ZFJ Textile Machinery Co.,Ltd.,established in 1949,is a key enterprise directly managed by China Hi-Tech Group Corporation and falls under the jurisdiction of China National Machinery Industry Corporation Limited(Sino...ZFJ Textile Machinery Co.,Ltd.,established in 1949,is a key enterprise directly managed by China Hi-Tech Group Corporation and falls under the jurisdiction of China National Machinery Industry Corporation Limited(Sinomach).As a leading enterprise in the textile machinery manufacturing industry,ZFJ is dedicated to providing global customers with complete equipment solutions covering the entire industry chain.During this exhibition,ZFJ primarily highlights three key features:"high-performance fibers,green fibers,and intelligent equipment,"with a focus on showcasing nine types of products,spanning various textile equipment categories,including chemical fiber,specialty fiber,nonwoven,sizing,and dyeing machinery.展开更多
Ultra-high performance fiber-reinforced concrete (UHPFRC) has received extensive attention from scholars and engineers due to its excellent mechanical properties and durability. However, there is a mutually restrictiv...Ultra-high performance fiber-reinforced concrete (UHPFRC) has received extensive attention from scholars and engineers due to its excellent mechanical properties and durability. However, there is a mutually restrictive relationship between the workability and mechanical properties of UHPFRC. Specifically, the addition of fibers will affect the workability of fresh UHPFRC, and the workability of fresh UHPFRC will also affect the dispersion and arrangement of fibers, thus significantly influencing the mechanical properties of hardened UHPFRC. This paper first analyzes the research status of UHPFRC and the relationship between its workability and mechanical properties. Subsequently, it outlines the test methods and indicators of UHPFRC workability, including fluidity, slump, V-funnel passing time, and rheology. Then, it reviews the impacts of metal fibers, synthetic fibers, hybrid fibers, and other fibers on the workability and mechanical properties of UHPFRC, and presents a reasonable range of fiber dosage for workability and mechanical properties. Key findings include: (1) Steel fibers within 1%–2% volume optimize workability-mechanical balance, while exceeding 2.5% reduces compressive strength by 7%–30%;(2) Hybrid steel-polypropylene fibers enhance toughness by 65%;(3) Fiber orientation control via rheology-modifying admixtures improves flexural strength by up to 64%. This review establishes a fiber factor (V·L/D) for predictive mix design, advancing beyond empirical approaches in prior studies.展开更多
Chinese top planner-State Development and Reform Commission,has decided to organize and coordinate an implementation of a special project for high tech industrialization of fiber-reinforced compound materials in 2008 ...Chinese top planner-State Development and Reform Commission,has decided to organize and coordinate an implementation of a special project for high tech industrialization of fiber-reinforced compound materials in 2008 up to 2009.The decision has recently been issued in its national circular(doc. 3177,Yr.2007)to call for local enterprises to apply for this special project support.展开更多
Ultra-high molecular weight polyethylene(UHMWPE)fiber is a new kind of high-performance fiber.Due to its excellent physical and chemical characteristics,it is widely used in various fields.However,the surface UHMWPE f...Ultra-high molecular weight polyethylene(UHMWPE)fiber is a new kind of high-performance fiber.Due to its excellent physical and chemical characteristics,it is widely used in various fields.However,the surface UHMWPE fiber is smooth and demonstrates no-polar groups.The weak interfacial adhesion between fiber and resin seri-ously restricts the applications of UHMWPE fiber.Therefore,the surface modification treatments of UHMWPE fiber are used to improve the interfacial adhesion strength.The modified method by adding nanomaterials elu-cidates the easy fabrication,advanced equipment and proper technology.Thus,the progress of UHMWPE nanocomposite fibers prepared via adding various nanofillers are reviewed.Meanwhile,the effects of other various methods on surface modification are also reviewed.This work advances the various design strategies about nano technologies on improving interfacial adhesion performance via treatment methodologies.展开更多
Ultrahigh-performance concrete(UHPC)is a groundbreaking kind of concrete that distinguishes itself from conventional concrete through its unique material properties.Understanding and managing the time-dependent charac...Ultrahigh-performance concrete(UHPC)is a groundbreaking kind of concrete that distinguishes itself from conventional concrete through its unique material properties.Understanding and managing the time-dependent characteristics of these materials is essential for their effective use in various construction applications.This study presents an experimental evaluation of the compressive and bending properties of the UHPC incorporating polypropylene,steel,and glass fibers.Based on ACI-211 guidelines,the UHPC mix was designed by using three types of aggregates:limestone,andesite,and quartzite,along with 5%fiber content(at varying percentages of 0,5%,10%,15%,and 20%)relative to the cementitious materials,and three different water-to-cement(w/c)ratios(0.24,0.3,and 0.4)were used.In this research,the compressive and flexural strength tests were conducted.The results show that increasing the values of the fibers significantly enhances the compressive strength of the studied samples.Furthermore,the utilization of fibers markedly improves the bending strength of the samples,demonstrating a strong correlation with the yield resistance of the material.Also,findings show that using steel fibers increases the compressive and bending strength of the tested samples more than polypropylene and glass fibers.For instance,in UHPC samples with 0.4 w/c,the average compressive strength values are 82.2 MPa,70.3 MPa,and 67.1 MPa for steel,polypropylene,and glass fibers,respectively.Also,in the flexural strength test,the modulus of rupture is obtained as an average of 6.24 MPa,5.24 MPa and 4.83 MPa for UHPC samples with steel,polypropylene and glass fibers,respectively.展开更多
