WorldWideScience

Sample records for carbon fiber polymer

  1. ELECTRODEPOSITION OF POLYMERS ON CARBON FIBERS

    Institute of Scientific and Technical Information of China (English)

    HE Jiasong; WU Renjie

    1983-01-01

    Styrene-co-maleic anhydride, vinyl acetate-co-maleic anhydride, methyl methacrylate-co-maleic anhydride copolymers were deposited on the surface of carbon fibers by an electrodeposition technique.The anion-free radical mechanism of this process and the physical adhesion to the surface were preliminarily confirmed. The adhesion at fiber-resin matrix interface in carbon fiber reinforced plastics was improved by the electrodeposited polymer interlayer and the shear failure occurred mainly in the matrix.Interlaminar shear strength of the unidirectional carbon fiber reinforced epoxy composite is increased from about 600 kg/cm2 to 1000 kg/cm2 by electrodeposition of polymers and the strength loss of the composite which has been immersed in boiling water for 100 hrs is decreased.

  2. Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Composites

    Science.gov (United States)

    Kang, Jin Ho; Cano, Roberto J.; Ratcliffe, James G.; Luong, Hoa; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strengthand stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Despite several attempts to solve these issues with the addition of carbon nanotubes (CNT) into polymer matrices, and/or by interleaving CNT sheets between conventional carbon fiber (CF) composite layers, there are still interfacial problems that exist between CNTs (or CF) and the resin. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing (double cantilever beam and end-notched flexure test). Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated. Interleaving CNT sheets significantly improved the in-plane (axial and perpendicular direction of CF alignment) thermal conductivity of the hybrid composite laminates by 50 - 400%.

  3. The dynamic response of carbon fiber-filled polymer composites

    OpenAIRE

    Patterson B.; Orler E.B.; Furmanski J.; Rigg P.A.; Scharff R.J.; Stahl D.B.; Sheffield S.A.; Gustavsen R.L.; Dattelbaum D.M.; Coe J.D.

    2012-01-01

    The dynamic (shock) responses of two carbon fiber-filled polymer composites have been quantified using gas gun-driven plate impact experimentation. The first composite is a filament-wound, highly unidirectional carbon fiber-filled epoxy with a high degree of porosity. The second composite is a chopped carbon fiber- and graphite-filled phenolic resin with little-to-no porosity. Hugoniot data are presented for the carbon fiber-epoxy (CE) composite to 18.6 GPa in the through-thickness direction,...

  4. Thermal Properties of Hybrid Carbon Nanotube/Carbon Fiber Polymer

    Science.gov (United States)

    Kang, Jin Ho; Cano, Roberto J.; Luong, Hoa; Ratcliffe, James G.; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    Carbon fiber reinforced polymer (CFRP) composites possess many advantages for aircraft structures over conventional aluminum alloys: light weight, higher strength- and stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low thermal and electrical conductivities of CFRP composites are deficient in providing structural safety under certain operational conditions such as lightning strikes. One possible solution to these issues is to interleave carbon nanotube (CNT) sheets between conventional carbon fiber (CF) composite layers. However, the thermal and electrical properties of the orthotropic hybrid CNT/CF composites have not been fully understood. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel (Registered Trademark) IM7/8852 prepreg. The CNT sheets were infused with a 5% solution of a compatible epoxy resin prior to composite fabrication. Orthotropic thermal and electrical conductivities of the hybrid polymer composites were evaluated. The interleaved CNT sheets improved the in-plane thermal conductivity of the hybrid composite laminates by about 400% and the electrical conductivity by about 3 orders of magnitude.

  5. On the nature of interface of carbon nanotube coated carbon fibers with different polymers

    Science.gov (United States)

    Singh Bedi, Harpreet; Padhee, Srikant S.; Agnihotri, Prabhat K.

    2016-07-01

    Experimental investigations are carried out to analyse the wetting behaviour of carbon nanotube (CNT) coated carbon fiber to determine their suitability to process carbon nanotube coated carbon fiber/polymer multiscale composites for structural applications. To overcome the problem of agglomeration, CNTs are grown directly on the surface of carbon fibers as well as fabric using thermal chemical vapour deposition (CVD) technique. The term multiscale is used because different reinforcement mechanisms operate at the scale of long fibers and CNTs which are of few micrometers in length. The load carrying capacity of these multiscale composites critically depends on the efficiency and extent of load transfer from low strength matrix to high strength fiber which in turn depends on the interfacial strength between CNT coated carbon fiber and polymer matrix. A systematic analysis of wetting behaviour of CNT coated carbon fiber with epoxy and polyester matrix is carried out in this study. It is shown that CNT coated carbon fibers as well as fabric show better wettability with epoxy matrix as compared to polyester matrix. This results in stronger interface of CNT coated carbon fiber with epoxy as compared to polyester in multiscale composite system. A similar observation is made in nanoindentation testing of single fiber multiscale composites processed with epoxy and polyester matrix. In addition, it is observed that wettability, interfacial strength and average properties of CNT coated carbon fiber/polymer composites are a function of CNT density on the surface of carbon fibers.

  6. The surface properties of carbon fibers and their adhesion to organic polymers

    Science.gov (United States)

    Bascom, W. D.; Drzal, L. T.

    1987-01-01

    The state of knowledge of the surface properties of carbon fibers is reviewed, with emphasis on fiber/matrix adhesion in carbon fiber reinforced plastics. Subjects treated include carbon fiber structure and chemistry, techniques for the study of the fiber surface, polymer/fiber bond strength and its measurement, variations in polymer properties in the interphase, and the influence of fiber matrix adhesion on composite mechanical properties. Critical issues are summarized and search recommendations are made.

  7. SURFACE MORPHOLOGY OF CARBON FIBER POLYMER COMPOSITES AFTER LASER STRUCTURING

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL; Chen, Jian [ORNL; Jones, Jonaaron F. [University of Tennessee (UT); Alexandra, Hackett [University of Tennessee (UT); Jellison Jr, Gerald Earle [ORNL; Daniel, Claus [ORNL; Warren, Charles David [ORNL; Rehkopf, Jackie D. [Plasan Carbon Composites

    2015-01-01

    The increasing use of Carbon Fiber Polymer Composite (CFPC) as a lightweight material in automotive and aerospace industries requires the control of surface morphology. In this study, the composites surface was prepared by ablating the resin in the top fiber layer of the composite using an Nd:YAG laser. The CFPC specimens with T700S carbon fiber and Prepreg - T83 resin (epoxy) were supplied by Plasan Carbon Composites, Inc. as 4 ply thick, 0/90o plaques. The effect of laser fluence, scanning speed, and wavelength was investigated to remove resin without an excessive damage of the fibers. In addition, resin ablation due to the power variation created by a laser interference technique is presented. Optical property measurements, optical micrographs, 3D imaging, and high-resolution optical profiler images were used to study the effect of the laser processing on the surface morphology.

  8. Polymer Coating of Carbon Nanotube Fibers for Electric Microcables

    Directory of Open Access Journals (Sweden)

    Noe T. Alvarez

    2014-11-01

    Full Text Available Carbon nanotubes (CNTs are considered the most promising candidates to replace Cu and Al in a large number of electrical, mechanical and thermal applications. Although most CNT industrial applications require macro and micro size CNT fiber assemblies, several techniques to make conducting CNT fibers, threads, yarns and ropes have been reported to this day, and improvement of their electrical and mechanical conductivity continues. Some electrical applications of these CNT conducting fibers require an insulating layer for electrical insulation and protection against mechanical tearing. Ideally, a flexible insulator such as hydrogenated nitrile butadiene rubber (HNBR on the CNT fiber can allow fabrication of CNT coils that can be assembled into lightweight, corrosion resistant electrical motors and transformers. HNBR is a largely used commercial polymer that unlike other cable-coating polymers such as polyvinyl chloride (PVC, it provides unique continuous and uniform coating on the CNT fibers. The polymer coated/insulated CNT fibers have a 26.54 μm average diameter—which is approximately four times the diameter of a red blood cell—is produced by a simple dip-coating process. Our results confirm that HNBR in solution creates a few microns uniform insulation and mechanical protection over a CNT fiber that is used as the electrically conducting core.

  9. The dynamic response of carbon fiber-filled polymer composites

    Directory of Open Access Journals (Sweden)

    Patterson B.

    2012-08-01

    Full Text Available The dynamic (shock responses of two carbon fiber-filled polymer composites have been quantified using gas gun-driven plate impact experimentation. The first composite is a filament-wound, highly unidirectional carbon fiber-filled epoxy with a high degree of porosity. The second composite is a chopped carbon fiber- and graphite-filled phenolic resin with little-to-no porosity. Hugoniot data are presented for the carbon fiber-epoxy (CE composite to 18.6 GPa in the through-thickness direction, in which the shock propagates normal to the fibers. The data are best represented by a linear Rankine-Hugoniot fit: Us = 2.87 + 1.17 ×up(ρ0 = 1.536g/cm3. The shock wave structures were found to be highly heterogeneous, both due to the anisotropic nature of the fiber-epoxy microstructure, and the high degree of void volume. Plate impact experiments were also performed on a carbon fiber-filled phenolic (CP composite to much higher shock input pressures, exceeding the reactants-to-products transition common to polymers. The CP was found to be stiffer than the filament-wound CE in the unreacted Hugoniot regime, and transformed to products near the shock-driven reaction threshold on the principal Hugoniot previously shown for the phenolic binder itself. [19] On-going research is focused on interrogating the direction-dependent dyanamic response and dynamic failure strength (spall for the CE composite in the TT and 0∘ (fiber directions.

  10. Defect depth measurement of carbon fiber reinforced polymers by thermography

    Science.gov (United States)

    Chen, Terry Y.; Chen, Jian-Lun

    2016-01-01

    Carbon fiber reinforced polymers has been widely used in all kind of the industries. However the internal defects can result in the change of material or mechanical properties, and cause safety problem. In this study, step-heating thermography is employed to measure the time series temperature distribution of composite plate. The principle of heat conduction in a flat plate with defect inside is introduced. A temperature separation criterion to determine the depth of defect inside the specimen is obtained experimentally. Applying this criterion to CFRP specimens with embedded defects, the depth of embedded defect in CFRP can be determined quite well from the time series thermograms obtained experimentally.

  11. Carbon Fiber Reinforced Polymer for Cable Structures—A Review

    Directory of Open Access Journals (Sweden)

    Yue Liu

    2015-10-01

    Full Text Available Carbon Fiber Reinforced Polymer (CFRP is an advanced composite material with the advantages of high strength, lightweight, no corrosion and excellent fatigue resistance. Therefore, unidirectional CFRP has great potential for cables and to replace steel cables in cable structures. However, CFRP is a typical orthotropic material and its strength and modulus perpendicular to the fiber direction are much lower than those in the fiber direction, which brings a challenge for anchoring CFRP cables. This paper presents an overview of application of CFRP cables in cable structures, including historical review, state of the art and prospects for the future. After introducing properties of carbon fibers, mechanical characteristics and structural forms of CFRP cables, existing CFRP cable structures in the world (all of them are cable bridges are reviewed. Especially, their CFRP cable anchorages are presented in detail. New applications for CFRP cables, i.e., cable roofs and cable facades, are also presented, including the introduction of a prototype CFRP cable roof and the conceptual design of a novel structure—CFRP Continuous Band Winding System. In addition, other challenges that impede widespread application of CFRP cable structures are briefly introduced.

  12. New generation fiber reinforced polymer composites incorporating carbon nanotubes

    Science.gov (United States)

    Soliman, Eslam

    The last five decades observed an increasing use of fiber reinforced polymer (FRP) composites as alternative construction materials for aerospace and infrastructure. The high specific strength of FRP attracted its use as non-corrosive reinforcement. However, FRP materials were characterized with a relatively low ductility and low shear strength compared with steel reinforcement. On the other hand, carbon nanotubes (CNTs) have been introduced in the last decade as a material with minimal defect that is capable of increasing the mechanical properties of polymer matrices. This dissertation reports experimental investigations on the use of multi-walled carbon nanotubes (MWCNTs) to produce a new generation of FRP composites. The experiments showed significant improvements in the flexure properties of the nanocomposite when functionalized MWCNTs were used. In addition, MWCNTs were used to produce FRP composites in order to examine static, dynamic, and creep behavior. The MWCNTs improved the off-axis tension, off-axis flexure, FRP lap shear joint responses. In addition, they reduced the creep of FRP-concrete interface, enhanced the fracture toughness, and altered the impact resistance significantly. In general, the MWCNTs are found to affect the behaviour of the FRP composites when matrix failure dominates the behaviour. The improvement in the mechanical response with the addition of low contents of MWCNTs would benefit many industrial and military applications such as strengthening structures using FRP composites, composite pipelines, aircrafts, and armoured vehicles.

  13. Ceramic silicon-boron-carbon fibers from organic silicon-boron-polymers

    Science.gov (United States)

    Riccitiello, Salvatore R. (Inventor); Hsu, Ming-Ta S. (Inventor); Chen, Timothy S. (Inventor)

    1993-01-01

    Novel high strength ceramic fibers derived from boron, silicon, and carbon organic precursor polymers are discussed. The ceramic fibers are thermally stable up to and beyond 1200 C in air. The method of preparation of the boron-silicon-carbon fibers from a low oxygen content organosilicon boron precursor polymer of the general formula Si(R2)BR(sup 1) includes melt-spinning, crosslinking, and pyrolysis. Specifically, the crosslinked (or cured) precursor organic polymer fibers do not melt or deform during pyrolysis to form the silicon-boron-carbon ceramic fiber. These novel silicon-boron-carbon ceramic fibers are useful in high temperature applications because they retain tensile and other properties up to 1200 C, from 1200 to 1300 C, and in some cases higher than 1300 C.

  14. Thermal diffusivity measurements on porous carbon fiber reinforced polymer tubes

    Science.gov (United States)

    Gruber, Jürgen; Gresslehner, Karl Heinz; Mayr, Günther; Hendorfer, Günther

    2017-02-01

    This work presents the application of methods for the determination of the thermal diffusivity well suited for flat bodies adapted to cylindrical bodies. Green's functions were used to get the temperature time history for small and large times, for the approach of intersecting these two straight lines. To verify the theoretical considerations noise free data are generated by finite element simulations. Furthermore effects of inhomogeneous excitation and the anisotropic heat conduction of carbon fiber reinforced polymers were taken into account in these numerical simulations. It could be shown that the intersection of the two straight lines is suitable for the determination of the thermal diffusivity, although the results have to be corrected depending on the ratio of the cylinders inner and outer radii. Inhomogeneous excitation affects the results of this approach as it lead to multidimensional heat flux. However, based on the numerical simulations a range of the azimuthal angle exists, where the thermal diffusivity is nearly independent of the angle. The method to determine the thermal diffusivity for curved geometries by the well suited Thermographic Signal Reconstruction method and taking into account deviations from the slab by a single correction factor has great advantages from an industrial point of view, just like an easy implementation into evaluation software and the Thermographic Signal Reconstruction methods rather short processing time.

  15. Shockwave response of two carbon fiber-polymer composites to 50 GPa

    Science.gov (United States)

    Dattelbaum, Dana M.; Coe, Joshua D.; Rigg, Paulo A.; Scharff, R. Jason; Gammel, J. Tinka

    2014-11-01

    Shock compression of two molded, carbon fiber-filled polymer composites was performed in gas gun-driven plate impact experiments at impact velocities up to ≈5 km/s. Hugoniot states for both composites were obtained from chopped carbon fibers, bound by either phenolic or cyanate ester polymeric resins. Their dynamic responses were similar, although the 10 wt. % difference of carbon fill produced measureable divergence in shock compressibility. The chopped carbon fibers in the polymer matrix led to moderately anisotropic shocks, particularly when compared with the more commonly encountered filament-wound carbon fiber-epoxy composites. A discontinuity, or cusp, was observed in the principal Hugoniot of both materials near 25 GPa. We attribute the accompanying volume collapse to shock-driven chemical decomposition above this condition. Inert and reacted products equations of state were used to capture the response of the two materials below and above the cusp.

  16. Bio-inspired hierarchical polymer fiber-carbon nanotube adhesives.

    Science.gov (United States)

    Rong, Zhuxia; Zhou, Yanmin; Chen, Bingan; Robertson, John; Federle, Walter; Hofmann, Stephan; Steiner, Ullrich; Goldberg-Oppenheimer, Pola

    2014-03-01

    Hierarchical pillar arrays consisting of micrometer-sized polymer setae covered by carbon nanotubes are engineered to deliver the role of spatulae, mimicking the fibrillar adhesive surfaces of geckos. These biomimetic structures conform well and achieve better attachment to rough surfaces, providing a new platform for a variety of applications.

  17. Effect of anodic surface treatment on PAN-based carbon fiber and its relationship to the fracture toughness of the carbon fiber-reinforced polymer composites

    DEFF Research Database (Denmark)

    Sarraf, Hamid; Skarpova, Ludmila

    2008-01-01

    The effect of anodic surface treatment on the polyacrylonitrile (PAN)-based carbon fibers surface properties and the mechanical behavior of the resulting carbon fiber-polymer composites has been studied in terms of the contact angle measurements of fibers and the fracture toughness of composites...... in the fiber surface nature and the mechanical interfacial properties between the carbon fiber and epoxy resin matrix of the resulting composites, i.e., the fracture toughness. We suggest that good wetting plays an important role in improving the degree of adhesion at interfaces between fibers and matrices...

  18. Properties of Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Matrix Composites

    Science.gov (United States)

    Cano, Roberto J.; Kang, Jin Ho; Grimsley, Brian W.; Ratcliffe, James G.; Siochi, Emilie J.

    2016-01-01

    For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strength- and stiffness-to-weight ratios, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Carbon nanotubes (CNT) offer the potential to enhance the multi-functionality of composites with improved thermal and electrical conductivity. In this study, hybrid CNT/carbon fiber (CF) polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing. Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated.

  19. Polymer-derived ceramic composite fibers with aligned pristine multiwalled carbon nanotubes.

    Science.gov (United States)

    Sarkar, Sourangsu; Zou, Jianhua; Liu, Jianhua; Xu, Chengying; An, Linan; Zhai, Lei

    2010-04-01

    Polymer-derived ceramic fibers with aligned multiwalled carbon nanotubes (MWCNTs) are fabricated through the electrospinning of polyaluminasilazane solutions with well-dispersed MWCNTs followed by pyrolysis. Poly(3-hexylthiophene)-b-poly (poly (ethylene glycol) methyl ether acrylate) (P3HT-b-PPEGA), a conjugated block copolymer compatible with polyaluminasilazane, is used to functionalize MWCNT surfaces with PPEGA, providing a noninvasive approach to disperse carbon nanotubes in polyaluminasilazane chloroform solutions. The electrospinning of the MWCNT/polyaluminasilazane solutions generates polymer fibers with aligned MWCNTs where MWCNTs are oriented along the electrospun jet by a sink flow. The subsequent pyrolysis of the obtained composite fibers produces ceramic fibers with aligned MWCNTs. The study of the effect of polymer and CNT concentration on the fiber structures shows that the fiber size increases with the increment of polymer concentration, whereas higher CNT content in the polymer solutions leads to thinner fibers attributable to the increased conductivity. Both the SEM and TEM characterization of the polymer and ceramic fibers demonstrates the uniform orientation of CNTs along the fibers, suggesting excellent dispersion of CNTs and efficient CNT alignment via the electrospinning. The electrical conductivity of a ceramic fibers with 1.2% aligned MWCNTs is measured to be 1.58 x 10(-6) S/cm, which is more than 500 times higher than that of bulk ceramic (3.43 x 10(-9) S/cm). Such an approach provides a versatile method to disperse CNTs in preceramic polymer solutions and offers a new approach to integrate aligned CNTs in ceramics.

  20. Bisphenyl-Polymer/Carbon-Fiber-Reinforced Composite Compared to Titanium Alloy Bone Implant

    Directory of Open Access Journals (Sweden)

    Richard C. Petersen

    2011-01-01

    Full Text Available Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resistivity properties close to bone with strengths much higher than metals on a per-weight basis. In vivo bone-marrow tests with Sprague-Dawley rats revealed far-reaching significant osseoconductivity increases from bisphenyl-polymer/carbon-fiber composites when compared to state-of-the-art titanium-6-4 alloy controls. Midtibial percent bone area measured from the implant surface increased when comparing the titanium alloy to the polymer composite from 10.5% to 41.6% at 0.8 mm, P<10−4, and 19.3% to 77.7% at 0.1 mm, P<10−8. Carbon-fiber fragments planned to occur in the test designs, instead of producing an inflammation, stimulated bone formation and increased bone integration to the implant. In addition, low-thermal polymer processing allows incorporation of minerals and pharmaceuticals for future major tissue-engineering potential.

  1. Carbon nanotube/polymer composite coated tapered fiber for four wave mixing based wavelength conversion.

    Science.gov (United States)

    Xu, Bo; Omura, Mika; Takiguchi, Masato; Martinez, Amos; Ishigure, Takaaki; Yamashita, Shinji; Kuga, Takahiro

    2013-02-11

    In this paper, we demonstrate a nonlinear optical device based on a fiber taper coated with a carbon nanotube (CNT)/polymer composite. Using this device, four wave mixing (FWM) based wavelength conversion of 10 Gb/s Non-return-to-zero signal is achieved. In addition, we investigate wavelength tuning, two photon absorption and estimate the effective nonlinear coefficient of the CNTs embedded in the tapered fiber to be 1816.8 W(-1)km(-1).

  2. Strain Measurement Using Embedded Fiber Bragg Grating Sensors Inside an Anchored Carbon Fiber Polymer Reinforcement Prestressing Rod for Structural Monitoring

    DEFF Research Database (Denmark)

    Kerrouche, Abdelfateh; Boyle, William J.O.; Sun, Tong

    2009-01-01

    Results are reported from a study carried out using a series of Bragg grating based optical fiber sensors written into a very short length (60mm) optical fiber net work and integrated into carbon fiber polymer reinforcement (CFPR) rod. Such rods are used as reinforcements in concrete structures...... from the calibrated force applied by the pulling machine and from a conventional resistive strain gauge mounted on the rod itself is obtained. Calculations from strain to shear stress show a relatively uniform stress distribution along the bar anchor used. The results give confidence to results from...... various methods of insitu monitoring of strains on such CFRP rods when used in different engineering structures....

  3. Surface Characterization of Carbon Fiber Polymer Composites and Aluminum Alloys After Laser Interference Structuring

    Science.gov (United States)

    Sabau, Adrian S.; Greer, Clayton M.; Chen, Jian; Warren, Charles D.; Daniel, Claus

    2016-07-01

    The increasing use of carbon fiber-reinforced polymer matrix composites (CFPC) and aluminum alloys as lightweight materials in the automotive and aerospace industries demands enhanced surface preparation and control of surface morphology prior to joining. In this study, surfaces of both composite and aluminum were prepared for joining using an Nd:YAG laser in a two-beam interference setup, enabling the (1) structuring of the AL 5182 surface, (2) removal of the resin layer on top of carbon fibers, and (3) structuring of the carbon fibers. CFPC specimens of T700S carbon fiber, Prepreg—T83 epoxy, 5 ply thick, 0°/90° plaques were used. The effects of laser fluence, scanning speed, and number of shots-per-spot were investigated on the removal rate of the resin without an excessive damage of the fibers. Optical micrographs, 3D imaging, and scanning electron microscope imaging were used to study the effect of the laser processing on the surface morphology. It was found that an effective resin ablation and a low density of broken fibers for CFPC specimens was attained using laser fluences of 1-2 J/cm2 and number of 2-4 pulses per spot. A relatively large area of periodic line structures due to energy interference were formed on the aluminum surface at laser fluences of 12 J/cm2 and number of 4-6 pulses per spot.

