The purpose of this study is to develop a standard methodology for measuring the surface free energy (SFE),and its component parts of bamboo fiber materials.The current methods was reviewed to determine the surface te...The purpose of this study is to develop a standard methodology for measuring the surface free energy (SFE),and its component parts of bamboo fiber materials.The current methods was reviewed to determine the surface tension of natural fibers and the disadvantages of techniques used were discussed.Although numerous techniques have been employed to characterize surface tension of natural fibers,it seems that the credibility of results obtained may often be dubious.In this paper,critical surface tension estimates were obtained from computer aided machine vision based measurement.Data were then analyzed by the least squares method to estimate the components of SFE.SFE was estimated by least squares analysis and also by Schultz' method.By using the Fowkes method the polar and disperse fractions of the surface free energy of bamboo fiber materials can be obtained.Strictly speaking,this method is based on a combination of the knowledge of Fowkes theory. SFE is desirable when adhesion is required,and it avoids some of the limitations of existing studies which has been proposed.The calculation steps described in this research are only intended to explain the methods.The results show that the method that only determines SFE as a single parameter may be unable to differentiate adequately between bamboo fiber materials,but it is feasible and very efficient.In order to obtain the maximum performance from the computer aided machine vision based measurement instruments,this measurement should be recommended and kept available for reference.展开更多
Porous titanium fiber materials with the fiber sizes of 70--120 μm in diameter were prepared by vacuum sintering technology. The morphology and compressive properties of porous titanium fiber materials were investiga...Porous titanium fiber materials with the fiber sizes of 70--120 μm in diameter were prepared by vacuum sintering technology. The morphology and compressive properties of porous titanium fiber materials were investigated by using a scanning electron microscope （SEM） and an MST 858 compression testing machine in quasi-static condition. The results show that porous titanium fibers form complex micro-networks. The stress-strain curves of por- ous titanium fiber materials exhibit elastic region, platform region and densification region and no collapse during platform region. The yield strength of porous titanium fiber materials decreases with increasing the porosity and increasing the fiber diameter.展开更多
The porous titanium fiber materials with open porosity were successfully prepared by the vacuum sintering technology. The morphology characteristics of sintering neck of porous titanium fiber materials were investigat...The porous titanium fiber materials with open porosity were successfully prepared by the vacuum sintering technology. The morphology characteristics of sintering neck of porous titanium fiber materials were investigated by scanning electron microscopy （SEM）. The results show that the formation and growth of sintering neck of porous ti- tanium fiber material approximately follow the rule that the primary mechanism is grain boundary diffusion and sub- sidiary mechanisms are other diffusion mechanisms during the sintering process. The formation and growth of the sintering neck depend mainly on the sintering temperature and slightly on the soaking time. The sintering system of porous titanium fiber material was determined and the equation of the sintering neck＇s length was established.展开更多
Additive manufacturing(AM)and Three-dimensional(3D)printing build complex structures layer by layer,greatly expanding design possibilities.Traditional thermoplastics like Polylactic Acid(PLA),Acrylonitrile Butadiene S...Additive manufacturing(AM)and Three-dimensional(3D)printing build complex structures layer by layer,greatly expanding design possibilities.Traditional thermoplastics like Polylactic Acid(PLA),Acrylonitrile Butadiene Styrene(ABS),and Polyethylene Terephthalate Glycol(PETG)are widely used in 3D printing,but their nonrenewable nature and limited biodegradability have driven research into plant fiber-based materials.These materials,mainly cellulose and lignin,come fromsources likewood and agriculturalwaste,offering renewability,biodegradability,and biocompatibility.This paper reviews recent advances in plant fiber-based materials for 3D printing,covering their development fromraw materials to applications.It highlights the sources,modification methods,and unique properties of cellulose and lignin in 3D printing,and examines processes like fused deposition modeling(FDM),direct ink writing(DIW),stereolithography(SLA),and digital light processing(DLP).The paper discusses key evaluation metrics,including mechanical properties,thermal stability,interlayer bonding strength,and biodegradability,and explores innovative applications in biomedicine(tissue engineering,wound healing),food(personalized nutrition),packaging(smart monitoring),and electronics and energy(flexible devices).Finally,it addresses challenges and future directions in material innovation,process optimization,and large-scale production,emphasizing the potential of interdisciplinary approaches and technology integration for sustainable manufacturing.展开更多