This study investigates the significance and prospects of utilizing high-performance fiber-reinforced concrete in airport pavements.With the rapid development of the aviation industry,higher performance demands are pl...This study investigates the significance and prospects of utilizing high-performance fiber-reinforced concrete in airport pavements.With the rapid development of the aviation industry,higher performance demands are placed on airport pavements.Traditional airport pavements are predominantly made from ordinary cement concrete,but this material exhibits significant issues of brittleness and low durability when subjected to heavy aircraft and harsh weather conditions.Consequently,fiber-reinforced concrete,known for its exceptional strength and toughness,has garnered considerable attention.This paper discusses in detail the application of various types of fiber materials in strengthening concrete,including steel and basalt fibers.These fibers,based on their chemical and physical properties,play distinct roles in the concrete,thereby enhancing its overall performance.For instance,steel fibers possess a high modulus of elasticity and tensile strength,but are prone to corrosion in acidic environments,while carbon fibers are renowned for their light weight,high strength,and stability.Additionally,the paper emphasizes the importance of mix design methods,as the incorporation of fibers alters the composition and structure of the concrete.Appropriate concrete mix design methods need to be selected.Although fiber-reinforced concrete is widely used in the field of construction engineering,its research and application in airport pavements are not yet sufficiently extensive.Studies should go beyond laboratory tests to explore the evolution of concrete performance in actual usage environments.Consideration should also be given to the unique usage scenarios and stress characteristics of airport pavements to select suitable types of fibers.Moreover,research on the dynamic mechanical properties of fiber-reinforced concrete is a key aspect in enhancing the performance and service life of airport pavements.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
The demand for high thermal stability and high strength agents is growing steadily as a result of their increasing application in advanced materials.A series of sulfonated poly(m-phenyleneisophthalamide)(SPMIA)copolym...The demand for high thermal stability and high strength agents is growing steadily as a result of their increasing application in advanced materials.A series of sulfonated poly(m-phenyleneisophthalamide)(SPMIA)copolymers with superior thermal stability and good mechanical properties have been prepared via low temperature polycondensation method.Then the structures of 5PMA copolymers with different content quantities of 2,4-diaminobenzenesulfonic acid(2,4-DABSA)were confimed by Fourier transform infrared(FTiR).Besides,their superior thermal properties were systematically investigated by differential canning calorimetry DSC),thermalgravimetreic analysis(TGA),and dynamic mechanical analysis(DMA).SPMA fbers were obtained by wet spinning using the resultant SPMIAsolutions.n addition,the obtained SPMIA fibers were proved to combine enhanced mechanical properties and unprecedented dyeability.Significantly,the SPMlA iber with great mechanical property,thermal stability,and dyeability shows great potential in easily dyeing high-performance protective fibers.展开更多
Although fibers are used only infrequently as an additive in concrete in the construction industry,fiberenhanced concrete is known to provide a wide range of advantages over conventional concrete.The main objective of...Although fibers are used only infrequently as an additive in concrete in the construction industry,fiberenhanced concrete is known to provide a wide range of advantages over conventional concrete.The main objective of this study was to investigate the influences of fiber type and content on the mechanical properties and durability of highperformance fiber-reinforced concrete(HPFRC)designed using a novel densified mixture design algorithm with fly ash and rice husk ash.Three types of fiber,including polypropylene(PP)fiber,steel fiber(SF),and hybrid fiber(HF),were considered.Based on the results,the inclusion of fibers decreased HPFRC flowability,regardless of fiber type.Although the compressive strength of HPFRC with 1.6%PP fiber content was 11.2%below that of the reference HPFRC specimen at 91 d of curing age,the 91-d compressive strengths of both SF and HF-enhanced HPFRC specimens were significantly better than that of the reference HPFRC specimen.Furthermore,the HPFRC specimens incorporating SF and HF both exhibited better splitting tensile and flexural strengths as well as less drying shrinkage than the HPFRC specimens incorporating PP fiber.However,the fiber-enhanced specimens,especially those with added SF,registered less surface electrical resistivity and greater vulnerability to chloride ion penetration than the reference HPFRC specimen.展开更多
Spalling and mechanical properties of FRHPC subjected to fire were tested on notched beams. The results confirm that the internal vapor pressure is the leading reason for spalling of high-performance concrete （HPC）....Spalling and mechanical properties of FRHPC subjected to fire were tested on notched beams. The results confirm that the internal vapor pressure is the leading reason for spalling of high-performance concrete （HPC）. At the same time, the temperature-increasing velocity and constrained conditions of concrete element also play significant roles in spalling. Steel fibers cannot reduce the risk of spalling, although they have obvious beneficial effects on the mechanical properties of concrete before and after exposure to fire. Polypropylene （PP） fibers are very useful in preventing HPC from spalling, however, they have negative effects on the strengths. By using hybrid fibers （steel fibers＋PP fibers）, both good anti-spalling performance and improved mechanical properties come true, which may provide necessary safe guarantee for the rescue work and structure repair after fire disaster.展开更多
A flexible electrode of nickel diselenide/carbon fiber cloth(NiSe/CFC) is fabricated at room temperature by a simple and efficient electrodeposition method. Owing to NiSecharacter of nanostructure and high conductivit...A flexible electrode of nickel diselenide/carbon fiber cloth(NiSe/CFC) is fabricated at room temperature by a simple and efficient electrodeposition method. Owing to NiSecharacter of nanostructure and high conductivity, the as-synthesized electrodes possess perfect pseudocapacitive property with high specific capacitance and excellent rate capability. In three-electrode system, the electrode specific capacitance of the NiSe/CFC electrode varies from 1058 F gto 996.3 F gat 2 A gto 10 A grespectively, which shows great rate capability. Moreover, the NiSeelectrode is assembled with an active carbon(AC) electrode to form an asymmetric supercapacitor with an extended potential window of 1.6 V. The asymmetric supercapacitor possesses an excellent energy density 32.7 Wh kgwith a power density 800 W kgat the current density of 1 A g. The nanosheet array on carbon fiber cloth with high flexibility, specific capacitance and rate capacitance render the NiSeto be regarded as the promising material for the high performance superconductor.展开更多