  4. Interlaminar damage of carbon fiber reinforced polymer composite laminate under continuous wave laser irradiation

    Science.gov (United States)

    Liu, Yan-Chi; Wu, Chen-Wu; Huang, Yi-Hui; Song, Hong-Wei; Huang, Chen-Guang

    2017-01-01

    The interlaminar damages were investigated on the carbon fiber reinforced polymer (CFRP) composite laminate under laser irradiation. Firstly, the laminated T700/BA9916 composites were exposed to continuous wave laser irradiation. Then, the interface cracking patterns of such composite laminates were examined by optical microscopy and scanning electron microscopy. Finally, the Finite Element Analysis (FEA) was performed to compute the interface stress of the laminates under laser irradiation. And the effects of the laser parameters on the interlaminar damage were discussed.

  5. Modal analysis of additive manufactured carbon fiber reinforced polymer composite framework: Experiment and modeling

    Science.gov (United States)

    Dryginin, N. V.; Krasnoveikin, V. A.; Filippov, A. V.; Tarasov, S. Yu.; Rubtsov, V. E.

    2016-11-01

    Additive manufacturing by 3D printing is the most advanced and promising trend for making the multicomponent composites. Polymer-based carbon fiber reinforced composites demonstrate high mechanical properties combined with low weight characteristics of the component. This paper shows the results of 3D modeling and experimental modal analysis on a polymer composite framework obtained using additive manufacturing. By the example of three oscillation modes it was shown the agreement between the results of modeling and experimental modal analysis with the use of laser Doppler vibrometry.

  6. Influence of Carbon & Glass Fiber Reinforcements on Flexural Strength of Epoxy Matrix Polymer Hybrid Composites

    Directory of Open Access Journals (Sweden)

    T.D. Jagannatha

    2015-04-01

    Full Text Available Hybrid composite materials are more attracted by the engineers because of their properties like stiffness and high specific strength which leads to the potential application in the area of aerospace, marine and automobile sectors. In the present investigation, the flexural strength and flexural modulus of carbon and glass fibers reinforced epoxy hybrid composites were studied. The vacuum bagging technique was adopted for the fabrication of polymer hybrid composite materials. The hardness, flexural strength and flexural modulus of the hybrid composites were determined as per ASTM standards. The hardness, flexural strength and flexural modulus were improved as the fiber reinforcement contents increased in the epoxy matrix material.

  7. Experimental analysis of reinforced concrete beams strengthened in bending with carbon fiber reinforced polymer

    Directory of Open Access Journals (Sweden)

    M. M. VIEIRA

    Full Text Available The use of carbon fiber reinforced polymer (CFRP has been widely used for the reinforcement of concrete structures due to its practicality and versatility in application, low weight, high tensile strength and corrosion resistance. Some construction companies use CFRP in flexural strengthening of reinforced concrete beams, but without anchor systems. Therefore, the aim of this study is analyze, through an experimental program, the structural behavior of reinforced concrete beams flexural strengthened by CFRP without anchor fibers, varying steel reinforcement and the amount of carbon fibers reinforcement layers. Thus, two groups of reinforced concrete beams were produced with the same geometric feature but with different steel reinforcement. Each group had five beams: one that is not reinforced with CFRP (reference and other reinforced with two, three, four and five layers of carbon fibers. Beams were designed using a computational routine developed in MAPLE software and subsequently tested in 4-point points flexural test up to collapse. Experimental tests have confirmed the effectiveness of the reinforcement, ratifying that beams collapse at higher loads and lower deformation as the amount of fibers in the reinforcing layers increased. However, the increase in the number of layers did not provide a significant increase in the performance of strengthened beams, indicating that it was not possible to take full advantage of strengthening applied due to the occurrence of premature failure mode in the strengthened beams for pullout of the cover that could have been avoided through the use of a suitable anchoring system for CFRP.

  8. Thermoplastic coating of carbon fibers

    Science.gov (United States)

    Edie, D. D.; Lickfield, G. C.; Drews, M. J.; Ellison, M. S.; Gantt, B. W.

    1989-01-01

    A process is being developed which evenly coats individual carbon fibers with thermoplastic polymers. In this novel, continuous coating process, the fiber tow bundle is first spread cover a series of convex rollers and then evenly coated with a fine powder of thermoplastic matrix polymer. Next, the fiber is heated internally by passing direct current through the powder coated fiber. The direct current is controlled to allow the carbon fiber temperature to slightly exceed the flow temperature of the matrix polymer. Analysis of the thermoplastic coated carbon fiber tows produced using this continuous process indicates that 30 to 70 vol pct fiber prepregs can be obtained.

  9. 3D-Printing of Meso-structurally Ordered Carbon Fiber/Polymer Composites with Unprecedented Orthotropic Physical Properties

    Science.gov (United States)

    Lewicki, James P.; Rodriguez, Jennifer N.; Zhu, Cheng; Worsley, Marcus A.; Wu, Amanda S.; Kanarska, Yuliya; Horn, John D.; Duoss, Eric B.; Ortega, Jason M.; Elmer, William; Hensleigh, Ryan; Fellini, Ryan A.; King, Michael J.

    2017-01-01

    Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignment within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Furthermore, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response. PMID:28262669

  10. 3D-Printing of Meso-structurally Ordered Carbon Fiber/Polymer Composites with Unprecedented Orthotropic Physical Properties

    Science.gov (United States)

    Lewicki, James P.; Rodriguez, Jennifer N.; Zhu, Cheng; Worsley, Marcus A.; Wu, Amanda S.; Kanarska, Yuliya; Horn, John D.; Duoss, Eric B.; Ortega, Jason M.; Elmer, William; Hensleigh, Ryan; Fellini, Ryan A.; King, Michael J.

    2017-03-01

    Here we report the first example of a class of additively manufactured carbon fiber reinforced composite (AMCFRC) materials which have been achieved through the use of a latent thermal cured aromatic thermoset resin system, through an adaptation of direct ink writing (DIW) 3D-printing technology. We have developed a means of printing high performance thermoset carbon fiber composites, which allow the fiber component of a resin and carbon fiber fluid to be aligned in three dimensions via controlled micro-extrusion and subsequently cured into complex geometries. Characterization of our composite systems clearly show that we achieved a high order of fiber alignment within the composite microstructure, which in turn allows these materials to outperform equivalently filled randomly oriented carbon fiber and polymer composites. Furthermore, our AM carbon fiber composite systems exhibit highly orthotropic mechanical and electrical responses as a direct result of the alignment of carbon fiber bundles in the microscale which we predict will ultimately lead to the design of truly tailorable carbon fiber/polymer hybrid materials having locally programmable complex electrical, thermal and mechanical response.

  11. SiC fibers with controllable thickness of carbon layer prepared directly by preceramic polymer pyrolysis routes

    Energy Technology Data Exchange (ETDEWEB)

    Hu Tianjiao, E-mail: tjhu617@gmail.com [College of Science, National University of Defense Technology, Changsha 410073 (China); Li Xiaodong; Li Gongyi [College of Science, National University of Defense Technology, Changsha 410073 (China); Wang Yingde; Wang Jun [State Key Laboratory of Advanced Ceramic Fibers and Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073 (China)

    2011-05-25

    Continuous SiC fibers with different thickness of carbon layer were prepared through three preceramic polymer pyrolysis routes. To make the carbon layer thickness controllable, a simple improvement by using a ceramic bushing was adopted to retard the deposition of the pyrolytic carbons. Auger electron spectroscopy (AES) analysis reveals that the carbon layer thickness varies from less than 5 nm to 40 nm. The specific resistivity of the fibers increases by 5 orders of magnitude as the carbon layer thickness decreases. All of the fibers exhibit a tensile strength of around 1.8 GPa which is independent of the carbon layer thickness. The formation process of the carbon layer is discussed in three steps: the decomposition, the carbonization and the deposition. The as-received fibers have a potential application as the reinforcement of functional materials.

  12. AE analysis of delamination crack propagation in carbon fiber-reinforced polymer materials

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Sang Jae; Arakawa, Kazuo [Kyushu University, kasuga (Japan); Chen, Dingding [National University of Defense Technology, Changsha (China); Han, Seung Wook; Choi, Nak Sam [Hanyang University, Seoul (Korea, Republic of)

    2015-01-15

    Delamination fracture behavior was investigated using acoustic emission (AE) analysis on carbon fiber-reinforced polymer (CFRP) samples manufactured using vacuum-assisted resin transfer molding (VARTM). CFRP plate was fabricated using unidirectional carbon fiber fabric with a lay-up of six plies [+30/-30]6 , and a Teflon film was inserted as a starter crack. Test pieces were sectioned from the inlet and vent of the mold, and packed between two rectangular epoxy plates to load using a universal testing machine. The AE signals were monitored during tensile loading using two sensors. The average tensile load of the inlet specimens was slightly larger than that of the vent specimens; however, the data exhibited significant scattering due to non-uniform resin distribution, and there was no statistically significant different between the strength of the samples sectioned from the inlet or outlet of the mold. Each of the specimens exhibited similar AE characteristics, regardless of whether they were from the inlet or vent of the mold. Four kinds of damage mechanism were observed: micro-cracking, fiber-resin matrix debonding, fiber pull-out, and fiber failure; and three stages of the crack propagation process were identified.

  13. Ligament and tendon repair with an absorbable polymer-coated carbon fiber stent.

    Science.gov (United States)

    Alexander, H; Weiss, A B; Parsons, J R

    1986-01-01

    Ribbon-like composite structures of filamentous carbon fiber and absorbable polymers have been used in the repair and replacement of both tendons and ligaments. The composite acts as a scaffold upon which new collagenous tissue can grow and has proved successful in a variety of animal models. The results of the first three years of human clinical trials have revealed ingrowth potential similar to that seen in the animal studies. Most patients have shown significant improvement, with many demonstrating good to excellent stability and function.

  14. Experimental study on fire protection methods of reinforced concrete beams strengthened with carbon fiber reinforced polymer

    Institute of Scientific and Technical Information of China (English)

    HU Kexu; HE Guisheng; LU Fan

    2007-01-01

    In this paper,two reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymer (CFRP)and attached with thick-painted fire resistant coating were tested for fire resistance following the standard fire testing procedures.The experimental results show that the specimen pasted with the insulated layer of 50 mm in thickness could resist fire for 2.5 h.It is also demonstrated that the steel wire mesh embedded in the insulated layer can effectively prevent it from cracking and eroding under firing.

  15. Durability of carbon fiber reinforced shape memory polymer composites in space

    Science.gov (United States)

    Jang, Joon Hyeok; Hong, Seok Bin; Ahn, Yong San; Kim, Jin-Gyun; Nam, Yong-Youn; Lee, Geun Ho; Yu, Woong-Ryeol

    2016-04-01

    Shape memory polymer (SMP) is one of smart polymers which exhibit shape memory effect upon external stimuli. Recently, shape memory polymer composites (SMPCs) have been considered for space structure instead of shape memory alloys due to their deformability, lightweight and large recovery ratio, requiring characterization of their mechanical properties against harsh space environment and further prediction of the durability of SMPCs in space. As such, the durability of carbon fiber reinforced shape memory polymer composites (CF-SMPCs) was investigated using accelerated testing method based on short-term testing of CF-SMPCs in harsh condition. CF-SMPCs were prepared using woven carbon fabrics and a thermoset SMP via vacuum assisted resin transfer molding process. Bending tests with constant strain rate of CF-SMPCs were conducted using universal tensile machine (UTM) and Storage modulus test were conducted using dynamic mechanical thermal analysis (DMTA). Using the results, a master curve based on time-temperature superposition principle was then constructed, through which the mechanical properties of CF-SMPCs at harsh temperature were predicted. CF-SMPCs would be exposed to simulated space environments under ultra-violet radiations at various temperatures. The mechanical properties including flexural and tensile strength and shape memory properties of SMPCs would be measured using UTM before and after such exposures for comparison. Finally, the durability of SMPCs in space would be assessed by developing a degradation model of SMPC.

  16. Moment redistribution in continuous reinforced concrete beams strengthened with carbon-fiber-reinforced polymer laminates

    Science.gov (United States)

    Aiello, M. A.; Valente, L.; Rizzo, A.

    2007-09-01

    The results of tests on continuous steel-fiber-reinforced concrete (RC) beams, with and without an external strengthening, are presented. The internal flexural steel reinforcement was designed so that to allow steel yielding before the collapse of the beams. To prevent the shear failure, steel stirrups were used. The tests also included two nonstrengthened control beams; the other specimens were strengthened with different configurations of externally bonded carbon-fiber-reinforced polymer (CFRP) laminates. In order to prevent the premature failure from delamination of the CFRP strengthening, a wrapping was also applied. The experimental results obtained show that it is possible to achieve a sufficient degree of moment redistribution if the strengthening configuration is chosen properly, confirming the results provided by two simple numerical models.

  17. Shear strengthening of pre-damaged reinforced concrete beams with carbon fiber reinforced polymer sheet strips

    Institute of Scientific and Technical Information of China (English)

    Feras ALZOUBI; ZHANG Qi; LI Zheng-liang

    2007-01-01

    This paper presents the results of an experimental investigation on the response of pre-damaged reinforced concrete (RC) beam strengthened in shear using applied-epoxy unidirectional carbon fiber reinforced polymer (CFRP) sheet. The reasearch included four test rectangular simply supported RC beams in shear capacity. One is the control beam, two RC beams are damaged to a predetermined degree from ultimate shear capacity of the control beam, and the last beam is left without pre-damaged and then strengthened with using externally bonded carbon fiber reinforced polymer to upgrade their shear capacity. We focused on the damage degree to beams during strengthening, therefore, only the beams with side-bonded CFRPs strips and horizontal anchored strips were used. The results show the feasibility of using CFRPs to restore or increase the load-carrying capacity in the shear of damaged RC beams. The failure mode of all the CFRP-strengthened beams is debonding of CFRP vertical strips. Two prediction available models in ACI-440 and fib European code were compared with the experimental results.

  18. Using in-situ polymerization of conductive polymers to enhance the electrical properties of solution-processed carbon nanotube films and fibers.

    Science.gov (United States)

    Allen, Ranulfo; Pan, Lijia; Fuller, Gerald G; Bao, Zhenan

    2014-07-09

    Single-walled carbon nanotubes/polymer composites typically have limited conductivity due to a low concentration of nanotubes and the insulating nature of the polymers used. Here we combined a method to align carbon nanotubes with in-situ polymerization of conductive polymer to form composite films and fibers. Use of the conducting polymer raised the conductivity of the films by 2 orders of magnitude. On the other hand, CNT fiber formation was made possible with in-situ polymerization to provide more mechanical support to the CNTs from the formed conducting polymer. The carbon nanotube/conductive polymer composite films and fibers had conductivities of 3300 and 170 S/cm, respectively. The relatively high conductivities were attributed to the polymerization process, which doped both the SWNTs and the polymer. In-situ polymerization can be a promising solution-processable method to enhance the conductivity of carbon nanotube films and fibers.

  19. ANALYTIC INVESTIGATIONS OF CARBON FIBER REINFORCED POLYMER STIFFENED CYLINDRICAL SUBMARINE HULL

    Directory of Open Access Journals (Sweden)

    ALICE MATHAI

    2013-07-01

    Full Text Available A submarine is any naval vessel that is capable of propelling itself beneath the water as well as on the water surface. Submersibles are capable of operating for extended period of time underwater and are subjected to heavy hydrostatic pressure. The conventional submarines made up of high strength steel and concrete prevents them from going to greater depth owing to its large dead weight. In the present work, the pressure hull of submarine is considered both in isotropic and composite material. Materials that have high strength to weight ratio include carbon fibre composites. Carbon-fibre reinforced polymer (CFRP is a very strong and light weight fibre reinforced polymer containing carbon fibers on various orientations. It has many applications in aerospace and automotive fields. A parametric study is conducted to find the optimum ply orientation by employing FiniteElement Analysis Software package, ANSYS. Also linear and nonlinear buckling analysis is used to predict the feasibility of CFRP submarine at the deep waters. From the studies conducted regarding the weight reduction, it is estimated that by replacing steel by CFRP results in saving of 67% in the structural weight.

  20. Wet spinning of continuous polymer-free carbon-nanotube fibers with high electrical conductivity and strength

    Science.gov (United States)

    Mukai, Ken; Asaka, Kinji; Wu, Xueli; Morimoto, Takahiro; Okazaki, Toshiya; Saito, Takeshi; Yumura, Motoo

    2016-05-01

    We report on the fabrication of polymer-free carbon nanotube (CNT) fibers by a novel wet spinning method combined with a very easy and straightforward fabrication process. These fibers exhibited high electrical conductivity (14,284 ± 169 S·cm-1) and tensile strength (887 ± 37 MPa). Such high performance was made possible by the preparation of free-standing CNT fibers from a surfactant solution containing uniformly dispersed CNTs, despite the use of an organic coagulating solvent and subsequent stretching to align the CNTs in the fiber.

  1. Carbon fiber polymer-matrix structural composites for electrical-resistance-based sensing

    Science.gov (United States)

    Wang, Daojun

    This dissertation has advanced the science and technology of electrical-resistance-based sensing of strain/stress and damage using continuous carbon fiber epoxy-matrix composites, which are widely used for aircraft structures. In particular, it has extended the technology of self-sensing of carbon fiber polymer-matrix composites from uniaxial longitudinal loading and flexural loading to uniaxial through-thickness loading and has extended the technology from structural composite self-sensing to the use of the composite (specifically a one-lamina composite) as an attached sensor. Through-thickness compression is encountered in the joining of composite components by fastening. Uniaxial through-thickness compression results in strain-induced reversible decreases in the through-thickness and longitudinal volume resistivities, due to increase in the fiber-fiber contact in the through-thickness direction, and minor-damage-induced irreversible changes in these resistivities. The Poisson effect plays a minor role. The effects in the longitudinal resistivity are small compared to those in the through-thickness direction, but longitudinal resistance measurement is more amenable to practical implementation in structures than through-thickness resistance measurement. The irreversible effects are associated with an increase in the through-thickness resistivity and a decrease in the longitudinal resistivity. The through-thickness gage factor is up to 5.1 and decreases with increasing compressive strain above 0.2%. The reversible fractional change in through-thickness resistivity per through-thickness strain is up to 4.0 and decreases with increasing compressive strain. The irreversible fractional change in through-thickness resistivity per unit through-thickness strain is around -1.1 and is independent of the strain. The sensing is feasible by measuring the resistance away from the stressed region, though the effectiveness is less than that at the stressed region. A one

  2. Electrical impedance spectroscopy for measuring the impedance response of carbon-fiber-reinforced polymer composite laminates

    KAUST Repository

    Almuhammadi, Khaled

    2017-02-16

    Techniques that monitor the change in the electrical properties of materials are promising for both non-destructive testing and structural health monitoring of carbon-fiber-reinforced polymers (CFRPs). However, achieving reliable monitoring using these techniques requires an in-depth understanding of the impedance response of these materials when subjected to an alternating electrical excitation, information that is only partially available in the literature. In this work, we investigate the electrical impedance spectroscopy response at various frequencies of laminates chosen to be representative of classical layups employed in composite structures. We clarify the relationship between the frequency of the electrical current, the conductivity of the surface ply and the probing depth for different CFRP configurations for more efficient electrical signal-based inspections. We also investigate the effect of the amplitude of the input signal.

  3. Influence of attenuation on acoustic emission signals in carbon fiber reinforced polymer panels.

    Science.gov (United States)

    Asamene, Kassahun; Hudson, Larry; Sundaresan, Mannur

    2015-05-01

    Influence of attenuation on acoustic emission (AE) signals in Carbon Fiber Reinforced Polymer (CFRP) crossply and quasi-isotropic panels is examined in this paper. Attenuation coefficients of the fundamental antisymmetric (A0) and symmetric (S0) wave modes were determined experimentally along different directions for the two types of CFRP panels. In the frequency range from 100 kHz to 500 kHz, the A0 mode undergoes significantly greater changes due to material related attenuation compared to the S0 mode. Moderate to strong changes in the attenuation levels were noted with propagation directions. Such mode and frequency dependent attenuation introduces major changes in the characteristics of AE signals depending on the position of the AE sensor relative to the source. Results from finite element simulations of a microscopic damage event in the composite laminates are used to illustrate attenuation related changes in modal and frequency components of AE signals.

  4. Nondestructive Evaluation of Carbon Fiber Reinforced Polymer Composites Using Reflective Terahertz Imaging

    Directory of Open Access Journals (Sweden)

    Jin Zhang

    2016-06-01

    Full Text Available Terahertz (THz time-domain spectroscopy (TDS imaging is considered a nondestructive evaluation method for composite materials used for examining various defects of carbon fiber reinforced polymer (CFRP composites and fire-retardant coatings in the reflective imaging modality. We demonstrate that hidden defects simulated by Teflon artificial inserts are imaged clearly in the perpendicular polarization mode. The THz TDS technique is also used to measure the thickness of thin fire-retardant coatings on CFRP composites with a typical accuracy of about 10 micrometers. In addition, coating debonding is successfully imaged based on the time-delay difference of the time-domain waveforms between closely adhered and debonded sample locations.

  5. Strength Analysis of the Carbon-Fiber Reinforced Polymer Impeller Based on Fluid Solid Coupling Method

    Directory of Open Access Journals (Sweden)

    Jinbao Lin

    2014-01-01

    Full Text Available Carbon-fiber reinforced polymer material impeller is designed for the centrifugal pump to deliver corrosive, toxic, and abrasive media in the chemical and pharmaceutical industries. The pressure-velocity coupling fields in the pump are obtained from the CFD simulation. The stress distribution of the impeller couple caused by the flow water pressure and rotation centrifugal force of the blade is analyzed using one-way fluid-solid coupling method. Results show that the strength of the impeller can meet the requirement of the centrifugal pumps, and the largest stress occurred around the blades root on a pressure side of blade surface. Due to the existence of stress concentration at the blades root, the fatigue limit of the impeller would be reduced greatly. In the further structure optimal design, the blade root should be strengthened.

  6. Segmenting delaminations in carbon fiber reinforced polymer composite CT using convolutional neural networks

    Science.gov (United States)

    Sammons, Daniel; Winfree, William P.; Burke, Eric; Ji, Shuiwang

    2016-02-01

    Nondestructive evaluation (NDE) utilizes a variety of techniques to inspect various materials for defects without causing changes to the material. X-ray computed tomography (CT) produces large volumes of three dimensional image data. Using the task of identifying delaminations in carbon fiber reinforced polymer (CFRP) composite CT, this work shows that it is possible to automate the analysis of these large volumes of CT data using a machine learning model known as a convolutional neural network (CNN). Further, tests on simulated data sets show that with a robust set of experimental data, it may be possible to go beyond just identification and instead accurately characterize the size and shape of the delaminations with CNNs.

  7. Mechanical and Electrochemical Performance of Carbon Fiber Reinforced Polymer in Oxygen Evolution Environment

    Directory of Open Access Journals (Sweden)

    Ji-Hua Zhu

    2016-11-01

    Full Text Available Carbon fiber-reinforced polymer (CFRP is recognized as a promising anode material to prevent steel corrosion in reinforced concrete. However, the electrochemical performance of CFRP itself is unclear. This paper focuses on the understanding of electrochemical and mechanical properties of CFRP in an oxygen evolution environment by conducting accelerated polarization tests. Different amounts of current density were applied in polarization tests with various test durations, and feeding voltage and potential were measured. Afterwards, tensile tests were carried out to investigate the failure modes for the post-polarization CFRP specimens. Results show that CFRP specimens had two typical tensile-failure modes and had a stable anodic performance in an oxygen evolution environment. As such, CFRP can be potentially used as an anode material for impressed current cathodic protection (ICCP of reinforced concrete structures, besides the fact that CFRP can strengthen the structural properties of reinforced concrete.