Carbon-based fiber materials are widely used in aerospace,military,and electronics owing to their outstanding comprehensive properties.However,the high degree of crystallization and chemical inertness of their surface...Carbon-based fiber materials are widely used in aerospace,military,and electronics owing to their outstanding comprehensive properties.However,the high degree of crystallization and chemical inertness of their surfaces impede the coloring of such materials by traditional dyeing methods,thereby limiting their application in a broader field.Exploring advanced micro/nano-processing technology for colored carbon-based fiber materials has become a growing interdisciplinary research area in recent years.Therefore,this review comprehensively discusses the structure‒color‒function relationships of carbon-based fiber materials.The structure of carbon-based fiber materials and their properties responsible for challenges in coloring by traditional dyeing methods are discussed.Moreover,the color-generating mechanisms underlying the display of structural colors by living organisms due to fundamental optical phenomena,including thin/multilayer-film interference,diffraction grating,scattering,and photonic crystals,are described.Furthermore,recent progress in bio-inspirated colored carbon-based fiber materials prepared via advanced micro/nanoscale manufacturing strategies is reviewed.In addition,emerging applications of colored carbon-based fiber materials in various fields are presented.Finally,the possible challenges and future directions for the design,large-scale production,and application of colored carbon-based fibermaterials and their composites are discussed,aiming to promote the material design of innovative next-generation systems and research in the advanced material and related engineering fields.展开更多
The electrical properties of high-entropy ceramics(HECs)have been extensively studied in recent years due to their unique structural characteristics and fascinating functional properties induced by entropy engineering...The electrical properties of high-entropy ceramics(HECs)have been extensively studied in recent years due to their unique structural characteristics and fascinating functional properties induced by entropy engineering.Novel high-entropy(Sm_(0.2)Eu_(0.2)Gd_(0.2)Ho_(0.2)Yb_(0.2))CrO_(3)(HE-RECrO_(3))nanofibers were prepared by electro spinning.This work demonstrates that HE-RECrO_(3)nanofibe rs were successfully synthesized at a low temperature(800℃),which is approximately 400℃lower than the temperatures at which chromate ceramics were synthesized via the sol-gel method and the solid-state reaction method.The resistivity of HE-RECrO_(3)nanofibers decreases exponentially with increasing temperature from 25 to600℃.The logarithm of the resistivity is linearly related to the inverse of the temperature,confirming the negative temperature coefficient property of HE-RECrO_(3)nanofibers.The B_(25/50)value of the HERECrO_(3)nanofibers reaches 4072 K.In conclusion,HE-RECrO_(3)nanofibers are expected to be potential candidates for negative-temperature-coefficient(NTC)thermistors.展开更多
Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission （AE） statistical analysis towards fi...Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission （AE） statistical analysis towards fiber composites under mode-Ⅱ delamination damage. The load curve, AE relative energy, amplitude distribution, and amplitude spectrum are obtained and the delamination damage mechanism of the composites is investigated by the microscopic observation of a fractured specimen. The results show that the micro-damage accumulation around the crack tip region has a great effect on the evolutionary process of delamination. AE characteristics and amplitude spectrum represent the damage and the physical mechanism originating from the hierarchical microstructure. Our finding provides a novel aud feasible strategy to simultaneously evaluate the dynamic response and micro-damage mechanism for fiber composites.展开更多
The high-temperature acoustic absorption performance of porous titanium fiber material was investigated in terms of sample thickness, porosity, temperature, air-cavity thickness and double-layer structure arrangement....The high-temperature acoustic absorption performance of porous titanium fiber material was investigated in terms of sample thickness, porosity, temperature, air-cavity thickness and double-layer structure arrangement. The effects on absorption coefficient were systematically assessed. The results show that the sound absorption performance is improved by increasing the sample porosity and/or thickness, and/or increasing the air-cavity thickness. Meanwhile, increasing the temperature gives better acoustic absorption performance in the low frequency range but also lowers the performance in the high frequency range, while double-layer structure enables better acoustic absorption performance.展开更多
This study examines the penetration of 12.7 mm armor piercing incendiary projectiles into SiC ceramic-fiber composite target plates.By observing the recovered projectile and the overall damage morphology of the cerami...This study examines the penetration of 12.7 mm armor piercing incendiary projectiles into SiC ceramic-fiber composite target plates.By observing the recovered projectile and the overall damage morphology of the ceramic-fiber composite target plates.Additionally,multi-level screening and weighing of the recovered projectile and ceramic fragments revealed that the mass distribution of the projectile and ceramic fragments under different backing structures conforms to a powerlaw distribution.Experimental results indicate that for single laminate as the backing,the fragmentation of the projectile and ceramics is highest when T300 is the material.Incorporating a T300 transition layer between the SiC ceramic and aramid fibers(Kevlar)or ultra-high molecular weight polyethylene(UHMWPE)increases the fragmentation of the projectile and ceramics,leading to increased energy absorption.The projectile’s head mainly exhibits pulverized abrasive fragmentation,while larger projectile fragments primarily result from shear and tensile stress-induced shear-tensile failure fractures.The primary damage mode of ceramics under high-speed impact is the expansion of ceramic cones and radial cracks.The main form of damage in UHMWPE laminate is interlayer separation caused by tensile waves,permanent plastic deformation at the back protrusion,and perforation failure primarily due to shear waves.The damage mode of Kevlar laminate is similar to that of UHMWPE,with the distinction being that Kevlar laminate primarily exhibits perforation failure caused by tensile waves.Carbon fiber T300 laminate damage mainly consists of cross-shaped brittle fractures caused by shear waves.展开更多
