Surface Treatment Of Carbon Fibers Research Articles

The Influence of Plasma Surface Treatment of Carbon Fibers on the Interfacial Adhesion Properties of UHMWPE Composite

Carbon fiber-reinforced Ultra High Molecular Weight Polyethylene (CF/UHMWPE) composites have been treated by oxygen plasma to enhance the adhesion. According to the plasma treatment, the interlaminar shear strength (ILSS) of composites has been greatly improved. The dynamic wetting method, FTIR and SEM are used to examine the microscopic properties of resultant composites. The enhanced ILSS is attributed to the plasma cavitation, which improves the wetting between carbon fibers and resins.

Control, Effection and Analysis of Voltage during Dielectric Barrier Discharges Plasma Surface Treated Carbon Fibers

The deposition of coatings on the surface of carbon fiber will be helpful to their applications. However, they are unsuitable to be deposited due to their low surface free energies, poor wettability and poor adhesions. The objective of this work is to modify carbon fibers by Dielectric barrier discharges(DBD)in ambient argon . The chemical and physical changes induced by the treatments on carbon fibers surface are examined using contact angle measurements and X-ray photoelectron spectroscopy (XPS). The interfacial adhesion of CF/EP composites are analyzed by a single fiber composite (SFC) for filament fragmentation test. The contact angles of the plasma-treated samples are visibly reduced than the untreated samples. XPS results reveal that the carbon fibers modified with the DBD at an atmospheric pressure show a significant increase in oxygen-containing groups, such as C–O,C=O and O–C=O. The results of SFC tests show that the treated carbon fibers composites could possess excellent interfacial properties with mixed resins. These results demonstrate that the surfaces of the carbon fibers samples are more active, hydrophilic and rough after plasma treatments using a DBD operating in ambient argon.

Research on Surface Treatment of Carbon Fiber and the Conductive Properties of Paper

The influences of the oxidative modification, coupling treatment and dispersing agent for carbon fiber dispersion and binding properties were investigated, and the relationships of different ratio of carbon fiber with the physical strength and electrical conductivity of the paper were analyzed. Meanwhile fiber surface morphology, zeta potential and absorbance slurry were tested. The result showed that: coupling modification significantly improved the dispersion performance of carbon fiber, superior than oxidative modification, the increase of the dispersion would enhance the conductivity of carbon fiber network, the effect of CPAM was best in four kinds of surface-active agent, and 30% content of carbon fiber achieved the "percolation threshold” of conductive material.

Effect of Fiber Surface Treatment Techniques on Properties of Short Carbon Fiber Reinforced Phenol Formaldehyde Resin/Graphite Composite Bipolar Plate

Research was done on carbon fiber surface treatment techniques on boundary-bonding state and properties of short carbon fiber reinforced phenol formaldehyde (PF) resin/graphite composite. By gas-phase oxidative surface treatment (GPOST)、gas-phase and liquid-phase oxidative surface treatment (GLPOST), carbon fiber and PF resin /graphite matrix is on weak boundary bonding state. The exerted outside stress can not be effectively transmitted, the composite strength is lower than that of PF resin/graphite matrix; By thick nitric acid liquid-phase oxidative surface treatment (TNALPOST) which the nitric acid has high density, fiber and matrix is on relatively weak boundary bonding state, the exerted outside stress can be effectively transmitted and composite strength can be raised on some degree. With carbon fiber content by TNALPOST 3.wt%~ 4.wt% and PF resin content 15.wt%, the composite can meet both the mechanical strength and electrical conductivity requirement on carbon filler/polymer bipolar plate by USA Department of Energy.

The Influence of Plasma Surface Treatment of Carbon Fibers on the Flexural and Tribological Properties of UHMWPE Composite

In this paper, the wear performance of a ultra-high molecular weight polyethylene composites filled with carbon fiber (CF/UHMWPE) were studied using a pin-on-disc method. The effects of surface treatment of CF and sliding load and on the friction and wear of the CF/UHMWPE composite are reported. It was observed that the sliding load is an important controlling factors; its effect is diminished when the CF is modified.