  8. Study the Effect of Carbon Fiber Volume Fraction and their Orientations on the Thermal Conductivity of the Polymer Composite Materials.

    Directory of Open Access Journals (Sweden)

    Mohammed Sellab Hamza

    2008-01-01

    Full Text Available The effect of fiber volume fraction of the carbon fiber on the thermal conductivity of the polymer composite material was studied. Different percentages of carbon fibers were used (5%, 10%, 15%, 20%, and 25%. Specimens were made in two groups for unsaturated polyester as a matrix and carbon fibers, first group has parallel arrangement of fibers and the second group has perpendicular arrangement of fibers on the thermal flow, Lee's disk method was used for testing the specimens. This study showed that the values of the of thermal conductivity of the specimens when the fibers arranged in parallel direction was higher than that when the fibers arranged in the perpendicular direction The results indicated that the thermal conductivity increases with the increasing the fiber volume fraction. Minimum value was (0.64 W/m.?C for parallel arrangement and (0.1715 W/m.?C for perpendicular arrangement at (Vf = 5% .Maximum value for parallel and perpendicular were (2.65 W/m. ?C and (0.215 W/m.?C at (Vf = 25% respectively.

  9. Recycling high-performance carbon fiber reinforced polymer composites using sub-critical and supercritical water

    Science.gov (United States)

    Knight, Chase C.

    Carbon fiber reinforced plastics (CFRP) are composite materials that consist of carbon fibers embedded in a polymer matrix, a combination that yields materials with properties exceeding the individual properties of each component. CFRP have several advantages over metals: they offer superior strength to weight ratios and superior resistance to corrosion and chemical attack. These advantages, along with continuing improvement in manufacturing processes, have resulted in rapid growth in the number of CFRP products and applications especially in the aerospace/aviation, wind energy, automotive, and sporting goods industries. Due to theses well-documented benefits and advancements in manufacturing capabilities, CFRP will continue to replace traditional materials of construction throughout several industries. However, some of the same properties that make CFRP outstanding materials also pose a major problem once these materials reach the end of service life. They become difficult to recycle. With composite consumption in North America growing by almost 5 times the rate of the US GDP in 2012, this lack of recyclability is a growing concern. As consumption increases, more waste will inevitably be generated. Current composite recycling technologies include mechanical recycling, thermal processing, and chemical processing. The major challenge of CFRP recycling is the ability to recover materials of high-value and preserve their properties. To this end, the most suitable technology is chemical processing, where the polymer matrix can be broken down and removed from the fiber, with limited damage to the fibers. This can be achieved using high concentration acids, but such a process is undesirable due to the toxicity of such materials. A viable alternative to acid is water in the sub-critical and supercritical region. Under these conditions, the behavior of this abundant and most environmentally friendly solvent resembles that of an organic compound, facilitating the breakdown

  10. Eddy current pulsed phase thermography considering volumetric induction heating for delamination evaluation in carbon fiber reinforced polymers

    Science.gov (United States)

    Yang, Ruizhen; He, Yunze

    2015-06-01

    Anisotropy and inhomogeneity of carbon fiber reinforced polymers (CFRPs) result in that many traditional non-destructive inspection techniques are inapplicable on the delamination evaluation. This letter introduces eddy current pulsed phase thermography (ECPPT) for CFRPs evaluation considering volumetric induction heating due to small electrical conductivity, abnormal thermal wave propagation, and Fourier analysis. The proposed methods were verified through experimental studies under transmission and reflection modes. Using ECPPT, the influence of the non-uniform heating effect and carbon fiber structures can be suppressed, and then delamination detectability can be improved dramatically over eddy current pulsed thermography.

  11. Nanoporous structured submicrometer carbon fibers prepared via solution electrospinning of polymer blends.

    Science.gov (United States)

    Peng, Mao; Li, Dasong; Shen, Lie; Chen, Ying; Zheng, Qiang; Wang, Huijun

    2006-10-24

    A facile means for obtaining submicrometer carbon fibers with a nanoporous structure is presented. A mixture of polyacrylonitrile (PAN) and a copolymer of acrylonitrile and methyl methacrylate (poly(AN-co-MMA)) in dimethylformamide was electrospun into submicrometer fibers with a microphase-separated structure. During the followed oxidation process, the copolymer domains were pyrolyzed, resulting in a nanoporous structure that was preserved after carbonization. The microphase-separated structure of the PAN/poly(AN-co-MMA) electrospun fibers, the morphology, and porous structure of both the oxidized and the carbonized fibers were observed with scanning electron microscopy and transmission electron microscopy. The carbon fibers have diameters ranging from several hundred nanometers to about 1 microm. The nanopores or nanoslits throughout the fiber surface and interior with diameters of several tens of nanometers are interconnected and oriented along the longitudinal axis of the fibers. This unique nanoporous morphology similar to the microphase-separated structure in the PAN/poly(AN-co-MMA) fibers is attributed to the rapid phase separation, solidification, as well as the stretching of the fibers during electrospinning. The pore volume and pore size distribution of the carbonized fibers were investigated by nitrogen adsorption and desorption.

  12. Wear and transfer characteristics of carbon fiber reinforced polymer composites under water lubrication

    Institute of Scientific and Technical Information of China (English)

    JIA Jun-hong; CHEN Jian-min; ZHOU Hui-di; CHEN Lei

    2004-01-01

    The tribological characteristics of carbon fiber reinforced polymer composites under distilled-water-lubricated-sliding and dry-sliding against stainless steel were comparatively investigated. Scanning electron microscopy (SEM) was utilized to examine composite microstructures and modes of failure. The typical chemical states of elements of the transfer film on the stainless steel were examined with X-ray photoelectron spectroscopy (XPS). Wear testing and SEM analysis show that all the composites hold the lowered friction coefficient and show much better wear resistance under water lubricated sliding against stainless steel than those under dry sliding. The wear of composites is characterized by plastic deformation, scuffing, micro cracking, and spalling under both dry-sliding and water lubricated conditions. Plastic deformation, scuffing, micro cracking, and spalling, however, are significantly abated under water-lubricated condition. XPS analysis conforms that none of the materials produces transfer films on the stainless steel counterface with the type familiar from dry sliding, and the transfer of composites onto the counterpart ring surface is significantly hindered while the oxidation of the stainless steel is speeded under water lubrication. The composites hinder transfer onto the steel surface and the boundary lubricating action of water accounts for the much smaller wear rate under water lubrication compared with that under dry sliding. The easier transfer of the composite onto the counterpart steel surface accounts for the larger wear rate of the polymer composite under dry sliding.

  13. Flash Thermography to Evaluate Porosity in Carbon Fiber Reinforced Polymer (CFRPs

    Directory of Open Access Journals (Sweden)

    Carosena Meola

    2014-02-01

    Full Text Available It is a fact that the presence of porosity in composites has detrimental effects on their mechanical properties. Then, due to the high probability of void formation during manufacturing processes, it is necessary to have the availability of non-destructive evaluation techniques, which may be able to discover the presence and the distribution of porosity in the final parts. In recent years, flash thermography has emerged as the most valuable method, but it is still not adequately enclosed in the industrial enterprise. The main reason of this is the lack of sufficient quantitative data for a full validation of such a technique. The intention of the present work is to supply an overview on the current state-of-the-art regarding the use of flash thermography to evaluate the porosity percentage in fiber reinforced composite materials and to present the latest results, which are gathered by the authors, on porous carbon fiber reinforced polymer laminates. To this end, several coupons of two different stacking sequences and including a different amount of porosity are fabricated and inspected with both non-destructive and destructive testing techniques. Data coming from non-destructive testing with either flash thermography or ultrasonics are plotted against the porosity percentage, which was previously estimated with the volumetric method. The new obtained results are a witness to the efficacy of flash thermography. Some key points that need further consideration are also highlighted.

  14. Mechanical characterization of fiber reinforced Polymer Concrete

    Directory of Open Access Journals (Sweden)

    João Marciano Laredo dos Reis

    2005-09-01

    Full Text Available A comparative study between epoxy Polymer Concrete plain, reinforced with carbon and glass fibers and commercial concrete mixes was made. The fibers are 6 mm long and the fiber content was 2% and 1%, respectively, in mass. Compressive tests were performed at room temperature and load vs. displacement curves were plotted up to failure. The carbon and glass fibers reinforcement were randomly dispersed into the matrix of polymer concrete. An increase in compressive properties was observed as function of reinforcement. The comparison also showed that Polymer Concrete, plain and reinforced, has a better performance than regular market concrete, suggesting that PC is a reliable alternative for construction industry.

  15. Self-Healing of Ionomeric Polymers with Carbon Fibers from Medium-Velocity Impact and Resistive Heating

    Directory of Open Access Journals (Sweden)

    Vishnu Baba Sundaresan

    2013-01-01

    Full Text Available Self-healing materials science has seen significant advances in the last decade. Recent efforts have demonstrated healing in polymeric materials through chemical reaction, thermal treatment, and ultraviolet irradiation. The existing technology for healing polymeric materials through the aforementioned mechanisms produces an irreversible change in the material and makes it unsuitable for subsequent healing cycles. To overcome these disadvantages, we demonstrate a new composite self-healing material made from an ionomer (Surlyn and carbon fiber that can sustain damage from medium-velocity impact and heal from the energy of the impact. Furthermore, the carbon fiber embedded in the polymer matrix results in resistive heating of the polymer matrix locally, melts the ionomer matrix around the damage, and heals the material at the damaged location. This paper presents methods to melt-process Surlyn with carbon fiber and demonstrates healing in the material through medium-velocity impact tests, resistive heating, and imaging through electron and optical microscopy. A new metric for quantifying self-healing in the sample, called width-heal ratio, is developed, and we report that the Surlyn-carbon fiber-based material under an optimal rate of heating and at the correct temperature has a width-heal ratio of >0.9, thereby demonstrating complete recovery from the damage.

  16. Parameters of static response of carbon fiber reinforced polymer (CFRP) suspension cables

    Institute of Scientific and Technical Information of China (English)

    王立彬; 吴勇

    2015-01-01

    The feasibility of longer spans relies on the successful implementation of new high-strength light weight materials such as carbon fiber reinforced polymer (CFRP). First, a dimensionless equilibrium equation and the corresponding compatibility equation are established to develop the cable force equation and cable displacement governing equation for suspension cables, respectively. Subsequently, the inextensible cable case is introduced. The formula of the Irvine parameter is considered and its physical interpretation as well as its relationship with the chord gravity stiffness is presented. The influences on the increment of cable force and displacement byλ2 and load ratiop′are analyzed, respectively. Based on these assumptions and the analytical formulations, a 2000 m span suspension cable is utilized as an example to verify the proposed formulation and the responses of the relative increment of cable force and cable displacement under symmetrical and asymmetrical loads are studied and presented. In each case, the deflections resulting from elastic elongation or solely due to geometrical displacement are analyzed for the lower elastic modulus CFRP. Finally, in comparison with steel cables, the influences on the cable force equation and the governing displacement equation by span and rise span ratio are analyzed. Moreover, the influences on the static performance of suspension bridge by span and sag ratios are also analyzed. The substantive characteristics of the static performance of super span CFRP suspension bridges are clarified and the superiority and the characteristics of CFRP cable structure are demonstrated analytically.

  17. Flexural Strength of Carbon Fiber Reinforced Polymer Repaired Cracked Rectangular Hollow Section Steel Beams

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2015-01-01

    Full Text Available The flexural behavior of rectangular hollow section (RHS steel beams with initial crack strengthened externally with carbon fiber reinforced polymer (CFRP plates was studied. Eight specimens were tested under three-point loading to failure. The experimental program included three beams as control specimens and five beams strengthened with CFRP plates with or without prestressing. The load deflection curves were graphed and failure patterns were observed. The yield loads and ultimate loads with or without repairing were compared together with the strain distributions of the CFRP plate. It was concluded that yield loads of cracked beams could be enhanced with repairing. Meanwhile, the ultimate loads were increased to some extent. The effect of repair became significant with the increase of the initial crack depth. The failure patterns of the repaired specimens were similar to those of the control ones. Mechanical clamping at the CFRP plate ends was necessary to avoid premature peeling between the CFRP plate and the steel beam. The stress levels in CFRP plates were relatively low during the tests. The use of prestressing could improve the utilization efficiency of CFRP plates. It could be concluded that the patching repair could be used to restore the load bearing capacity of the deficient steel beams.

  18. Dual Function Behavior of Carbon Fiber-Reinforced Polymer in Simulated Pore Solution

    Directory of Open Access Journals (Sweden)

    Ji-Hua Zhu

    2016-02-01

    Full Text Available The mechanical and electrochemical performance of carbon fiber-reinforced polymer (CFRP were investigated regarding a novel improvement in the load-carrying capacity and durability of reinforced concrete structures by adopting CFRP as both a structural strengthener and an anode of the impressed current cathodic protection (ICCP system. The mechanical and anode performance of CFRP were investigated in an aqueous pore solution in which the electrolytes were available to the anode in a cured concrete structure. Accelerated polarization tests were designed with different test durations and various levels of applied currents in accordance with the international standard. The CFRP specimens were mechanically characterized after polarization. The measured feeding voltage and potential during the test period indicates CFRP have stable anode performance in a simulated pore solution. Two failure modes were observed through tensile testing. The tensile properties of the post-polarization CFRP specimens declined with an increased charge density. The CFRP demonstrated success as a structural strengthener and ICCP anode. We propose a mathematic model predicting the tensile strengths of CFRP with varied impressed charge densities.

  19. Hysteretic Behavior of Tubular Steel Braces Having Carbon Fiber Reinforced Polymer Reinforcement Around End Net Sections

    Directory of Open Access Journals (Sweden)

    Cem Haydaroğlu

    2015-12-01

    Full Text Available This study presents an experimental investigation into the seismic retrofit of tubular steel braces using carbon fiber reinforced polymer (CFRP members. CFRP retrofitting of net sections for compact tubes are proposed for delaying potential local net section failure. A total of almost full-scale three (TB-1, TB-2, and TB-3 compact steel tubular specimens were designed per AISC specifications, constructed, and cyclically tested to fracture. Retrofitted braces, when compared to the reference specimen, developed fuller hysteretic curves. Increase in cumulative hysteretic energy dissipation and the elongation in fracture life in the specimen retrofitted with CFRP plates and CFRP sheet wraps at net sections are observed during testing. This resulted in a maximum of 82.5% more dissipated energy for compact tube specimens. Also, this retrofit provided a longer experimental fracture life (maximum 59% more. Due to fracture initiation during the last cycles, significant reductions in strength and stiffness have been obtained. No significant change (maximum 10% in the brace stiffness was observed, which could be desirable in seismic retrofit applications. Pushover analysis per FEMA 356 for the bare specimen shows that FEMA does not represent actual brace behavior in the compression side although pushover and experimental results are in good agreement in the tension side.

  20. Load Transfer Analysis in Short Carbon Fibers with Radially-Aligned Carbon Nanotubes Embedded in a Polymer Matrix

    OpenAIRE

    2009-01-01

    A novel shortfiber composite in which the microscopic advanced fiber reinforcements are coated with radially aligned carbon nanotubes (CNTs) is analyzed in this study. A shear-lag model is developed to analyze the load transferred to such coated fibers from the aligned-CNT reinforced matrix in a hybrid composite application. It is found that if the carbon fibers are coated with radially aligned CNTs, then the axial load transferred to the fiber is reduced due to stiffening of the matrix by th...

  1. Polymer optical fiber fuse

    CERN Document Server

    Mizuno, Yosuke; Tanaka, Hiroki; Nakamura, Kentaro

    2013-01-01

    Although high-transmission-capacity optical fibers are in demand, the problem of the fiber fuse phenomenon needs to be resolved to prevent the destruction of fibers. As polymer optical fibers become more prevalent, clarifying their fuse properties has become important. Here, we experimentally demonstrate a fuse propagation velocity of 21.9 mm/s, which is 1 to 2 orders of magnitude slower than that in standard silica fibers. The achieved threshold power density and proportionality constant between the propagation velocity and the power density are respectively 1/186 of and 16.8 times the values for silica fibers. An oscillatory continuous curve instead of periodic voids is formed after the passage of the fuse. An easy fuse termination method is presented herein, along with its potential plasma applications.

  2. Investigating the efficiency of using the carbon fiber polymer on beam–column connection

    Directory of Open Access Journals (Sweden)

    Mahmoud M. Eldeeb

    2016-03-01

    Full Text Available Due to the huge amount of energy induced from earthquakes, such natural hazards usually represent the most significant threat on existing and new buildings. Recently, a lot of considerable efforts were dedicated to design buildings capable of withstanding earthquakes' ground motions by utilizing lateral resisting elements, such as reinforced concrete shear walls, cores, frames, and steel bracing. Contrasting the experience gained from the previously designed guidelines and provisions for lateral resisting systems, recent studies illustrated that the existence of lateral resisting system in low-rise buildings is essential in order to resist ground motions. As such, some endeavors are directed to reinforce old buildings against seismic loads. This paper focuses on investigating the efficiency of using Carbon Fiber Polymer (CFRP sheets on the behavior of beam–column connections considering a cantilever beam with concentrated load at its free end. In addition, to complement the published data, finite element model using the computer package ANSYS was used. The additional beam–column connections in this study are classified in 4 groups (A, B, C, and D depending on the percentage of reinforcement at the bottom and top of the beam (%As. The efficiency of using CFRP was concluded; the CFRP sheet improves or decreases the efficiency of beam–column connection depending on %As in the beam. The paper investigates the influence of boundary condition, columns as hinged supports, and the efficiency of using CFRP. It is concluded that the CFRP sheet improves or decreases the efficiency of beam–column connection depending on %As in the beam.

  3. In situ corrosion monitoring of PC structures with distributed hybrid carbon fiber reinforced polymer sensors

    Science.gov (United States)

    Yang, C. Q.; Wu, Z. S.

    2007-08-01

    Firstly, the fabrication and sensing properties of hybrid carbon fiber reinforced polymer (HCFRP) composite sensors are addressed. In order to provide a distributed sensing manner, the HCFRP sensors were divided into multi-zones with electrodes, and each zone was regarded as a separate sensor. Secondly, their application is studied to monitor the steel corrosion of prestressed concrete (PC) beams. The HCFRP sensors with different gauge lengths were mounted on a PC tendon, steel bar and embedded in tensile and compressive sides of the PC beam. The experiment was carried out under an electric accelerated corrosion and a constant load of about 54 kN. The results reveal that the corrosion of the PC tendon can be monitored through measuring the electrical resistance (ER) change of the HCFRP sensors. For the sensors embedded in tensile side of the PC beam, their ER increases as the corrosion progresses, whereas for the sensors embedded in compressive side, their ER decreases with corrosion time. Moreover, the strains due to the corrosion can be obtained based on the ER change and calibration curves of HCFRP sensors. The strains measured with traditional strain gauges agree with the strains calculated from the ER changes of HCFRP sensors. The electrical behavior of the zones where the corrosion was performed is much different from those of the other zones. In these zones, either there exist jumps in ER, or the ER increases with a much larger rate than those of the other zones. Distributed corrosion monitoring for PC structures is thus demonstrated with the application of HCFRP sensors through a proper installation of multi-electrodes.

  4. Properties of glass/carbon fiber reinforced epoxy hybrid polymer composites

    Science.gov (United States)

    Patel, R. H.; Sevkani, V. R.; Patel, B. R.; Patel, V. B.

    2016-05-01

    Composite Materials are well known for their tailor-made properties. For the fabrication of composites different types of reinforcements are used for different applications. Sometimes for a particular application, one type of reinforcement may not fulfill the requirements. Therefore, more than one type of reinforcements may be used. Thus, the idea of hybrid composites arises. Hybrid composites are made by joining two or more different reinforcements with suitable matrix system. It helps to improve the properties of composite materials. In the present work glass/carbon fiber reinforcement have been used with a matrix triglycidyl ether of tris(m-hydroxy phenyl) phosphate epoxy resin using amine curing agent. Different physical and mechanical properties of the glass, carbon and glass/carbon fiber reinforced polymeric systems have been found out.

  5. Mechanical analysis of carbon fiber reinforced shape memory polymer composite for self-deployable structure in space environment

    Science.gov (United States)

    Hong, Seok Bin; Ahn, Yong San; Jang, Joon Hyeok; Kim, Jin-Gyun; Goo, Nam Seo; Yu, Woong-Ryeol

    2016-04-01

    Shape memory polymer (SMP) is one of smart polymers which exhibit shape memory effect upon external stimuli. Reinforcements as carbon fiber had been used for making shape memory polymer composite (CF-SMPC). This study investigated a possibility of designing self-deployable structures in harsh space condition using CF-SMPCs and analyzed their shape memory behaviors with constitutive equation model.CF-SMPCs were prepared using woven carbon fabrics and a thermoset epoxy based SMP to obtain their basic mechanical properties including actuation in harsh environment. The mechanical and shape memory properties of SMP and CF-SMPCs were characterized using dynamic mechanical analysis (DMA) and universal tensile machine (UTM) with an environmental chamber. The mechanical properties such as flexural strength and tensile strength of SMP and CF-SMPC were measured with simple tensile/bending test and time dependent shape memory behavior was characterized with designed shape memory bending test. For mechanical analysis of CF-SMPCs, a 3D constitutive equation of SMP, which had been developed using multiplicative decomposition of the deformation gradient and shape memory strains, was used with material parameters determined from CF-SMPCs. Carbon fibers in composites reinforced tensile and flexural strength of SMP and acted as strong elastic springs in rheology based equation models. The actuation behavior of SMP matrix and CF-SMPCs was then simulated as 3D shape memory bending cases. Fiber bundle property was imbued with shell model for more precise analysis and it would be used for prediction of deploying behavior in self-deployable hinge structure.

  6. Electrical and Mechanical Performance of Carbon Fiber-Reinforced Polymer Used as the Impressed Current Anode Material

    Directory of Open Access Journals (Sweden)

    Ji-Hua Zhu

    2014-07-01

    Full Text Available An investigation was performed by using carbon fiber-reinforced polymer (CFRP as the anode material in the impressed current cathodic protection (ICCP system of steel reinforced concrete structures. The service life and performance of CFRP were investigated in simulated ICCP systems with various configurations. Constant current densities were maintained during the tests. No significant degradation in electrical and mechanical properties was found for CFRP subjected to anodic polarization with the selected applied current densities. The service life of the CFRP-based ICCP system was discussed based on the practical reinforced concrete structure layout.

  7. UV-Assisted 3D Printing of Glass and Carbon Fiber-Reinforced Dual-Cure Polymer Composites

    Directory of Open Access Journals (Sweden)

    Marta Invernizzi

    2016-07-01

    Full Text Available Glass (GFR and carbon fiber-reinforced (CFR dual-cure polymer composites fabricated by UV-assisted three-dimensional (UV-3D printing are presented. The resin material combines an acrylic-based photocurable resin with a low temperature (140 °C thermally-curable resin system based on bisphenol A diglycidyl ether as base component, an aliphatic anhydride (hexahydro-4-methylphthalic anhydride as hardener and (2,4,6,-tris(dimethylaminomethylphenol as catalyst. A thorough rheological characterization of these formulations allowed us to define their 3D printability window. UV-3D printed macrostructures were successfully demonstrated, giving a clear indication of their potential use in real-life structural applications. Differential scanning calorimetry and dynamic mechanical analysis highlighted the good thermal stability and mechanical properties of the printed parts. In addition, uniaxial tensile tests were used to assess the fiber reinforcing effect on the UV-3D printed objects. Finally, an initial study was conducted on the use of a sizing treatment on carbon fibers to improve the fiber/matrix interfacial adhesion, giving preliminary indications on the potential of this approach to improve the mechanical properties of the 3D printed CFR components.