The interfacial performance of the Fiber Bragg grating（FGB） embedded in the composite was studied and the influence of interface modification on the final profile of the spectra of the FBG sensor was examined. A typ...The interfacial performance of the Fiber Bragg grating（FGB） embedded in the composite was studied and the influence of interface modification on the final profile of the spectra of the FBG sensor was examined. A type of polyamine（Pentaethylenehexamine, PEHA） was proposed to modify the coating of PI on FBG, and the interfacial performance was evaluated by a pull-out test. Sharp improvements of the interfacial shear strength（77%） were obtained by 40 min treatment of PEHA. Compared with untreated specimen, FGB spectra of treated specimen in the tensile tests show improved linearity within the test regime, which proves that the enhanced interface is beneficial for the sensing performance.展开更多
Donghua University develops novel photothermal fabric to address freshwater crisis 2D photothermal membranes have demonstrated numerous advantages in solar desalination due to their flexibility,scalability,and low cos...Donghua University develops novel photothermal fabric to address freshwater crisis 2D photothermal membranes have demonstrated numerous advantages in solar desalination due to their flexibility,scalability,and low cost.However,their practical applications are limited by the restricted evaporation area and obstructed vapor channels.The research team led by Chen Zhigang,a researcher from the State Key Laboratory of Advanced Fiber Materials and the School of Materials Science and Engineering at Donghua University,has designed a novel biomimetic photothermal fabric,which is composed of two carbon-nanotube-hydrogel-coated polyester(PET)fabrics separated by fiber pillars,with the upper fabric layer having a hole array as stomatal channels.This fabric shows high solar-absorption efficiency(96.1%)and decreased water-evaporation enthalpy(1664.6 kJ kg^(-1)).展开更多
The penetration resistance of Kevlar-129 fiber reinforced composite materials was investigated with AUTODYN software.The ballistic limits of the fragment that pierced 6kinds of target plates were obtained by finite el...The penetration resistance of Kevlar-129 fiber reinforced composite materials was investigated with AUTODYN software.The ballistic limits of the fragment that pierced 6kinds of target plates were obtained by finite element simulation when the 10 g fragment simulation projectile（FSP）impacting to the target plates of different thickness values of 8,10,12,14,16 and 18mm with appropriate velocity,respectively,and the influences of thickness on the ballistic limits and the specific energy absorption were analyzed.The results show that the ballistic limit of Kevlar-129 fiber reinforced composite plates presents linear growth with the increase of the target thickness in the range from 8to 18 mm.The specific energy absorption of plates presents approximately linear growth,but there is slightly slow growth in the range from 10 to 16mm of the target thickness.It also can be found that the influences of plate thickness and surface density on the varying pattern of specific energy absorption are almost the same.Therefore,both of them can be used to characterize the variation of specific energy absorption under the impact of the FSP fragment.展开更多
The mechanical properties of the SiC fiber-reinforced Mg-Al metal matrix composite materials have been studied on internal microstructure by (scanning electron microscopy) SEM in-situ tensile test. The emergence and p...The mechanical properties of the SiC fiber-reinforced Mg-Al metal matrix composite materials have been studied on internal microstructure by (scanning electron microscopy) SEM in-situ tensile test. The emergence and propagation of the crack, and the fracture behavior in materials have been observed and studied. It is found that in the case of the tensile test, the crack emerged in SiC fiber initially. In the case of the strong cohesion of the fiber-metal interface, the crack propagated in the fiber, meanwhile the fibers in the neighborhood of the cracked fiber began to crack and the Mg-Al metal deformed plastically, and at last the material fractured. Otherwise the toughness of the materials grows in the case of the lower cohesion of the fiber-metal matrix interface.展开更多
To estimate the shape of tapered fibers using tapering machines with movable large-zone furnaces, a new calculation method is proposed based on the discrete deducing method and the principle of the volume conservation...To estimate the shape of tapered fibers using tapering machines with movable large-zone furnaces, a new calculation method is proposed based on the discrete deducing method and the principle of the volume conservation of the fiber materials. This method can estimate the tapering results, i.e., the shape of the tapered fibers, based on arbitrary moving parameters of the large-zone furnace and the fiber holders. The theoretical estimated results agree with the experimental measuring shape of the tapered fibers quite well.展开更多