Effect of Fiber Surface Treatment on Interfacial Mechano-Electric Properties of Carbon Fiber Reinforced Concrete

The effect of carbon fiber surface treatment on interfacial mechano-electric properties of carbon fiber reinforced concrete is studied by single fiber pull-out testing. As-received carbon fiber is with poor surface polarity, and the fiber-matrix interface bonding strength is low. Surface treatment of the carbon fiber improves both the interfacial bonding strength and the interfacial ductility. The interfacial bonding force and interfacial resistance increased linearly with increasing displacement until the fiber-matrix debonding was completed. The superior interfacial mechanical properties can help improve the strain-sensing ability relates to the better repeatability and reliability. But the sensitivity decreases to some extent.

Investigation on mechanism of the improvement in tribological properties of carbon fiber reinforced polytetrafluoroethylene composites by surface treatment

Tribological properties of polytetrafluoroethylene (PTFE) composites filled with differently surface treated carbon fibers (CF), sliding against GCr15 steel under dry sliding conditions, were investigated on a block-on-ring M-2000 tribometer. Experimental results reveal that rare earths (RE) surface treatment reduces the friction and wear of CF-reinforced PTFE (CF/PTFE) composites. Scanning electron microscopy (SEM) investigation of worn surfaces of CF/PTFE composites shows that cracks or pores are visible on the worn surfaces of untreated and air-oxidated composite, while no crack and very few pores present on the worn surface of REtreated composite. The fiber-friction-angling effect makes carbon fibers angled and oriented along the frictional shearing force, and finally parallel to the friction surface, which makes interfacial adhesion become a key factor to tribological properties of CF/PTFE composite. With strong interfacial adhesion between carbon fiber and PTFE after RE surface treatment, carbon fibers are not easily detachable from the PTFE matrix in the process of fiber-friction-angling, which prevents the rubbing-off of PTFE, and accordingly improves the friction and wear properties of the composite.

Effect of carbon fiber surface treatment on Cu electrodeposition: The electrochemical behavior and the morphology of Cu deposits

The relationship between surface functional groups and electrochemical behaviors of polyacrylonitrile (PAN)-based carbon fibers (CFs) differentiated by oxidation treatment in air was studied. The chemical character of the CFs surface was estimated by X-ray photoelectron spectroscopy (XPS) and the electrochemical behavior of treated CFs in CuSO4 plating solution was studied by electrochemical setup. The influence of functional groups on the morphology of copper deposits was characterized by field-emission scanning electron microscopy (FESEM). It was found that the O/C atomic ratio rose rapidly from 23.05% (as-received carbon fibers) to 42.83% as the oxidation temperature was increased to 400°C and the content of –CO was the highest. Concentrations and types of the functional groups on CFs surface showed a close connection with the electrochemical response of CFs in CuSO4 plating bath. It was showed that Cu electrodeposition was the interaction of applied voltage and the reduction of surface functional groups. With the functional groups increased, the quantities of the Cu nuclei increased, further the morphology of deposited Cu was affected.

Effect of short carbon fiber surface treatment on composite properties

The effects of whiskerized carbon fibers (WCF) embedded as filler into polymer matrix were investigated. In this respect, composites consisting of pure polypropylene and also carbon fiber (CF)/polypropylene (PP) was fabricated and compared. Polypropylene matrix was reinforced with 2% concentration of WCF and prepared by a melt-mixing method. The tensile test indicated that the addition of 2% WCF enhanced the tensile strength and Young’s modulus by 38.1% and 28.2%, respectively. Besides that, the elongation was decreased for that sample. Dynamic mechanical analysis showed an increase of 39.2% in the stiffness of the WCF/PP composite and an improvement in the storage modulus. The tan δ for the sample was also smaller than unfilled PP and CF/PP composites. Furthermore, thermogravimetric analyses in an inert atmosphere showed a shift of temperature to the higher temperature with the addition of fillers.

