Carbon Fiber Material Research Articles

Thermogravimetric analysis of bamboo-tar under different heating rates based on distributed activation energy model

Carbon fiber is a kind of new polymer material with excellent mechanical properties and being applied widely. The process of carbon fiber prepared by bamboo tar, including extraction, condensation, spinning, oxidation and carbonation, is influenced by the pyrolysis kinetics significantly. In this paper, the thermogravimetric analysis (TGA) of bamboo tar produced in the process of pyrolysis and gasification of the bamboo which is known as Phylostachys sulphurea, was analyzed by the distributed activation energy model (DAEM) to understand the kinetic properties and parameters of bamboo tar. The thermogravimetric analysis of bamboo tar which is used as the raw material of carbon fiber was conducted under 5 different heating rates (i.e. 5, 10, 15, 30 and 50 °C/min, etc.) in nitrogen atmosphere. The results show that the activation energy of bamboo tar and the exponential factor increased significantly with the increase of the heating rate, and the low heating rate is advantageous to the extraction of bamboo tar solvent and the thermal polycondensation, which can provide scientific reference for the optimization of carbon fiber technology. The thermal weight results show that the temperature range of bamboo tar being decomposed rapidly is 213°C-410°C. The ranges of the activation energy were calculated by DAEM, which have small difference in comparisons with five heating rates when the conversion rate is at 0.1-0.6 and the average value of the activation energy is 119 kJ/mol. The stability range of the activation energy is enlarged when the conversion rate is greater than 0.6 and heating rate increases. Keywords: bamboo tar, carbon fiber, thermogravimetric analysis (TGA), distributed activation energy model (DAEM) DOI: 10.25165/j.ijabe.20181106.3839 Citation: Zhang H, Yan B B, Lei T Z, Liu T, Hu J J, Li Y M, et al. Thermogravimetric analysis of bamboo-tar under different heating rates based on distributed activation energy model. Int J Agric & Biol Eng, 2018; 11(6): 180–186.

WEAR BEHAVIOUR OF VANES FOR A ROTARY VANE EXPANDER WITH VARIOUS GRAPHITE MATERIALS UNDER DRY SLIDING CONDITIONS

This study presents tribological properties of various graphite materials of vanes for rotary vane expanders. A test device was developed in order to measure the wear and power dissipation under conditions similar to a real operation of a vane expander. Subsequently, the friction coefficients of vanes for a rotary vane expander were evaluated. Parameters of the test device are based on the vane expander used for an experimental organic Rankine cycle unit. Four materials in total were tested: graphite, antimony-impregnated graphite, 2D carbon fibre-reinforced graphite, and 2.5D carbon fibre-reinforced graphite. Wear tests were performed under dry sliding conditions at the temperature of 115 °C and at 3030 rpm for the total time of about 400 hours. The method of evaluating the wear involved measuring the vane weight loss in relation to the duration of the load. Furthermore, specific wear coefficients were established in order to evaluate the tribological properties of the tested materials. Measurements have shown that carbon fibre materials are the most advantageous in terms of wear. The best friction properties were obtained for the pure graphite.

The Encountered Problems and Solutions in the Development of Coal Mine Rescue Robot

Based on the various problems in the process of coal robot applications, from three-dimensional analysis of the key technology, market demand, and policy regulations and standardization, the paper reviews the use of carbon fiber material, elastic material of traditional surface spraying and integral casting technology to realize lightweight robot, by using the dual redundant design to improve the reliability of the rescue robot CPU, through the functions of voice recognition obstacle sensor, gas sensor acquisition components, and distribution information to realize the underground rescue mission. In addition, virtual test technology, hardware in the loop simulation technology, and shrinkage model technology are proposed to solve the difficulties of hard field testing of rescue robots. These suggest that concrete measures have been pointed out to break the problem of the development of the coal mine relief robot.

Recycled Carbon Fiber-Supported Polyaniline/Manganese Dioxide Prepared via One-Step Electrodeposition for Flexible Supercapacitor Integrated Electrodes.

The exploration of multifunctional electrode materials has been a hotspot for the development of high-performance supercapacitors. We have used carbon fiber plates recovered from construction waste to prepare high-quality flexible carbon fiber materials by pyrolysis of epoxy resin. The as-prepared recycled carbon fiber has a diameter of 8 μm and is the perfect substrate material for flexible electrode materials. Furthermore, polyaniline and manganese dioxide are uniformly deposited on the recycled carbon fiber by one-step electrodeposition to form an active film. The recycled carbon fiber/polyaniline/MnO2 composite shows an excellent specific capacitance of 475.1 F·g−1 and capacitance retention of 86.1% after 5000 GCD cycles at 1 A·g−1 in 1 M Na2SO4 electrolyte. The composites optimized for electrodeposition time have more electroactive sites, faster ions and electron transfer, structural stability and higher conductivity, endowing the composites promising application prospect.