  8. Loading of a coordination polymer nanobelt on a functional carbon fiber: a feasible strategy for visible-light-active and highly efficient coordination-polymer-based photocatalysts.

    Science.gov (United States)

    Xu, Xin-Xin; Yang, Hong-Yu; Li, Zhen-Yu; Liu, Xiao-Xia; Wang, Xiu-Li

    2015-02-23

    To improve the photocatalytic properties of coordination polymers under irradiation in the visible-light region, coordination polymer nanobelts (CPNB) were loaded on functional carbon fiber (FCF) through the use of a simple colloidal blending process. The resulting coordination polymer nanobelt loaded functional carbon fiber composite material (CPNB/FCF) exhibited dramatically improved photocatalytic activity for the degradation of rhodamine B (RhB) under visible-light irradiation. Optical and electrochemical methods illustrated the enhanced photocatalytic activity of CPNB/FCF originated from high separation efficiency of photogenerated electrons and holes on the interface of CPNB and FCF, which was produced by the synergy effect between them. In the composite material, the role of FCF could be described as photosensitizer and good electron transporter. For FCF, the number of functional groups on its surface has a significant influence on the photocatalytic performance of the resulting CPNB/FCF composite material, and an ideal FCF carrier was obtained as a highly efficient CPNB/FCF photocatalyst. CPNB/FCF showed outstanding stability during the degradation of rhodamine B (RhB); thus, the material is suitable for use as a photocatalyst in the treatment of organic dyes in water.

  9. Carbon nanotube fiber spun from wetted ribbon

    Science.gov (United States)

    Zhu, Yuntian T; Arendt, Paul; Zhang, Xiefei; Li, Qingwen; Fu, Lei; Zheng, Lianxi

    2014-04-29

    A fiber of carbon nanotubes was prepared by a wet-spinning method involving drawing carbon nanotubes away from a substantially aligned, supported array of carbon nanotubes to form a ribbon, wetting the ribbon with a liquid, and spinning a fiber from the wetted ribbon. The liquid can be a polymer solution and after forming the fiber, the polymer can be cured. The resulting fiber has a higher tensile strength and higher conductivity compared to dry-spun fibers and to wet-spun fibers prepared by other methods.

  10. Carbon Fibers: Reexamination of the Critical Low-Temperature (200-300C) Stabilization of Polyacrylonitrile,

    Science.gov (United States)

    CARBON FIBERS , SYNTHESIS(CHEMISTRY)), (*ACRYLONITRILE POLYMERS, CARBON FIBERS ), SHEETS, CARBON, FILMS, OXIDATION, THERMAL ANALYSIS, CHEMICAL BONDS, INFRARED SPECTRA, MOLECULAR STRUCTURE, HEAT TREATMENT

  11. Light-induced electron paramagnetic resonance evidence of charge transfer in electrospun fibers containing conjugated polymer/fullerene and conjugated polymer/fullerene/carbon nanotube blends

    Science.gov (United States)

    Shames, Alexander I.; Bounioux, Céline; Katz, Eugene A.; Yerushalmi-Rozen, Rachel; Zussman, Eyal

    2012-03-01

    Electrospun sub-micron fibers containing conjugated polymer (poly(3-hexylthiophene), P3HT) with a fullerene derivative, phenyl-C61-butyric acid methylester (PCBM) or a mixture of PCBM and single-walled carbon nanotubes (SWCNTs) were studied by light-induced electron paramagnetic resonance spectroscopy. The results provide experimental evidence of electron transfer between PCBM and P3HT components in both fiber systems and suggest that the presence of a dispersing block-copolymer, which acts via physical adsorption onto the PCBM and SWCNT moieties, does not prevent electron transfer at the P3HT-PCBM interface. These findings suggest a research perspective towards utilization of fibers of functional nanocomposites in fiber-based organic optoelectronic and photovoltaic devices. The latter can be developed in the textile-type large area photovoltaics or individual fiber-based solar cells that will broaden energy applications from macro-power tools to micro-nanoscale power conversion devices and smart textiles.

  12. Preparation, characterization, and analytical applications of a novel polymer stationary phase with embedded or grafted carbon fibers.

    Science.gov (United States)

    Zhong, Yingying; Zhou, Wenfang; Zhang, Peimin; Zhu, Yan

    2010-09-15

    A polymer-based chromatographic stationary phase with embedded or grafted multi-walled carbon nanotubes (MWCNTs) has been developed. Three different synthetic methods were utilized to combine the nano-fibers with the substrate of polystyrene-divinylbenzene (PS-DVB). After optimizing the synthetic conditions, this novel polystyrene-divinylbenzene-carbon nanotube (PS-DVB-CNT) stationary phase was characterized by scanning electron microscopy, Raman spectroscopy, thermogravimetric analysis, chemical adsorption and desorption measurement, and mechanical stability test. Compared to PS-DVB particles, PS-DVB-CNT particles have certain improvement in physical and chromatographic performances because the addition of MWCNTs has altered the structures of the particles. The novel stationary phase owns satisfactory resolution, wide pH endurance, and long lifetime, which can be used as an extent to normal HPLC.

  13. Tolerancing of a carbon fiber reinforced polymer metering tube structure of a high-resolution space-borne telescope

    Science.gov (United States)

    Ekinci, Mustafa

    2016-07-01

    High resolution space borne telescopes require dimensionally stable structures to meet very stringent optical requirements. Furthermore, high resolution space borne telescope structures need to have high stiffness and be lightweight in order to survive launch loads. Carbon fiber reinforced polymers (CFRP) are lightweight and have tailorable mechanical properties like stiffness and coefficient of thermal expansion. However, mechanical properties are highly dependent on manufacturing processes and manufacturing precision. Moreover CFRP tend to absorb moisture which affects dimensional stability of the structure in the vacuum environment. In order to get specified properties out of manufacturing, tolerances need to be defined very accurately. In this paper, behavior of CFRP metering tube structure of a high resolution space borne camera is investigated for ply orientation, fiber and void content deviations which may arise from manufacturing errors and limitations. A computer code is generated to determine laminate properties of stacked up uni-directional (UD) laminae using classical laminate theory with fiber and matrix properties obtained from suppliers and literature. After defining laminate stackup, many samples are virtually created with ply orientations, volumetric fiber and void content that randomly deviates in a tolerance range which will be used in manufacturing. Normal distribution, standard deviation and mean values are presented for elasticity modulus, coefficient of thermal expansion (CTE), coefficient of moisture expansion (CME) and thermal conductivity in axial and transverse directions of quasi-isotropic stackups and other stackups which have properties presented in literature.

  14. Carbon Fiber Biocompatibility for Implants

    Directory of Open Access Journals (Sweden)

    Richard Petersen

    2016-01-01

    Full Text Available Carbon fibers have multiple potential advantages in developing high-strength biomaterials with a density close to bone for better stress transfer and electrical properties that enhance tissue formation. As a breakthrough example in biomaterials, a 1.5 mm diameter bisphenol-epoxy/carbon-fiber-reinforced composite rod was compared for two weeks in a rat tibia model with a similar 1.5 mm diameter titanium-6-4 alloy screw manufactured to retain bone implants. Results showed that carbon-fiber-reinforced composite stimulated osseointegration inside the tibia bone marrow measured as percent bone area (PBA to a great extent when compared to the titanium-6-4 alloy at statistically significant levels. PBA increased significantly with the carbon-fiber composite over the titanium-6-4 alloy for distances from the implant surfaces of 0.1 mm at 77.7% vs. 19.3% (p < 10−8 and 0.8 mm at 41.6% vs. 19.5% (p < 10−4, respectively. The review focuses on carbon fiber properties that increased PBA for enhanced implant osseointegration. Carbon fibers acting as polymer coated electrically conducting micro-biocircuits appear to provide a biocompatible semi-antioxidant property to remove damaging electron free radicals from the surrounding implant surface. Further, carbon fibers by removing excess electrons produced from the cellular mitochondrial electron transport chain during periods of hypoxia perhaps stimulate bone cell recruitment by free-radical chemotactic influences. In addition, well-studied bioorganic cell actin carbon fiber growth would appear to interface in close contact with the carbon-fiber-reinforced composite implant. Resulting subsequent actin carbon fiber/implant carbon fiber contacts then could help in discharging the electron biological overloads through electrochemical gradients to lower negative charges and lower concentration.

  15. Reinforced concrete T-beams externally prestressed with unbonded carbon fiber-reinforced polymer tendons

    DEFF Research Database (Denmark)

    Bennitz, Anders; Nilimaa, Jonny; Ravn, Dorthe Lund

    2012-01-01

    This study describes a series of experiments examining the behavior of seven beams prestressed with unbonded external carbon fiberreinforced polymer (CFRP) tendons anchored using a newly developed anchorage and post-tensioning system. The effects of varying the initial tendon depth, prestressing...... force, and the presence of a deviator were investigated. The results were compared to those observed with analogous beams prestressed with steel tendons, common beam theory, and predictions made using an analytical model adapted from the literature. It was found that steel and CFRP tendons had very...

  16. Computational modeling of the electromagnetic characteristics of carbon fiber-reinforced polymer composites with different weave structures

    Science.gov (United States)

    Hassan, A. M.; Douglas, J. F.; Garboczi, E. J.

    2014-02-01

    Carbon fiber reinforced polymer composites (CFRPC) are of great interest in the aerospace and automotive industries due to their exceptional mechanical properties. Carbon fibers are typically woven and inter-laced perpendicularly in warps and wefts to form a carbon fabric that can be embedded in a binding matrix. The warps and wefts can be interlaced in different patterns called weaving structures. The primary weaving structures are the plain, twill, and satin weaves, which give different mechanical composite properties. The goal of this work is to computationally investigate the dependence of CFRPC microwave and terahertz electromagnetic characteristics on weave structure. These bands are good candidates for the Nondestructive Evaluation (NDE) of CFRPC since their wavelengths are comparable to the main weave features. 3D full wave electromagnetic simulations of several different weave models have been performed using a finite element (FEM) simulator, which is able to accurately model the complex weave structure. The computational experiments demonstrate that the reflection of electromagnetic waves from CFRPC depend sensitively on weave structure. The reflection spectra calculated in this work can be used to identify the optimal frequencies for the NDE of each weave structure.

  17. High-cycle Fatigue Life Extension of Glass Fiber/Polymer Composites with Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    Christopher S Grimmer; C K H Dharan

    2009-01-01

    The present work shows that the addition of small volume fractions of multi-walled carbon nanotubes (CNTs) to the matrix results in a significant increase in the high-cycle fatigue life. It is proposed that carbon nanotubes tend to inhibit the formation of large cracks by nucleating nano-scale damage zones. In addition, the contribution to energy absorption from the fracture of nanotubes bridging across nano-scale cracks and from nanotube pull-out from the matrix are mechanisms that can improve the fatigue life. An energy-based model was proposed to estimate the additional strain energy absorbed in fatigue. The distributed nanotubes in the matrix appear to both distribute damage as well as inhibit damage propagation resulting in an overall improvement in the fatigue strength of glass fiber composites.

  18. Mechanical properties of neat polymer matrix materials and their unidirectional carbon fiber-reinforced composites

    Science.gov (United States)

    Zimmerman, Richard S.; Adams, Donald F.

    1988-01-01

    The mechanical properties of two neat resin systems for use in carbon fiber epoxy composites were characterized. This included tensile and shear stiffness and strengths, coefficients of thermal and moisture expansion, and fracture toughness. Tests were conducted on specimens in the dry and moisture-saturated states, at temperatures of 23, 82 and 121 C. The neat resins tested were American Cyanamid 1806 and Union Carbide ERX-4901B(MPDA). Results were compared to previously tested neat resins. Four unidirectional carbon fiber reinforced composites were mechanically characterized. Axial and transverse tension and in-plane shear strengths and stiffness were measured, as well as transverse coefficients of thermal and moisture expansion. Tests were conducted on dry specimens only at 23 and 100 C. The materials tested were AS4/3502, AS6/5245-C, T300/BP907, and C6000/1806 unidirectional composites. Scanning electron microscopic examination of fracture surfaces was performed to permit the correlation of observed failure modes with the environmental test conditions.

  19. Determining the material parameters for the reconstruction of defects in carbon fiber reinforced polymers from data measured by flash thermography

    Science.gov (United States)

    Müller, Jan P.; Götschel, Sebastian; Maierhofer, Christiane; Weiser, Martin

    2017-02-01

    Flash thermography is a fast and reliable non-destructive testing method for the investigation of defects in carbon fiber reinforced polymer (CFRP) materials. In this paper numerical simulations of transient thermography data are presented, calculated for a quasi-isotropic flat bottom hole sample. They are compared to experimental data. These simulations are one important step towards the quantitative reconstruction of a flaw by assessing thermographic data. The applied numerical model is based on the finite-element method, extended by a semi-analytical treatment of the boundary of the sample, which is heated by the flash light. A crucial part for a reliable numerical model is the prior determination of the material parameters of the specimen as well as of the experimental parameters of the set-up. The material parameters in plane and in depth diffusivity are measured using laser line excitation. In addition, the absorption and heat transfer process of the first layers is investigated using an IR microscopic lens. The performance of the two distinct components of CFRP during heating - epoxy resin and carbon fibers - is examined. Finally, the material parameters are optimized by variation and comparison of the simulation results to the experimental data. The optimized parameters are compared to the measured ones and further methods to ensure precise material parameter measurements are discussed.

  20. An electrical-heating and self-sensing shape memory polymer composite incorporated with carbon fiber felt

    Science.gov (United States)

    Gong, Xiaobo; Liu, Liwu; Liu, Yanju; Leng, Jinsong

    2016-03-01

    Shape memory polymers (SMPs) have the ability to adjust their stiffness, lock a temporary shape, and recover the permanent shape upon imposing an appropriate stimulus. They have found their way into the field of morphing structures. The electrically Joule resistive heating of the conductive composite can be a desirable stimulus to activate the shape memory effect of SMPs without external heating equipment. Electro-induced SMP composites incorporated with carbon fiber felt (CFF) were explored in this work. The CFF is an excellent conductive filler which can easily spread throughout the composite. It has a huge advantage in terms of low cost, simple manufacturing process, and uniform and tunable temperature distribution while heating. A continuous and compact conductive network made of carbon fibers and the overlap joints among them was observed from the microscopy images, and this network contributes to the high conductive properties of the CFF/SMP composites. The CFF/SMP composites can be electrical-heated rapidly and uniformly, and its’ shape recovery effect can be actuated by the electrical resistance Joule heating of the CFF without an external heater. The CFF/SMP composite get higher modulus and higher strength than the pure SMP without losing any strain recovery property. The high dependence of temperature and strain on the electrical resistance also make the composite a good self-sensing material. In general, the CFF/SMP composite shows great prospects as a potential material for the future morphing structures.

  1. Damage Tolerance Enhancement of Carbon Fiber Reinforced Polymer Composites by Nanoreinforcement of Matrix

    Science.gov (United States)

    Fenner, Joel Stewart

    Nanocomposites are a relatively new class of materials which incorporate exotic, engineered nanoparticles to achieve superior material properties. Because of their extremely small size and well-ordered structure, many nanoparticles possess properties that exceed those offered by a wide range of other known materials, making them attractive candidates for novel materials engineering development. Their small size is also an impediment to their practical use, as they typically cannot be employed by themselves to realize those properties in large structures. Furthermore, nanoparticles typically possess strong self-affinity, rendering them difficult to disperse uniformly into a composite. However, contemporary research has shown that, if well-dispersed, nanoparticles have great capacity to improve the mechanical properties of composites, especially damage tolerance, in the form of fracture toughness, fatigue life, and impact damage mitigation. This research focuses on the development, manufacturing, and testing of hybrid micro/nanocomposites comprised of woven carbon fibers with a carbon nanotube reinforced epoxy matrix. Material processing consisted of dispersant-and-sonication based methods to disperse nanotubes into the matrix, and a vacuum-assisted wet lay-up process to prepare the hybrid composite laminates. Various damage tolerance properties of the hybrid composite were examined, including static strength, fracture toughness, fatigue life, fatigue crack growth rate, and impact damage behavior, and compared with similarly-processed reference material produced without nanoreinforcement. Significant improvements were obtained in interlaminar shear strength (15%), Mode-I fracture toughness (180%), shear fatigue life (order of magnitude), Mode-I fatigue crack growth rate (factor of 2), and effective impact damage toughness (40%). Observations by optical microscopy, scanning electron microscopy, and ultrasonic imaging showed significant differences in failure behavior

  2. SILICA SURFACED CARBON FIBERS.

    Science.gov (United States)

    carbon fibers . Several economical and simple processes were developed for obtaining research quantities of silica surfaced carbon filaments. Vat dipping processes were utilized to deposit an oxide such as silica onto the surface and into the micropores of available carbon or graphite base fibers. High performance composite materials were prepared with the surface treated carbon fibers and various resin matrices. The ablative characteristics of these composites were very promising and exhibited fewer limitations than either silica or...treated

  3. Mechanical properties of several neat polymer matrix materials and unidirectional carbon fiber-reinforced composites

    Science.gov (United States)

    Coguill, Scott L.; Adams, Donald F.

    1989-01-01

    The mechanical and physical properties of three neat matrix materials, i.e., PEEK (polyetheretherketone) thermoplastic, Hexcel F155 rubber-toughened epoxy and Hercules 8551-7 rubber-toughened epoxy, were experimentally determined. Twelve unidirectional carbon fiber composites, incorporating matrix materials characterized in this or earlier studies (with one exception; the PISO(sub 2)-TPI matrix itself was not characterized), were also tested. These composite systems included AS4/2220-1, AS4/2220-3, T500/R914, IM6/HX1504, T300/4901A (MDA), T700/4901A (MDA), T300/4901B (MPDA), T700/4901B (MPDA), APC2 (AS4/PEEK, ICI), APC2 (AS4/PEEK, Langley Research Center), AS4/8551-7, and AS4/PISO(sub 2)-TPI. For the neat matrix materials, the tensile, shear, fracture toughness, coefficient of thermal expansion, and coefficient of moisture expansion properties were measured as a function of both temperature and moisture content. For the unidirectional composites, axial and transverse tensile, longitudinal shear, coefficient of thermal expansion, and coefficient of moisture expansion properties were determined, at room temperature and 100 C.

  4. Reusing recycled fibers in high-value fiber-reinforced polymer composites: Improving bending strength by surface cleaning

    OpenAIRE

    Shi, Jian; Bao, Limin; Kobayashi, Ryouhei; Kato, Jun; Kemmochi, Kiyoshi

    2012-01-01

    Glass fiber-reinforced polymer (GFRP) composites and carbon fiber-reinforced polymer (CFRP) composites were recycled using superheated steam. Recycled glass fibers (R-GFs) and recycled carbon fibers (R-CFs) were surface treated for reuse as fiber-reinforced polymer (FRP) composites. Treated R-GFs (TR-GFs) and treated R-CFs (TR-CFs) were characterized by scanning electron microscopy (SEM) and remanufactured by vacuum-assisted resin transfer molding (VARTM). Most residual resin impurities were ...

  5. Carbon fiber reinforced polymer (CFRP inserted in different configurations of the tensile zone retrofitting with microconcrete containing steel fibers to the strengthening of beams

    Directory of Open Access Journals (Sweden)

    Vladimir José Ferrari

    2016-08-01

    Full Text Available It is researched, in this study, the strengthening technique known as Near Surface Mounted (NSM, which consists of the insertion of laminates of Carbon Fiber Reinforced Polymer (CFRP into notches in the covering concrete structures. In the strengthening in beams, the tensile zone is found damaged for several reasons (cracking and corrosion, for instance, which demands, in the practice of engineering, its preliminary retrofitting. It should be considered that the good performance of the material used in this retrofitting is fundamental for a higher efficiency of the strengthening. Therefore, it is proposed a methodology that consists of the reconstitution of the tensile zone of the beams with a cement-based composite of high performance (CCAD, which acts as a substrate for the application of CFRP and as an element for the transfer of efforts to the part strengthened. The retrofitting of this tensile zone was performed only in the shear span, as well as throughout of the zone with a view to evaluating the influence of this aspect on the performance of the beams. The CCAD, produced from Portland cement, steel fibers and microfibers, was evaluated using the Rilem (2002, showed to be able to delay the cracking. Tests performed in the beams with the tensile zone retrofitting by CCAD and strengthening using the technique NSM showed the efficiency of the proposed methodology.

  6. Novel Interphases: Synthesis, Molecular Orientation and Grafting of Liquid Crystal Polymers on Carbon Fibers

    Science.gov (United States)

    1990-01-01

    presumably due to the alkaline nature of the TBAF solution bringing about a base - catalyzed ester hydrolysis of the more susceptible biphenyl benzoate...polymer- based composites. A protection- polymerization-deprotection scheo.e was developed for the synthesis of these functionallzed polymers. Optical... Transesterification . 26 1.2.4.2 Grafting via Esterification in Solution ...... .. 41 1.3 Summary ....... .................... .. 43 1.4 Experimental

  7. Quantitative assessment on the orientation and distribution of carbon fibers in a conductive polymer composite using high-frequency ultrasound.

    Science.gov (United States)

    Lin, Yi-Hsun; Huang, Chih-Chung; Wang, Shyh-Hau

    2012-05-01

    Conductive polymer composites, typically fabricated from a mix of conductive fillers and a polymer substrate, are commonly applied as bipolar plates in a fuel cell stack. Electrical conductivity is a crucial property that greatly depends on the distribution and orientation of the fillers. In this study, a 50-MHz ultrasound imaging system and analysis techniques capable of nondestructively assessing the properties of carbon fibers (CFs) in conductive polymer composites were developed. Composite materials containing a mix of polycarbonate substrates and 0 to 0.3 wt% of CFs were prepared using an injection molding technique. Ultrasonic A-line signals and C-scan images were acquired from each composite sample in regions at a depth of 0.15 mm beneath the sample surface (region A) and those at a depth of 0.3 mm (region B). The integrated backscatter (IB) and the Nakagami statistical parameter were calculated to quantitatively assess the samples. The area ratio, defined as the percentage of areas composed of CF images normalized by that of the whole C-scan image, was applied to further quantify the orientation of CFs perpendicular to the sample surface. Corresponding to the increase in CF concentrations from 0.1 to 0.3 wt%, the average IB and Nakagami parameter (m) of the composite samples increased from -78.10 ± 2.20 (mean ± standard deviation) to -72.66 ± 1.40 dB and from 0.024 ± 0.012 to 0.048 ± 0.011, respectively. The corresponding area ratios were respectively estimated to be 0.78 ± 0.35%, 2.33 ± 0.66%, and 2.20 ± 0.60% in region A of the samples; those of CFs with a perpendicular orientation were 0.04 ± 0.03%, 0.08 ± 0.02%, and 0.12 ± 0.05%. The area ratios in region B of the samples were calculated to be 1.19 ± 0.54%, 2.81 ± 0.42%, and 2.64 ± 0.76%, and those of CFs with a perpendicular orientation were 0.07 ± 0.04%, 0.12 ± 0.04%, and 0.14 ± 0.03%. According to the results of the orientations and ultrasonic images, CFs tended to distribute more

  8. The meter-class carbon fiber reinforced polymer mirror and segmented mirror telescope at the Naval Postgraduate School

    Science.gov (United States)

    Wilcox, Christopher; Fernandez, Bautista; Bagnasco, John; Martinez, Ty; Romeo, Robert; Agrawal, Brij

    2015-03-01

    The Adaptive Optics Center of Excellence for National Security at the Naval Postgraduate School has implemented a technology testing platform and array of facilities for next-generation space-based telescopes and imaging system development. The Segmented Mirror Telescope is a 3-meter, 6 segment telescope with actuators on its mirrors for system optical correction. Currently, investigation is being conducted in the use of lightweight carbon fiber reinforced polymer structures for large monolithic optics. Advantages of this material include lower manufacturing costs, very low weight, and high durability and survivability compared to its glass counterparts. Design and testing has begun on a 1-meter, optical quality CFRP parabolic mirror for the purpose of injecting collimated laser light through the SMT primary and secondary mirrors as well as the following aft optics that include wavefront sensors and deformable mirrors. This paper will present the design, testing, and usage of this CFRP parabolic mirror and the current path moving forward with this ever-evolving technology.

