via the solvent extraction process was estimated to be$11.50/kg for 50,000-tow pitch carbon fiber with a production volume of 3750 MT/year.The estimated carbon fiber cost was significantly lower than the current commercially available PAN-based carbon fiber price($20–$30/kg).With decant oil recycling rates of 50%and 70%in the solvent extraction process,the manufacturing cost of carbon fiber was estimated to be$9.90/kg and$9.50/kg of carbon fiber,respectively.A cradle-to-gate energy assessment revealed that carbon fiber derived from coal exhibited an embodied energy of 510 MJ/kg,significantly lower than that of conventionally produced carbon fiber from PAN.This notable difference is primarily attributed to the substantially higher conversion rate of coal-based mesophase pitch fibers into carbon fiber,surpassing PAN fibers by 1.6 times.These findings indicate that using coal for carbon fiber production through solvent extraction methods could offer a more energy-efficient and cost-competitive alternative to the traditional PAN based approach.展开更多
Polyacrylonitrile (PAN) precursor is a core precursor for the preparation of high-performance carbon fibers. Its unique chemical structure and physical properties directly contributes to the microstructure and mechani...Polyacrylonitrile (PAN) precursor is a core precursor for the preparation of high-performance carbon fibers. Its unique chemical structure and physical properties directly contributes to the microstructure and mechanical properties of carbon fibers, and therefore affect the overall performance of pultruded composites. This study systematically investigated the influence of PAN precursor properties on the degree of graphitization, surface morphology and mechanical properties of carbon fibers by regulating the molecular weight distribution, stretching ratio and impurity content of PAN precursor, and analyzed the mechanism of action of carbon fiber properties on the interfacial bonding strength and tensile/ bending properties of composites in combination with the pultrusion process. The results showed that when the filament stretchability was increased to 4.5 times, the axial orientation of carbon fibers increased by 18% and the tensile strength reached 520 MPa;Filaments with impurity content below 0.3% increase carbon fiber yield by 5.2% and interlaminar shear strength of composites by 23%. This study provides a theoretical basis for raw material screening and process optimization of high-performance carbon fibers and their composites.展开更多
Carbon fibers(CFs)with notable comprehensive properties,such as light weight,high specific strength,and stiffness,have garnered considerable interest in both academic and industrial fields due to their diverse and adv...Carbon fibers(CFs)with notable comprehensive properties,such as light weight,high specific strength,and stiffness,have garnered considerable interest in both academic and industrial fields due to their diverse and advanced applications.However,the commonly utilized precursors,such as polyacrylonitrile and pitch,exhibit a lack of environmental sustainability,and their costs are heavily reliant on fluctuating petroleum prices.To meet the substantial market demand for CFs,significant efforts have been made to develop cost-effective and sustainable CFs derived from biomass.Lignin,the most abundant polyphenolic compound in nature,is emerging as a promising precursor which is well-suited for the production of CFs due to its renewable nature,low cost,high carbon content,and aromatic structures.Nevertheless,the majority of lignin raw materials are currently derived from pulping and biorefining industrial by-products,which are diverse and heterogeneous in nature,restricting the industrialization of lignin-derived CFs.This review classifies fossil-derived and biomass-derived CFs,starting from the sources and chemical structures of raw lignin,and outlines the preparation methods linked to the performance of lignin-derived CFs.A comprehensive discussion is presented on the relationship between the structural characteristics of lignin,spinning preparation,and structure-morphology-property of ligninderived CFs.Additionally,the potential applications of these materials in various domains,including energy,catalysis,composites,and other advanced products,are also described with the objective of spotlighting the unique merits of lignin.Finally,the current challenges faced and future prospects for the advancement of lignin-derived CFs are proposed.展开更多
This study proposes a pre-strain optimization strategy for carbon fiber structural lithium-ion battery(SLIB) composites to inhibit the interfacial debonding between carbon fibers and solid-state electrolytes due to fi...This study proposes a pre-strain optimization strategy for carbon fiber structural lithium-ion battery(SLIB) composites to inhibit the interfacial debonding between carbon fibers and solid-state electrolytes due to fiber lithiation. Through an analytical shear-lag model and finite element simulations, it is demonstrated that applying tensile pre-strain to carbon fibers before electrode assembly effectively reduces the interfacial shear stress, thereby suppressing debonding. However, the excessive pre-strain can induce the interfacial damage in the unlithiated state, necessitating careful control of the pre-strain within a feasible range. This range is influenced by electrode material properties and geometric parameters. Specifically, the electrodes with the higher solid-state electrolyte elastic modulus and larger electrolyte volume fraction exhibit more significant interfacial damage, making pre-strain application increasingly critical. However, these conditions also impose stricter constraints on the feasible pre-strain range. By elucidating the interplay between pre-strain, material properties, and geometric factors, this study provides valuable insights for optimizing the design of carbon fiber SLIBs.展开更多
The poor surface antibacterial properties are one of the important factors limiting the application of Carbon Fibers Reinforced Polyetheretherketone (CFR-P) composites as artificial bone replace materials. Some of the...The poor surface antibacterial properties are one of the important factors limiting the application of Carbon Fibers Reinforced Polyetheretherketone (CFR-P) composites as artificial bone replace materials. Some of the Two-Dimensional (2D) nanomaterials with unique lamellar structures and biological properties have been demonstrated to have excellent antibacterial properties. Antibacterial properties can be improved by feasible chemical strategies for preparing 2D nanomaterials coating on the surface of CFR-P. In this work, Black Phosphorus (BP) coating was prepared on the originally chemically inert CFR-P surface based on wet chemical pretreatment. The physical and chemical properties, including surface microstructure, chemical composition and state, roughness and hydrophilicity were characterized. The antibacterial ratios against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Streptococcus mutans (S. mutans) were evaluated. The results indicated that hydrophilicity of BP coating on CFR-P was significantly higher compared to that of the pure CFR-P. Wet chemical pretreatment using mixed acid reagents (concentrated sulfuric acid and concentrated nitric acid) introduced hydroxyl, carboxyl and nitro groups on CFR-P. The BP coating exhibited the antibacterial rate of over 98% against both S. aureus and E. coli. In addition, the antibacterial rate of BP coating against the main pathogenic bacteria of dental caries, Streptococcus mutans, reached 45%.展开更多