Numerical simulation of stress distribution for CF/EP composites in high temperatures

The high-performance carbon fiber materials can be obtained by decomposing carbon fiber reinforced resin matrix composites using thermally activated oxide semiconductors. This paper established the representative volume element (RVE) of carbon fiber/epoxy resin composites, and investigated the structure destruction of composites in the recycling process based on analysis of the stress and strain distribution by the thermomechanical coupling module of Digimat. The results indicated that the maximum thermal stress of the epoxy resin appeared in the poor resin region, while the minimum appeared in the resin-rich region; the stress of the carbon fibers in poor resin region was greater than that in the resin-rich region; the maximum stress of composites appeared in the interface layers when the temperature ranged from 350 to 500 °C, and the maximum thermal stress was 196.9–281.3 MPa, as well as the maximum shear stress was 98.2–140.3 MPa; the maximum peeling stress perpendicular to the fiber directions was 53.7–157.3 MPa; the strain of the interface layers and carbon fibers were the smaller than that of the resin matrix, whose maximum strain ranged from 0.0622 to 0.0889. The structure destruction of the composites was caused by both the peeling stress and the interfacial shear stress in recycling.

On the separation and recycling behaviour of textile reinforced concrete: an experimental study

This paper presents the results of recent experiments on the recyclability of the textile components in textile reinforced concrete (TRC). TRC as a multi-component system often contains organic ingredients such as carbon fibres and polymer impregnations. Consequently, the recycling of TRC is not trivial and has not yet been sufficiently clarified until now. In this study, an impregnated, bi-axially reinforced, and warp-knitted textiles made of carbon fibres was used in combination with a fine grained concrete. Flexural tests on TRC specimens containing recycled epoxy-impregnated carbon reinforcement were performed, whereby the recycling was simulated by a pre-treatment of the carbon fibre material in a jaw crusher. The results showed a pronounced decrease in flexural strength compared to untreated carbon reinforcement. Moreover, three different crushing methods were investigated with respect to their influence on the recovery of styrene-butadiene-rubber impregnated carbon textiles. Besides jaw crushing and impact milling, crushing with a hammer mill showed the best degree of purity but also caused the highest mechanical damage to the textile. The impact of material, structure of the composite and crushing methods on the separation behaviour could be deduced from the experiments.

Biomechanical behavior of modular acetabular cups made of poly-ether-ether-ketone: A finite element study.

After total hip arthroplasty, stress-shielding is a potential risk factor for aseptic loosening of acetabular cups made of metals. This might be avoided by the use of acetabular cups made of implant materials with lower stiffness. The purpose of this numerical study was to determine whether a modular acetabular cup with a shell made of poly-ether-ether-ketone or poly-ether-ether-ketone reinforced with carbon fibers might be an alternative to conventional metallic shells. Therefore, the press-fit implantation of modular cups with shells made of different materials (Ti6Al4V, poly-ether-ether-ketone, and poly-ether-ether-ketone reinforced with carbon fibers) and varying liner materials (ceramics and ultra-high-molecular-weight polyethylene) into an artificial bone cavity was simulated using finite element analysis. The shell material had a major impact on the radial shell deformation determined at the rim of the shell, ranging from 17.9 µm for titanium over 92.2 µm for poly-ether-ether-ketone reinforced with carbon fibers up to 475.9 µm for poly-ether-ether-ketone. Larger radial liner deformations (up to 618.4 µm) occurred in combination with the shells made of poly-ether-ether-ketone compared to titanium and poly-ether-ether-ketone reinforced with carbon fibers. Hence, it can be stated that conventional poly-ether-ether-ketone is not a suitable shell material for modular acetabular cups. However, the radial shell deformation can be reduced if the poly-ether-ether-ketone reinforced with carbon fiber material is used, while deformation of ceramic liners is similar to the deformation in combination with titanium shells.