Buoyancy material technology is of paramount importance for the development of marine engineering.In this study,a novel carbon fiber buoyancy material(CFBM)is designed and prepared by utilizing composite circular tube...Buoyancy material technology is of paramount importance for the development of marine engineering.In this study,a novel carbon fiber buoyancy material(CFBM)is designed and prepared by utilizing composite circular tubes with light weight and high strength.To reveal the failure mechanism under hydrostatic pressure,a finite element model(FEM)based on the three-dimensional Hashin and Yeh failure criterion is developed and validated experimentally.Both the simulated and experimental results indicate that the hydrostatic strength of the CFBM is mainly determined by the buckling of carbon fiber tubes located at the edges of the CFBM.Parametric analysis is conducted to investigate the effect of the number of unit-cells,length,and wall thickness of carbon fiber tubes on the mechanical properties of the CFBM.In addition,a 60-day water absorption test of the CFBM at 12.5 MPa is conducted to characterize its durability.Experimental results indicate that the maximum water absorption rate of the CFBM is 0.59%and the hydrostatic strength is reduced by only 7.97%during the 60-day test period.Finally,the designed CFBM is used at the water depth of 1000 m as buoyancy material.Compared with traditional buoyancy materials,the proposed CFBM has significant advantages in both hydrostatic strength and density.This work has broad engineering application prospects and is of high significance for promoting the implementation of carbon fiber composites in the ocean engineering field.展开更多
For steady-state heat conduction,a new variational functional for a unit cell of composites with periodic microstructures is constructed by considering the quasi-periodicity of the temperature field and in the periodi...For steady-state heat conduction,a new variational functional for a unit cell of composites with periodic microstructures is constructed by considering the quasi-periodicity of the temperature field and in the periodicity of the heat flux fields. Then by combining with the eigenfunction expansion of complex potential which satisfies the fiber-matrix interface conditions, an eigenfunction expansion-variational method （EEVM）based on a unit cell is developed. The effective transverse thermal conductivities of doubly-periodic fiber reinforced composites are calculated, and the first-order approximation formula for the square and hexagonal arrays is presented, which is convenient for engineering application. The numerical results show a good convergency of the presented method,even though the fiber volume fraction is relatively high. Comparisons with the existing analytical and experimental results are made to demonstrate the accuracy and validity of the first-order approximation formula for the hexagonal array.展开更多
Kapok fiber corresponds to the seed hairs of the kapok tree（Ceiba pentandra）, and is a typical cellulosic fiber with the features of thin cell wall, large lumen, low density and hydrophobic–oleophilic properties. A...Kapok fiber corresponds to the seed hairs of the kapok tree（Ceiba pentandra）, and is a typical cellulosic fiber with the features of thin cell wall, large lumen, low density and hydrophobic–oleophilic properties. As a type of renewable natural plant fiber, kapok fiber is abundant,biocompatible and biodegradable, and its full exploration and potential application have received increasing attention in both academic and industrial fields. Based on the structure and properties of kapok fiber, this review provides a summary of recent research on kapok fiber including chemical and physical treatments, kapok fiber-based composite materials, and the application of kapok fiber as an absorbent material for oils, metal ions, dyes, and sound,with special attention to its use as an oil-absorbing material, one predominant application of kapok fiber in the coming future.展开更多
Modern wearable electronics are thirsty for flexible, lightweight energy storage and supply devices. Flexible fiber-shaped supercapacitors, possess good flexibility, high power density, fast charging capability and lo...Modern wearable electronics are thirsty for flexible, lightweight energy storage and supply devices. Flexible fiber-shaped supercapacitors, possess good flexibility, high power density, fast charging capability and long cycle life, becoming a promising option for wearable devices. The past decade has witnessed the emergence of graphene fiber based supercapacitors（GFSCs） as one of the most active vicinity in fiber-supercapactiors, for their excellent properties including high surface area, chemical stability, excellent electrical conductivity, lightweight and mechanical properties. In this perspective, we introduced the basic energy storage mechanisms of GFSCs, followed by the analysis in improving their overall performances, recent advances, and a conclusive discussion on the challenges and opportunities.展开更多
In order to research the field sensing characteristic of the carbon fiber smart material, the Tikhonov regularization principle and the modified Newton-Raphson(MNR) algorithm were adopted to solve the inverse problem ...In order to research the field sensing characteristic of the carbon fiber smart material, the Tikhonov regularization principle and the modified Newton-Raphson(MNR) algorithm were adopted to solve the inverse problem of the electrical resistance tomography(ERT). An ERT system of carbon fiber smart material was developed. Field sensing characteristic was researched with the experiment. The experimental results show that the specific resistance distribution of carbon fiber smart material is highly consistent with the distribution of structural strain. High resistance zone responds to high strain area, and the specific resistance distribution of carbon fiber smart material reflects the distribution of sample strain in covering area. Monitoring by carbon fiber smart material on complicated strain status in sample field domain is realized through theoretical and experimental study.展开更多