The effective thermal management of lithium-ion batteries is the key to ensuring their fast charging-discharging,safe and efficient operation.Herein,inspired by transpiration-driven water transport in plants,we report...The effective thermal management of lithium-ion batteries is the key to ensuring their fast charging-discharging,safe and efficient operation.Herein,inspired by transpiration-driven water transport in plants,we report a highly hygroscopic needle-punched carbon fiber felt(HS/CFF)with high evaporative cooling efficiency and fire resistance for the safe operation of lithium-ion batteries working at ultrahigh-rate conditions.The three-dimensional fiber skeleton structure constructed by needle punching in the carbon fiber felt enables effective water transport and storage in HS/CFF,without any water leakage.At an ultra-high discharge rate of 10 C,HS/CFF can reduce the maximum temperature of commercial lithium-ion batteries by 18°C,and can keep the battery temperature below 60°C.During 500 cycles of charge-discharge,HS/CFF maintains stable evaporative heat dissipation performance,which helps to improve the safety of lithium-ion batteries and extend their service life.Moreover,HS/CFF remains non-combustible even under exposure to a flame(600-700°C)for 10 min,and the HS/CFF can be reused after the burning test,with the original excellent heat dissipation effect unchanged.This flexible,fire-resistant cooling material offers a promising avenue for low-energy intelligent thermal management of lithium-ion batteries and other heat-generating electronic devices.展开更多
3D printing has emerged as an advanced manufacturing technique for carbon fiber reinforced composites and relevant structures that endure significant dynamic loads in engineering applications.The dynamic behavior of t...3D printing has emerged as an advanced manufacturing technique for carbon fiber reinforced composites and relevant structures that endure significant dynamic loads in engineering applications.The dynamic behavior of these materials,primarily influenced by the dynamic fiber pullout interface strength necessitates investigation into the rate-dependent fiber/matrix interfacial strength.This study modifies a Hopkinson tension bar to conduct dynamic pullout tests on a single fiber bundle,utilizing a low-impedance bar and an in-situ calibrated semiconductor strain gauge to capture weak stress signals.Stress equilibrium analyses are performed to validate the transient dynamic loading on single fiber bundle specimens.The results reveal that the fiber/matrix interfacial strength is rate-dependent,increasing with the loading rate,while remaining unaffected by the embedded length.Fracture microstructural analyses show minimal fiber pullout due to high interfacial stresses induced by longer embedded lengths.Lastly,suggestions are made for the efficient design of fiber pullout experiments.展开更多
The ACF adsorbent with high Cu loading was treated with dielectric barrier discharge plasma to mitigate the negative effects of high Cu loading and enhance PH_(3)and H_(2)S adsorption and oxidation.Bruno-Emmett-Taylor...The ACF adsorbent with high Cu loading was treated with dielectric barrier discharge plasma to mitigate the negative effects of high Cu loading and enhance PH_(3)and H_(2)S adsorption and oxidation.Bruno-Emmett-Taylor(BET)result showed that the specific surface area of the adsorbent after air plasma modification was almost three times that before modification.X-ray photoelectron spectroscopy(XPS)findings revealed that the amino group was added to the adsorbent's surface,increasing lattice oxygen and chemisorbed oxygen.The adsorbent's large specific surface area,excellent surface active oxygen,and abundance of basic groups facilitate PH_(3)and H_(2)S adsorption and oxidation.The scanning electron microscopy showed that air plasma modification exposed more active components and uniformly dispersed them on the surface of adsorbent,thereby improving the adsorption performance.Activity evaluation results showed that the adsorbent has the best ability to capture PH_(3)and H_(2)S after being modified by air plasma at 4 kV voltage for 10 min.The adsorbent's breakthrough ability at high space velocity(WHSV:60,000 h^(−1))is 190 mg P/g and 146 mg S/g,respectively,which is 74%and 60%greater than that before modification.This is a great improvement over previous studies.In addition,the possible mechanism of adsorbent deactivation was proposed.展开更多
Solar interfacial evaporation(SIE),is currently one of the most potential water supply technologies in the remote,insular,and disaster-stricken areas.However,the existence of volatile organic compounds(VOCs)in water d...Solar interfacial evaporation(SIE),is currently one of the most potential water supply technologies in the remote,insular,and disaster-stricken areas.However,the existence of volatile organic compounds(VOCs)in water deteriorates the distillate quality,threatening human health.Herein,we constructed a carbonbased bimetallic(C/FeCo)photothermal membrane by electrospinning technique.Results illustrated that the membrane can catalytically degrade VOCs during SIE with persulfate(PDS)mediation.PDS,as well as phenol,was mainly reacted on the interface of the photothermal membrane instead of in the bulk solution.The interception efficiency of phenol achieved nearly 100%using the C/FeCo membrane during SIE.Hydroxyl radical(•OH),sulfate radical(SO_(4)•−),superoxide radical(O_(2)•−),and singlet oxygen(^(1)O_(2))were identified as the main active substances to degrade VOCs.We also conducted SIE experiments using actual river water to evaluate the practical performance of the C/FeCo membrane.This work holds the promise of VOCs interception during SIE and enlarges the application of solar distillation in water/wastewater treatment.展开更多