  9. Surface characterization in composite and titanium bonding: Carbon fiber surface treatments for improved adhesion to thermoplastic polymers

    Science.gov (United States)

    Devilbiss, T. A.; Wightman, J. P.

    1987-01-01

    The effect of anodization in NaOH, H2SO4, and amine salts on the surface chemistry of carbon fibers was examined by X-ray photoelectron spectroscopy (XPS). The surfaces of carbon fibers after anodization in NaOH and H2SO4 were examined by scanning transmission electron microscopy (STEM), angular dependent XPS, UV absorption spectroscopy of the anodization bath, secondary ion mass spectrometry, and polar/dispersive surface energy analysis. Hercules AS-4, Dexter Hysol XAS, and Union Carbide T-300 fibers were examined by STEM, angular dependent XPS, and breaking strength measurement before and after commercial surface treatment. Oxygen and nitrogen were added to the fiber surfaces by anodization in amine salts. Analysis of the plasmon peak in the carbon 1s signal indicated that H2SO4 anodization affected the morphological structure of the carbon fiber surface. The work of adhesion of carbon fibers to thermoplastic resins was calculated using the geometric mean relationship. A correlation was observed between the dispersive component of the work of adhesion and the interfacial adhesion.

  10. Carbon fiber-reinforced polymer strengthening and monitoring of the grondals bridge in Sweden

    DEFF Research Database (Denmark)

    Täljsten, Björn; Hejll, Arvid; James, Gerard

    2007-01-01

    to be strengthened. The strengthening methods used were CFRP plates at the serviceability limit state and prestressed dywidag stays at the ultimate limit state. The strengthening was carried out during 2002. At the same time monitoring of the bridge commenced, using LVDT crack gauges as well as optical fiber sensors....

  11. Coating for gasifiable carbon-graphite fibers

    Science.gov (United States)

    Harper-Tervet, Jan (Inventor); Dowler, Warren L. (Inventor); Yen, Shiao-Ping S. (Inventor); Mueller, William A. (Inventor)

    1982-01-01

    A thin, uniform, firmly adherent coating of metal gasification catalyst is applied to a carbon-graphite fiber by first coating the fiber with a film-forming polymer containing functional moieties capable of reaction with the catalytic metal ions. Multivalent metal cations such as calcium cross-link the polymer such as a polyacrylic acid to insolubilize the film by forming catalytic metal macro-salt links between adjacent polymer chains. The coated fibers are used as reinforcement for resin composites and will gasify upon combustion without evolving conductive airborne fragments.

  12. Fabrication and characterization of Polymer laminate composites reinforced with bi-woven carbon fibers

    Directory of Open Access Journals (Sweden)

    P.V.Sanjeev Kumar

    2015-04-01

    Full Text Available The present paper evaluate slaminatedcarbonbi-wove fibers Reinforced with vinyl ester composites. Vinyl ester was used as a matrix to prepare composites by in situ polymerization technique. Four planar layers were made simultaneously by keeping one over the other and each layer made sure to be weighed off by 15% which was maintained in all layers with different orientations. Pre-assumed Layer-1 is (50/5050%,0º; Layer-2 is (35/35/30 35% 0º, 35% +45º,30%,0;Layer-3is (25/50/25 25% 0º, 50%+45º,25-45º; and Layer-4is (25/25/25/25 (25% 0º, 25% +45º,25% -45º,25% 90º.The composite was prepared with the help of hand layup technique. Test ready specimens were tested with the help of shearing machine in accordance with ASTM Standards .It was observed that vinyl ester made good interface with parent fiber material. Flexural strength and Tensile strength have improved up to 3rd layer and decreased afterwards whereas Flexural modulus and Tensile modulus have linearly increased up to 4th layer. Thermal stability and Glass transition temperature have also been found to be satisfactory for all the laminated layers. Chemical resistance was good for the entire chemicals except sodium hydroxide.

  13. A Retrofit Theory to Prevent Fatigue Crack Initiation in Aging Riveted Bridges Using Carbon Fiber-Reinforced Polymer Materials

    Directory of Open Access Journals (Sweden)

    Elyas Ghafoori

    2016-08-01

    Full Text Available Most research on fatigue strengthening of steel has focused on carbon fiber-reinforced polymer (CFRP strengthening of steel members with existing cracks. However, in many practical cases, aging steel members do not yet have existing cracks but rather are nearing the end of their designed fatigue life. Therefore, there is a need to develop a “proactive” retrofit solution that can prevent fatigue crack initiation in aging bridge members. Such a proactive retrofit approach can be applied to bridge members that have been identified to be deficient, based on structural standards, to enhance their safety margins by extending the design service life. This paper explains a proactive retrofit design approach based on constant life diagram (CLD methodology. The CLD approach is a method that can take into account the combined effect of alternating and mean stress magnitudes to predict the high-cycle fatigue life of a material. To validate the retrofit model, a series of new fatigue tests on steel I-beams retrofitted by the non-prestressed un-bonded CFRP plates have been conducted. Furthermore, this paper attempts to provide a better understanding of the behavior of un-bonded retrofit (UR and bonded retrofit (BR systems. Retrofitting the steel beams using the UR system took less than half of the time that was needed for strengthening with the BR system. The results show that the non-prestressed un-bonded ultra-high modulus (UHM CFRP plates can be effective in preventing fatigue crack initiation in steel members.

  14. Polymer optical fiber bragg grating sensors

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, Søren

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings are reported. We have written fiber Bragg gratings for 1550 nm and 850 nm operations, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  15. Polymer-Derived Ceramic Fibers

    Science.gov (United States)

    Ichikawa, Hiroshi

    2016-07-01

    SiC-based ceramic fibers are derived from polycarbosilane or polymetallocarbosilane precursors and are classified into three groups according to their chemical composition, oxygen content, and C/Si atomic ratio. The first-generation fibers are Si-C-O (Nicalon) fibers and Si-Ti-C-O (Tyranno Lox M) fibers. Both fibers contain more than 10-wt% oxygen owing to oxidation during curing and lead to degradation in strength at temperatures exceeding 1,300°C. The maximum use temperature is 1,100°C. The second-generation fibers are SiC (Hi-Nicalon) fibers and Si-Zr-C-O (Tyranno ZMI) fibers. The oxygen content of these fibers is reduced to less than 1 wt% by electron beam irradiation curing in He. The thermal stability of these fibers is improved (they are stable up to 1,500°C), but their creep resistance is limited to a maximum of 1,150°C because their C/Si atomic ratio results in excess carbon. The third-generation fibers are stoichiometric SiC fibers, i.e., Hi-Nicalon Type S (hereafter Type S), Tyranno SA, and Sylramic™ fibers. They exhibit improved thermal stability and creep resistance up to 1,400°C. Stoichiometric SiC fibers meet many of the requirements for the use of ceramic matrix composites for high-temperature structural application. SiBN3C fibers derived from polyborosilazane also show promise for structural applications, remain in the amorphous state up to 1,800°C, and have good high-temperature creep resistance.

  16. Porous nitrogen doped carbon fiber with churros morphology derived from electrospun bicomponent polymer as highly efficient electrocatalyst for Zn-air batteries

    Science.gov (United States)

    Park, Gi Su; Lee, Jang-Soo; Kim, Sun Tai; Park, Soojin; Cho, Jaephil

    2013-12-01

    Highly porous nitrogen doped carbon fibers like churros morphology are prepared from a simple and cost-effective fabrication process, electrospinning with bicomponent polymer consisting of polystyrene (PS) and polyacrylonitrile (PAN). From appropriate ratio of two polymer and pyrolysis at 1100 °C, newly churros morphology with extremely high surface area (1271 m2 g-1) is prepared. During carbonization, more unstable PS than PAN plays a critical role in forming such morphology by acting as sacrifice materials, thus providing additional formation of inner pores and outer etched surfaces. Furthermore, it demonstrates excellent electrocatalytic activity toward ORR, which is attributed to highly meso- and macro porous nitrogen-doped large surface area and enhanced graphitic-nitrogen groups of carbon fibers. For example, the performance of a Zn-air cell based on the nitrogen-doped porous carbon nanofibers exhibits a peak power density of 194 mW cm-2, comparable to that based on a commercial Pt/C catalyst (192 mW cm-2). Further, the generation of hydrogen peroxide ions (<20%) in a half cell is similar to that on the commercial Pt/C catalyst.

  17. Global Carbon Fiber Composites Supply Chain Competitiveness Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Sujit Das, Josh Warren, Devin West, Susan M. Schexnayder

    2016-05-01

    This analysis identifies key opportunities in the carbon fiber supply chain where resources and investments can help advance the clean energy economy. The report focuses on four application areas — wind energy, aerospace, automotive, and pressure vessels — that top the list of industries using carbon fiber and carbon fiber reinforced polymers. For each of the four application areas, the report addresses the supply and demand trends within that sector, supply chain, and costs of carbon fiber and components.

  18. Patterned functional carbon fibers from polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, Marcus A [ORNL; Saito, Tomonori [ORNL; Brown, Rebecca H [ORNL; Kumbhar, Amar S [University of North Carolina, Chapel Hill; Naskar, Amit K [ORNL

    2012-01-01

    Patterned, continuous carbon fibers with controlled surface geometry were produced from a novel melt-processible carbon precursor. This portends the use of a unique technique to produce such technologically innovative fibers in large volume for important applications. The novelties of this technique include ease of designing and fabricating fibers with customized surface contour, the ability to manipulate filament diameter from submicron scale to a couple of orders of magnitude larger scale, and the amenable porosity gradient across the carbon wall by diffusion controlled functionalization of precursor. The geometry of fiber cross-section was tailored by using bicomponent melt-spinning with shaped dies and controlling the melt-processing of the precursor polymer. Circular, trilobal, gear-shaped hollow fibers, and solid star-shaped carbon fibers of 0.5 - 20 um diameters, either in self-assembled bundle form, or non-bonded loose filament form, were produced by carbonizing functionalized-polyethylene fibers. Prior to carbonization, melt-spun fibers were converted to a char-forming mass by optimizing the sulfonation on polyethylene macromolecules. The fibers exhibited distinctly ordered carbon morphologies at the outside skin compared to the inner surface or fiber core. Such order in carbon microstructure can be further tuned by altering processing parameters. Partially sulfonated polyethylene-derived hollow carbon fibers exhibit 2-10 fold surface area (50-500 m2/g) compared to the solid fibers (10-25 m2/g) with pore sizes closer to the inside diameter of the filaments larger than the sizes on the outer layer. These specially functionalized carbon fibers hold promise for extraordinary performance improvements when used, for example, as composite reinforcements, catalyst support media, membranes for gas separation, CO2 sorbents, and active electrodes and current collectors for energy storage applications.

  19. Photorefractive Polymer Fibers and Devices

    Science.gov (United States)

    2008-10-31

    Emission and Recoverable Photodegradation in a Robust Dye -Doped Polymer," Proc. SPIE 4798, 60-68 (2002). 21. J. J. Park, S. Bian, and M. G. Kuzyk, "Dynamics...be possible to make arrays of RGB fibers so that full color perception is possible. We have been using the photoisomerization mechanisms in azo- dyes to...azo- dye -doped polymer. The resulting decrease in the refractive index yields beam spreading. Beam defocusing in DRI/PMMA thick sample 647 nm We have

  20. Carbonized asphaltene-based carbon-carbon fiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Bohnert, George; Lula, James; Bowen, III, Daniel E.

    2016-12-27

    A method of making a carbon binder-reinforced carbon fiber composite is provided using carbonized asphaltenes as the carbon binder. Combinations of carbon fiber and asphaltenes are also provided, along with the resulting composites and articles of manufacture.

  1. Wettability of a Single Carbon Fiber.

    Science.gov (United States)

    Qiu, Si; Fuentes, Carlos A; Zhang, Dongxing; Van Vuure, Aart Willem; Seveno, David

    2016-09-27

    Wettability as determined from contact angle measurements is a suitable parameter for characterizing the physical bonding of a polymer matrix and reinforcing fibers, but it is very challenging to measure the capillary force exerted by a probe liquid on a fiber accurately for very fine fibers such as single carbon fibers. Herein, we propose an innovative method for measuring dynamic contact angles with a tensiometer, considering both the intrinsic variability of the carbon fiber diameter and the extremely small amplitude of the capillary forces, allowing the measurement of reliable dynamic contact angles over a large range of contact line velocities. The analysis of the contact angle dynamics by the molecular-kinetic theory permits us to check the relevancy of the measured contact angles and to obtain the static contact angle value, improving the prospect of employing tensiometry to better understand the wetting behavior of carbon fibers.

  2. Properties of Fiber Reinforced Polymer Concrete

    Directory of Open Access Journals (Sweden)

    Marinela Bărbuţă

    2008-01-01

    Full Text Available Polymer concrete is a composite material realized with resin and aggregates. In the present study the epoxy resin was used for binding the aggregates. In the composition were introduced near the fly ash, used as filler, the cellulose fibers. The mechanical characteristics such as compressive strength, flexural strength and split tensile strength of polymer concrete with fibers were investigated. The fiber percentage was constant, the epoxy resin and the filler dosages were varied. The cellulose fiber had not improved the mechanical characteristics of the polymer concrete in comparison to that of polymer concrete without cellulose fibers.

  3. Processes for preparing carbon fibers using gaseous sulfur trioxide

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Bryan E.; Lysenko, Zenon; Bernius, Mark T.; Hukkanen, Eric J.

    2016-01-05

    Disclosed herein are processes for preparing carbonized polymers, such as carbon fibers, comprising: sulfonating a polymer with a sulfonating agent that comprises SO.sub.3 gas to form a sulfonated polymer; treating the sulfonated polymer with a heated solvent, wherein the temperature of said solvent is at least 95.degree. C.; and carbonizing the resulting product by heating it to a temperature of 500-3000.degree. C.

  4. 177 fs erbium-doped fiber laser mode locked with a cellulose polymer film containing single-wall carbon nanotubes

    Science.gov (United States)

    Tausenev, A. V.; Obraztsova, E. D.; Lobach, A. S.; Chernov, A. I.; Konov, V. I.; Kryukov, P. G.; Konyashchenko, A. V.; Dianov, E. M.

    2008-04-01

    A mode-locked soliton erbium-doped fiber laser generating 177fs pulses is demonstrated. The laser pumped by a 85mW, 980nm laser diode emits 7mW at 1.56μm at a pulse repetition rate of 50MHz. Passive mode locking is achieved with a saturable absorber made of a high-optical quality film based on cellulose derivative with dispersed carbon single-wall nanotubes. The film is prepared with the original technique by using carbon nanotubes synthesized by the arc-discharge method.

  5. Polymer fiber waveguides for terahertz radiation

    DEFF Research Database (Denmark)

    Nielsen, Kristian

    Terahertz radiation offers many exciting applications noticeably in spectroscopy and it is showing promising results in imaging, mainly for security applications. In this project the study of using structured polymer fibers for THz waveguiding is presented. The inspiration for the THz fiber...... is taken from microstructured polymer optical fibers (mPOFs) used at optical wavelengths for sensing and communication. The fibers investigated can be divided into two groups, the solid core fibers and the hollow core fibers. The solid core fibers offer the broadest bandwidth with the best dispersion....... The polymer material with lowest loss is Topas and all the solid core fibers are manufactured using this material. The polymer PMMA however has higher refractive index along with higher loss, and this higher refractive index is utilized to achieve a large bandwidth hollow core fiber with a low air...

  6. Carbon fiber content measurement in composite

    Science.gov (United States)

    Wang, Qiushi

    Carbon fiber reinforced polymers (CFRPs) have been widely used in various structural applications in industries such as aerospace and automotive because of their high specific stiffness and specific strength. Their mechanical properties are strongly influenced by the carbon fiber content in the composites. Measurement of the carbon fiber content in CFRPs is essential for product quality control and process optimization. In this work, a novel carbonization-in-nitrogen method (CIN) is developed to characterize the fiber content in carbon fiber reinforced thermoset and thermoplastic composites. In this method, a carbon fiber composite sample is carbonized in a nitrogen environment at elevated temperatures, alongside a neat resin sample. The carbon fibers are protected from oxidization while the resin (the neat resin and the resin matrix in the composite sample) is carbonized under the nitrogen environment. The residue of the carbonized neat resin sample is used to calibrate the resin carbonization rate and calculate the amount of the resin matrix in the composite sample. The new method has been validated on several thermoset and thermoplastic resin systems and found to yield an accurate measurement of fiber content in carbon fiber polymer composites. In order to further understand the thermal degradation behavior of the high temperature thermoplastic polymer during the carbonization process, the mechanism and the kinetic model of thermal degradation behavior of carbon fiber reinforced poly (phenylene sulfide) (CPPS) are studied using thermogravimetry analysis (TGA). The CPPS is subjected to TGA in an air and nitrogen atmosphere at heating rates from 5 to 40°C min--1. The TGA curves obtained in air are different from those in nitrogen. This demonstrates that weight loss occurs in a single stage in nitrogen but in two stages in air. To elucidate this difference, thermal decomposition kinetics is analyzed by applying the Kissinger, Flynn-Wall-Ozawa, Coat-Redfern and

  7. Boron nitride converted carbon fiber

    Science.gov (United States)

    Rousseas, Michael; Mickelson, William; Zettl, Alexander K.

    2016-04-05

    This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

  8. Stability of carbon fiber surface chemistry under temperature and its influence on interfacial adhesion with polymer matrices

    Energy Technology Data Exchange (ETDEWEB)

    Vautard, Frederic [ORNL; Grappe, Hippolyte A [ORNL; Ozcan, Soydan [ORNL

    2013-01-01

    The thermal stability of the surface chemistry of a surface treated carbon fiber was investigated by X-ray Photoelectron Spectroscopy. Within a range of temperatures from room temperature to 400 C, the only surface functionalities that decomposed were carboxylic acids and dangling nitrogen containing functionalities like amines, amides or nitriles. Significant amounts of water were desorbed as well. This study enabled the testing of the coherence our the fitting of the C(1s), O(1s) and N(1s) peaks. Particularly, when considering the fitting of in the O(1s) peak, carboxylic acids were shown to be included in a single component peak centered at a binding energy of 532.1 eV. The reaction of the carbon fiber surface and an acrylate resin at high temperature, because of the decomposition of carboxylic acids, was highlighted by Differential Scanning Calorimetry. The thermal history of the composite material during its manufacture appeared to be a major influence on the nature of the interactions generated at the fiber-matrix interface and the resulting mechanical properties.

  9. Hybrid solar cell on a carbon fiber

    Science.gov (United States)

    Grynko, Dmytro A.; Fedoryak, Alexander N.; Smertenko, Petro S.; Dimitriev, Oleg P.; Ogurtsov, Nikolay A.; Pud, Alexander A.

    2016-05-01

    In this work, a method to assemble nanoscale hybrid solar cells in the form of a brush of radially oriented CdS nanowire crystals around a single carbon fiber is demonstrated for the first time. A solar cell was assembled on a carbon fiber with a diameter of ~5-10 μm which served as a core electrode; inorganic CdS nanowire crystals and organic dye or polymer layers were successively deposited on the carbon fiber as active components resulting in a core-shell photovoltaic structure. Polymer, dye-sensitized, and inverted solar cells have been prepared and compared with their analogues made on the flat indium-tin oxide electrode.

  10. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    Directory of Open Access Journals (Sweden)

    Mehran Tehrani

    2014-05-01

    Full Text Available Carbon nanofilament and nanotubes (CNTs have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers employing a synthesis method, graphitic structures by design (GSD, in which carbon structures are grown from fuel mixtures using nickel particles as the catalyst. The synthesis technique is proven feasible to grow nanofilament structures—from ethylene mixtures at 550 °C—on commercial polyacrylonitrile (PAN-based carbon fibers. Raman spectroscopy and electron microscopy were employed to characterize the surface-grown carbon species. For comparison purposes, a catalytic chemical vapor deposition (CCVD technique was also utilized to grow multiwall CNTs (MWCNTs on carbon fiber yarns. The mechanical characterization showed that composites using the GSD-grown carbon nanofilaments outperform those using the CCVD-grown CNTs in terms of stiffness and tensile strength. The results suggest that further optimization of the GSD growth time, patterning and thermal shield coating of the carbon fibers is required to fully materialize the potential benefits of the GSD technique.

  11. Temperature and electrical memory of polymer fibers

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Jinkai; Zakri, Cécile; Grillard, Fabienne; Neri, Wilfrid; Poulin, Philippe [Centre de Recherche Paul Pascal - CNRS, University of Bordeaux, Avenue Schweitzer, 33600 Pessac (France)

    2014-05-15

    We report in this work studies of the shape memory behavior of polymer fibers loaded with carbon nanotubes or graphene flakes. These materials exhibit enhanced shape memory properties with the generation of a giant stress upon shape recovery. In addition, they exhibit a surprising temperature memory with a peak of generated stress at a temperature nearly equal to the temperature of programming. This temperature memory is ascribed to the presence of dynamical heterogeneities and to the intrinsic broadness of the glass transition. We present recent experiments related to observables other than mechanical properties. In particular nanocomposite fibers exhibit variations of electrical conductivity with an accurate memory. Indeed, the rate of conductivity variations during temperature changes reaches a well defined maximum at a temperature equal to the temperature of programming. Such materials are promising for future actuators that couple dimensional changes with sensing electronic functionalities.

  12. Self-healing in single and multiple fiber(s reinforced polymer composites

    Directory of Open Access Journals (Sweden)

    Woldesenbet E.

    2010-06-01

    Full Text Available You Polymer composites have been attractive medium to introduce the autonomic healing concept into modern day engineering materials. To date, there has been significant research in self-healing polymeric materials including several studies specifically in fiber reinforced polymers. Even though several methods have been suggested in autonomic healing materials, the concept of repair by bleeding of enclosed functional agents has garnered wide attention by the scientific community. A self-healing fiber reinforced polymer composite has been developed. Tensile tests are carried out on specimens that are fabricated by using the following components: hollow and solid glass fibers, healing agent, catalysts, multi-walled carbon nanotubes, and a polymer resin matrix. The test results have demonstrated that single fiber polymer composites and multiple fiber reinforced polymer matrix composites with healing agents and catalysts have provided 90.7% and 76.55% restoration of the original tensile strength, respectively. Incorporation of functionalized multi-walled carbon nanotubes in the healing medium of the single fiber polymer composite has provided additional efficiency. Healing is found to be localized, allowing multiple healing in the presence of several cracks.