Equilibrium paths of post-buckling are measured for large slenderness column specimens made of the fiber reinforced composite material. The influence of the initial curvature is investigated experimentally and compare...Equilibrium paths of post-buckling are measured for large slenderness column specimens made of the fiber reinforced composite material. The influence of the initial curvature is investigated experimentally and compared with the result of the initial post-buckling theory. Both the theoretical and experimental results reveal that the column with the initial curvature has stable post-buckling behaviors and is not sensitive to the imperfection in the form of initial curvature. The experimental results show that when the lateral buckling displacement is less than 20 percent of the column length, the experimental results agree with the results from the theory of initial post-buckling quite well, while they agree with the results from the large deflection theory in a quite large range.展开更多
基金the National Natural Science Foundation of China(No.31101085)the Scientific Research and Development Foundation for Start-up Projects of Zhejiang Agriculture and Forestry University (No.2034020044)
文摘The purpose of this study is to develop a standard methodology for measuring the surface free energy (SFE),and its component parts of bamboo fiber materials.The current methods was reviewed to determine the surface tension of natural fibers and the disadvantages of techniques used were discussed.Although numerous techniques have been employed to characterize surface tension of natural fibers,it seems that the credibility of results obtained may often be dubious.In this paper,critical surface tension estimates were obtained from computer aided machine vision based measurement.Data were then analyzed by the least squares method to estimate the components of SFE.SFE was estimated by least squares analysis and also by Schultz' method.By using the Fowkes method the polar and disperse fractions of the surface free energy of bamboo fiber materials can be obtained.Strictly speaking,this method is based on a combination of the knowledge of Fowkes theory. SFE is desirable when adhesion is required,and it avoids some of the limitations of existing studies which has been proposed.The calculation steps described in this research are only intended to explain the methods.The results show that the method that only determines SFE as a single parameter may be unable to differentiate adequately between bamboo fiber materials,but it is feasible and very efficient.In order to obtain the maximum performance from the computer aided machine vision based measurement instruments,this measurement should be recommended and kept available for reference.
基金Item Sponsored by National Natural Science Foundation of China(51304153)Natural Science Foundation of Shaanxi Province of China(2012JM6017)
文摘Porous titanium fiber materials with the fiber sizes of 70--120 μm in diameter were prepared by vacuum sintering technology. The morphology and compressive properties of porous titanium fiber materials were investigated by using a scanning electron microscope （SEM） and an MST 858 compression testing machine in quasi-static condition. The results show that porous titanium fibers form complex micro-networks. The stress-strain curves of por- ous titanium fiber materials exhibit elastic region, platform region and densification region and no collapse during platform region. The yield strength of porous titanium fiber materials decreases with increasing the porosity and increasing the fiber diameter.
基金Item Sponsored by National Natural Science Foundation of China(51304153)Natural Science Foundation of Shaanxi Province of China(2012JM6017)
文摘The porous titanium fiber materials with open porosity were successfully prepared by the vacuum sintering technology. The morphology characteristics of sintering neck of porous titanium fiber materials were investigated by scanning electron microscopy （SEM）. The results show that the formation and growth of sintering neck of porous ti- tanium fiber material approximately follow the rule that the primary mechanism is grain boundary diffusion and sub- sidiary mechanisms are other diffusion mechanisms during the sintering process. The formation and growth of the sintering neck depend mainly on the sintering temperature and slightly on the soaking time. The sintering system of porous titanium fiber material was determined and the equation of the sintering neck＇s length was established.
文摘Additive manufacturing(AM)and Three-dimensional(3D)printing build complex structures layer by layer,greatly expanding design possibilities.Traditional thermoplastics like Polylactic Acid(PLA),Acrylonitrile Butadiene Styrene(ABS),and Polyethylene Terephthalate Glycol(PETG)are widely used in 3D printing,but their nonrenewable nature and limited biodegradability have driven research into plant fiber-based materials.These materials,mainly cellulose and lignin,come fromsources likewood and agriculturalwaste,offering renewability,biodegradability,and biocompatibility.This paper reviews recent advances in plant fiber-based materials for 3D printing,covering their development fromraw materials to applications.It highlights the sources,modification methods,and unique properties of cellulose and lignin in 3D printing,and examines processes like fused deposition modeling(FDM),direct ink writing(DIW),stereolithography(SLA),and digital light processing(DLP).The paper discusses key evaluation metrics,including mechanical properties,thermal stability,interlayer bonding strength,and biodegradability,and explores innovative applications in biomedicine(tissue engineering,wound healing),food(personalized nutrition),packaging(smart monitoring),and electronics and energy(flexible devices).Finally,it addresses challenges and future directions in material innovation,process optimization,and large-scale production,emphasizing the potential of interdisciplinary approaches and technology integration for sustainable manufacturing.