Many natural fibers are lightweight and display remarkable strength and toughness.These properties originate from the fibers’hierarchical structures,assembled from the molecular to macroscopic scale.The natural spinn...Many natural fibers are lightweight and display remarkable strength and toughness.These properties originate from the fibers’hierarchical structures,assembled from the molecular to macroscopic scale.The natural spinning systems that produce such fibers are highly energy efficient,inspiring researchers to mimic these processes to realize robust artificial spinning.Significant developments have been achieved in recent years toward the preparation of high-performance bio-based fibers.Beyond excellent mechanical properties,bio-based fibers can be functionalized with a series of new features,thus expanding their sophisticated applications in smart textiles,electronic sensors,and biomedical engineering.Here,recent progress in the construction of bio-based fibers is outlined.Various bioinspired spinning methods,strengthening strategies for mechanically strong fibers,and the diverse applications of these fibers are discussed.Moreover,challenges in reproducing the mechanical performance of natural systems and understanding their dynamic spinning process are presented.Finally,a perspective on the development of biological fibers is given.展开更多
In dual-ion batteries (DIBs), energy storage is achieved by intercalation/de-intercalation of both cations and anions. Due to the mismatch between ion diameter and layer space of active materials, however, volume expa...In dual-ion batteries (DIBs), energy storage is achieved by intercalation/de-intercalation of both cations and anions. Due to the mismatch between ion diameter and layer space of active materials, however, volume expansion and exfoliation always occur for electrode materials. Herein, an integrated electrode Co3O4/carbon fiber paper (CFP) is prepared as the anode of DIB. As the Co3O4 nanosheets grow on CFP substrate vertically, it promotes the immersion of electrolyte and shortens the pathway for ionic transport. Besides, the strong interaction between Co3O4 and CFP substrate reduces the possibility of sheet exfoliation. An integrated-electrode-based DIB is therefore packaged using Co3O4/CFP as anode and graphite as cathode. As a result, a high energy density of 72 Wh/kg is achieved at a power density of 150 W/kg. The design of integrated electrode provides a new route for the development of high-performance DIBs.展开更多
A series of polyamic acid copolymers(co-PAAs) with para-hydroxyl groups was synthesized using two diamine monomers,namely p-phenylenediamine(p-PDA) and 5-amino-2-(2-hydroxy-5-aminobenzene)-benzoxazole(m-pHBOA), of dif...A series of polyamic acid copolymers(co-PAAs) with para-hydroxyl groups was synthesized using two diamine monomers,namely p-phenylenediamine(p-PDA) and 5-amino-2-(2-hydroxy-5-aminobenzene)-benzoxazole(m-pHBOA), of different molar ratios through copolymerization with 3,3′,4,4′-biphenyltetracarboxylic dianhydride(BPDA) in N,N-dimethyacetamine(DMAc). The co-PAA solutions were used to fabricate fibers by dry-jet wet spinning, and thermal imidization was conducted to obtain polyimide copolymer(coPI) fibers. The effects of the m-pHBOA moiety on molecular packing and physical properties of the prepared fibers were investigated.Fourier transform infrared(FTIR) spectroscopic results confirmed that intra/intermolecular hydrogen bonds originated from the hydroxyl group and the nitrogen atom of the benzoxazole group and/or the hydroxyl group and the oxygen atom of the carbonyl group of cyclic imide. As-prepared PI fibers displayed homogenous and smooth surface and uniform diameter. The glass transition temperatures(Tgs) of PI fibers were within 311-337 °C. The polyimide fibers showed 5% weight loss temperature(T5%) at above 510 °C in air. Twodimensional wide-angle X-ray diffraction(WXRD) patterns indicated that the homo-PI and co-PI fibers presented regularly arranged polymer chains along the fiber axial direction. The ordered molecular packing along the transversal direction was destroyed by introducing the m-pHBOA moiety. Moreover, the crystallinity and orientation factors increased with increasing draw ratio. Small-angle X-ray scattering(SAXS) results showed that it is beneficial to reduce defects in the fibers by increasing the draw ratio. The resultant PI fibers exhibited excellent mechanical properties with fracture strength and initial modulus of 2.48 and 89.73 GPa, respectively, when the molar ratio of p-PDA/m-pHBOA was 5/5 and the draw ratio was 3.0.展开更多
In graphene-based optoelectronic devices,the ultraweak interaction between a light and monolayer graphene leads to low optical absorption and low responsivity for the photodetectors and relative high half-wave voltage...In graphene-based optoelectronic devices,the ultraweak interaction between a light and monolayer graphene leads to low optical absorption and low responsivity for the photodetectors and relative high half-wave voltage for the phase modulator.Here,an integration of the monolayer graphene onto the side-polished optical fiber is demonstrated,which is capable of providing a cost-effective strategy to enhance the light–graphene interaction,allowing us to obtain a highly efficient optical absorption in graphene and achieve multifunctions:photodetection and optical phase modulation.As a photodetector,the device has ultrahigh responsivity(1.5×10^(7) A/W)and high external quantum efficiency(>1.2×10^(9)%).Additionally,the polybutadiene/polymethyl methacrylate(PMMA)film on the graphene can render the device an optical phase modulator through the large thermo-optic effect of the PMMA.As a phase modulator,the device has a relatively low half-wave voltage of 3 V with a 16 dB extinction ratio in Mach–Zehnder interferometer configuration.展开更多