  13. Self-healing in single and multiple fiber(s) reinforced polymer composites

    Science.gov (United States)

    Woldesenbet, E.

    2010-06-01

    You Polymer composites have been attractive medium to introduce the autonomic healing concept into modern day engineering materials. To date, there has been significant research in self-healing polymeric materials including several studies specifically in fiber reinforced polymers. Even though several methods have been suggested in autonomic healing materials, the concept of repair by bleeding of enclosed functional agents has garnered wide attention by the scientific community. A self-healing fiber reinforced polymer composite has been developed. Tensile tests are carried out on specimens that are fabricated by using the following components: hollow and solid glass fibers, healing agent, catalysts, multi-walled carbon nanotubes, and a polymer resin matrix. The test results have demonstrated that single fiber polymer composites and multiple fiber reinforced polymer matrix composites with healing agents and catalysts have provided 90.7% and 76.55% restoration of the original tensile strength, respectively. Incorporation of functionalized multi-walled carbon nanotubes in the healing medium of the single fiber polymer composite has provided additional efficiency. Healing is found to be localized, allowing multiple healing in the presence of several cracks.

  14. Method for the preparation of carbon fiber from polyolefin fiber precursor, and carbon fibers made thereby

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit Kumar; Hunt, Marcus Andrew; Saito, Tomonori

    2015-08-04

    Methods for the preparation of carbon fiber from polyolefin fiber precursor, wherein the polyolefin fiber precursor is partially sulfonated and then carbonized to produce carbon fiber. Methods for producing hollow carbon fibers, wherein the hollow core is circular- or complex-shaped, are also described. Methods for producing carbon fibers possessing a circular- or complex-shaped outer surface, which may be solid or hollow, are also described.

  15. Multimetallic Electrodeposition on Carbon Fibers

    Science.gov (United States)

    Böttger-Hiller, F.; Kleiber, J.; Böttger, T.; Lampke, T.

    2016-03-01

    Efficient lightweight design requires intelligent materials that meet versatile functions. One approach is to extend the range of properties of carbon fiber reinforced plastics (CFRP) by plating the fiber component. Electroplating leads to metalized layers on carbon fibers. Herein only cyanide-free electrolytes where used. Until now dendrite-free layers were only obtained using current densities below 1.0 A dm-2. In this work, dendrite-free tin and copper coatings were achieved by pre-metalizing the carbon fiber substrates. Furthermore, applying a combination of two metals with different sized thermal expansion coefficient lead to a bimetallic coating on carbon fiber rovings, which show an actuatory effect.

  16. Flexural strengthening of reinforced concrete beams with carbon fibers reinforced polymer (CFRP sheet bonded to a transition layer of high performance cement-based composite

    Directory of Open Access Journals (Sweden)

    V. J. Ferrari

    Full Text Available Resistance to corrosion, high tensile strength, low weight, easiness and rapidity of application, are characteristics that have contributed to the spread of the strengthening technique characterized by bonding of carbon fibers reinforced polymer (CFRP. This research aimed to develop an innovate strengthening method for RC beams, based on a high performance cement-based composite of steel fibers (macro + microfibers to be applied as a transition layer. The purpose of this transition layer is better control the cracking of concrete and detain or even avoid premature debonding of strengthening. A preliminary study in short beams molded with steel fibers and strengthened with CFRP sheet, was carried out where was verified that the conception of the transition layer is valid. Tests were developed to get a cement-based composite with adequate characteristics to constitute the layer transition. Results showed the possibility to develop a high performance material with a pseudo strain-hardening behavior, high strength and fracture toughness. The application of the strengthening on the transition layer surface had significantly to improve the performance levels of the strengthened beam. It summary, it was proven the efficiency of the new strengthening technique, and much information can be used as criteria of projects for repaired and strengthened structures.

  17. Electron beam irradiation-enhanced wettability of carbon fibers.

    Science.gov (United States)

    Kim, Bo-Hye; Lee, Dong Hun; Yang, Kap Seung; Lee, Byung-Cheol; Kim, Yoong Ahm; Endo, Morinobu

    2011-02-01

    A simple but controllable way of altering the surface nature of carbon fibers, without sacrificing their intrinsic mechanical properties, is demonstrated using electron beam irradiation. Such treatment leads to physically improved roughness as well as chemically introduced hydrophilic oxygen-containing functional groups on the surface of carbon fibers that are essential for assuring an efficient stress transfer from carbon fibers to a polymer matrix.

  18. Tribology of natural fiber polymer composites

    CERN Document Server

    Chand, N

    2008-01-01

    Environmental concerns are driving demand for bio-degradable materials such as plant-based natural fiber reinforced polymer composites. These composites are fast replacing conventional materials in many applications, especially in automobiles, where tribology (friction, lubrication and wear) is important. This book covers the availability and processing of natural fiber polymer composites and their structural, thermal, mechanical and, in particular, tribological properties.Chapter 1 discusses sources of natural fibers, their extraction and surface modification. It also reviews the ther

  19. Effects of the Amount and Shape of Carbon Fiber-Reinforced Polymer Strengthening Elements on the Ductile Behavior of Reinforced Concrete Beams

    Science.gov (United States)

    Hong, Sungnam

    2014-09-01

    A series of beam tests were performed to evaluate the ductility of reinforced concrete (RC) beams strengthened with carbon-fiber-reinforced polymer (CFRP) elements. A total of nine RC beams were produced and loaded up to failure in three-point bending under deflection control. In addition, the amount and shape of the CFRP elements (plates/sheets) were considered as the key test variables. Test results revealed that the strengthening with CFRP elements in the width direction was more effective than the strengthening across their height. The energy method used in an analysis showed that the energy ratio of the beams strengthened with CFRP plates were half or less than half of the energy ratio of the beams strengthened with CFRP sheets. In addition, the ductility of the beams decreased as the strengthening ratio of the CFRP elements increased.

  20. Electrospinning of ultra-thin polymer fibers

    NARCIS (Netherlands)

    Jaeger, C.R.; Bergshoef, M.M.; Martin i Batlle, C.; Schönherr, H.; Vancso, G.J.

    1998-01-01

    The electrospinning technique was used to spin ultra-thin fibers from several polymer/solvent systems. The diameter of the electrospun fibers ranged from 16 nm to 2 μm. The morphology of these fibers was investigated with an atomic force microscope (AFM) and an optical microscope. Polyethylene oxide

  1. Investigating the energy harvesting capabilities of a hybrid ZnO nanowires/carbon fiber polymer composite beam.

    Science.gov (United States)

    Masghouni, N; Burton, J; Philen, M K; Al-Haik, M

    2015-03-06

    Hybrid piezoelectric composite structures that are able to convert mechanical energy into electricity have gained growing attention in the past few years. In this work, an energy harvesting composite beam is developed by growing piezoelectric zinc oxide nanowires on the surface of carbon fiber prior to forming structural composites. The piezoelectric behavior of the composite beam was demonstrated under different vibration sources such as water bath sonicator and permanent magnet vibration shaker. The beam was excited at its fundamental natural frequency (43.2 Hz) and the open circuit voltage and the short circuit current were measured to be 3.1 mV and 23 nA, respectively. Upon connecting an optimal resistor (1.2 kΩ) in series with the beam a maximum power output 2.5 nW was achieved.

  2. Biodegradable polymer optical fiber (Conference Presentation)

    Science.gov (United States)

    Zhang, Chenji; Kalaba, Surge; Shan, Dingying; Xu, Kaitian; Yang, Jian; Liu, Zhiwen

    2016-10-01

    Biocompatible and even biodegradable polymers have unique advantages in various biomedical applications. Recent years, photonic devices fabricated using biocompatible polymers have been widely studied. In this work, we manufactured an optical fiber using biodegradable polymer POC and POMC. This step index optical fiber is flexible and easy to handle. Light was coupled into this polymer fiber by directly using objective. The fiber has a good light guiding property and an approximate loss of 2db/cm. Due to the two layer structure, our fiber is able to support applications inside biological tissue. Apart from remarkable optical performance, our fiber was also found capable of performing imaging. By measuring the impulse response of this multimode polymer fiber and using the linear inversion algorithm, concept proving experiments were completed. Images input into our fiber were able to be retrieved from the intensity distribution of the light at the output end. Experiment result proves the capability of our optical fiber to be used as a fiber endoscopy no needs to remove.

  3. Processes for preparing carbon fibers using sulfur trioxide in a halogenated solvent

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Jasson T.; Barton, Bryan E.; Bernius, Mark T.; Chen, Xiaoyun; Hukkanen, Eric J.; Rhoton, Christina A.; Lysenko, Zenon

    2015-12-29

    Disclosed here are processes for preparing carbonized polymers (preferably carbon fibers), comprising sulfonating a polymer with a sulfonating agent that comprises SO.sub.3 dissolved in a solvent to form a sulfonated polymer; treating the sulfonated polymer with a heated solvent, wherein the temperature of the solvent is at least 95.degree. C.; and carbonizing the resulting product by heating it to a temperature of 500-3000.degree. C. Carbon fibers made according to these methods are also disclosed herein.

  4. Experimental Study of Concrete-filled Carbon Fiber Reinforced Polymer Tube with Internal Reinforcement under Axially Loading

    Directory of Open Access Journals (Sweden)

    Wenbin SUN

    2014-12-01

    Full Text Available Comparing with the circular concrete columns confined with fiber reinforced polymer (FRP wrap or tube, the rectilinear confined columns were reported much less. Due to the non-uniform distribution of confining pressure in the rectilinear confined columns, the FRP confinement effectiveness was significant reduced. This paper presents findings of an experimental program where nine prefabricated rectangular cross-section CFRP tubes with CFRP integrated crossties filled concrete to form concrete-filled FRP tube (CFFT short columns and three plain concrete control specimens were tested. All specimens were axially loaded until failure. The rest results showed that the stress-strain curves of CFFTs consisted of two distinct branches, an ascending branch before the concrete peak stress was reaches and a second branch that terminated when the tube ruptured, and that the CFFTs with integrated crossties experienced most uniform confinement pressure distribution. Test research also found that the stress-strain curves of CFFTs indicated an increase in ductility. These demonstrate that this confinement system can produce higher lateral confinement stiffness. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6035

  5. Electrospun Polymer Fibers for Electronic Applications

    Directory of Open Access Journals (Sweden)

    Alessandro Luzio

    2014-01-01

    Full Text Available Nano- and micro- fibers of conjugated polymer semiconductors are particularly interesting both for applications and for fundamental research. They allow an investigation into how electronic properties are influenced by size confinement and chain orientation within microstructures that are not readily accessible within thin films. Moreover, they open the way to many applications in organic electronics, optoelectronics and sensing. Electro-spinning, the technique subject of this review, is a simple method to effectively form and control conjugated polymer fibers. We provide the basics of the technique and its recent advancements for the formation of highly conducting and high mobility polymer fibers towards their adoption in electronic applications.

  6. Thermoplastic coated carbon fibers for textile preforms

    Science.gov (United States)

    Allen, L. E.; Edie, D. D.; Lickfield, G. C.; Mccollum, J. R.

    1988-01-01

    A continuous process for producing prepreg from carbon fiber and thermoplastic matrix is described. After the tow has been spread using a pneumatic device, the process utilizes a fluidized bed to apply thermoplastic powder to the bundle. Finally, direct electrical heating of the coated fiber tow melts the polymer on the individual fibers, creating a uniform and extremely flexible prepreg. The efficiency of the process was evaluated during initial trials in which a thermoplastic polyimide, LaRC-TPI, was applied to T-300, 3K (3000 filament) carbon fiber tow. The physical properties of unidirectional composite specimens fabricated from this prepreg were measured, and the matrix uniformity and void content of the samples was determined. The results of these evaluations are detailed and discussed.

  7. A microstructured Polymer Optical Fiber Biosensor

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Jensen, Jesper Bo; Hoiby, Poul E.

    2006-01-01

    We demonstrate selective detection of fluorophore labeled antibodies from minute samples probed by a sensor layer of the complementary biomolecules immobilized inside the air holes of microstructured Polymer Optical Fibers....

  8. All-solid-state supercapacitors with poly(3,4-ethylenedioxythiophene)-coated carbon fiber paper electrodes and ionic liquid gel polymer electrolyte

    Science.gov (United States)

    Pandey, G. P.; Rastogi, A. C.; Westgate, Charles R.

    2014-01-01

    All-solid-state thin supercapacitors have been fabricated using current pulse polymerized poly(3,4-ethylenedioxythiophene) (PEDOT) over carbon fiber paper and ionic liquid based gel polymer electrolyte. The PEDOT-coated carbon paper electrodes were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) which confirm the porous morphology of PEDOT at the nanoscale and a high degree of ClO4- dopant ion conjugation. The performance characteristics of the supercapacitor cells have been evaluated by ac impedance spectroscopy, cyclic voltammetry and galvanostatic charge-discharge techniques. The PEDOT electrode shows specific capacitance of ∼154.5 F g-1, which correspond to the cell area-normalized capacitance of 85 mF cm-2. The maximum specific energy and specific power of the solid-state supercapacitor cell, calculated from charge-discharge characteristics, are 6.5 Wh kg-1 and 11.3 kW kg-1, respectively. The solid-state supercapacitor shows good cycle durability and time stability. The thin, lightweight, gel electrolyte based supercapacitor shows considerable potential for low-cost, high-performance energy storage applications.

  9. Machinability study of Carbon Fiber Reinforced Polymer in the longitudinal and transverse direction and optimization of process parameters using PSO–GSA

    Directory of Open Access Journals (Sweden)

    K. Shunmugesh

    2016-09-01

    Full Text Available Carbon Fiber Reinforced Polymer (CFRP composites are widely used in aerospace industry in lieu of its high strength to weight ratio. This study is an attempt to evaluate the machinability of Bi-Directional Carbon Fiber–Epoxy composite and optimize the process parameters of cutting speed, feed rate and drill tool material. Machining trials were carried using drill bits made of high speed steel, TiN and TiAlN at different cutting speeds and feed rates. Output parameters of thrust force and torque were monitored using Kistler multicomponent dynamometer 9257B and vibrations occurring during machining normal to the work surface were measured by a vibration sensor (Dytran 3055B. Linear regression analysis was carried out by using Response Surface Methodology (RSM, to correlate the input and output parameters in drilling of the composite in the longitudinal and transverse directions. The optimization of process parameters were attempted using Genetic Algorithm (GA and Particle Swarm Optimization–Gravitational Search Algorithm (PSO–GSA techniques.

  10. PREPARATION OF CARBON NANOFIBERS BY POLYMER BLEND TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The polymer blend technique is a novel method to produced carbon nanofibers. In this paper, we have prepared fine carbon fibers and porous carbon materials by this technique, and we will discuss the experiment results by means of SEM, TGA, Element Analysis, etc.

  11. Passive and Portable Polymer Optical Fiber Cleaver

    DEFF Research Database (Denmark)

    Saez-Rodriguez, D.; Min, R.; Ortega, B.

    2016-01-01

    Polymer optical fiber (POF) is a growing technology in short distance telecommunication due to its flexibility, easy connectorization, and lower cost than the mostly deployed silica optical fiber technology. Microstructured POFs (mPOFs) have particular promising potential applications...... in the sensors and telecommunications field, and they could specially help to reduce losses in polymer fibers by using hollow-core fibers or reduce the modal dispersion by providing a large mode area endlessly single-mode. However, mPOFs are intrinsically more difficult to cut due to the cladding hole structure...... and it becomes necessary to have a high quality POF cleaver. In the well-known hot-blade cutting process, fiber and blade are heated, which requires electrical components and increases cost. A new method has recently been identified, allowing POF to be cut without the need for heating the blade and fiber, thus...

  12. Novel method for carbon nanofilament growth on carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Johathan [Los Alamos National Laboratory; Luhrs, Claudia [UNM MECH.ENG.; Terani, Mehran [UNM MECH.ENG.; Al - Haik, Marwan [UNM MECH.ENG.; Garcia, Daniel [UNM MECH.ENG.; Taha, Mahmoud R [UNM MECH.ENG.

    2009-01-01

    Fiber reinforced structural composites such as fiber reinforced polymers (FRPs) have proven to be key materials for blast mitigation due to their enhanced mechanical performance. However, there is a need to further increase total energy absorption of the composites in order to retain structural integrity in high energy environments, for example, blast events. Research has shown that composite failure in high energy environments can be traced to their relatively low shear strength attributed to the limited bond strength between the matrix and the fibers. One area of focus for improving the strength of composite materials has been to create 'multi-scale' composites. The most common approach to date is to introduce carbon nanotubes into a more traditional composite consisting of epoxy with embedded micron scale fibers. The inclusion of carbon nanotubes (CNT) clearly toughens different matrices. Depositing CNT in brittle matrix increases stiffness by orders of magnitude. Currently, this approach to create multiscale composites is limited due to the difficulty of dispersing significant amounts of nanotubes. It has repeatedly been reported that phase separation occurs above relatively low weight percent loading (ca. 3%) due to the strong van der Waals forces between CNTs compared with that between CNT and polymer. Hence, the nanotubes tend to segregate and form inclusions. One means to prevent nanotube or nanofilament agglomeration is to anchor one end of the nanostructure, thereby creating a stable multi-phase structure. This is most easily done by literally growing the CNTs directly on micron scale fibers. Recently, CNT were grown on carbon fibers, both polyacrylonitrile- (PAN-) and pitch-based, by hot filament chemical vapor deposition (HFCVD) using H2 and CH4 as precursors. Nickel clusters were electrodeposited on the fiber surfaces to catalyze the growth and uniform CNT coatings were obtained on both the PAN- and pitch-based carbon fibers. Multiwalled CNTs

  13. Nano polypeptide particles reinforced polymer composite fibers.

    Science.gov (United States)

    Li, Jiashen; Li, Yi; Zhang, Jing; Li, Gang; Liu, Xuan; Li, Zhi; Liu, Xuqing; Han, Yanxia; Zhao, Zheng

    2015-02-25

    Because of the intensified competition of land resources for growing food and natural textile fibers, there is an urgent need to reuse and recycle the consumed/wasted natural fibers as regenerated green materials. Although polypeptide was extracted from wool by alkaline hydrolysis, the size of the polypeptide fragments could be reduced to nanoscale. The wool polypeptide particles were fragile and could be crushed down to nano size again and dispersed evenly among polymer matrix under melt extrusion condition. The nano polypeptide particles could reinforce antiultraviolet capability, moisture regain, and mechanical properties of the polymer-polypeptide composite fibers.

  14. Dynamic Characterization of Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Andresen, Søren; Yuan, Wu;

    2012-01-01

    With the increasing interest in fiber sensors based on polymer optical fibers, it becomes fundamental to determine the real applicability and reliability of this type of sensor. The viscoelastic nature of polymers gives rise to questions about the mechanical behavior of the fibers. In particular...... to the limit set by our measurement system. A more detailed analysis shows that viscoelastic effects are present and that they increase with both applied strain and frequency. However, the possibility of developing sensors that measure small dynamic deformations is not compromised. A stress...

  15. 聚合物涂层对高模量碳纤维表面性能的影响%Effects of polymer coating on the properties of high modulus carbon fiber

    Institute of Scientific and Technical Information of China (English)

    刘占清; 张学军; 康素梅; 田艳红

    2012-01-01

    In order to improve the surface properties of carbon fibers and the interface properties of carbon fiber/resin composites,high modulus carbon fibers(HMCF) were treated with the polymer coating.The influence of the content of latent curing agent(LCA) in the coating layer on the carbon fiber surface properties and interface properties of carbon fiber/resin composites were studied.The results show that the polymer coating may have chemical reaction with carbon fiber or resin by IR analysis.SEM and DMTA also show polymer coating can improve the interfacical properties of carbon fiber/resin composites.The amount of LCA in the coating layer is the crucial factor to improve interfacial properties of carbon fiber/resin composites.When the content of the LCA is 20%,the interlaminar shear strength(ILSS) of the sized HMCF/epoxy resin composites is improved to 77.9 MPa,increased by 8.6% compared with that of the composites reinforced by unsized HMCF.%为改善碳纤维表面性能以及碳纤维/树脂复合材料的界面性能,对PAN基高模量碳纤维(HMCF)表面进行聚合物涂层处理。研究了不同潜伏性固化剂含量的聚合物涂层对HMCF表面以及碳纤维/树脂复合材料的界面性能的影响。IR分析表明,聚合物涂层与纤维或树脂基体发生了化学反应。扫描电镜和动态机械热分析的结果也说明,聚合物涂层能够提高HMCF/树脂复合材料的界面性能。潜伏性固化剂的含量是影响纤维/树脂复合材料的界面性能的关键因素。潜伏性固化剂含量为20%的聚合物涂层涂覆后的HMCF/树脂复合材料的层间剪切强度显著提高,达到了77.9MPa,较未涂覆聚合物涂层的HMCF/树脂复合材料提高了8.6%。

  16. Carbon Fiber Biocompatibility for Implants

    OpenAIRE

    Richard Petersen

    2016-01-01

    Carbon fibers have multiple potential advantages in developing high-strength biomaterials with a density close to bone for better stress transfer and electrical properties that enhance tissue formation. As a breakthrough example in biomaterials, a 1.5 mm diameter bisphenol-epoxy/carbon-fiber-reinforced composite rod was compared for two weeks in a rat tibia model with a similar 1.5 mm diameter titanium-6-4 alloy screw manufactured to retain bone implants. Results showed that carbon-fiber-rein...

  17. The Evaluation of the Possibilities of Using PLGA Co-Polymer and Its Composites with Carbon Fibers or Hydroxyapatite in the Bone Tissue Regeneration Process – in Vitro and in Vivo Examinations

    Directory of Open Access Journals (Sweden)

    Tadeusz Cieślik

    2009-07-01

    Full Text Available Synthetic polymers belonging to the aliphatic polyester group have become highly promising biomaterials for reconstructive medicine. The purpose of the present work is a biological evaluation of lactide-glycolide co-polymer (PLGA and its composites with carbon fibers (PLGA+CF or hydroxyapatite (PLGA+HA. The cytotoxicity of the evaluated materials towards hFOB 1.19 human osteoblast-like cells was assessed. Moreover, during the one-year contact of the assessed materials with living osseous tissue, the progress of bone formation was analyzed and the accompanying process of the materials’ degradation was evaluated. The materials under evaluation proved to be biocompatible.

  18. The evaluation of the possibilities of using PLGA co-polymer and its composites with carbon fibers or hydroxyapatite in the bone tissue regeneration process - in vitro and in vivo examinations.

    Science.gov (United States)

    Cieślik, Magdalena; Mertas, Anna; Morawska-Chochól, Anna; Sabat, Daniel; Orlicki, Rajmund; Owczarek, Aleksander; Król, Wojciech; Cieślik, Tadeusz

    2009-07-15

    Synthetic polymers belonging to the aliphatic polyester group have become highly promising biomaterials for reconstructive medicine. The purpose of the present work is a biological evaluation of lactide-glycolide co-polymer (PLGA) and its composites with carbon fibers (PLGA+CF) or hydroxyapatite (PLGA+HA). The cytotoxicity of the evaluated materials towards hFOB 1.19 human osteoblast-like cells was assessed. Moreover, during the one-year contact of the assessed materials with living osseous tissue, the progress of bone formation was analyzed and the accompanying process of the materials' degradation was evaluated. The materials under evaluation proved to be biocompatible.