Carbon Fiber Anode of Biofuel Cell with Immobilized Bacteria and Membrane Fractions

Four types of carbon fiber materials (CFMs) obtained by electrospinning polyacrylonitrile solutions are considered. The CFMs intertwine with cells of Gluconobacter oxydans or with their membrane fractions (MFs). Bioelectrochemical characteristics of the electrodes (chrono- and voltamperometric, as well as impedance spectra) are studied. Electrodes are considered a model of the anode of the microbial biofuel cell (MFC). Ethyl alcohol is the oxidized substrate. MALDI-TOF MS demonstrates that MFs retain the protein structure of whole cells and therefore can be used as analogues of whole cells. It is shown that the MFC based on carbon fiber material obtained after 30-min treatment at 1000°C has the highest power and stability. When MFs are used as a biocatalyst, nonmediated charge transfer is observed for all studied CFMs. These results can be successfully used for the design of biosensors and MFCs.

Synthesis and Characterization of Supercapacitor Electrode Materials Based on Carbon Fiber Materials and Metal Oxyhydroxides

Composite materials (CMs) based on activated carbon fiber material (ACFM) modified with oxygen-containing transition metal compounds (MnO2, Ni(OH)2, and Co(OH)2) by using colloid electrophoresis are studied. All prepared CMs have higher capacitance than the individual parental materials, with the CM ACFM–Ni(OH)2 exhibiting the maximum capacitance (~380 F g–1). Changes in the capacitances of ACFM and prepared ACFM-based CMs induced by potential cycling, the time of exposure to electrolyte solution, and potential scan rate are investigated. The capacitances of all CMs are found to increase with the number of cycles, but tend to decrease at higher potential scan rates.

Heat transfer modelling of CFRP strengthened and insulated steel tubular columns

The lack of knowledge of the fire performance of CFRP strengthened and insulated steel tubular columns has hindered the CFRP usage in steel columns, which require certain structural fire ratings. In this research, a numerical modelling approach was used to investigate the heat transfer behaviour of CFRP strengthened and insulated steel columns, and thus to enhance the knowledge of their fire performance characteristics. For this purpose, an experimental investigation was also conducted to determine the thermal properties of carbon fibre, adhesive, CFRP and insulation materials at elevated temperatures. These thermal properties were idealized and used to develop heat transfer finite element models in ABAQUS/CAE to simulate the behaviour of CFRP strengthened and insulated steel columns exposed to fire. The developed models were validated by using experimental results and a parametric study was then conducted to investigate the influence of insulation thickness on the heat transfer behaviour. This paper presents the details of this research and the results. It provides the details of the validated heat transfer finite element models and the important thermal properties of CFRP and insulation materials. An approach to determine the fire resistance level of CFRP strengthened and insulated columns is also presented in this paper.

Electrochemical study of composite materials for coal-based direct carbon fuel cell

The efficient conversion of solid carbon fuels into energy by reducing the emission of harmful gases is important for clean environment. In this regards, direct carbon fuel cell (DCFC) is a system that converts solid carbon directly into electrical energy with high thermodynamic efficiency (100%), system efficiency of 80% and half emission of gases compared to conventional coal power plants. This can generate electricity from any carbonaceous fuel such as charcoal, carbon black, carbon fiber, graphite, lignite, bituminous coal and waste materials. In this paper, ternary carbonate-samarium doped ceria (LNK-SDC) electrolyte has been synthesized via co-precipitation technique, while LiNiCuZnFeO (LNCZFO) electrode has been prepared using solid state reaction method. Due to significant ionic conductivity of electrolyte LNK-SDC, it is used in DCFC. Three types of solid carbon (lignite, bituminous, sub-bituminous) are used as fuel to generate power. The X-ray diffraction confirmed the cubic crystalline structure of samarium doped ceria, whereas XRD pattern of LNCZFO showed its composite structure.The proximate and ultimate coal analysis showed that fuel (carbon) with higher carbon content and lower ash content was promising fuel for DCFC. The measured ionic conductivity of LNK-SDC is 0.0998 Scm−1 and electronic conductivity of LNCZFO is 10.1 Scm−1 at 700 °C, respectively. A maximum power density of 58 mWcm−2 is obtained using sub-bituminous fuel.

VZLUSAT‐1: Health monitoring system, preliminary results

The health monitoring (HM) system placed on VZLUSAT‐1 nondestructively measures the mechanical and thermal properties of the newly developed carbon fiber material for space usage. The carbon material is exposed to the vacuum, radiation, and temperature changes in space. It can be used as a substitute for the currently used aluminum alloys because it has lower mass density and better mechanical properties compared to aluminum. The HM payload evaluates the quality changes of a material according to the difference in Young's modulus. Young's modulus of elasticity is a characteristic property of every solid material, and on VZLUSAT‐1 it is measured in terms of the eigenfrequencies of a free‐hanging beam. In this paper we present the first data measured in orbit – the eigenfrequencies, attenuation, and six temperatures from a carbon fiber panel. Based on these data, the quality of the mechanical properties and time stability are determined over the VZLUSAT‐1's life span.