Fe-N-C single-atom catalysts are considered among the most promising non-precious metal-based catalysts for oxygen reduction reaction(ORR),but issues such as low utilization of active sites and the easy aggregation of...Fe-N-C single-atom catalysts are considered among the most promising non-precious metal-based catalysts for oxygen reduction reaction(ORR),but issues such as low utilization of active sites and the easy aggregation of single atoms severely hinder their application in fuel cells and metal-air batteries.Herein,a single-atom Fe-embedded hierarchical porous hollow carbon fiber catalyst(Fe S AC/HCNF) is reported for ORR.The hollow channels and the porous structure of the fibers facilitate the exposure of single-atom active sites,and offer multidimensional mass transfer pathways to promote the transport of reactants,thus significantly enhancing catalytic performance.Additionally,the abundant micropores exert spatial confinement,which is beneficial for preventing the aggregation of single atoms.Leveraging its unique structural advantages,the Fe S AC/HCNF catalyst demonstrates outstanding ORR activity with low metal loading,boasting a high half-wave potential of 0.905 V,a substantial double-layer capacitance(C_(d1)) of 41.1 mF cm^(-2),and a notable kinetic current density of 45.2 mA cm^(-2)in alkaline media.Furthermore,the liquid Zn-air battery(ZAB) using Fe SAC/HCNF catalyst as the air cathode exhibits excellent battery performance and long-term cycling durability nearly 600 h.And the flexible quasi-solid-state ZAB can be stably cycled in various flat/bent states,which is promising for applications in flexible electronic devices.展开更多
Carbon fiber/phenolic resin composites have great potential application in the field of electronic information,where excellent structural-functional integration is required.In this work,the establishment of interfacia...Carbon fiber/phenolic resin composites have great potential application in the field of electronic information,where excellent structural-functional integration is required.In this work,the establishment of interfacial structures consisting of carbon nanotubes with different morphologies at the fiber/matrix interface is conducive to the further modulation of the mechanical,tribological,electromagnetic interference(EMI)shielding and thermal conductivity properties of carbon fiber/phenolic resin composites.Specially,array carbon nanotubes can deep into the resin matrix,effectively hindering crack extension,and constructing an electrically and thermally conductive network.Compared with the carbon fiber/phenolic composites,the tensile strength and modulus of elasticity(163.86±9.60 MPa,5.06±0.25 GPa)of the array carbon nanotubes reinforced carbon fiber/phenolic composites were enhanced by 57.09%and 22.22%.The average friction coefficient and wear rate(0.20±0.02,1.11×10^(-13)±0.13×10^(-13)m^(3)N^(−1)m^(−1))were reduced by 39.39%and 74.31%.EMI shielding effectiveness up to 40 dB in the X-band at 0.4 mm sample thickness,diffusion coefficient(0.39±0.003 mm^(2)/s)and thermal conductivity(0.54±0.004 W/(m K))were enhanced by up to 14.37%and 50.42%.This study reveals the beneficial effects of morphological changes of carbon nanotubes on the design of interfacial structure,proposes the reinforcement mechanism of array carbon nanotubes,and opens up the prospect of carbon fiber/phenolic composites for electronic applications.展开更多
This study investigates the long-term thermal-oxidative stability and mechanical properties of phenolcontaining phthalonitrile monomer(PN75)and dicyanate ester of bisphenol-A(DCBA)composites reinforced with short carb...This study investigates the long-term thermal-oxidative stability and mechanical properties of phenolcontaining phthalonitrile monomer(PN75)and dicyanate ester of bisphenol-A(DCBA)composites reinforced with short carbon fibers T700SC(SCF)within a temperature range of 330375℃.The research focuses on the PN75 monomer and DCBA blend reinforced SCF composites with varying SCF content,examining mass loss and changes in flexural strength after thermal aging for 50 h(h).Results show that the SCF-reinforced composites based on the PN75/DCBA blend consistently outperform the neat blend in flexural strength,both at room temperature and after thermal aging.The introduction of the SCF significantly improves the composites'thermal stability and mechanical retention,with higher SCF content correlating to better performance.Notably,after aging at 350℃,the SCF-reinforced composites based(30%(mass)SCF)retained 88.8%of its flexural strength,compared to 61.1%for the neat blend.Morphological analysis reveals that while thermal aging causes degradation of the PN75/DCBA blend layer on SCF surfaces,the overall composite structure maintains good mechanical properties up to 350℃.At 375℃,significant degradation occurs,yet the composites still retain flexural strengths above 78 MPa.This study demonstrates the potential of the SCF-reinforced composites based on PN75/DCBA blend for high-temperature applications,establishing their upper-temperature limit for long-term use in oxidative environments.展开更多
To effectively enhance the catalytic activity of NiS,NiS particles confined into carbon fibers were prepared by electrostatic spinning followed pyrolyzation and NiS particles decorating was performed by further hydrot...To effectively enhance the catalytic activity of NiS,NiS particles confined into carbon fibers were prepared by electrostatic spinning followed pyrolyzation and NiS particles decorating was performed by further hydrothermal loading.The decorated NiS exhibits particle(NiS@PAN-NiS)and needle-like(NiS@PAN-NiS^(*))morphologies.After adding the catalysts into MgH_(2),the synthesized MgH_(2)-5 wt%NiS@PAN-NiS composite can absorb 2.6 wt%hydrogen at 353 K and release 5.0 wt%hydrogen within 1 h at 573 K.The initial hydrogen desorption temperature was reduced to 539 K.The activation energies for hydrogen absorption/desorption were greatly reduced to 66.76 and 89.95 kJ mol^(-1),respectively.The method of confining by electrospinning and particle decoration by hydrothermal loading reduce NiS particle agglomeration.The Mg_(2)Ni/Mg_(2)NiH_(4)hydrogen pump formed by reaction between NiS and MgH_(2)effectively enhanced hydrogen absorption and desorption kinetics.The formed MgS also improved the catalytic activity on the transformation of Mg and MgH_(2).Moreover,the carbon fibers should influence the contact between in situ formed MgS and Mg_(2)Ni,providing more catalytic sites and hydrogen diffusion pathways.The construction of NiS/carbon fibers confined NiS composite by carbon fibers derived from pyrolyzation as medium provides considerable way for designing NiS-based catalysts to enhance the hydrogen storage performances of MgH_(2).展开更多
The automobile industry is the first to form a typical representative of the global industry in modern industry,with the increase of the national emphasis on the environment,the automobile industry was regarded as an ...The automobile industry is the first to form a typical representative of the global industry in modern industry,with the increase of the national emphasis on the environment,the automobile industry was regarded as an important energy consumption and one of the sources of environmental pollution,the policy of energy conservation and emission reduction requirements for the automobile industry are becoming stricter over the years,energy conservation and emission reduction has becomes the main direction of product optimization in the automobile industry in recent years.Due of a series of excellent properties such as light weight and high strength,composite materials have become the main material for the development of lightweight vehicles.With the development of material technology and the update and iteration of manufacturing technology,composite materials are currently popular being adopted in the automotive field.展开更多