  19. Carbon Fiber from Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Milbrandt, Anelia [Clean Energy Manufacturing Analysis Center, Godlen, CO (United States); Booth, Samuel [Clean Energy Manufacturing Analysis Center, Godlen, CO (United States)

    2016-09-01

    Carbon fiber (CF), known also as graphite fiber, is a lightweight, strong, and flexible material used in both structural (load-bearing) and non-structural applications (e.g., thermal insulation). The high cost of precursors (the starting material used to make CF, which comes predominately from fossil sources) and manufacturing have kept CF a niche market with applications limited mostly to high-performance structural materials (e.g., aerospace). Alternative precursors to reduce CF cost and dependence on fossil sources have been investigated over the years, including biomass-derived precursors such as rayon, lignin, glycerol, and lignocellulosic sugars. The purpose of this study is to provide a comprehensive overview of CF precursors from biomass and their market potential. We examine the potential CF production from these precursors, the state of technology and applications, and the production cost (when data are available). We discuss their advantages and limitations. We also discuss the physical properties of biomass-based CF, and we compare them to those of polyacrylonitrile (PAN)-based CF. We also discuss manufacturing and end-product considerations for bio-based CF, as well as considerations for plant siting and biomass feedstock logistics, feedstock competition, and risk mitigation strategies. The main contribution of this study is that it provides detailed technical and market information about each bio-based CF precursor in one document while other studies focus on one precursor at a time or a particular topic (e.g., processing). Thus, this publication allows for a comprehensive view of the CF potential from all biomass sources and serves as a reference for both novice and experienced professionals interested in CF production from alternative sources.

  20. Comparative study on submillimeter flaws in stitched T-joint carbon fiber reinforced polymer by infrared thermography, microcomputed tomography, ultrasonic c-scan and microscopic inspection

    Science.gov (United States)

    Zhang, Hai; Hassler, Ulf; Genest, Marc; Fernandes, Henrique; Robitaille, Francois; Ibarra-Castanedo, Clemente; Joncas, Simon; Maldague, Xavier

    2015-10-01

    Stitching is used to reduce dry-core (incomplete infusion of T-joint core) and reinforce T-joint structure. However, it may cause new types of flaws, especially submillimeter flaws. Microscopic inspection, ultrasonic c-scan, pulsed thermography, vibrothermography, and laser spot thermography are used to investigate the internal flaws in a stitched T-joint carbon fiber-reinforced polymer (CFRP) matrix composites. Then, a new microlaser line thermography is proposed. Microcomputed tomography (microCT) is used to validate the infrared results. A comparison between microlaser line thermography and microCT is performed. It was concluded that microlaser line thermography can detect the internal submillimeter defects. However, the depth and size of the defects can affect the detection results. The microporosities with a diameter of less than 54 μm are not detected in the microlaser line thermography results. Microlaser line thermography can detect the microporosity (a diameter of 0.162 mm) from a depth of 90 μm. However, it cannot detect the internal microporosity (a diameter of 0.216 mm) from a depth of 0.18 mm. The potential causes are given. Finally, a comparative study is conducted.

  1. Characterization of carbon fibers and fiber-matrix adhesion in composites

    Science.gov (United States)

    Wightman, J. P.; Devilbiss, T. A.

    1985-01-01

    The effect of fiber/matrix interactions on the mechanical properties of thermoplastic carbon fiber composites was determined. The experimental approach was a multi-faceted one involving the following areas: characterization of the surface of carbon fibers using X-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS) and scanning transmission electron microcopy (STEM); determination of the functional groups on carbon fiber surfaces using an elemental tagging scheme - derivatization; determination of the polar and dispersion contribution to the surface energy of carbon fibers by measuring wetting forces in a series of liquids having known polar and dispersion components; and study of the interaction of thermoplastic polymers with carbon surfaces by solution adsorption, STEM and fiber critical length.

  2. Multifunctional Carbon Nanotube Fiber Composites

    Science.gov (United States)

    2007-11-02

    coagulant. The second process (patent pending) is novel in that it directly results polymer-free nanotube fibers without using a super acid spinning...chemical and electrochemical stability, hydrophobicity and viscosity . The generic structure, chemical name and abbreviations for the most common ions...modification procedure involved the electrochemical infiltration of small amounts of the polypyrrole/p-toluene sulphonate (PPy/PTS) conducting polymer

  3. Adsorption characteristics of activated carbon hollow fibers

    OpenAIRE

    2009-01-01

    Carbon hollow fibers were prepared with regenerated cellulose or polysulfone hollow fibers by chemical activation using sodium phosphate dibasic followed by the carbonization process. The activation process increases the adsorption properties of fibers which is more prominent for active carbone fibers obtained from the cellulose precursor. Chemical activation with sodium phosphate dibasic produces an active carbon material with both mesopores and micropores.

  4. Coating Carbon Fibers With Platinum

    Science.gov (United States)

    Effinger, Michael R.; Duncan, Peter; Coupland, Duncan; Rigali, Mark J.

    2007-01-01

    A process for coating carbon fibers with platinum has been developed. The process may also be adaptable to coating carbon fibers with other noble and refractory metals, including rhenium and iridium. The coated carbon fibers would be used as ingredients of matrix/fiber composite materials that would resist oxidation at high temperatures. The metal coats would contribute to oxidation resistance by keeping atmospheric oxygen away from fibers when cracks form in the matrices. Other processes that have been used to coat carbon fibers with metals have significant disadvantages: Metal-vapor deposition processes yield coats that are nonuniform along both the lengths and the circumferences of the fibers. The electrical resistivities of carbon fibers are too high to be compatible with electrolytic processes. Metal/organic vapor deposition entails the use of expensive starting materials, it may be necessary to use a furnace, and the starting materials and/or materials generated in the process may be hazardous. The present process does not have these disadvantages. It yields uniform, nonporous coats and is relatively inexpensive. The process can be summarized as one of pretreatment followed by electroless deposition. The process consists of the following steps: The surfaces of the fiber are activated by deposition of palladium crystallites from a solution. The surface-activated fibers are immersed in a solution that contains platinum. A reducing agent is used to supply electrons to effect a chemical reduction in situ. The chemical reduction displaces the platinum from the solution. The displaced platinum becomes deposited on the fibers. Each platinum atom that has been deposited acts as a catalytic site for the deposition of another platinum atom. Hence, the deposition process can also be characterized as autocatalytic. The thickness of the deposited metal can be tailored via the duration of immersion and the chemical activity of the solution.

  5. Carbon Fiber Technology Facility (CFTF)

    Data.gov (United States)

    Federal Laboratory Consortium — Functionally within the MDF, ORNL operates DOE’s unique Carbon Fiber Technology Facility (CFTF)—a 42,000 ft2 innovative technology facility and works with leading...

  6. Effect of plasma surface treatment of recycled carbon fiber on carbon fiber-reinforced plastics (CFRP) interfacial properties

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hooseok, E-mail: hooseok.lee@gmail.com; Ohsawa, Isamu; Takahashi, Jun

    2015-02-15

    Highlights: • Plasma treatment was used to improve the adhesion property between the recycled CF and polymer matrix. • In order to evaluate the adhesion between plasma treated recycled CF and polymer, micro droplet test was conducted. • The interfacial shear strength and the interfacial adhesion of recycled carbon fiber increased. - Abstract: We studied the effects of plasma surface treatment of recycled carbon fiber on adhesion of the fiber to polymers after various treatment times. Conventional surface treatment methods have been attempted for recycled carbon fiber, but most require very long processing times, which may increase cost. Hence, in this study, plasma processing was performed for 0.5 s or less. Surface functionalization was quantified by X-ray photoelectron spectroscopy. O/C increased from approximately 11% to 25%. The micro-droplet test of adhesion properties and the mechanical properties of CFRP were also investigated.

  7. Plasma electrolytic polishing of metalized carbon fibers

    Directory of Open Access Journals (Sweden)

    Falko Böttger-Hiller

    2016-02-01

    Full Text Available Efficient lightweight structures require intelligent materials that meet versatile functions. Especially, carbon-fiber-reinforced polymers (CFRPs are gaining relevance. Their increasing use aims at reducing energy consumption in many applications. CFRPs are generally very light in weight, while at the same time being extremely stiff and strong (specific strength: CFRPs: 1.3 Nm kg–1, steel: 0.27 Nm kg–1; specific stiffness: CFRPs: 100 Nm kg–1, steel: 25 Nm kg–1. To increase performance and especially functionality of CFRPs, the integration of microelectronic components into CFRP parts is aspired. The functionalization by sensors, actuators and electronics can enable a high lightweight factor and a new level of failure-safety. The integration of microelectronic components for this purpose requires a working procedure to provide electrical contacts for a reliable connection to energy supply and data interfaces. To overcome this challenge, metalized carbon fibers are used. Metalized fibers are, similar to the usual reinforcing fibers, able to be soldered and therefore easy to incorporate into CFRPs. Unfortunately, metalized fibers have to be pre-treated by flux-agents. Until now, there is no flux which is suitable for mass production without destroying the polymer of the CFRP. The process of plasma electrolytic polishing (PeP could be an option, but is so far not available for copper. Thus, in this study, plasma electrolytic polishing is transferred to copper and its alloys. To achieve this, electrolytic parameters as well as the electrical setup are adapted. It can be observed that the gloss and roughness can be adjusted by means of this procedure. Finally, plasma electrolytic polishing is used to treat thin copper layers on carbon fibers.

  8. High efficient preparation of carbon nanotube-grafted carbon fibers with the improved tensile strength

    Science.gov (United States)

    Fan, Wenxin; Wang, Yanxiang; Wang, Chengguo; Chen, Jiqiang; Wang, Qifen; Yuan, Yan; Niu, Fangxu

    2016-02-01

    An innovative technique has been developed to obtain the uniform catalyst coating on continuously moving carbon fibers. Carbon nanotube (CNT)-grafted carbon fibers with significantly improved tensile strength have been succeeded to produce by using chemical vapor deposition (CVD) when compared to the tensile strength of untreated carbon fibers. The critical requirements for preparation of CNT-grafted carbon fibers with high tensile strength have been found, mainly including (i) the obtainment of uniform coating of catalyst particles with small particle size, (ii) the low catalyst-induced and mechano-chemical degradation of carbon fibers, and (iii) the high catalyst activity which could facilitate the healing and strengthening of carbon fibers during the growth of CNTs. The optimum growth temperature was found to be about 500 °C, and the optimum catalyst is Ni due to its highest activity, there is a pronounced increase of 10% in tensile strength of carbon fibers after CNT growth at 500 °C by using Ni catalyst. Based on the observation from HRTEM images, a healing and crosslink model of neighboring carbon crystals by CNTs has been formulated to reveal the main reason that causes an increase in tensile strength of carbon fibers after the growth of CNTs. Such results have provided the theoretical and experimental foundation for the large-scale preparation of CNT-grafted carbon fibers with the improved tensile strength, significantly promoting the development of CNT-grafted carbon fiber reinforced polymer composites.

  9. Experimental study about laser cutting of carbon fiber reinforced polymer%激光切割碳纤维复合材料的实验研究

    Institute of Scientific and Technical Information of China (English)

    花银群; 肖淘; 薛青; 刘海霞; 叶云霞; 陈瑞芳

    2013-01-01

    In order to obtain the influence rule of laser cutting parameters on carbon fiber reinforced polymer (CFRP), CFRPs were cut with a 500W millisecond pulsed Nd∶YAG laser in air and under the water respectively .The relationships of pulse energy , frequency, cutting speed, gas pressure with the cutting quality were investigated by means of the one-factor experimental design .The influence of the laser cutting parameters on kerf width , fiber pull out at the beam entrance , fiber pull out at the beam exit and taper angle were obtained .The laser cutting mechanism was also analyzed and studied .The research shows that the laser cutting under the water can greatly reduce the heat affected zone generated by the laser cutting, which provides some reference for the further research of the laser cutting CFRP under the water .%  为了获得激光切割参量对碳纤维复合材料的影响规律,利用额定功率为500W的毫秒脉冲Nd∶YAG激光器,分别进行了在空气中和水下切割碳纤维复合材料( CFRP )的实验研究。采用单因素实验法,考察了脉冲能量、频率、切割速度与气体压力等激光参量对切割质量的影响,获得了激光参量对切割CFRP材料切口的切缝宽度、正面纤维拔出长度、背面纤维拔出长度与锥角的影响规律,并对激光切割机理进行了分析研究。结果表明,水下切割能有效地减小激光切割产生的热影响区。这为继续开展激光水下切割CFRP的研究提供了参考。

  10. Research Progress on Thermal Conductivity of Carbon Fiber Reinforced Polymer Matrix Composites%导热型碳纤维增强聚合物基复合材料的研究进展

    Institute of Scientific and Technical Information of China (English)

    李仕通; 彭超义; 邢素丽; 肖加余

    2012-01-01

    The present state and development of thermal conductivity of carbon fiber reinforced polymer matrix composites (CFRP) are reviewed. Phonon and photon thermal conduction mechanism of CFRP are described. The computing models and testing methods for the thermal conductivity of CFRP, prepared by different ply angles and different packing fractions, are illustrated. The effects of the resin systems (including epoxy resin, cyanate ester, bisma-leimide resin), carbon fibers (including PAN carbon fibers, mesophase pitch carbon fibers, vapor grown carbon fibers, carbon nanotube fibers), processing technologies etc. on the thermal conductivity of CFRP are also analyzed.%综述了导热型连续碳纤维增强聚合物基复合材料(CFRP)的研究与应用现状和进展,阐述了CFRP的声子导热和光子导热机理,介绍了不同铺层角度和铺层比的CFRP面内和厚度方向热导率计算模型及测试方法,分析了环氧树脂、氰酸酯、双马来酰亚胺等3类树脂体系和聚丙烯腈基(PAN)碳纤维、中间相沥青基碳纤维、气相生长碳纤维、碳纳米管纤维等4类增强体以及工艺方法等因素对CFRP热导率的影响.

  11. Nanotailored Carbon Fibers

    Science.gov (United States)

    2012-04-27

    precursor fiber and also utilize bi- component spinning along with gel spinning, to obtain small diameter fibers. Various processing parameters during...shape of the fiber. In this regard, we have also conducted single component gel spinning using different gelation bath temperatures (100% methanol). SEM...domestic dishwashing detergent, Palmolive antibacterial , 3 wt% detergent and 97% water) for about a week and retested. *** For 5th trial, tungsten

  12. Jilin Chemical Fiber Group Launches Its Largest Carbon Fiber Preject

    Institute of Scientific and Technical Information of China (English)

    Flora

    2011-01-01

    China's carbon fiber precursor production line with 5,000 tons of annual output was put into operation in Jilin Chemical Fiber Group on November 18th this year, creating the maximum production capacity currently in China, for which Jilin Chemical Fiber Group become China's largest carbon fiber precursor production base, The smooth operation of the project has laid a solid foundation for promoting China's carbon fiber industry steady, rapid, and healthy development,

  13. Smart polymer fibers with shape memory effect

    Science.gov (United States)

    Ji, Feng Long; Zhu, Yong; Lian Hu, Jin; Liu, Yan; Yeung, Lap-Yan; Dou Ye, Guang

    2006-12-01

    In this study, a series of smart polymer fibers with a shape memory effect were developed. Firstly, a set of shape memory polyurethanes with varying hard-segment content were synthesized. Then, the solutions of the shape memory polyurethanes were spun into fibers through wet spinning. The thin films of the polyurethanes were considered to represent the nature of the polyurethanes. Differential scanning calorimetry tests were performed on both the thin films and the fibers to compare their thermal properties. Wide angle x-ray diffraction and small angle x-ray scattering techniques were applied to investigate the structure of the thin films and the fibers, and the structure change taking place in the spinning process was therefore revealed. The spinning process resulted in the polyurethane molecules being partially oriented in the direction of the fiber axis. The molecular orientation prompted the aggregation of the hard segments and the formation of hard-segment microdomains. The mechanical properties of the fibers were examined through tensile tests. The shape memory effect of the thin films and the fibers was investigated through a series of thermomechanical cyclic tensile tests. It was found that the fibers showed less shape fixity but more shape recovery compared with the thin films. Further investigations revealed that the recovery stress of the fibers was higher than that of the thin films. The smart fibers may exert the recovery force of shape memory polymers to an extreme extent in the direction of the fiber axis and therefore provide a possibility for producing high-performance actuators.

  14. Structural health monitoring system/method using electroactive polymer fibers

    Science.gov (United States)

    Scott-Carnell, Lisa A. (Inventor); Siochi, Emilie J. (Inventor)

    2013-01-01

    A method for monitoring the structural health of a structure of interest by coupling one or more electroactive polymer fibers to the structure and monitoring the electroactive responses of the polymer fiber(s). Load changes that are experienced by the structure cause changes in the baseline responses of the polymer fiber(s). A system for monitoring the structural health of the structure is also provided.

  15. Carbon nanotube reinforced polyacrylonitrile and poly(etherketone) fibers

    Science.gov (United States)

    Jain, Rahul

    The graphitic nature, continuous structure, and high mechanical properties of carbon nanotubes (CNTs) make them good candidate for reinforcing polymer fiber. The different types of CNTs including single-wall carbon nanotubes (SWNTs), few-wall carbon nanotubes (FWNTs), and multi-wall carbon nanotubes (MWNTs), and carbon nanofibers (CNFs) differ in terms of their diameter and number of graphitic walls. The desire has been to increase the concentration of CNTs as much as possible to make next generation multi-functional materials. The work in this thesis is mainly focused on MWNT and CNF reinforced polyacrylonitrile (PAN) composite fibers, and SWNT, FWNT, and MWNT reinforced poly(etherketone) (PEK) composite fibers. To the best of our knowledge, this is the first study to report the spinning of 20% MWNT or 30% CNF reinforced polymer fiber spun using conventional fiber spinning. Also, this is the first study to report the PEK/CNT composite fibers. The fibers were characterized for their thermal, tensile, mechanical, and dynamic mechanical properties. The fiber structure and morphology was studied using WAXD and SEM. The effect of two-stage heat drawing, sonication time for CNF dispersion, fiber drying temperature, and molecular weight of PAN was also studied. Other challenges associated with processing high concentrations of solutions for making composite fibers have been identified and reported. The effect of CNT diameter and concentration on fiber spinnability and electrical conductivity of composite fiber have also been studied. This work suggests that CNT diameter controls the maximum possible concentration of CNTs in a composite fiber. The results show that by properly choosing the type of CNT, length of CNTs, dispersion of CNTs, fiber spinning method, fiber draw ratio, and type of polymer, one can get electrically conducting fibers with wide range of conductivities for different applications. The PEK based control and composite fibers possess high thermal

  16. Global Carbon Fiber Composites. Supply Chain Competitiveness Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sujit [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Warren, Joshua A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); West, Devin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Schexnayder, Susan M. [Univ. of Tennessee, Knoxville, TN (United States)

    2016-05-01

    The objective of this study is to identify key opportunities in the carbon fiber (CF) supply chain where resources and investments can help advance the clean energy economy. The report focuses on four application areas—wind energy, aerospace, automotive, and pressure vessels—that top the list of industries using CF and carbon fiber reinforced polymers (CFRP) and are particularly relevant to the mission of U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (DOE EERE). For each of the four application areas, the report addresses the supply and demand trends within that sector, supply chain, and costs of carbon fiber and components.

  17. Field Strain Measurement on the Fiber Scale in Carbon Fiber Reinforced Polymers Using Global Finite-Element Based Digital Image Correlation

    KAUST Repository

    Tao, Ran

    2015-05-01

    Laminated composites are materials with complex architecture made of continuous fibers embedded within a polymeric resin. The properties of the raw materials can vary from one point to another due to different local processing conditions or complex geometrical features for example. A first step towards the identification of these spatially varying material parameters is to image with precision the displacement fields in this complex microstructure when subjected to mechanical loading. This thesis is aimed to accurately measure the displacement and strain fields at the fiber-matrix scale in a cross-ply composite. First, the theories of both local subset-based digital image correlation (DIC) and global finite-element based DIC are outlined. Second, in-situ secondary electron tensile images obtained by scanning electron microscopy (SEM) are post-processed by both DIC techniques. Finally, it is shown that when global DIC is applied with a conformal mesh, it can capture more accurately sharp local variations in the strain fields as it takes into account the underlying microstructure. In comparison to subset-based local DIC, finite-element based global DIC is better suited for capturing gradients across the fiber-matrix interfaces.

  18. All-round joining method with carbon fiber reinforced interface

    Science.gov (United States)

    Miwa, Noriyoshi; Tanaka, Kazunori; Kamiya, Yoshiko; Nishi, Yoshitake

    2008-08-01

    Carbon fiber reinforced polymer (CFRP) has been recently applied to not only wing, but also fan blades of turbo fan engines. To prevent impact force, leading edge of titanium was often mounted on the CFRP fan blades with adhesive force. In order to enhance the joining strength, a joining method with carbon fiber reinforced interface has been developed. By using nickel-coated carbon fibers, a joining sample with carbon fiber-reinforced interface between CFRP and CFRM has been successfully developed. The joining sample with nickel-coated carbon fiber interface exhibits the high tensile strength, which was about 10 times higher than that with conventional adhesion. On the other hand, Al-welding methods to steel, Cu and Ti with carbon fiber reinforced interface have been successfully developed to lighten the parts of machines of racing car and airplane. Carbon fibers in felt are covered with metals to protect the interfacial reaction. The first step of the welding method is that the Al coated felt is contacted and wrapped with molten aluminum solidified under gravity pressure, whereas the second step is that the felt with double layer of Ni and Al is contacted and wrapped with molten steel (Cu or Ti) solidified under gravity pressure. Tensile strength of Al-Fe (Cu or Ti) welded sample with carbon fiber reinforced interface is higher than those of Al-Fe (Cu or Ti) welded sample.

  19. 碳纤维表面聚合物接枝改性的研究进展%Research Progress on Surface Modification of Polymer Grafted on Carbon Fiber

    Institute of Scientific and Technical Information of China (English)

    汪怀远; 姜丽丽; 朱艳吉

    2012-01-01

    碳纤维以轻质高强、耐热耐腐蚀、抗蠕变等优点成为十分重要的增强材料.但未经处理的碳纤维表面光滑、呈惰性、界面的粘结性差,需对其表面处理.聚合接技改性具有不损坏基体、稳定性好且可以接枝特定聚合物等使它成为改性碳纤维的主要方法,详细综述了辐射接枝、光表面接枝、等离子接枝和化学接枝4种聚合接枝改性方法的研究与应用,并比较了它们的优缺点,为碳纤维表面改性研究提供了参考.%The carbon fiber is an important reinforcing material owing to many excellent performances, such as the high specific modulus, the heaten durance, anti-corrosion, anti-creep, However, the surface of untreated carbon fiber is smooth, inert, and the poor adhension of resin,so it is necessary for surface modification. Graft modification of polymerization is the primary method of modified carbon fiber,because it do not damage the substrate, good stability and it can be grafted specific polymer. Four surface modification methods for carbon fibers is summarized,such as radiation grafting, light surface grafting,chemical grafting and plasma grafting. By comparing several treatment approaches, it can be provided reference for the carbon fiber surface modification study.

  20. PROGRESS ON ACTIVATED CARBON FIBERS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Activated carbon fiber is one kind of important adsorption materials. These novel fibrousadsorbents have high specific surface areas or abundant functional groups, which make them havegreater adsorption/desorption rates and larger adsorption capacities than other adsorbents. They canbe prepared as bundle, paper, cloth and felt to meet various technical requirement. They also showreduction property. In this paper the latest progress on the studies of the preparation and adsorptionproperties of activated carbon fibers is reviewed. The application of these materials in drinking waterpurification, environmental control, resource recovery, chemical industry, and in medicine and healthcare is also presented.

  1. Methods of making carbon fiber from asphaltenes

    Energy Technology Data Exchange (ETDEWEB)

    Bohnert, George; Bowen, III, Daniel E.