In this work, a fully rigid coplanar symmetric heterocyclic unit was introduced into the rigid polyimide macromolecular backbone structure to prepare high-performance polyimide fibers. The novel co-polyimide(co-PI) fi...In this work, a fully rigid coplanar symmetric heterocyclic unit was introduced into the rigid polyimide macromolecular backbone structure to prepare high-performance polyimide fibers. The novel co-polyimide(co-PI) fibers based on 3,3',4,4'-biphenyltetracarboxylic anhydride(BPDA), p-phenylenediamine(PDA) and 2,6-(4,4'-diaminodiphenyl) benzo[1,2-d:5,4-d'] bisoxazole(PBOA) were fabricated via a twostep wet-spinning method. The effects of benzobisoxazole moiety on spinnability, aggregation structure, and mechanical properties of fibers were systematically discussed. The detailed structural analysis revealed that the well-defined aggregation structures of co-PI fibers were obtained from initial amorphous structure when post hot-drawing temperature was higher than 460 ℃ under proper drawing ratio, and the incorporation PBOA into BPDA-PDA structures produced more compact structural co-PI fiber than homo BPDA-PDA fiber. The BPDA-PDA/PBOA co-PI fibers exhibited optimum tensile strength and modulus of 2.65 and 103 GPa, which increased by 182% and 84% compared to the homo BPDA-PDA fiber, respectively.展开更多
In this study,we synthesized high-performance Carbon Fiber/Gold/Copper(CF/Au/Cu)composite wires by using a 2-step deposition method via sputtering and electrodeposition.After Au was sputtered on PANbased CFs as a pre-...In this study,we synthesized high-performance Carbon Fiber/Gold/Copper(CF/Au/Cu)composite wires by using a 2-step deposition method via sputtering and electrodeposition.After Au was sputtered on PANbased CFs as a pre-treatment,the wettability and surface reactivity of the CFs were improved,resulting in a homogeneous deposition of Cu on their surface.At different Cu electrodeposition time,the resulting CF/Au/Cu composite wires could possess a high strength of up to 3.27 GPa(~10 times stronger than copper wires)while their electrical conductivity could be as high as 4.4×10^5 S/cm(~75%of that for copper).More importantly,since the composite wires were lightweight(up to 70%lower than Cu mass density),they are a promising candidate to substitute conventional heavy metal wires in the future electrical applications.展开更多
Spider silks are well known for their exceptional mechanical properties that are tougher than Kevlar and steel.However,the restricted production amounts from their native sources limit applications of spider silks.Ove...Spider silks are well known for their exceptional mechanical properties that are tougher than Kevlar and steel.However,the restricted production amounts from their native sources limit applications of spider silks.Over the decades,there have been significant interests in fabricating man-made silk fibers with comparable performance to natural silks,inspiring many efforts both for biosynthesizing recombinant spider silk proteins(spidroins)in amenable heterologous hosts and biomimetic spinning of artificial spider silks.These strategies provide promising routes to produce high-performance and functionally optimized fibers with diverse applications.Herein,we summarize the hosts that have been applied to produce recombinant spidroins.In addition,the fabrication and mechanical properties of recombinant spidroin fibers and their composite fibers are also introduced.Furthermore,we demonstrate the applications of recombinant spidroin-based fibers.Finally,facing the challenges in biosynthesis,scalable production,and hierarchical assembly of high-performance recombinant spidroins,we give a summary and perspective on future development.展开更多
ZnO and TiO_(2) nanofibers are synthesized via electrospinning methods and characterized by x−ray diffraction,scanning electron microscopy,and transmission electron microscopy.Humidity sensors with double-layer sensin...ZnO and TiO_(2) nanofibers are synthesized via electrospinning methods and characterized by x−ray diffraction,scanning electron microscopy,and transmission electron microscopy.Humidity sensors with double-layer sensing films are fabricated by spinning the ZnO and TiO_(2) nanofibers on ceramic substrates sequentially.Compared with sensors loading only one type of nanofiber,the double-layer sensors exhibit much better sensing properties.The corresponding impedance changes more than four orders of magnitude within the whole humidity range from 11%to 95%relative humidity,and the response and recovery times are about 11 and 7 s,respectively.Maximum hysteresis is around 1.5%RH,and excellent stability is also observed after 180 days.The humidity sensing mechanism is discussed in terms of the sensor structure.The experimental results provide a possible route for the design and fabrication of high performance humidity sensors based on one-dimensional nanomaterials.展开更多
The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of society.Since the existence of dynamic chemical bonds in vitrimers often reduces both the ther...The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of society.Since the existence of dynamic chemical bonds in vitrimers often reduces both the thermal and mechanical properties of epoxy resins, it is challenging to produce recyclable epoxy vitrimers with both excellent mechanical properties and good thermal stability. Herein, a monomer 4-(((5-(hydroxymethyl)furan-2-yl)methylene)amino)phenol(FCN) containing furan ring with potential to form high density of hydrogen bonding among repeating units is designed and copolymerized with glycerol triglycidyl ether to yield epoxy resin(FCN-GTE), which intrinsically has dual hydrogen bond networks, dynamic imine structure and resultant high performance. Importantly, as compared to the BPA-GTE, the FCN-GTE exhibits significantly improved mechanical properties owing to the increased density of hydrogen bond network and physical crosslinking interaction. Furthermore, density functional theory(DFT) calculation and in situ FTIR analysis is conducted to decipher the formation mechanism of hydrogen bond network. In addition, the FCN-GTE possesses superior UV shielding, chemical degradation, and recyclability because of the existence of abundant imine bonds. Notably, the FCN-GTE-based carbon fiber composites could be completely recycled in an amine solution.This study provides a facile strategy for synthesizing recyclable biomass-based high-performance epoxy vitrimers and carbon fiber composites.展开更多
文摘ZFJ Textile Machinery Co.,Ltd.,established in 1949,is a key enterprise directly managed by China Hi-Tech Group Corporation and falls under the jurisdiction of China National Machinery Industry Corporation Limited(Sinomach).As a leading enterprise in the textile machinery manufacturing industry,ZFJ is dedicated to providing global customers with complete equipment solutions covering the entire industry chain.During this exhibition,ZFJ primarily highlights three key features:"high-performance fibers,green fibers,and intelligent equipment,"with a focus on showcasing nine types of products,spanning various textile equipment categories,including chemical fiber,specialty fiber,nonwoven,sizing,and dyeing machinery.