Carbon fiber reinforced polymer(CFRP)is an advanced material widely used in bridge structures,demonstrating a promising application prospect.CFRP possesses excellent mechanical properties,construction advantages,and d...Carbon fiber reinforced polymer(CFRP)is an advanced material widely used in bridge structures,demonstrating a promising application prospect.CFRP possesses excellent mechanical properties,construction advantages,and durability benefits.Its application in bridge reinforcement can significantly enhance the overall performance of the reinforced bridge,thereby improving the durability and extending the service life of the bridge.Therefore,it is necessary to further explore how CFRP can be effectively applied in bridge reinforcement projects to improve the quality of such projects and ensure the safety of bridges during operation.展开更多
Ceramic matrix composites(CMC)are widely utilized in high-temperature components of aero-engines for load-bearing and electromagnetic stealth synergy due to their superior toughening and designable electromagnetic pro...Ceramic matrix composites(CMC)are widely utilized in high-temperature components of aero-engines for load-bearing and electromagnetic stealth synergy due to their superior toughening and designable electromagnetic properties.However,the design of ultra-broadband electromagnetic wave(EMW)absorp-tion at thin thicknesses(d<10 mm)has been difficult and focused,especially the design of metama-terial.Inspired by 3D printing technology and the structural characteristic of 2D CMC,this study inge-niously devised and proposed a novel carbon fiber gradient periodic structure in Al_(2)O_(3f)/SiOC composites to enhance the ultra-broadband EMW absorption properties at a wide temperature range.By optimizing the geometric structure parameters,the Al_(2)O_(3f)/SiOC composites with the carbon fiber gradient periodic structure have exhibited exceptional ultra-broadband EMW absorption properties at elevated tempera-tures and excellent mechanical performance.The composites have attained a minimum reflection loss(RLmin)of-30 dB and a high absorption efficiency of more than 84%,ranging from 9.3 to 40 GHz at a thickness of 9 mm.Due to the temperature insensitivity of discrete periodic structures,the composites can adapt to high temperatures up to 700℃.Additionally,compared to the Al_(2)O_(3f)/SiOC composites,the flexural strength and fracture toughness of the Al_(2)O_(3f)/SiOC composites with carbon fiber gradient peri-odic structure have significantly increased to 398 MPa and 15.6 MPa m1/2,respectively.This work breaks through the limitation of the design and fabrication of 3D periodic structures in CMC,creating a novel oxide-CMC with ultra-broadband EMW absorption properties at a wide temperature range and enhanced mechanical properties.展开更多
基金National Natural Science Foundation of China,Grant/Award Number:51971065Innovation Program of Shanghai Municipal Education Commission,Grant/Award Number:2019-01-07-00-07-E00028。
文摘SnO_(2) has been extensively investigated as an anode material for sodium-ion batteries(SIBs)and potassium-ion batteries(PIBs)due to its high Na/K storage capacity,high abundance,and low toxicity.However,the sluggish reaction kinetics,low electronic conductivity,and large volume changes during charge and discharge hinder the practical applications of SnO_(2)-based electrodes for SIBs and PIBs.Engineering rational structures with fast charge/ion transfer and robust stability is important to overcoming these challenges.Herein,S-doped SnO_(2)(S-SnO_(2))quantum dots(QDs)(≈3 nm)encapsulated in an N,S codoped carbon fiber networks(S-SnO_(2)-CFN)are rationally fabricated using a sequential freeze-drying,calcination,and S-doping strategy.Experimental analysis and density functional theory calculations reveal that the integration of S-SnO_(2) QDs with N,S codoped carbon fiber network remarkably decreases the adsorption energies of Na/K atoms in the interlayer of SnO_(2)-CFN,and the S doping can increase the conductivity of SnO_(2),thereby enhancing the ion transfer kinetics.The synergistic interaction between S-SnO_(2) QDs and N,S codoped carbon fiber network results in a composite with fast Na+/K+storage and extraordinary long-term cyclability.Specifically,the S-SnO_(2)-CFN delivers high rate capacities of 141.0 mAh g^(−1) at 20 A g^(−1) in SIBs and 102.8 mAh g^(−1) at 10 A g^(−1) in PIBs.Impressively,it delivers ultra-stable sodium storage up to 10,000 cycles at 5 A g^(−1) and potassium storage up to 5000 cycles at 2 A g^(−1).This study provides insights into constructing metal oxide-based carbon fiber network structures for high-performance electrochemical energy storage and conversion devices.
基金supported by the National Natural Science Foundation of China(No.52373085)Natural Science Foundation of Hubei Province(No.2023AFB828)+4 种基金Innovative Team Program ofNatural Science Foundation of Hubei Province(No.2023AFA027)Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2023433)Natural Science Foundation of Shanxi Province(Grant No.20210302124128)Open Fund for Hubei Key Laboratory of Digital Textile Equipment(No.DTL 2023022)the Open Fund for National Local Joint Laboratory for Advanced Textile Processing and Clean Production(No.17)。
文摘Carbon fibers(CFs)are widely used in cutting-edge and civilian fields due to their excellent comprehensive properties such as high strength and high modulus,superior corrosion and friction resistances,excellent thermal stability,light weight,and high electrical conductivity.However,their natural ultra-black appearance is difficult to meet the aesthetic needs of today's civilian sector and the need for optical stealth in the military field.In addition,conventional coloring methods are difficult to effectively adhere to CF surfaces due to high crystallinity and highly inert surface caused by their graphite-like structure.In this work,inspired by the nacre structural color of pearls,colored CFs with 1D photonic crystal structure are prepared by cyclically depositing amorphous(Al_(2)O_(3)+TiO_(2))layers on the surface of carbon CFs through atomic layer deposition(ALD).The obtained CFs exhibit brilliant colors and excellent environmental durability in extreme environments.Moreover,the colored CFs also exhibit high EMI shielding effectiveness(45 dB)and optical stealth properties,which can be used in emerging optical devices and electromagnetic and optical stealth equipment.