촉매에 따른 다양한 탄소나노구조체 합성

탄소 섬유소재는 가벼우면서고 강건한 특성과 화학적 안정성 등으로 인해 항공기, 자동차, 레저, 우주항공, 풍력, 연료전지, 방위 산업 등의 분야를 비롯하여 최근에는 다양한 산업용 복합재료 및 보강용 분야에서 많이 사용되고 있다. 본 연구에서는 탄소섬유의 기능성 향상 및 다양한 응용 분야 확대를 위하여 물리적, 화학적 특성이 우수한 탄소나노튜브와 같은 다양한 탄소나노구조체를 탄소섬유상에 하이브리드화 하는 연구를 진행하였다. ELP(Electroless plating)법을 이용하여 탄소섬유 표면처리 및 촉매 입자 형성을 동시에 진행하였으며, Thermal CVD법을 이용하여 탄소나노구조체를 형성한 결과, 탄소섬유상 Pd/Ni 복합 촉매의 비율에 따라서 탄소나노튜브, 탄소나노필라멘트 등 다양한 형태의 탄소섬유상 탄소나노구조체가 형성되는 것을 알 수 있었다. Pd촉매의 비율이 높을 수록 다중벽 탄소나노튜브(Multiwall carbon naotube)의 생성 비율이 높아지고, Ni촉매의 비율이 상대적으로 증가할 수록 탄소나노필라멘트(Carbon nanofilament)의 생성 비율이 높아짐을 알 수 있었다. Carbon fiber has many potential applications in a wide array of fields of solar cell, fuel cell, batteries, and polymer matrix composites due to an exceptional mechanical properties and chemical stability. In this study, the effects of catalysts on the property of carbon nanostructures grown on the carbon fiber were systematically investigated. The surface treatment of carbon fiber and catalysts synthesis for carbon nanostructures growth were carried out by one-pot ELP method and thermal CVD, respectively. The surface morphology and crystal structure of carbon nanostructures were examined using a field emission scanning electron microscope and transmission electron microscope. Depending on the type of catalysts and the molar ratio, various types of carbon nanostructures like carbon nanotube, carbon nanofilament, carbon nanospring and etc. were synthesized on the surface of carbon fibers surface.

The carbon fiber surface treatment and addition of PA6 on tensile properties of ABS composites

In this study acrylonitrile-butadiene-styrene (ABS) terpolymer was reinforced with HNO 3-treated short carbon fibers (HCFs). The effects of HCF concentration on the tensile properties of the composites were examined. Increasing the HCF concentration in the ABS matrix from 10 wt% to 30 wt% resulted in improved tensile strength and tensile modulus. To obtain a strong interaction at the interface, polyamide-6 (PA6) at varying concentrations was introduced into the ABS/10 wt% HCF composite. The incorporation and increasing amount of PA6 in the composites increased tensile properties of the ABS/PA6/HCF systems due to the improved adhesion at the interface, which was confirmed by the ratio of tensile strength as an adhesion parameter. These results were also supported by scanning electron micrographs of the ABS/PA6/HCF composites, which exhibited an improved adhesion between the HCFs and the ABS/PA6 matrix.

A surface treatment technique of electrochemical oxidation to simultaneously improve the interfacial bonding strength and the tensile strength of PAN-based carbon fibers