基金financed by Guangxi Transportation Science and Technology Achievement Promotion Project(GXJT-YFZX-2024-01-01):Intelligent Detection and Data Application R&D Center for Guangxi Transportation Industry.
文摘Ultra-high performance fiber-reinforced concrete (UHPFRC) has received extensive attention from scholars and engineers due to its excellent mechanical properties and durability. However, there is a mutually restrictive relationship between the workability and mechanical properties of UHPFRC. Specifically, the addition of fibers will affect the workability of fresh UHPFRC, and the workability of fresh UHPFRC will also affect the dispersion and arrangement of fibers, thus significantly influencing the mechanical properties of hardened UHPFRC. This paper first analyzes the research status of UHPFRC and the relationship between its workability and mechanical properties. Subsequently, it outlines the test methods and indicators of UHPFRC workability, including fluidity, slump, V-funnel passing time, and rheology. Then, it reviews the impacts of metal fibers, synthetic fibers, hybrid fibers, and other fibers on the workability and mechanical properties of UHPFRC, and presents a reasonable range of fiber dosage for workability and mechanical properties. Key findings include: (1) Steel fibers within 1%–2% volume optimize workability-mechanical balance, while exceeding 2.5% reduces compressive strength by 7%–30%;(2) Hybrid steel-polypropylene fibers enhance toughness by 65%;(3) Fiber orientation control via rheology-modifying admixtures improves flexural strength by up to 64%. This review establishes a fiber factor (V·L/D) for predictive mix design, advancing beyond empirical approaches in prior studies.
文摘Chinese top planner-State Development and Reform Commission,has decided to organize and coordinate an implementation of a special project for high tech industrialization of fiber-reinforced compound materials in 2008 up to 2009.The decision has recently been issued in its national circular(doc. 3177,Yr.2007)to call for local enterprises to apply for this special project support.
文摘Ultra-high molecular weight polyethylene(UHMWPE)fiber is a new kind of high-performance fiber.Due to its excellent physical and chemical characteristics,it is widely used in various fields.However,the surface UHMWPE fiber is smooth and demonstrates no-polar groups.The weak interfacial adhesion between fiber and resin seri-ously restricts the applications of UHMWPE fiber.Therefore,the surface modification treatments of UHMWPE fiber are used to improve the interfacial adhesion strength.The modified method by adding nanomaterials elu-cidates the easy fabrication,advanced equipment and proper technology.Thus,the progress of UHMWPE nanocomposite fibers prepared via adding various nanofillers are reviewed.Meanwhile,the effects of other various methods on surface modification are also reviewed.This work advances the various design strategies about nano technologies on improving interfacial adhesion performance via treatment methodologies.
文摘Ultrahigh-performance concrete(UHPC)is a groundbreaking kind of concrete that distinguishes itself from conventional concrete through its unique material properties.Understanding and managing the time-dependent characteristics of these materials is essential for their effective use in various construction applications.This study presents an experimental evaluation of the compressive and bending properties of the UHPC incorporating polypropylene,steel,and glass fibers.Based on ACI-211 guidelines,the UHPC mix was designed by using three types of aggregates:limestone,andesite,and quartzite,along with 5%fiber content(at varying percentages of 0,5%,10%,15%,and 20%)relative to the cementitious materials,and three different water-to-cement(w/c)ratios(0.24,0.3,and 0.4)were used.In this research,the compressive and flexural strength tests were conducted.The results show that increasing the values of the fibers significantly enhances the compressive strength of the studied samples.Furthermore,the utilization of fibers markedly improves the bending strength of the samples,demonstrating a strong correlation with the yield resistance of the material.Also,findings show that using steel fibers increases the compressive and bending strength of the tested samples more than polypropylene and glass fibers.For instance,in UHPC samples with 0.4 w/c,the average compressive strength values are 82.2 MPa,70.3 MPa,and 67.1 MPa for steel,polypropylene,and glass fibers,respectively.Also,in the flexural strength test,the modulus of rupture is obtained as an average of 6.24 MPa,5.24 MPa and 4.83 MPa for UHPC samples with steel,polypropylene and glass fibers,respectively.
基金supported by Jiangsu Transportation Science and Technology Project (grant number 2020Y19-1(1)).
文摘This study investigates the significance and prospects of utilizing high-performance fiber-reinforced concrete in airport pavements.With the rapid development of the aviation industry,higher performance demands are placed on airport pavements.Traditional airport pavements are predominantly made from ordinary cement concrete,but this material exhibits significant issues of brittleness and low durability when subjected to heavy aircraft and harsh weather conditions.Consequently,fiber-reinforced concrete,known for its exceptional strength and toughness,has garnered considerable attention.This paper discusses in detail the application of various types of fiber materials in strengthening concrete,including steel and basalt fibers.These fibers,based on their chemical and physical properties,play distinct roles in the concrete,thereby enhancing its overall performance.For instance,steel fibers possess a high modulus of elasticity and tensile strength,but are prone to corrosion in acidic environments,while carbon fibers are renowned for their light weight,high strength,and stability.Additionally,the paper emphasizes the importance of mix design methods,as the incorporation of fibers alters the composition and structure of the concrete.Appropriate concrete mix design methods need to be selected.Although fiber-reinforced concrete is widely used in the field of construction engineering,its research and application in airport pavements are not yet sufficiently extensive.Studies should go beyond laboratory tests to explore the evolution of concrete performance in actual usage environments.Consideration should also be given to the unique usage scenarios and stress characteristics of airport pavements to select suitable types of fibers.Moreover,research on the dynamic mechanical properties of fiber-reinforced concrete is a key aspect in enhancing the performance and service life of airport pavements.