基金supported by the Science and Technology Development Program of Jilin Province(No.20240101122JC)and(No.20240101143JC)the Key Scientific and Technological Research and Development Projects of Jilin Provincial Science and Technology Department(Grant Number 20230201108GX)。
文摘Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics(CFRP).Owl feathers are known for their unique compact structure;they are not only lightweight but also strong.In this study,an in-depth look at owl feathers was made and it found that owl feathers not only have the macro branches structure between feather shafts and branches but also have fine feather structures on the branches.The presence of these fine feather structures increases the specific surface area of the plume branches and allows neighboring plume branches to hook up with each other,forming an effective mechanical interlocking structure.These structures bring owl feathers excellent mechanical properties.Inspired by the natural structure of owl feathers,a weaving technique and a sizing process were combined to prepare bionic Carbon Fiber(CF)fabrics and then to fabricate the bionic CFRP with structural characteristics similar to owl feathers.To evaluate the effect of the fine feather structure on the mechanical properties of CFRP,a mechanical property study on CFRP with and without the fine feather imitation structure were conducted.The experimental results show that the introduction of the fine feather branch structure enhance the mechanical properties of CFRP significantly.Specifically,the tensile strength of the composites increased by 6.42%and 13.06%and the flexural strength increased by 8.02%and 16.87%in the 0°and 90°sample directions,respectively.These results provide a new design idea for the improvement of the mechanical properties of the CFRP,promoting the application of CFRP in engineering fields,such as automotive transportation,rail transit,aerospace,and construction.
基金financially supported by the National Natural Science Foundation of China(Nos.U23A2069 and 51403242)the Natural Science Foundation of Hubei Province(No.2024AFB800)+5 种基金the Fundamental Research Funds for the Central Universities,South-Central Minzu University(Nos.CZY23017 and CZD24001)the Innovation Group of National Ethnic Affairs Commission of China(No.MZR20006)the Fund for Academic Innovation Teams of South-Central Minzu University(No.XTZ24012)Scientific Research Platforms of South-Central Minzu University(No.PTZ24013)the Open Fund for Key Lab of Guangdong High Property and Functional Macromolecular Materials,China(No.20240007)State Key Laboratory of New Textile Materials and Advanced Processing Technologies(No.FZ20230012)。
文摘Recycling of carbon fiber reinforced composites is important for sustainable development and the circular economy.Despite the use of dynamic chemistry,developing high-strength recyclable CFRPs remains a major challenge due to the mutual exclusivity between the dynamic and mechanical properties of materials.Here,we developed a high-strength recyclable epoxy resin(HREP)based on dynamic dithioacetal covalent adaptive network using diglycidyl ether bisphenol A(DGEBA),pentaerythritol tetra(3-mercapto-propionate)(PETMP),and vanillin epoxy resin(VEPR).At high temperatures,the exchange reaction of thermally activated dithioacetals accelerated the rearrangement of the network,giving it significant reprocessing ability.Moreover,HREP exhibited excellent solvent resistance due to the increased cross-linking density.Using this high-strength recyclable epoxy resin as the matrix and carbon fiber modified with hyperbranched ionic liquids(HBP-AMIM+PF6-)as the reinforcing agent,high performance CFRPs were successfully prepared.The tensile strength,interfacial shear strength(IFSS)and interlaminar shear strength(ILSS)of the optimized formulation(HREP20/CF-HBPPF6)were 1016.1,70.8 and 76.0 MPa,respectively.In addition,the CFRPs demonstrated excellent solvent and acid/alkali-resistance.The CFRPs could completely degrade within 24 h in DMSO at 140℃,and the recycled CF still maintained the same tensile strength and ILSS as the original after multiple degradation cycles.
基金sponsored by the US Department of Energy Fossil Energy and Carbon Management Program,project FEAA157 under contract DE-AC05-00OR22725 with UTBattelle,LLC.
文摘Coal is a versatile energy resource and was a driver of the industrial revolution that transformed the economies of Europe and North America and the trajectory of civilization.In this work,a technoeconomic analysis was performed for a coal-to-carbonfiber manufacture process developed at the University of Kentucky’s Center for Applied Energy Research.According to this process,coal,with decant oil as the solvent,was converted to mesophase pitch via solvent extraction,and the mesophase pitch was subsequently converted to carbon fiber.The total cost to produce carbon fibers from coal and decant oil via the solvent extraction process was estimated to be$11.50/kg for 50,000-tow pitch carbon fiber with a production volume of 3750 MT/year.The estimated carbon fiber cost was significantly lower than the current commercially available PAN-based carbon fiber price($20–$30/kg).With decant oil recycling rates of 50%and 70%in the solvent extraction process,the manufacturing cost of carbon fiber was estimated to be$9.90/kg and$9.50/kg of carbon fiber,respectively.A cradle-to-gate energy assessment revealed that carbon fiber derived from coal exhibited an embodied energy of 510 MJ/kg,significantly lower than that of conventionally produced carbon fiber from PAN.This notable difference is primarily attributed to the substantially higher conversion rate of coal-based mesophase pitch fibers into carbon fiber,surpassing PAN fibers by 1.6 times.These findings indicate that using coal for carbon fiber production through solvent extraction methods could offer a more energy-efficient and cost-competitive alternative to the traditional PAN based approach.
文摘Polyacrylonitrile (PAN) precursor is a core precursor for the preparation of high-performance carbon fibers. Its unique chemical structure and physical properties directly contributes to the microstructure and mechanical properties of carbon fibers, and therefore affect the overall performance of pultruded composites. This study systematically investigated the influence of PAN precursor properties on the degree of graphitization, surface morphology and mechanical properties of carbon fibers by regulating the molecular weight distribution, stretching ratio and impurity content of PAN precursor, and analyzed the mechanism of action of carbon fiber properties on the interfacial bonding strength and tensile/ bending properties of composites in combination with the pultrusion process. The results showed that when the filament stretchability was increased to 4.5 times, the axial orientation of carbon fibers increased by 18% and the tensile strength reached 520 MPa;Filaments with impurity content below 0.3% increase carbon fiber yield by 5.2% and interlaminar shear strength of composites by 23%. This study provides a theoretical basis for raw material screening and process optimization of high-performance carbon fibers and their composites.