基金National Natural Science Foundation of China,Grant/Award Number:52373085Natural Science Foundation of Hubei Province,Grant/Award Number:2023AFB828+2 种基金Innovative Team Program of Natural Science Foundation of Hubei Province,Grant/Award Number:2023AFA027Open Fund for Hubei Key Laboratory of Digital Textile Equipment,Grant/Award Number:DTL 2023022Open Fund for National Local Joint Laboratory for Advanced Textile Processing and Clean Production,Grant/Award Number:17。
文摘Carbon-based fiber materials are widely used in aerospace,military,and electronics owing to their outstanding comprehensive properties.However,the high degree of crystallization and chemical inertness of their surfaces impede the coloring of such materials by traditional dyeing methods,thereby limiting their application in a broader field.Exploring advanced micro/nano-processing technology for colored carbon-based fiber materials has become a growing interdisciplinary research area in recent years.Therefore,this review comprehensively discusses the structure‒color‒function relationships of carbon-based fiber materials.The structure of carbon-based fiber materials and their properties responsible for challenges in coloring by traditional dyeing methods are discussed.Moreover,the color-generating mechanisms underlying the display of structural colors by living organisms due to fundamental optical phenomena,including thin/multilayer-film interference,diffraction grating,scattering,and photonic crystals,are described.Furthermore,recent progress in bio-inspirated colored carbon-based fiber materials prepared via advanced micro/nanoscale manufacturing strategies is reviewed.In addition,emerging applications of colored carbon-based fiber materials in various fields are presented.Finally,the possible challenges and future directions for the design,large-scale production,and application of colored carbon-based fibermaterials and their composites are discussed,aiming to promote the material design of innovative next-generation systems and research in the advanced material and related engineering fields.
基金Project supported by the National Key Research and Development Program of China(2019YFC0605000)the"Transformational Technologies for Clean Energy and Demonstration",Strategic Priority Research Program of the Chinese Academy of Sciences(XDA21000000)+4 种基金the Independent Deployment Project of Ganjiang Innovation Research Institute of Chinese Academy of Sciences(E055A002)the Independent Deployment Project of China Fujian Innovation Laboratory of Optoelectronic Information Technology(2021ZZ109)the Fujian Provincial Natural Fund(2021J05101)the National Natural Science Foundation of China(21771196,62275276)Advanced Energy Science and Technology Guangdong Laboratory(HND20TDGFDC00)。
文摘The electrical properties of high-entropy ceramics(HECs)have been extensively studied in recent years due to their unique structural characteristics and fascinating functional properties induced by entropy engineering.Novel high-entropy(Sm_(0.2)Eu_(0.2)Gd_(0.2)Ho_(0.2)Yb_(0.2))CrO_(3)(HE-RECrO_(3))nanofibers were prepared by electro spinning.This work demonstrates that HE-RECrO_(3)nanofibe rs were successfully synthesized at a low temperature(800℃),which is approximately 400℃lower than the temperatures at which chromate ceramics were synthesized via the sol-gel method and the solid-state reaction method.The resistivity of HE-RECrO_(3)nanofibers decreases exponentially with increasing temperature from 25 to600℃.The logarithm of the resistivity is linearly related to the inverse of the temperature,confirming the negative temperature coefficient property of HE-RECrO_(3)nanofibers.The B_(25/50)value of the HERECrO_(3)nanofibers reaches 4072 K.In conclusion,HE-RECrO_(3)nanofibers are expected to be potential candidates for negative-temperature-coefficient(NTC)thermistors.
基金Supported by the Natural Science Foundation of Hebei Province under Grant No E2012201084the National University Students’ Innovative Training Program under Grant No 201410075004
文摘Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission （AE） statistical analysis towards fiber composites under mode-Ⅱ delamination damage. The load curve, AE relative energy, amplitude distribution, and amplitude spectrum are obtained and the delamination damage mechanism of the composites is investigated by the microscopic observation of a fractured specimen. The results show that the micro-damage accumulation around the crack tip region has a great effect on the evolutionary process of delamination. AE characteristics and amplitude spectrum represent the damage and the physical mechanism originating from the hierarchical microstructure. Our finding provides a novel aud feasible strategy to simultaneously evaluate the dynamic response and micro-damage mechanism for fiber composites.
基金Projects(51671152,51304153)supported by the National Natural Science Foundation of China
文摘The high-temperature acoustic absorption performance of porous titanium fiber material was investigated in terms of sample thickness, porosity, temperature, air-cavity thickness and double-layer structure arrangement. The effects on absorption coefficient were systematically assessed. The results show that the sound absorption performance is improved by increasing the sample porosity and/or thickness, and/or increasing the air-cavity thickness. Meanwhile, increasing the temperature gives better acoustic absorption performance in the low frequency range but also lowers the performance in the high frequency range, while double-layer structure enables better acoustic absorption performance.