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the Central Universities and Graduate Student Innovation Fund of Donghua University(No.CUSF-DHD-2019012)。
文摘The demand for high thermal stability and high strength agents is growing steadily as a result of their increasing application in advanced materials.A series of sulfonated poly(m-phenyleneisophthalamide)(SPMIA)copolymers with superior thermal stability and good mechanical properties have been prepared via low temperature polycondensation method.Then the structures of 5PMA copolymers with different content quantities of 2,4-diaminobenzenesulfonic acid(2,4-DABSA)were confimed by Fourier transform infrared(FTiR).Besides,their superior thermal properties were systematically investigated by differential canning calorimetry DSC),thermalgravimetreic analysis(TGA),and dynamic mechanical analysis(DMA).SPMA fbers were obtained by wet spinning using the resultant SPMIAsolutions.n addition,the obtained SPMIA fibers were proved to combine enhanced mechanical properties and unprecedented dyeability.Significantly,the SPMlA iber with great mechanical property,thermal stability,and dyeability shows great potential in easily dyeing high-performance protective fibers.
文摘Although fibers are used only infrequently as an additive in concrete in the construction industry,fiberenhanced concrete is known to provide a wide range of advantages over conventional concrete.The main objective of this study was to investigate the influences of fiber type and content on the mechanical properties and durability of highperformance fiber-reinforced concrete(HPFRC)designed using a novel densified mixture design algorithm with fly ash and rice husk ash.Three types of fiber,including polypropylene(PP)fiber,steel fiber(SF),and hybrid fiber(HF),were considered.Based on the results,the inclusion of fibers decreased HPFRC flowability,regardless of fiber type.Although the compressive strength of HPFRC with 1.6%PP fiber content was 11.2%below that of the reference HPFRC specimen at 91 d of curing age,the 91-d compressive strengths of both SF and HF-enhanced HPFRC specimens were significantly better than that of the reference HPFRC specimen.Furthermore,the HPFRC specimens incorporating SF and HF both exhibited better splitting tensile and flexural strengths as well as less drying shrinkage than the HPFRC specimens incorporating PP fiber.However,the fiber-enhanced specimens,especially those with added SF,registered less surface electrical resistivity and greater vulnerability to chloride ion penetration than the reference HPFRC specimen.
基金the National Natural Science Foundation of China (No. 50278013)
文摘Spalling and mechanical properties of FRHPC subjected to fire were tested on notched beams. The results confirm that the internal vapor pressure is the leading reason for spalling of high-performance concrete （HPC）. At the same time, the temperature-increasing velocity and constrained conditions of concrete element also play significant roles in spalling. Steel fibers cannot reduce the risk of spalling, although they have obvious beneficial effects on the mechanical properties of concrete before and after exposure to fire. Polypropylene （PP） fibers are very useful in preventing HPC from spalling, however, they have negative effects on the strengths. By using hybrid fibers （steel fibers＋PP fibers）, both good anti-spalling performance and improved mechanical properties come true, which may provide necessary safe guarantee for the rescue work and structure repair after fire disaster.
基金the financial joint support by the National Natural Science Foundation of China(nos.91422301,51472094,61474047)
文摘A flexible electrode of nickel diselenide/carbon fiber cloth(NiSe/CFC) is fabricated at room temperature by a simple and efficient electrodeposition method. Owing to NiSecharacter of nanostructure and high conductivity, the as-synthesized electrodes possess perfect pseudocapacitive property with high specific capacitance and excellent rate capability. In three-electrode system, the electrode specific capacitance of the NiSe/CFC electrode varies from 1058 F gto 996.3 F gat 2 A gto 10 A grespectively, which shows great rate capability. Moreover, the NiSeelectrode is assembled with an active carbon(AC) electrode to form an asymmetric supercapacitor with an extended potential window of 1.6 V. The asymmetric supercapacitor possesses an excellent energy density 32.7 Wh kgwith a power density 800 W kgat the current density of 1 A g. The nanosheet array on carbon fiber cloth with high flexibility, specific capacitance and rate capacitance render the NiSeto be regarded as the promising material for the high performance superconductor.
基金the National Key Research and Development Program of China(2017YFC1103900)the National Natural Science Foundation of China(22075244 and 51722306)+1 种基金Natural Science Foundation of Zhejiang Province(LZ22E030001)Shanxi-Zheda Institute of Advanced Materials and Chemical Engi-neering(2021SZ-TD009).
文摘Many natural fibers are lightweight and display remarkable strength and toughness.These properties originate from the fibers’hierarchical structures,assembled from the molecular to macroscopic scale.The natural spinning systems that produce such fibers are highly energy efficient,inspiring researchers to mimic these processes to realize robust artificial spinning.Significant developments have been achieved in recent years toward the preparation of high-performance bio-based fibers.Beyond excellent mechanical properties,bio-based fibers can be functionalized with a series of new features,thus expanding their sophisticated applications in smart textiles,electronic sensors,and biomedical engineering.Here,recent progress in the construction of bio-based fibers is outlined.Various bioinspired spinning methods,strengthening strategies for mechanically strong fibers,and the diverse applications of these fibers are discussed.Moreover,challenges in reproducing the mechanical performance of natural systems and understanding their dynamic spinning process are presented.Finally,a perspective on the development of biological fibers is given.