基金National Natural Science Foundation of China,Grant/Award Numbers:32171717,32271814Natural Science Foundation of Tianjin Municipality,Grant/Award Numbers:24JCJQJC00030,22JCYBJC01560,23JCZDJC00630China Postdoctoral Science Foundation,Grant/Award Number:2023M740562。
文摘Carbon fibers(CFs)with notable comprehensive properties,such as light weight,high specific strength,and stiffness,have garnered considerable interest in both academic and industrial fields due to their diverse and advanced applications.However,the commonly utilized precursors,such as polyacrylonitrile and pitch,exhibit a lack of environmental sustainability,and their costs are heavily reliant on fluctuating petroleum prices.To meet the substantial market demand for CFs,significant efforts have been made to develop cost-effective and sustainable CFs derived from biomass.Lignin,the most abundant polyphenolic compound in nature,is emerging as a promising precursor which is well-suited for the production of CFs due to its renewable nature,low cost,high carbon content,and aromatic structures.Nevertheless,the majority of lignin raw materials are currently derived from pulping and biorefining industrial by-products,which are diverse and heterogeneous in nature,restricting the industrialization of lignin-derived CFs.This review classifies fossil-derived and biomass-derived CFs,starting from the sources and chemical structures of raw lignin,and outlines the preparation methods linked to the performance of lignin-derived CFs.A comprehensive discussion is presented on the relationship between the structural characteristics of lignin,spinning preparation,and structure-morphology-property of ligninderived CFs.Additionally,the potential applications of these materials in various domains,including energy,catalysis,composites,and other advanced products,are also described with the objective of spotlighting the unique merits of lignin.Finally,the current challenges faced and future prospects for the advancement of lignin-derived CFs are proposed.
基金supported by the National Natural Science Foundation of China(Nos.12172205,12072183,12102244,and 12472174)。
文摘This study proposes a pre-strain optimization strategy for carbon fiber structural lithium-ion battery(SLIB) composites to inhibit the interfacial debonding between carbon fibers and solid-state electrolytes due to fiber lithiation. Through an analytical shear-lag model and finite element simulations, it is demonstrated that applying tensile pre-strain to carbon fibers before electrode assembly effectively reduces the interfacial shear stress, thereby suppressing debonding. However, the excessive pre-strain can induce the interfacial damage in the unlithiated state, necessitating careful control of the pre-strain within a feasible range. This range is influenced by electrode material properties and geometric parameters. Specifically, the electrodes with the higher solid-state electrolyte elastic modulus and larger electrolyte volume fraction exhibit more significant interfacial damage, making pre-strain application increasingly critical. However, these conditions also impose stricter constraints on the feasible pre-strain range. By elucidating the interplay between pre-strain, material properties, and geometric factors, this study provides valuable insights for optimizing the design of carbon fiber SLIBs.
基金support of the National Natural Science Foundation of China(61971301)In part by the Central Guidance on Local Science and Technology Development Fund of Shanxi Province under Grant YDZJSX2021A018+1 种基金Shanxi Province Higher Education Science and Technology Innovation Plan Project(2022L060)the Fundamental Research Program of Shanxi Province(Nos.202203021212227,202303021212082).
文摘The poor surface antibacterial properties are one of the important factors limiting the application of Carbon Fibers Reinforced Polyetheretherketone (CFR-P) composites as artificial bone replace materials. Some of the Two-Dimensional (2D) nanomaterials with unique lamellar structures and biological properties have been demonstrated to have excellent antibacterial properties. Antibacterial properties can be improved by feasible chemical strategies for preparing 2D nanomaterials coating on the surface of CFR-P. In this work, Black Phosphorus (BP) coating was prepared on the originally chemically inert CFR-P surface based on wet chemical pretreatment. The physical and chemical properties, including surface microstructure, chemical composition and state, roughness and hydrophilicity were characterized. The antibacterial ratios against Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Streptococcus mutans (S. mutans) were evaluated. The results indicated that hydrophilicity of BP coating on CFR-P was significantly higher compared to that of the pure CFR-P. Wet chemical pretreatment using mixed acid reagents (concentrated sulfuric acid and concentrated nitric acid) introduced hydroxyl, carboxyl and nitro groups on CFR-P. The BP coating exhibited the antibacterial rate of over 98% against both S. aureus and E. coli. In addition, the antibacterial rate of BP coating against the main pathogenic bacteria of dental caries, Streptococcus mutans, reached 45%.
基金supported by the Key Laboratory of Flame Retardancy Finishing of Textile Materials,CNTAC(No.Q811580421)the Qianjiang Talent Plan of Zhejiang Province(No.QJD1902018).
文摘The effective thermal management of lithium-ion batteries is the key to ensuring their fast charging-discharging,safe and efficient operation.Herein,inspired by transpiration-driven water transport in plants,we report a highly hygroscopic needle-punched carbon fiber felt(HS/CFF)with high evaporative cooling efficiency and fire resistance for the safe operation of lithium-ion batteries working at ultrahigh-rate conditions.The three-dimensional fiber skeleton structure constructed by needle punching in the carbon fiber felt enables effective water transport and storage in HS/CFF,without any water leakage.At an ultra-high discharge rate of 10 C,HS/CFF can reduce the maximum temperature of commercial lithium-ion batteries by 18°C,and can keep the battery temperature below 60°C.During 500 cycles of charge-discharge,HS/CFF maintains stable evaporative heat dissipation performance,which helps to improve the safety of lithium-ion batteries and extend their service life.Moreover,HS/CFF remains non-combustible even under exposure to a flame(600-700°C)for 10 min,and the HS/CFF can be reused after the burning test,with the original excellent heat dissipation effect unchanged.This flexible,fire-resistant cooling material offers a promising avenue for low-energy intelligent thermal management of lithium-ion batteries and other heat-generating electronic devices.
基金supported by the Key Research and Development Plan of Shaanxi Province(No.2023-GHZD-12)the Chinese Aeronautical Establishment Aeronautical Science Foundation(No.20230041053006)the National Natural Science Foundation of China(Nos.12472392 and 12172304).
文摘3D printing has emerged as an advanced manufacturing technique for carbon fiber reinforced composites and relevant structures that endure significant dynamic loads in engineering applications.The dynamic behavior of these materials,primarily influenced by the dynamic fiber pullout interface strength necessitates investigation into the rate-dependent fiber/matrix interfacial strength.This study modifies a Hopkinson tension bar to conduct dynamic pullout tests on a single fiber bundle,utilizing a low-impedance bar and an in-situ calibrated semiconductor strain gauge to capture weak stress signals.Stress equilibrium analyses are performed to validate the transient dynamic loading on single fiber bundle specimens.The results reveal that the fiber/matrix interfacial strength is rate-dependent,increasing with the loading rate,while remaining unaffected by the embedded length.Fracture microstructural analyses show minimal fiber pullout due to high interfacial stresses induced by longer embedded lengths.Lastly,suggestions are made for the efficient design of fiber pullout experiments.