Electrochemical oxidation surface treatment of polyacrylonitrile-based carbon fibers (CFs) in 0.5 M ammonium oxalate aqueous solution for 94 s with the electric current density being 0.6 mA cm −2 resulted in simultaneous improvements of interfacial bonding strength and tensile strength by ∼8.6% and ∼16.6%, respectively. The improvements were due to the following reasons: (1) besides creating active surface functional groups, the electrochemical oxidation treatment with optimal processing conditions also generated a suitable electrolytic etching capability, which was powerful enough to remove mechanically weak carbonaceous components deposited on the surface of CFs, while was gentle enough not to distinguishably remove structurally ordered sheath region of CFs; (2) the treatment also refined the graphitic crystallites in the sheath region and created additional crystalline impingements/boundaries that could resist to crack growth; and (3) the electrochemical oxidation that preferably started from sharp edges including the tips of micro-cracks mitigated the stress development and propagation. XRD, SEM, Raman, FT-IR, XPS, and an electronic single-filament tensile tester were used to study the structural, morphological, chemical, and mechanical properties of the CFs before and after the treatment. A theoretical model, namely “physical and chemical dual effects through layer-by-layer electrolytic etching”, was proposed to explain the improvements.

Effect of Fiber Surface Treatment on Wear Characteristics of Carbon Fiber Reinforced Polyamide 6 Composites

Ozone modification method and air-oxidation were used for the surface treatment of polyacrylonitrile(PAN)-based carbon fiber. The surface characteristics of carbon fibers were characterized by X-ray photoelectron spectroscopy (XPS). The interfacial properties of carbon fiber reinforced polyamide 6 (CF/PA6) composites were investigated by means of the single fiber pull-out tests. As a result, it was found that IFSS values of the composites with ozone treated carbon fiber are increased by 60% compared to that without treatment. XPS results show that ozone treatment increases the amount of carboxyl groups on carbon fiber surface, thus the interfacial adhesion between carbon fiber and PA6 matrix is effectively promoted. The effect of surface treatment of carbon fibers on the tribological properties of CF/PA6 composites was comparatively investigated. Experimental results revealed that surface treatment can effectively improve the wear resistance of CF/PA6.

Effect of surface oxidation treatment on the tribological performance of carbon fiber reinforced polyimide composites

AbstractThe effect of ozone surface treatment of carbon fibers (CF) on the tensile strength and tribological properties of carbon fiber reinforced polyimide (CF/PI) composite was investigated. Experimental results revealed that the tensile strength of ozone and air oxidation treated CF reinforced PI composite was improved compared with that of untreated composite. Compared with the untreated and air‐oxidated CF/PI composite, the ozone treated composite had the lowest friction coefficient and specific wear rate under given applied load and reciprocating sliding frequency. Ozone treatment effectively improved the interfacial adhesion between CF and PI. The strong interfacial adhesion of the composite made CF not easy to detach from the PI matrix, and prevented the rubbing‐off of PI, accordingly improved the friction and wear properties of the composite.

Effect of Carbon Fiber Surface Oxidation on Tribological Properties of PTFE Composite under Oil-Lubricated Conditions

Air-oxidation and ozone surface treatment of carbon fibers (CF) on tribological properties of CF reinforced polytetrafluoroethylene (PTFE) composites under oil-lubricated conditions was investigated. Experimental results revealed that ozone treated CF reinforced PTFE (CF/PTFE) composite had the lowest friction coefficient and wear under various applied loads and sliding speeds compared with untreated and air-oxidated composites. X-ray photoelectron spectroscopy (XPS) study of the carbon fiber surface showed that, after ozone treatment, oxygen concentration was obviously increased, and the amount of oxygen-containing groups on CF surfaces were increased greatly. The increase in the amount of oxygen-containing groups enhanced interfacial adhesion between CF and PTFE matrix, and large scale rubbing-off of PTFE was prevented; therefore, the tribological properties of the composite were improved.

A Review of Interphase Formation and Design in Fibre-Reinforced Composites

This paper reviews the surface treatment and sizing of reinforcing fibres used for manufacturing composites. Carbon fibre surface treatment and coating is discussed primarily to identify the mechanism of interphase formation. In this case, adsorption of sizing polymers is shown to be an integral part of the interaction with matrix polymers. ToFSIMS imaging was used to identify the locus of failure and confirm the nature of the interphase. In the case of glass fibres the hydrolysis of the silane coupling agent is shown to be critical. The surface chemistry of the glass controls the degree of polymerisation of the polysiloxane and hence the interaction with the matrix polymer whether it be thermoplastic or thermoset. For completeness a brief review of the surface treatments of advanced polymer fibres is also included. The role of the interphase in the micromechanics of the failure of fibre composites is also modelled and discussed in an attempt to provide design guidelines for composite manufacture.