Electroless decoration of cellulose paper with nickel nanoparticles: A hybrid carbon fiber for supercapacitors

A facile scale-up process was used to fabricate a novel hybrid carbon fiber material decorated with nickel nanoparticles for use as a supercapacitor electrode. Biomass-derived soft wood was transformed into cellulose fibers via papermaking technology. The cellulose fibers were then decorated with nickel nanoparticles via electroless decoration. The hybrid carbon fiber material was obtained by subsequent carbonization at 700 °C. The hybrid carbon fiber material exhibited promising capacitive performance as an electrode, showing a high specific capacitance of 268 F/g in 6 M KOH at a current density of 0.2 A/g, and excellent electrochemical stability of 97% capacity retention after 2000 cycles because of the synergistic effects of EDLC (carbon with a high specific surface area) and pseudocapacitor (slightly redox reaction) features.

Highly nitrogen-doped graphitic carbon fibers from sustainable plant protein for supercapacitor

In this research, a novel biomass-based, highly nitrogen-doped carbon fiber material has been synthesized from electrospun plant protein fibers by one-step carbonization. The material fibrous structure was well maintained during pyrolysis by incorporating Ca2+ in the protein fiber matrix, since Ca2+ increased the thermal stability of the protein and the calcium salt/oxide provided a solid support during pyrolysis. In addition, the calcium salt served as a template to generate pores on the carbon samples. X-ray photoelectron spectra showed that the fibrous carbon materials possessed large nitrogen content (7.5%), mainly in the form of pyridonic/pyrrolic and pyridinic nitrogen. The optimized sample P-10% Ca-CL exhibited an interconnected carbon fiber network with meso and micropores on the fiber surface. Moreover, the well aligned granular graphitic structure observed embedded within the carbon fibers, which has been found for the first time from biomass derived carbon fiber materials. The optimized carbon fibers (P-10% Ca-CL) showed an exceptional areal specific capacitance of 64 μF/cm2 at 0.5 A/g. This is attributed to the large number of N functional groups which induced a pseudocapacitance and improved the wettability of the carbon surface. The carbon fibers also exhibited excellent cyclic stability with 98% retention after 5000 cycles at a current density of 10 A/g. This research is the first publication of highly N-doped carbon fibers derived from plant proteins and show potential to be used as a supercapacitor electrode. Additionally, these materials were prepared by a convenient and environmentally-friendly method, not requiring a large energy input or corrosive chemicals.

Investigation into Composites Property Effect on the Forming Limits of Multi-Layer Hybrid Sheets Using Hydroforming Technology

Fiber-metal laminates (FMLs) such as Kevlar reinforced aluminum laminate (ARALL), Carbon reinforced aluminum laminate (CARALL), and Glass reinforced aluminum laminate (GLARE) offer great potential for weight reduction applications in automobile and aerospace construction. In order to investigate the feasibility for utilizing such materials in the form of laminates, sheet hydroforming technology are studied under the condition of uniform blank holder force for three-layered aluminum and aluminum-composite laminates using orthogonal carbon and Kevlar as well as glass fiber in the middle. The experimental results validate the finite element results and they exhibited that the forming limit of glass fiber in the middle is the highest among the studied materials, while carbon fiber material performs the worst. Furthermore, the crack modes are different for the three kinds of fiber materials investigated in the research. This study provides fundamental guidance for the selection of multi-layer sheet materials in the future manufacturing field.

Bioinspired Electro-Organocatalytic Material Efficient for Hydrogen Production.

Commercial carbon fibers can be used as electrodes with high conductive surfaces in reduced devices. Oxidative treatment of such electrodes results in a chemically robust material with high catalytic activity for electrochemical proton reduction, enabling the measurement of quantitative faradaic yields (>95 %) and high current densities. Combination of experiments and DFT calculations reveals that the presence of carboxylic groups triggers such electrocatalytic activity in a bioinspired manner. Analogously to the known Hantzsch esters, the oxidized carbon fiber material is able to transfer hydrides, which can react with protons, generating H2 , or with organic substrates resulting in their hydrogenation. A plausible mechanism is proposed based on DFT calculations on model systems.