基金supported by Yunnan Major Scientific and Technological Projects(No.202202AG050005)Yunnan Fundamental Research Projects(No.202101BE070001-001).
文摘The ACF adsorbent with high Cu loading was treated with dielectric barrier discharge plasma to mitigate the negative effects of high Cu loading and enhance PH_(3)and H_(2)S adsorption and oxidation.Bruno-Emmett-Taylor(BET)result showed that the specific surface area of the adsorbent after air plasma modification was almost three times that before modification.X-ray photoelectron spectroscopy(XPS)findings revealed that the amino group was added to the adsorbent's surface,increasing lattice oxygen and chemisorbed oxygen.The adsorbent's large specific surface area,excellent surface active oxygen,and abundance of basic groups facilitate PH_(3)and H_(2)S adsorption and oxidation.The scanning electron microscopy showed that air plasma modification exposed more active components and uniformly dispersed them on the surface of adsorbent,thereby improving the adsorption performance.Activity evaluation results showed that the adsorbent has the best ability to capture PH_(3)and H_(2)S after being modified by air plasma at 4 kV voltage for 10 min.The adsorbent's breakthrough ability at high space velocity(WHSV:60,000 h^(−1))is 190 mg P/g and 146 mg S/g,respectively,which is 74%and 60%greater than that before modification.This is a great improvement over previous studies.In addition,the possible mechanism of adsorbent deactivation was proposed.
基金the National Natural Science Foundation of China(No.52070052)the National Natural Science Foundation of China(No.52300082)+3 种基金National Key Research and Development Program of China(No.2022YFB3805903)the State Key Laboratory of Urban Water Resource and Environment in HIT of China(No.2022TS14)the China Postdoctoral Science Foundation(No.2023M730881)Postdoctoral Fellowship Program of CPSF(No.GZB20230964)。
文摘Solar interfacial evaporation(SIE),is currently one of the most potential water supply technologies in the remote,insular,and disaster-stricken areas.However,the existence of volatile organic compounds(VOCs)in water deteriorates the distillate quality,threatening human health.Herein,we constructed a carbonbased bimetallic(C/FeCo)photothermal membrane by electrospinning technique.Results illustrated that the membrane can catalytically degrade VOCs during SIE with persulfate(PDS)mediation.PDS,as well as phenol,was mainly reacted on the interface of the photothermal membrane instead of in the bulk solution.The interception efficiency of phenol achieved nearly 100%using the C/FeCo membrane during SIE.Hydroxyl radical(•OH),sulfate radical(SO_(4)•−),superoxide radical(O_(2)•−),and singlet oxygen(^(1)O_(2))were identified as the main active substances to degrade VOCs.We also conducted SIE experiments using actual river water to evaluate the practical performance of the C/FeCo membrane.This work holds the promise of VOCs interception during SIE and enlarges the application of solar distillation in water/wastewater treatment.
基金financially supported by the National Natural Science Foundation of China(No.22408391)the Fundamental Research Funds for the Central Universities(No.2024ZKPYHH04)
文摘Fe-N-C single-atom catalysts are considered among the most promising non-precious metal-based catalysts for oxygen reduction reaction(ORR),but issues such as low utilization of active sites and the easy aggregation of single atoms severely hinder their application in fuel cells and metal-air batteries.Herein,a single-atom Fe-embedded hierarchical porous hollow carbon fiber catalyst(Fe S AC/HCNF) is reported for ORR.The hollow channels and the porous structure of the fibers facilitate the exposure of single-atom active sites,and offer multidimensional mass transfer pathways to promote the transport of reactants,thus significantly enhancing catalytic performance.Additionally,the abundant micropores exert spatial confinement,which is beneficial for preventing the aggregation of single atoms.Leveraging its unique structural advantages,the Fe S AC/HCNF catalyst demonstrates outstanding ORR activity with low metal loading,boasting a high half-wave potential of 0.905 V,a substantial double-layer capacitance(C_(d1)) of 41.1 mF cm^(-2),and a notable kinetic current density of 45.2 mA cm^(-2)in alkaline media.Furthermore,the liquid Zn-air battery(ZAB) using Fe SAC/HCNF catalyst as the air cathode exhibits excellent battery performance and long-term cycling durability nearly 600 h.And the flexible quasi-solid-state ZAB can be stably cycled in various flat/bent states,which is promising for applications in flexible electronic devices.
基金supported by the National Natural Science Foundation of China(No.51872232)the Key Scientific and Technological Innovation Research Team of Shaanxi Province(No.2022TD-31)the Key R&D Program of Shaanxi Province(No.2021ZDLGY14-04).
文摘Carbon fiber/phenolic resin composites have great potential application in the field of electronic information,where excellent structural-functional integration is required.In this work,the establishment of interfacial structures consisting of carbon nanotubes with different morphologies at the fiber/matrix interface is conducive to the further modulation of the mechanical,tribological,electromagnetic interference(EMI)shielding and thermal conductivity properties of carbon fiber/phenolic resin composites.Specially,array carbon nanotubes can deep into the resin matrix,effectively hindering crack extension,and constructing an electrically and thermally conductive network.Compared with the carbon fiber/phenolic composites,the tensile strength and modulus of elasticity(163.86±9.60 MPa,5.06±0.25 GPa)of the array carbon nanotubes reinforced carbon fiber/phenolic composites were enhanced by 57.09%and 22.22%.The average friction coefficient and wear rate(0.20±0.02,1.11×10^(-13)±0.13×10^(-13)m^(3)N^(−1)m^(−1))were reduced by 39.39%and 74.31%.EMI shielding effectiveness up to 40 dB in the X-band at 0.4 mm sample thickness,diffusion coefficient(0.39±0.003 mm^(2)/s)and thermal conductivity(0.54±0.004 W/(m K))were enhanced by up to 14.37%and 50.42%.This study reveals the beneficial effects of morphological changes of carbon nanotubes on the design of interfacial structure,proposes the reinforcement mechanism of array carbon nanotubes,and opens up the prospect of carbon fiber/phenolic composites for electronic applications.
基金funded by the Innovative Research Group project of the National Natural Science Foundation of China(52373003).