文摘This study examines the penetration of 12.7 mm armor piercing incendiary projectiles into SiC ceramic-fiber composite target plates.By observing the recovered projectile and the overall damage morphology of the ceramic-fiber composite target plates.Additionally,multi-level screening and weighing of the recovered projectile and ceramic fragments revealed that the mass distribution of the projectile and ceramic fragments under different backing structures conforms to a powerlaw distribution.Experimental results indicate that for single laminate as the backing,the fragmentation of the projectile and ceramics is highest when T300 is the material.Incorporating a T300 transition layer between the SiC ceramic and aramid fibers(Kevlar)or ultra-high molecular weight polyethylene(UHMWPE)increases the fragmentation of the projectile and ceramics,leading to increased energy absorption.The projectile’s head mainly exhibits pulverized abrasive fragmentation,while larger projectile fragments primarily result from shear and tensile stress-induced shear-tensile failure fractures.The primary damage mode of ceramics under high-speed impact is the expansion of ceramic cones and radial cracks.The main form of damage in UHMWPE laminate is interlayer separation caused by tensile waves,permanent plastic deformation at the back protrusion,and perforation failure primarily due to shear waves.The damage mode of Kevlar laminate is similar to that of UHMWPE,with the distinction being that Kevlar laminate primarily exhibits perforation failure caused by tensile waves.Carbon fiber T300 laminate damage mainly consists of cross-shaped brittle fractures caused by shear waves.
基金Funded by the Fundamental Research Funds for the Central Universities(xjj2017160)the National Science and Technology Major Project(2014ZX04001091)
文摘The interfacial performance of the Fiber Bragg grating（FGB） embedded in the composite was studied and the influence of interface modification on the final profile of the spectra of the FBG sensor was examined. A type of polyamine（Pentaethylenehexamine, PEHA） was proposed to modify the coating of PI on FBG, and the interfacial performance was evaluated by a pull-out test. Sharp improvements of the interfacial shear strength（77%） were obtained by 40 min treatment of PEHA. Compared with untreated specimen, FGB spectra of treated specimen in the tensile tests show improved linearity within the test regime, which proves that the enhanced interface is beneficial for the sensing performance.
文摘Donghua University develops novel photothermal fabric to address freshwater crisis 2D photothermal membranes have demonstrated numerous advantages in solar desalination due to their flexibility,scalability,and low cost.However,their practical applications are limited by the restricted evaporation area and obstructed vapor channels.The research team led by Chen Zhigang,a researcher from the State Key Laboratory of Advanced Fiber Materials and the School of Materials Science and Engineering at Donghua University,has designed a novel biomimetic photothermal fabric,which is composed of two carbon-nanotube-hydrogel-coated polyester(PET)fabrics separated by fiber pillars,with the upper fabric layer having a hole array as stomatal channels.This fabric shows high solar-absorption efficiency(96.1%)and decreased water-evaporation enthalpy(1664.6 kJ kg^(-1)).
文摘The penetration resistance of Kevlar-129 fiber reinforced composite materials was investigated with AUTODYN software.The ballistic limits of the fragment that pierced 6kinds of target plates were obtained by finite element simulation when the 10 g fragment simulation projectile（FSP）impacting to the target plates of different thickness values of 8,10,12,14,16 and 18mm with appropriate velocity,respectively,and the influences of thickness on the ballistic limits and the specific energy absorption were analyzed.The results show that the ballistic limit of Kevlar-129 fiber reinforced composite plates presents linear growth with the increase of the target thickness in the range from 8to 18 mm.The specific energy absorption of plates presents approximately linear growth,but there is slightly slow growth in the range from 10 to 16mm of the target thickness.It also can be found that the influences of plate thickness and surface density on the varying pattern of specific energy absorption are almost the same.Therefore,both of them can be used to characterize the variation of specific energy absorption under the impact of the FSP fragment.
文摘The mechanical properties of the SiC fiber-reinforced Mg-Al metal matrix composite materials have been studied on internal microstructure by (scanning electron microscopy) SEM in-situ tensile test. The emergence and propagation of the crack, and the fracture behavior in materials have been observed and studied. It is found that in the case of the tensile test, the crack emerged in SiC fiber initially. In the case of the strong cohesion of the fiber-metal interface, the crack propagated in the fiber, meanwhile the fibers in the neighborhood of the cracked fiber began to crack and the Mg-Al metal deformed plastically, and at last the material fractured. Otherwise the toughness of the materials grows in the case of the lower cohesion of the fiber-metal matrix interface.
基金supported by the National Natural Science Foundation of China (No.11078009)the Natural Science Foundation of Heilongjiang Province (No.A200914)
文摘To estimate the shape of tapered fibers using tapering machines with movable large-zone furnaces, a new calculation method is proposed based on the discrete deducing method and the principle of the volume conservation of the fiber materials. This method can estimate the tapering results, i.e., the shape of the tapered fibers, based on arbitrary moving parameters of the large-zone furnace and the fiber holders. The theoretical estimated results agree with the experimental measuring shape of the tapered fibers quite well.