Advance on friction of stamping forming

Stamping forming is a method of pressure processing that has been widely applied to automotive manufacturing, household electrical appliance production, aviation, and other fields. Stamping friction plays a substantial role in the quality of stamping forming and the service life of the die. However, the problem of friction in stamping forming has not yet been solved due to several critical difficulties. In particular, with the application of hot forming technology and new lightweight materials in stamping forming, such as advanced high-strength steel sheets, aluminum alloy sheets, and carbon fiber materials, stamping friction has become more complex. Therefore, it is of paramount practical significance to study stamping friction. In this paper, state of the art research concerning the mechanism and factors influencing friction in stamping forming is reviewed. Investigations of the friction mechanism are described, starting by introducing the development process of traditional and modern friction theory. The present friction mechanism fails to adequately describe the frictional process occurring in stamping forming due to complex and variable factors. A survey of existing works reveals several gaps in the study of factors that influence stamping forming: the friction model is very fragile; the accuracy is not high because only a few factors are considered; and more importantly, some important factors are often ignored, such as temperature and coating. Therefore, different dynamic friction models with multifactor coupling should be established for different stamping processes and materials to fully reflect the characteristics and mechanisms of stamping friction. The present review is aimed at providing an insight into the shortcomings of the existing research background, and it demonstrates the enormous potential for further investigation and innovation in the field of friction of stamping forming.

Mechanical Properties of Hybrid Composites with Date Palm Fibre Reinforcement

Plant-based fibres are commonly used as reinforcements in polymer composites for applications such as packaging, construction, automotive, and decorative household items. This process will reduce the cost of production along with eliminating solid wastes. Here, composite materials were prepared using epoxy resin as the matrix and date palm fibres, polyester, and carbon fibre mats as the reinforcement. The date palm fibres were pre-treated in a 10% alkali solution before use. Composites laminates were prepared using vacuum moulding technique. As these composites are intended to use for structural applications, it is necessary to study the tensile and flexural strength of the prepared composites. The effects of the date palm fiber with polyester and carbon fiber materials on the mechanical properties were determined. Along with The mechanical properties, the morphology of the fibre-matrix interface after fracture was evaluated. It was realized that the composites materials fails due to fiberpullout and debonding. It was also found that natural fibers are hydrophilic in nature, which causes delamination. These results were supported by scanning electron micrographs taken of the fracture surfaces. The hybrid composite containing date palm fibres and the polyester mat showed the highest ultimate tensile strength of 43.41 MPa, which was attributed to enhanced fibre-matrix adhesion due to the alkali pre-treatment. The results indicated that when the date palm fiber were added along with polyester mat, the tensile and bending strength were incresed. whereas both the strength uneffected when datepalmfiber added along with hybrid combination of carbon and polyester mat.

Thermogravimetric analysis of bamboo-tar under different heating rates based on distributed activation energy model

Carbon fiber is a kind of new polymer material with excellent mechanical properties and being applied widely. The process of carbon fiber prepared by bamboo tar, including extraction, condensation, spinning, oxidation and carbonation, is influenced by the pyrolysis kinetics significantly. In this paper, the thermogravimetric analysis (TGA) of bamboo tar produced in the process of pyrolysis and gasification of the bamboo which is known as Phylostachys sulphurea, was analyzed by the distributed activation energy model (DAEM) to understand the kinetic properties and parameters of bamboo tar. The thermogravimetric analysis of bamboo tar which is used as the raw material of carbon fiber was conducted under 5 different heating rates (i.e. 5, 10, 15, 30 and 50 °C/min, etc.) in nitrogen atmosphere. The results show that the activation energy of bamboo tar and the exponential factor increased significantly with the increase of the heating rate, and the low heating rate is advantageous to the extraction of bamboo tar solvent and the thermal polycondensation, which can provide scientific reference for the optimization of carbon fiber technology. The thermal weight results show that the temperature range of bamboo tar being decomposed rapidly is 213°C-410°C. The ranges of the activation energy were calculated by DAEM, which have small difference in comparisons with five heating rates when the conversion rate is at 0.1-0.6 and the average value of the activation energy is 119 kJ/mol. The stability range of the activation energy is enlarged when the conversion rate is greater than 0.6 and heating rate increases. Keywords: bamboo tar, carbon fiber, thermogravimetric analysis (TGA), distributed activation energy model (DAEM) DOI: 10.25165/j.ijabe.20181106.3839 Citation: Zhang H, Yan B B, Lei T Z, Liu T, Hu J J, Li Y M, et al. Thermogravimetric analysis of bamboo-tar under different heating rates based on distributed activation energy model. Int J Agric & Biol Eng, 2018; 11(6): 180–186.

碳纤维材料的发展及应用

碳纤维材料的发展及应用