基金Supports from the National Natural Science Foundation of China (51872115 and 51802110)the National Key R&D Program of China (2016YFA0200400)+2 种基金the Jilin Province/Jilin University Co-construction Project-Funds for New Materials (SXGJSF20173, Branch-2/440050316A36)the Program for JLU Science and Technology Innovative Research Team (JLUSTIRT, 2017TD-09)“Double-First Class” Discipline for Materials Science & Engineering, are greatly acknowledged
文摘In dual-ion batteries (DIBs), energy storage is achieved by intercalation/de-intercalation of both cations and anions. Due to the mismatch between ion diameter and layer space of active materials, however, volume expansion and exfoliation always occur for electrode materials. Herein, an integrated electrode Co3O4/carbon fiber paper (CFP) is prepared as the anode of DIB. As the Co3O4 nanosheets grow on CFP substrate vertically, it promotes the immersion of electrolyte and shortens the pathway for ionic transport. Besides, the strong interaction between Co3O4 and CFP substrate reduces the possibility of sheet exfoliation. An integrated-electrode-based DIB is therefore packaged using Co3O4/CFP as anode and graphite as cathode. As a result, a high energy density of 72 Wh/kg is achieved at a power density of 150 W/kg. The design of integrated electrode provides a new route for the development of high-performance DIBs.
基金financially supported by the National Key R&D Program of China(No.2017YFB0308300)the National Basic Research Program of China(No.2014CB643603)
文摘A series of polyamic acid copolymers(co-PAAs) with para-hydroxyl groups was synthesized using two diamine monomers,namely p-phenylenediamine(p-PDA) and 5-amino-2-(2-hydroxy-5-aminobenzene)-benzoxazole(m-pHBOA), of different molar ratios through copolymerization with 3,3′,4,4′-biphenyltetracarboxylic dianhydride(BPDA) in N,N-dimethyacetamine(DMAc). The co-PAA solutions were used to fabricate fibers by dry-jet wet spinning, and thermal imidization was conducted to obtain polyimide copolymer(coPI) fibers. The effects of the m-pHBOA moiety on molecular packing and physical properties of the prepared fibers were investigated.Fourier transform infrared(FTIR) spectroscopic results confirmed that intra/intermolecular hydrogen bonds originated from the hydroxyl group and the nitrogen atom of the benzoxazole group and/or the hydroxyl group and the oxygen atom of the carbonyl group of cyclic imide. As-prepared PI fibers displayed homogenous and smooth surface and uniform diameter. The glass transition temperatures(Tgs) of PI fibers were within 311-337 °C. The polyimide fibers showed 5% weight loss temperature(T5%) at above 510 °C in air. Twodimensional wide-angle X-ray diffraction(WXRD) patterns indicated that the homo-PI and co-PI fibers presented regularly arranged polymer chains along the fiber axial direction. The ordered molecular packing along the transversal direction was destroyed by introducing the m-pHBOA moiety. Moreover, the crystallinity and orientation factors increased with increasing draw ratio. Small-angle X-ray scattering(SAXS) results showed that it is beneficial to reduce defects in the fibers by increasing the draw ratio. The resultant PI fibers exhibited excellent mechanical properties with fracture strength and initial modulus of 2.48 and 89.73 GPa, respectively, when the molar ratio of p-PDA/m-pHBOA was 5/5 and the draw ratio was 3.0.
基金State Key Laboratory of Applied Optics(SKLAO-201914)Fundamental Research Funds for the Central Universities(11618413,21619402)+8 种基金Foundation for Distinguished Young Talents in Higher Education of Guangdong(2018KQNCX009)Open Foundation of CEPREI(19D09)Joint Fund of Pre-Research for Equipment,Ministry of Education of China(6141A02022124)Aeronautical Science Foundation of China(201708W4001,201808W4001)Planned Science Technology Project of Guangzhou(2016B010111003,201707010396)Project of Guangzhou Industry Leading Talents(CXLJTD-201607)Key-Area Research and Development Program of Guangdong Province(2015B010125007,2017A010102006,2019B010138004)Natural Science Foundation of Guangdong Province(2016A030311019,2016A030313079,2017A030313375,2019A1515011380,2020B1515020024)National Natural Science Foundation of China(61601404,61675092,61705086)。
文摘In graphene-based optoelectronic devices,the ultraweak interaction between a light and monolayer graphene leads to low optical absorption and low responsivity for the photodetectors and relative high half-wave voltage for the phase modulator.Here,an integration of the monolayer graphene onto the side-polished optical fiber is demonstrated,which is capable of providing a cost-effective strategy to enhance the light–graphene interaction,allowing us to obtain a highly efficient optical absorption in graphene and achieve multifunctions:photodetection and optical phase modulation.As a photodetector,the device has ultrahigh responsivity(1.5×10^(7) A/W)and high external quantum efficiency(>1.2×10^(9)%).Additionally,the polybutadiene/polymethyl methacrylate(PMMA)film on the graphene can render the device an optical phase modulator through the large thermo-optic effect of the PMMA.As a phase modulator,the device has a relatively low half-wave voltage of 3 V with a 16 dB extinction ratio in Mach–Zehnder interferometer configuration.
基金financially supported by the National Natural Science Foundation of China (Nos. 51903038 and 21975040)Guangdong Basic and Applied Basic Research Foundation (No. 2020A1515110897)。
文摘In this work, a fully rigid coplanar symmetric heterocyclic unit was introduced into the rigid polyimide macromolecular backbone structure to prepare high-performance polyimide fibers. The novel co-polyimide(co-PI) fibers based on 3,3',4,4'-biphenyltetracarboxylic anhydride(BPDA), p-phenylenediamine(PDA) and 2,6-(4,4'-diaminodiphenyl) benzo[1,2-d:5,4-d'] bisoxazole(PBOA) were fabricated via a twostep wet-spinning method. The effects of benzobisoxazole moiety on spinnability, aggregation structure, and mechanical properties of fibers were systematically discussed. The detailed structural analysis revealed that the well-defined aggregation structures of co-PI fibers were obtained from initial amorphous structure when post hot-drawing temperature was higher than 460 ℃ under proper drawing ratio, and the incorporation PBOA into BPDA-PDA structures produced more compact structural co-PI fiber than homo BPDA-PDA fiber. The BPDA-PDA/PBOA co-PI fibers exhibited optimum tensile strength and modulus of 2.65 and 103 GPa, which increased by 182% and 84% compared to the homo BPDA-PDA fiber, respectively.