The Tribological Properties of Oxidation-Treated Carbon Fiber-Reinforced PTFE Composite under Oil-Lubricated Conditions

The effect of air-oxidation and ozone surface treatment of carbon fibers (CF) on tribological properties of CF reinforced Polytetrafluoroethylene (PTFE) composites under oil-lubricated condition was investigated. Experimental results revealed that ozone treated CF reinforced PTFE (CF/PTFE) composite had the lowest friction coefficient and wear. X-ray photoelectron spectroscopy (XPS) study of carbon fiber surface showed that the increase in the amount of oxygen-containing groups enhanced interfacial adhesion between CF and PTFE matrix. With strong interfacial adhesion of the composite, stress could be effectively transmitted to carbon fibers; carbon fibers were strongly bonded with PTFE matrix.

The effect of carbon fibre surface oxidation on the friction and wear properties of polytetrafluoroethylene composites under oil-lubricated conditions

In this study, the effect of air oxidation and ozone surface treatment of carbon fibres (CFs) on tribological properties of CF-reinforced polytetrafluoroethylene (PTFE) composites under oil-lubricated condition was investigated. Experimental results revealed that ozone-treated CF-reinforced PTFE (CF/PTFE) composite had the lowest friction coefficient and wear compared with untreated and air-oxidated composites. An X-ray photoelectron spectroscopy study of the CF surface showed that, after ozone treatment, oxygen concentration was obviously increased, and the amount of oxygen-containing groups on CF surfaces was largely increased. The increase in the amount of oxygen-containing groups enhanced interfacial adhesion between CF and PTFE matrix. With strong interfacial adhesion of the composite, CFs were strongly bonded with PTFE matrix, and large-scale rubbing-off of PTFE was prevented; therefore, the tribological properties of the composite was improved.

Surface oxidation of carbon fibre on tribological properties of PEEK composites

In this work, ozone modification method and air oxidation were used for the surface treatment of polyacrylonitrile (PAN) based carbon fibre. The surface characteristics of carbon fibres were characterised by X-ray photoelectron spectroscopy. The interfacial properties of carbon fibre reinforced PEEK (CF/PEEK) composites were investigated by means of the single fibre pull-out tests. As a result, it was found that IFSS values of the composites with ozone treated carbon fibre are increased by 60% compared with that without treatment. X-ray photoelectron spectroscopy results show that ozone treatment increases the amount of carboxyl groups on carbon fibre surface, thus the interfacial adhesion between carbon fibre and PEEK matrix is effectively promoted. The effect of surface treatment of carbon fibres on the tribological properties of CF/PEEK composites was comparatively investigated. Experimental results revealed that surface treatment can effectively improve the interfacial adhesion between carbon fibre and PEEK matrix. Thus the wear resistance was significantly improved.

The research on the interfacial compatibility of polypropylene composite filled with surface treated carbon fiber

Dielectric barrier discharges (DBD) in ambient air are used on carbon fiber to improve the fiber surface activity. Carbon fibers with length of 75 μm are placed into the plasma configuration. The interaction between modified carbon fibers and polypropylene (PP) was studied by three-point bending (TPB) test. The chemical changes induced by the treatments on carbon fiber surface are examined using X-ray photoelectron spectroscopy (XPS). XPS results reveal that the carbon fiber modified with the DBD at atmospheric pressure show a significant increase in oxygen and nitrogen concentration. These results demonstrate that the surface of the carbon fiber is more active and hydrophilic after plasma treatments using a DBD operating in ambient air.