文摘This study investigates the long-term thermal-oxidative stability and mechanical properties of phenolcontaining phthalonitrile monomer(PN75)and dicyanate ester of bisphenol-A(DCBA)composites reinforced with short carbon fibers T700SC(SCF)within a temperature range of 330375℃.The research focuses on the PN75 monomer and DCBA blend reinforced SCF composites with varying SCF content,examining mass loss and changes in flexural strength after thermal aging for 50 h(h).Results show that the SCF-reinforced composites based on the PN75/DCBA blend consistently outperform the neat blend in flexural strength,both at room temperature and after thermal aging.The introduction of the SCF significantly improves the composites'thermal stability and mechanical retention,with higher SCF content correlating to better performance.Notably,after aging at 350℃,the SCF-reinforced composites based(30%(mass)SCF)retained 88.8%of its flexural strength,compared to 61.1%for the neat blend.Morphological analysis reveals that while thermal aging causes degradation of the PN75/DCBA blend layer on SCF surfaces,the overall composite structure maintains good mechanical properties up to 350℃.At 375℃,significant degradation occurs,yet the composites still retain flexural strengths above 78 MPa.This study demonstrates the potential of the SCF-reinforced composites based on PN75/DCBA blend for high-temperature applications,establishing their upper-temperature limit for long-term use in oxidative environments.
基金financially supported by the National Natural Science Foundation of China(Nos.52101274 and 52472131)the Natural Science Foundation of Shandong Province(Nos.ZR2020QE011 and ZR2022ME089)+6 种基金Yantai Basic Research Project(No.2024JCYJ097)the Key Research and Development Projects of Shandong Province(No.2024TSGC0402)the Youth Top Talent Foundation of Yantai University(No.2219008)the Graduate Innovation Foundation of Yantai University(No.GIFYTU2240)the Natural Science Foundation of Qinghai Province for Distinguished Young Scholars(No.2025-ZJ-966J)the Talent Youth Project of Chinese Academy of Sciences(No.E410GC03)the CollegeStudent Innovation and Entrepreneurship Training Program Project(No.202311066088)
文摘To effectively enhance the catalytic activity of NiS,NiS particles confined into carbon fibers were prepared by electrostatic spinning followed pyrolyzation and NiS particles decorating was performed by further hydrothermal loading.The decorated NiS exhibits particle(NiS@PAN-NiS)and needle-like(NiS@PAN-NiS^(*))morphologies.After adding the catalysts into MgH_(2),the synthesized MgH_(2)-5 wt%NiS@PAN-NiS composite can absorb 2.6 wt%hydrogen at 353 K and release 5.0 wt%hydrogen within 1 h at 573 K.The initial hydrogen desorption temperature was reduced to 539 K.The activation energies for hydrogen absorption/desorption were greatly reduced to 66.76 and 89.95 kJ mol^(-1),respectively.The method of confining by electrospinning and particle decoration by hydrothermal loading reduce NiS particle agglomeration.The Mg_(2)Ni/Mg_(2)NiH_(4)hydrogen pump formed by reaction between NiS and MgH_(2)effectively enhanced hydrogen absorption and desorption kinetics.The formed MgS also improved the catalytic activity on the transformation of Mg and MgH_(2).Moreover,the carbon fibers should influence the contact between in situ formed MgS and Mg_(2)Ni,providing more catalytic sites and hydrogen diffusion pathways.The construction of NiS/carbon fibers confined NiS composite by carbon fibers derived from pyrolyzation as medium provides considerable way for designing NiS-based catalysts to enhance the hydrogen storage performances of MgH_(2).
文摘The automobile industry is the first to form a typical representative of the global industry in modern industry,with the increase of the national emphasis on the environment,the automobile industry was regarded as an important energy consumption and one of the sources of environmental pollution,the policy of energy conservation and emission reduction requirements for the automobile industry are becoming stricter over the years,energy conservation and emission reduction has becomes the main direction of product optimization in the automobile industry in recent years.Due of a series of excellent properties such as light weight and high strength,composite materials have become the main material for the development of lightweight vehicles.With the development of material technology and the update and iteration of manufacturing technology,composite materials are currently popular being adopted in the automotive field.
文摘Carbon fiber reinforced polymer(CFRP)is an advanced material widely used in bridge structures,demonstrating a promising application prospect.CFRP possesses excellent mechanical properties,construction advantages,and durability benefits.Its application in bridge reinforcement can significantly enhance the overall performance of the reinforced bridge,thereby improving the durability and extending the service life of the bridge.Therefore,it is necessary to further explore how CFRP can be effectively applied in bridge reinforcement projects to improve the quality of such projects and ensure the safety of bridges during operation.
基金supported by the National Key R&D Program of China(No.2022YFC2204500)the Aviation Science Foundation Project(No.2023Z055053001).
文摘Ceramic matrix composites(CMC)are widely utilized in high-temperature components of aero-engines for load-bearing and electromagnetic stealth synergy due to their superior toughening and designable electromagnetic properties.However,the design of ultra-broadband electromagnetic wave(EMW)absorp-tion at thin thicknesses(d<10 mm)has been difficult and focused,especially the design of metama-terial.Inspired by 3D printing technology and the structural characteristic of 2D CMC,this study inge-niously devised and proposed a novel carbon fiber gradient periodic structure in Al_(2)O_(3f)/SiOC composites to enhance the ultra-broadband EMW absorption properties at a wide temperature range.By optimizing the geometric structure parameters,the Al_(2)O_(3f)/SiOC composites with the carbon fiber gradient periodic structure have exhibited exceptional ultra-broadband EMW absorption properties at elevated tempera-tures and excellent mechanical performance.The composites have attained a minimum reflection loss(RLmin)of-30 dB and a high absorption efficiency of more than 84%,ranging from 9.3 to 40 GHz at a thickness of 9 mm.Due to the temperature insensitivity of discrete periodic structures,the composites can adapt to high temperatures up to 700℃.Additionally,compared to the Al_(2)O_(3f)/SiOC composites,the flexural strength and fracture toughness of the Al_(2)O_(3f)/SiOC composites with carbon fiber gradient peri-odic structure have significantly increased to 398 MPa and 15.6 MPa m1/2,respectively.This work breaks through the limitation of the design and fabrication of 3D periodic structures in CMC,creating a novel oxide-CMC with ultra-broadband EMW absorption properties at a wide temperature range and enhanced mechanical properties.