基金Lloyd’s Register Foundation(R-265-000-553-597)for the financial support for this project.
文摘In this study,we synthesized high-performance Carbon Fiber/Gold/Copper(CF/Au/Cu)composite wires by using a 2-step deposition method via sputtering and electrodeposition.After Au was sputtered on PANbased CFs as a pre-treatment,the wettability and surface reactivity of the CFs were improved,resulting in a homogeneous deposition of Cu on their surface.At different Cu electrodeposition time,the resulting CF/Au/Cu composite wires could possess a high strength of up to 3.27 GPa(~10 times stronger than copper wires)while their electrical conductivity could be as high as 4.4×10^5 S/cm(~75%of that for copper).More importantly,since the composite wires were lightweight(up to 70%lower than Cu mass density),they are a promising candidate to substitute conventional heavy metal wires in the future electrical applications.
基金supported by the National Key R&D Program of China(No.2022YFA0913200)the National Natural Science Foundation of China(Nos.22107097,22020102003,22125701,22175053,and 21771050)the Youth Innovation Promotion Association of CAS(No.2021226).
文摘Spider silks are well known for their exceptional mechanical properties that are tougher than Kevlar and steel.However,the restricted production amounts from their native sources limit applications of spider silks.Over the decades,there have been significant interests in fabricating man-made silk fibers with comparable performance to natural silks,inspiring many efforts both for biosynthesizing recombinant spider silk proteins(spidroins)in amenable heterologous hosts and biomimetic spinning of artificial spider silks.These strategies provide promising routes to produce high-performance and functionally optimized fibers with diverse applications.Herein,we summarize the hosts that have been applied to produce recombinant spidroins.In addition,the fabrication and mechanical properties of recombinant spidroin fibers and their composite fibers are also introduced.Furthermore,we demonstrate the applications of recombinant spidroin-based fibers.Finally,facing the challenges in biosynthesis,scalable production,and hierarchical assembly of high-performance recombinant spidroins,we give a summary and perspective on future development.
基金by Special Fund for Agro-scientific Research in the Public Interest of China(No 200903023)Development and Extension of Practical Low-Cost Low-Power Automatic Drip Irrigation Controller(2010GA780046)Research and Application Demonstration of Orchard Water and Fertilizer Drip Irrigation Controller(2010B020314007).
文摘ZnO and TiO_(2) nanofibers are synthesized via electrospinning methods and characterized by x−ray diffraction,scanning electron microscopy,and transmission electron microscopy.Humidity sensors with double-layer sensing films are fabricated by spinning the ZnO and TiO_(2) nanofibers on ceramic substrates sequentially.Compared with sensors loading only one type of nanofiber,the double-layer sensors exhibit much better sensing properties.The corresponding impedance changes more than four orders of magnitude within the whole humidity range from 11%to 95%relative humidity,and the response and recovery times are about 11 and 7 s,respectively.Maximum hysteresis is around 1.5%RH,and excellent stability is also observed after 180 days.The humidity sensing mechanism is discussed in terms of the sensor structure.The experimental results provide a possible route for the design and fabrication of high performance humidity sensors based on one-dimensional nanomaterials.
基金financially supported by the National Natural Science Foundation of China (Nos.51973118, 22175121,52003160 and 22001175)Key-Area Research and Development Program of Guangdong Province (Nos.2019B010941001 and2019B010929002)+7 种基金the Natural Science Foundation of Guangdong Province (No.2020A1515010644)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2019ZT08C642)Shenzhen Science and Technology Program (Nos.JCYJ20220818095810022, JSGGZD20220822095201003 and JCYJ20210324095412035)the start-up fund of Shenzhen University (No.000002110820)the Guangdong Natural Science Foundation (Nos.2022A1515011781 and2021A1515110086)Science and Technology Innovation Commission of Shenzhen,China (Nos.RCBS20200714114910141 and JCYJ20210324132816039)the Start-up Grant at Harbin Institute of Technology (Shenzhen),China (Nos.HA45001108 and HA11409049)Shenzhen Key Laboratory of Advanced Functional Carbon Materials Research and Comprehensive Application (No.ZDSYS20220527171407017)。
文摘The emerging biomass-based epoxy vitrimers hold great potential to fulfill the requirements for sustainable development of society.Since the existence of dynamic chemical bonds in vitrimers often reduces both the thermal and mechanical properties of epoxy resins, it is challenging to produce recyclable epoxy vitrimers with both excellent mechanical properties and good thermal stability. Herein, a monomer 4-(((5-(hydroxymethyl)furan-2-yl)methylene)amino)phenol(FCN) containing furan ring with potential to form high density of hydrogen bonding among repeating units is designed and copolymerized with glycerol triglycidyl ether to yield epoxy resin(FCN-GTE), which intrinsically has dual hydrogen bond networks, dynamic imine structure and resultant high performance. Importantly, as compared to the BPA-GTE, the FCN-GTE exhibits significantly improved mechanical properties owing to the increased density of hydrogen bond network and physical crosslinking interaction. Furthermore, density functional theory(DFT) calculation and in situ FTIR analysis is conducted to decipher the formation mechanism of hydrogen bond network. In addition, the FCN-GTE possesses superior UV shielding, chemical degradation, and recyclability because of the existence of abundant imine bonds. Notably, the FCN-GTE-based carbon fiber composites could be completely recycled in an amine solution.This study provides a facile strategy for synthesizing recyclable biomass-based high-performance epoxy vitrimers and carbon fiber composites.