基金supported by the Heilongjiang Touyan Innovation Team Program(Grant No.TY2000010602)。
文摘Buoyancy material technology is of paramount importance for the development of marine engineering.In this study,a novel carbon fiber buoyancy material(CFBM)is designed and prepared by utilizing composite circular tubes with light weight and high strength.To reveal the failure mechanism under hydrostatic pressure,a finite element model(FEM)based on the three-dimensional Hashin and Yeh failure criterion is developed and validated experimentally.Both the simulated and experimental results indicate that the hydrostatic strength of the CFBM is mainly determined by the buckling of carbon fiber tubes located at the edges of the CFBM.Parametric analysis is conducted to investigate the effect of the number of unit-cells,length,and wall thickness of carbon fiber tubes on the mechanical properties of the CFBM.In addition,a 60-day water absorption test of the CFBM at 12.5 MPa is conducted to characterize its durability.Experimental results indicate that the maximum water absorption rate of the CFBM is 0.59%and the hydrostatic strength is reduced by only 7.97%during the 60-day test period.Finally,the designed CFBM is used at the water depth of 1000 m as buoyancy material.Compared with traditional buoyancy materials,the proposed CFBM has significant advantages in both hydrostatic strength and density.This work has broad engineering application prospects and is of high significance for promoting the implementation of carbon fiber composites in the ocean engineering field.
基金National Natural Science Foundation of China(90716002)The Open Fund of LNM
文摘For steady-state heat conduction,a new variational functional for a unit cell of composites with periodic microstructures is constructed by considering the quasi-periodicity of the temperature field and in the periodicity of the heat flux fields. Then by combining with the eigenfunction expansion of complex potential which satisfies the fiber-matrix interface conditions, an eigenfunction expansion-variational method （EEVM）based on a unit cell is developed. The effective transverse thermal conductivities of doubly-periodic fiber reinforced composites are calculated, and the first-order approximation formula for the square and hexagonal arrays is presented, which is convenient for engineering application. The numerical results show a good convergency of the presented method,even though the fiber volume fraction is relatively high. Comparisons with the existing analytical and experimental results are made to demonstrate the accuracy and validity of the first-order approximation formula for the hexagonal array.
基金supported by the National Natural Science Foundation of China (Nos. 21107116, 21477135)
文摘Kapok fiber corresponds to the seed hairs of the kapok tree（Ceiba pentandra）, and is a typical cellulosic fiber with the features of thin cell wall, large lumen, low density and hydrophobic–oleophilic properties. As a type of renewable natural plant fiber, kapok fiber is abundant,biocompatible and biodegradable, and its full exploration and potential application have received increasing attention in both academic and industrial fields. Based on the structure and properties of kapok fiber, this review provides a summary of recent research on kapok fiber including chemical and physical treatments, kapok fiber-based composite materials, and the application of kapok fiber as an absorbent material for oils, metal ions, dyes, and sound,with special attention to its use as an oil-absorbing material, one predominant application of kapok fiber in the coming future.
基金supported by the National Natural Science Foundation of China(Nos.21325417 and 51533008)National Key R&D Program of China(No.2016YFA0200200)+1 种基金Fundamental Research Funds for the Central Universities(No.2017XZZX008-06)the China Postdoctoral Science Foundation(No.2017M621927)
文摘Modern wearable electronics are thirsty for flexible, lightweight energy storage and supply devices. Flexible fiber-shaped supercapacitors, possess good flexibility, high power density, fast charging capability and long cycle life, becoming a promising option for wearable devices. The past decade has witnessed the emergence of graphene fiber based supercapacitors（GFSCs） as one of the most active vicinity in fiber-supercapactiors, for their excellent properties including high surface area, chemical stability, excellent electrical conductivity, lightweight and mechanical properties. In this perspective, we introduced the basic energy storage mechanisms of GFSCs, followed by the analysis in improving their overall performances, recent advances, and a conclusive discussion on the challenges and opportunities.
基金Funded by the National High-tech Research and Development Program of China(863 Program)(No.2013AA031306)
文摘In order to research the field sensing characteristic of the carbon fiber smart material, the Tikhonov regularization principle and the modified Newton-Raphson(MNR) algorithm were adopted to solve the inverse problem of the electrical resistance tomography(ERT). An ERT system of carbon fiber smart material was developed. Field sensing characteristic was researched with the experiment. The experimental results show that the specific resistance distribution of carbon fiber smart material is highly consistent with the distribution of structural strain. High resistance zone responds to high strain area, and the specific resistance distribution of carbon fiber smart material reflects the distribution of sample strain in covering area. Monitoring by carbon fiber smart material on complicated strain status in sample field domain is realized through theoretical and experimental study.
文摘Equilibrium paths of post-buckling are measured for large slenderness column specimens made of the fiber reinforced composite material. The influence of the initial curvature is investigated experimentally and compared with the result of the initial post-buckling theory. Both the theoretical and experimental results reveal that the column with the initial curvature has stable post-buckling behaviors and is not sensitive to the imperfection in the form of initial curvature. The experimental results show that when the lateral buckling displacement is less than 20 percent of the column length, the experimental results agree with the results from the theory of initial post-buckling quite well, while they agree with the results from the large deflection theory in a quite large range.