    2017-02-28

    Making carbon fiber from asphaltenes obtained through heavy oil upgrading. In more detail, carbon fiber is made from asphaltenes obtained from heavy oil feedstocks undergoing upgrading in a continuous coking reactor.

  2. Advanced Carbon Fiber Nears Broad Automotive Use

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    General Motors and Teijin Limited, a leader in the carbon fiber and composites industry, will co-develop advanced carbon fiber composite technologies for potential high-volume use globally in GM cars, trucks and crossovers.

  3. Carbon fiber/carbon nanotube reinforced hierarchical composites: Effect of CNT distribution on shearing strength

    DEFF Research Database (Denmark)

    Zhou, H. W.; Mishnaevsky, Leon; Yi, H. Y.;

    2016-01-01

    The strength and fracture behavior of carbon fiber reinforced polymer composites with carbon nanotube (CNT) secondary reinforcement are investigated experimentally and numerically. Short Beam Shearing tests have been carried out, with SEM observations of the damage evolution in the composites. 3D...... multiscale computational (FE) models of the carbon/polymer composite with varied CNT distributions have been developed and employed to study the effect of the secondary CNT reinforcement, its distribution and content on the strength and fracture behavior of the composites. It is shown that adding secondary...... CNT nanoreinforcement into the matrix and/or the sizing of carbon fiber/reinforced composites ensures strong increase of the composite strength. The effect of secondary CNTs reinforcement is strongest when some small addition of CNTs in the polymer matrix is complemented by the fiber sizing with high...

  4. Carbon fiber reinforced thermoplastic composites for future automotive applications

    Science.gov (United States)

    Friedrich, K.

    2016-05-01

    After a brief introduction to polymer composite properties and markets, the state of the art activities in the field of manufacturing of advanced composites for automotive applications are elucidated. These include (a) long fiber reinforced thermoplastics (LFT) for secondary automotive components, and (b) continuous carbon fiber reinforced thermosetting composites for car body applications. It is followed by future possibilities of carbon fiber reinforced thermoplastic composites for e.g. (i) crash elements, (ii) racing car seats, and (iii) production and recycling of automotive fenders.

  5. The effect of bromination of carbon fibers on the coefficient of thermal expansion of graphite fiber-epoxy composites

    Science.gov (United States)

    Jaworske, D. A.; Maciag, C.

    1987-01-01

    To examine the effect of bromination of carbon fibers on the coefficient of thermal expansion (CTE) of carbon fiber epoxy composites, several pristine and brominated carbon fiber-epoxy composite samples were subjected to thermomechanical analysis. The CTE's of these samples were measured in the uniaxial and transverse directions. The CTE was dominated by the fibers in the uniaxial direction, while it was dominated by the matrix in the transverse directions. Bromination had no effect on the CTE of any of the composites. In addition, the CTE of fiber tow was measured in the absence of a polymer matrix, using an extension probe. The results from this technique were inconclusive.

  6. Formation of aromatic thermoplastic and carbon-fiber prepreg by electrochemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Li Hong.

    1991-01-01

    A new technique was developed and demonstrated for combining carbon fibers with aromatic thermoplastic matrices to form a high-quality towpreg. The developed technique utilizes an in-situ electrochemical process (Electrochemical polymerization - ECP) to create the entire polymer matrix surrounding the fiber array by direct polymerization of monomer. Poly-paraxylylene (PPX) and derivatives are successfully polymerized in-situ on carbon fiber surfaces through ECP. A PPX/carbon-fiber towpreg with 40 vol % of matrix is achieved in a fairly short reaction time with a high polymer-coating efficiency. Vapor deposition polymerization (VDP) was also studied. PPX and carbon-fiber towpreg were made successfully by this process. A comparison between ECP and VDP was conducted. A study on electrochemical oxidation (ECO) of carbon fibers was also performed. The ECO treatment may be suitable for carbon fibers incorporated in composites with high-temperature curing resins and thermoplastic matrices.

  7. Spectrally efficient polymer optical fiber transmission

    Science.gov (United States)

    Randel, Sebastian; Bunge, Christian-Alexander

    2011-01-01

    The step-index polymer optical fiber (SI-POF) is an attractive transmission medium for high speed communication links in automotive infotainment networks, in industrial automation, and in home networks. Growing demands for quality of service, e.g., for IPTV distribution in homes and for Ethernet based industrial control networks will necessitate Gigabit speeds in the near future. We present an overview on recent advances in the design of spectrally efficient and robust Gigabit-over-SI-POF transmission systems.

  8. Effect of plasma surface treatment of recycled carbon fiber on carbon fiber-reinforced plastics (CFRP) interfacial properties

    Science.gov (United States)

    Lee, Hooseok; Ohsawa, Isamu; Takahashi, Jun

    2015-02-01

    We studied the effects of plasma surface treatment of recycled carbon fiber on adhesion of the fiber to polymers after various treatment times. Conventional surface treatment methods have been attempted for recycled carbon fiber, but most require very long processing times, which may increase cost. Hence, in this study, plasma processing was performed for 0.5 s or less. Surface functionalization was quantified by X-ray photoelectron spectroscopy. O/C increased from approximately 11% to 25%. The micro-droplet test of adhesion properties and the mechanical properties of CFRP were also investigated.

  9. Fiber reinforced polymer composites for bridge structures

    Directory of Open Access Journals (Sweden)

    Alexandra CANTORIU

    2013-12-01

    Full Text Available Rapid advances in construction materials technology have led to the emergence of new materials with special properties, aiming at safety, economy and functionality of bridges structures. A class of structural materials which was originally developed many years ago, but recently caught the attention of engineers involved in the construction of bridges is fiber reinforced polymer composites. This paper provides an overview of fiber reinforced polymer composites used in bridge structures including types, properties, applications and future trends. The results of this study have revealed that this class of materials presents outstanding properties such as high specific strength, high fatigue and environmental resistance, lightweight, stiffness, magnetic transparency, highly cost-effective, and quick assembly, but in the same time high initial costs, lack of data on long-term field performance, low fire resistance. Fiber reinforced polymer composites were widely used in construction of different bridge structures such as: deck and tower, I-beams, tendons, cable stands and proved to be materials for future in this field.

  10. Global Carbon Fiber Composites Supply Chain Competitiveness Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sujit [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Warren, Josh [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); West, Devin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Schexnayder, Susan M. [Univ. of Tennessee, Knoxville, TN (United States)

    2016-05-01

    This study identifies key opportunities in the carbon fiber supply chain where the United States Department of Energy's Office of Energy Efficiency and Renewable Energy resources and investments can help the United States achieve or maintain a competitive advantage. The report focuses on four application areas--wind energy, aerospace, automotive, and pressure vessels--that top the list of industries using carbon fiber and carbon fiber reinforced polymers and are also particularly relevant to EERE's mission. For each of the four application areas, the report addresses the supply and demand trends within that sector, supply chain, and costs of carbon fiber and components, all contributing to a competitiveness assessment that addresses the United States' role in future industry growth. This report was prepared by researchers at Oak Ridge National Laboratory and the University of Tennessee for the Clean Energy Manufacturing Analysis Center.

  11. The preparation, properties and application of carbon fibers for SPME.

    Science.gov (United States)

    Gierak, A; Seredych, M; Bartnicki, A

    2006-07-15

    The conditions of preparation of new types of carbon fibers for solid phase micro extraction (SPME) prepared by methylene chloride pyrolysis (at 600 degrees C) on the quartz fiber (100 microm) as well as by supporting synthetic active carbon (prepared especially for this purposes) supported in a special epoxide-acrylic polymer is described. The properties of such carbon fibers for SPME were defined by determination of the partition coefficient of the tested substances (i.e., benzene, toluene, xylenes, trichloromethane and tetrachloromethane) and by the microscopic investigations with the application of the optical and scanning electron microscope. The obtained carbon SPME fibers were applied to the analysis of some volatile organic compounds from its aqueous matrix. During chromatographic GC test, at the investigated SPME carbon fibers, we obtained different but mostly high partition coefficients for the determined compounds (Kfs from 120 for trichloromethane up to 11,500 for tetrachloromethane). Owing to the high partition coefficients of the studied substances obtained on carbon fibers, it was possible to do the analysis of organic substances occurring in trace amounts in different matrices. In this paper, we present the analysis of BTX contents in the petrol analyzed with the application carbonized with CH(2)Cl(2) SPME fiber (C1NM) and a headspace over the petrol sample (concentration of each BTX approximately g/dm(3)).

  12. Automatic Fiber Orientation Detection for Sewed Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Automatic production and precise positioning of carbon fiber reinforced plastics (FRP) require precise detection of the fiber orientations. This paper presents an automatic method for detecting fiber orientations of sewed carbon fibers in the production of FRP. Detection was achieved by appropriate use of regional filling, edge detection operators, autocorrelation methods, and the Hough transformation. Regional filling was used to reduce the influence of the sewed regions, autocorrelation was used to clarify the fiber directions, edge detection operators were used to extract the edge features for the fiber orientations, and the Hough transformation was used to calculate the angles. Results for two kinds of carbon fiber materials show that the method is relatively quick and precise for detecting carbon fiber orientations.

  13. Puncture-Healing Thermoplastic Resin Carbon-Fiber-Reinforced Composites

    Science.gov (United States)

    Gordon, Keith L. (Inventor); Siochi, Emilie J. (Inventor); Grimsley, Brian W. (Inventor); Cano, Roberto J. (Inventor); Czabaj, Michael W. (Inventor)

    2015-01-01

    A composite comprising a combination of a self-healing polymer matrix and a carbon fiber reinforcement is described. In one embodiment, the matrix is a polybutadiene graft copolymer matrix, such as polybutadiene graft copolymer comprising poly(butadiene)-graft-poly(methyl acrylate-co-acrylonitrile). A method of fabricating the composite is also described, comprising the steps of manufacturing a pre-impregnated unidirectional carbon fiber preform by wetting a plurality of carbon fibers with a solution, the solution comprising a self-healing polymer and a solvent, and curing the preform. A method of repairing a structure made from the composite of the invention is described. A novel prepreg material used to manufacture the composite of the invention is described.

  14. Aligning carbon fibers in micro-extruded composite ink

    Science.gov (United States)

    Mahajan, Chaitanya G.

    Direct write processes include a wide range of additive manufacturing techniques with the ability to fabricate structures directly onto planar and non-planar surfaces. Most additive manufacturing techniques use unreinforced polymers to produce parts. By adding carbon fiber as a reinforcing material, properties such as mechanical strength, electrical conductivity, and thermal conductivity can be enhanced. Carbon fibers can be long and continuous, or short and discontinuous. The strength of carbon fiber composite parts is greatly increased when the fibers are preferentially aligned. This research focuses on increasing the strength of additively manufactured parts reinforced using discontinuous carbon fibers that have been aligned during the micro extrusion process. A design of experiments (DOE) approach was used to identify significant process parameters affecting fiber alignment. Factors such as the length of carbon fibers, nozzle diameter, fiber loading fraction, air pressure, translational speed and standoff distance were considered. A two dimensional Fast Fourier Transform (2D FFT) was used to quantify the degree of fiber alignment in the extruded composite inks. ImageJ software supported by an oval profile plugin was used with micrographs of printed samples to obtain the carbon fiber alignment values. The optimal value for the factors was derived by identifying the significant main and interaction effects. Based on the results of the DOE, tensile test samples were printed with fibers aligned parallel and perpendicular to the tensile axis. A standard test method for tensile properties of plastic revealed that the extruded parts with fibers aligned along the tensile axis were better in tensile strength and modulus.

  15. MODIFYING V-14 RUBBER WITH CARBON FIBERS

    Directory of Open Access Journals (Sweden)

    Shadrinov N. V.

    2016-01-01

    Full Text Available The influence of carbon fibers and modified carbon fibers on properties of industrially produced V-14 rubber is examined. The dependences of physical and mechanical properties, hardness, abrasion resistance and resistance in aggressive environment on few amount of filled fiber are established. Structural properties of reinforced elastomeric composites are studied by scanning electron microscopy. Elastomeric layer on the surface of modified carbon fiber, confirmed with high adhesion is identified

  16. Electrical Properties of Carbon Fiber Support Systems

    CERN Document Server

    Cooper, W; Demarteau, M; Fast, J; Hanagaki, K; Johnson, M; Kuykendall, W; Lubatti, H; Matulik, M; Nomerotski, A; Quinn, B; Wang, J

    2005-01-01

    Carbon fiber support structures have become common elements of detector designs for high energy physics experiments. Carbon fiber has many mechanical advantages but it is also characterized by high conductivity, particularly at high frequency, with associated design issues. This paper discusses the elements required for sound electrical performance of silicon detectors employing carbon fiber support elements. Tests on carbon fiber structures are presented indicating that carbon fiber must be regarded as a conductor for the frequency region of 10 to 100 MHz. The general principles of grounding configurations involving carbon fiber structures will be discussed. To illustrate the design requirements, measurements performed with a silicon detector on a carbon fiber support structure at small radius are presented. A grounding scheme employing copper-kapton mesh circuits is described and shown to provide adequate and robust detector performance.

  17. Influence of different glass fiber reinforcements on denture base polymer strength (Fiber reinforcements of dental polymer)

    OpenAIRE

    Ketij Mehulić,; Asja Čelebić,; Zdravko Schauperl,; Dragutin Komar,; Denis Vojvodić,; Domagoj Žabarović

    2009-01-01

    Aim Assessment of flexural strength values of dental base polymersreinforced with different glass fibers (“dental” and “industrial”origin) after performed artificial ageing procedures.Methods Three hundred specimens (dimensions 18 x 10 x 3 mm)were produced of denture base polymers reinforced with differentglass fibers. The “short beam” testing method was used to determinethe flexural strength of the specimens after polymerization,immersion in water of temperature 37oC for 28 days, and thermoc...

  18. Optical sensors from electrohydrodynamic jetted polymer fiber resonators

    DEFF Research Database (Denmark)

    Laye, Fabrice; Kraemmer, Sarah; Castillo, Alejandro;

    2016-01-01

    Electrohydrodynamic jetting is used to manufacture dye-doped polymer fiber resonators. We present comb-like laser emission from different polymer/dye combinations and report the use of these structures as sensitive detection of ethanol and methanol....

  19. Carbon nanotube-polymer composite actuators

    Science.gov (United States)

    Gennett, Thomas; Raffaelle, Ryne P.; Landi, Brian J.; Heben, Michael J.

    2008-04-22

    The present invention discloses a carbon nanotube (SWNT)-polymer composite actuator and method to make such actuator. A series of uniform composites was prepared by dispersing purified single wall nanotubes with varying weight percents into a polymer matrix, followed by solution casting. The resulting nanotube-polymer composite was then successfully used to form a nanotube polymer actuator.

  20. Carbon dioxide foaming of glassy polymers

    NARCIS (Netherlands)

    Wessling, M.; Borneman, Z.; Boomgaard, van den Th.; Smolders, C.A.

    1994-01-01

    The mechanism of foaming a glassy polymer using sorbed carbon dioxide is studied in detail. A glassy polymer supersaturated with nitrogen forms a microcellular foam, if the polymer is quickly heated above its glass transition temperature. A glassy polymer supersaturated with CO2 forms this foam-like

  1. A New Fiber Preform with Nanocarbon Binder for Manufacturing Carbon Fiber Reinforced Composite by Liquid Molding Process.

    Science.gov (United States)

    Seong, Dong Gi; Ha, Jong Rok; Lee, Jea Uk; Lee, Wonoh; Kim, Byung Sun

    2015-11-01

    Carbon fiber reinforced composite has been a good candidate of lightweight structural component in the automotive industry. As fast production speed is essential to apply the composite materials for the mass production area such as automotive components, the high speed liquid composite molding processes have been developed. Fast resin injection through the fiber preform by high pressure is required to improve the production speed, but it often results in undesirable deformations of the fiber preform which causes defectives in size and properties of the final composite products. In order to prevent the undesirable deformation and improve the stability of preform shape, polymer type binder materials are used. More stable fiber preform can be obtained by increasing the amount of binder material, but it disturbs the resin impregnation through the fiber preform. In this study, carbon nanomaterials such as graphene oxide were embedded on the surface of carbon fiber by electrophoretic deposition method in order to improve the shape stability of fiber preform and interfacial bonding between polymer and the reinforcing fiber. Effects of the modified reinforcing fiber were investigated in two respects. One is to increase the binding energy between fiber tows, and the other is to increase the interfacial bonding between polymer matrix and fiber surface. The effects were analyzed by measuring the binding force of fiber preform and interlaminar shear strength of the composite. This study also investigated the high speed liquid molding process of the composite materials composed of polymer matrix and the carbon fiber preforms embedded by carbon nanomaterials. Process parameter such as permeability of fiber preform was measured to investigate the effect of nanoscale surface modification on the macroscale processing condition for composite manufacturing.

  2. Polymer-coated hollow fiber for CO(2) laser delivery.

    Science.gov (United States)

    Abe, Y; Matsuura, Y; Shi, Y W; Wang, Y; Uyama, H; Miyagi, M

    1998-01-15

    Hollow fibers for CO(2) laser light have been fabricated with a cyclic olefin polymer as the inner dielectric. A film of cyclic olefin polymer was coated inside the glass capillary tubing by a simple liquid-flowing process. A polymer-coated fiber with a 700-microm bore showed a loss of 0.06 dB/m for CO(2) laser light because cyclic olefin polymer has low absorption at a 10.6-microm wavelength.

  3. A novel carbon fiber based porous carbon monolith

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T.D.; Klett, J.W.; Weaver, C.E.

    1995-06-01

    A novel porous carbon material based on carbon fibers has been developed. The material, when activated, develops a significant micro- or mesopore volume dependent upon the carbon fiber type utilized (isotropic pitch or polyacrylonitrile). The materials will find applications in the field of fluid separations or as a catalyst support. Here, the manufacture and characterization of our porous carbon monoliths are described. A novel adsorbent carbon composite material has been developed comprising carbon fibers and a binder. The material, called carbon fiber composite molecular sieve (CFCMS), was developed through a joint research program between Oak Ridge National Laboratory (ORNL) and the University of Kentucky, Center for Applied Energy Research (UKCAER).

  4. Interfacial Studies of Sized Carbon Fiber

    Science.gov (United States)

    Shahrul, S. N.; Hartini, M. N.; Hilmi, E. A.; Nizam, A.

    2010-03-01

    This study was performed to investigate the influence of sizing treatment on carbon fiber in respect of interfacial adhesion in composite materials, Epolam® 2025. Fortafil unsized carbon fiber was used to performed the experiment. The fiber was commercially surface treated and it was a polyacrylonitrile based carbon fiber with 3000 filament per strand. Epicure® 3370 was used as basic sizing chemical and dissolved in two types of solvent, ethanol and acetone for the comparison purpose. The single pull out test has been used to determine the influence of sizing on carbon fiber. The morphology of carbon fiber was observed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The apparent interfacial strength IFSS values determined by pull out test for the Epicure® 3370/ethanol sized carbon fiber pointed to a good interfacial behaviour compared to the Epicure® 3370/acetone sized carbon fiber. The Epicure® 3370/ethanol sizing agent was found to be effective in promoting adhesion because of the chemical reactions between the sizing and Epolam® 2025 during the curing process. From this work, it showed that sized carbon fiber using Epicure® 3370 with addition of ethanol give higher mechanical properties of carbon fiber in terms of shear strength and also provided a good adhesion between fiber and matrix compared to the sizing chemical that contain acetone as a solvent.

  5. Carbonate polymers containing ethenyl aryl moieties

    OpenAIRE

    1993-01-01

    There are disclosed carbonate polymers having ethenyl aryl moieties. Such carbonate polymers are prepared from one or more multi-hydric compounds and have an average degree of polymerization of at least about 1 based on multi-hydric compound. These polymers, including blends thereof, can be easily processed and shaped into various forms and structures according to the known techniques. During or subsequent to the processing, the polymers can be crosslinked, by exposure to heat or radiation, f...

  6. Microfluidic Fabrication of Conjugated Polymer Sensor Fibers

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Imsung; Song, Simon [Hanyang University, Seoul (Korea, Republic of)

    2014-10-15

    We propose a fabrication method for polydiacetylene (PDA)-embedded hydrogel microfibers on a microfluidic chip. These fibers can be applied to the detection of cyclodextrines (CDs), which are a family of sugar and aluminum ions. PDA, a family of conjugated polymers, has unique characteristics when used for a sensor, because it undergoes a blue-to-red color transition and nonfluorescence-to-fluorescence transition in response to environmental stimulation. PDAs have different sensing characteristics depending on the head group of PCDA. By taking advantage of ionic crosslinking-induced hydrogel formation and the 3D hydrodynamic focusing effect on a microfluidic chip, PCDA-EDEA-derived diacetylene (DA) monomer-embedded microfibers were successfully fabricated. UV irradiation of the fibers afforded blue-colored PDA, and the resulting blue PDA fibers underwent a phase transition to red and emitted red fluorescence upon exposure to CDs and aluminum ions. Their fluorescence intensity varied depending on the CDs and aluminum ion concentrations. This phase transition was also observed when the fibers were dried.

  7. Electron microscopy investigation of interface between carbon fiber and ultra high molecular weight polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Stepashkin, A.A.; Chukov, D.I., E-mail: dil_chukov@yahoo.com; Gorshenkov, M.V.; Tcherdyntsev, V.V.; Kaloshkin, S.D.

    2014-02-15

    Highlights: • Effect of the carbon fibers surface treatments on the adhesive interactions in UHMWPE composites was studied. • Air oxidation of carbon filler ensures most significant increase in adhesion interaction in UHMWPE based composites. • Nanosized UHMWPE fibers with 20–40 nm in diameter and with 6–10 μm in length, was observed on the surface of carbon fibers. -- Abstract: Scanning electron microscopy was used to investigate the surface of initial and modified high-strength and high-modulus carbon fibers as well as interfaces in the ultra high molecular weight polyethylene, filled with above-mentioned fibers. Effect of the fibers surface modifying method on the adhesive interactions in composites was studied. It was observed that interaction of matrix with a modified surface of fibers results in a formation of bonds with strength higher than the yield strength of the polymer. It results in a formation of long nanosized polymer wires at tensile fracture of composites.

  8. Highly Stretchable Conductive Fibers from Few-Walled Carbon Nanotubes Coated on Poly(m-phenylene isophthalamide) Polymer Core/Shell Structures.

    Science.gov (United States)

    Jiang, Shujuan; Zhang, Hongbo; Song, Shaoqing; Ma, Yanwen; Li, Jinghua; Lee, Gyeong Hee; Han, Qiwei; Liu, Jie

    2015-10-27

    A core/shell stretchable conductive composite of a few-walled carbon nanotube network coated on a poly(m-phenylene isophthalamide) fiber (FWNT/PMIA) was fabricated by a dip-coating method and an annealing process that greatly enhanced interactions between the FWNT network and PMIA core as well as within the FWNT network. The first strain-conductivity test of the as-prepared FWNT/PMIA fiber showed a stretching-induced alignment of nanotubes in the shell during the deformation process and a good conductivity stability with a slight conductivity drop from 109.63 S/cm to 98.74 S/cm (Δσ/σ0 = 10%) at a strain of ∼150% (2.5 times the original length). More importantly, after the first stretching process, the fiber can be recovered with a slight increase in length but a greatly improved conductivity of 167.41 S/cm through an additional annealing treatment. The recovered fiber displays a similarly superb conductivity stability against stretching, with a decrease of only ∼13 S/cm to 154.49 S/cm (Δσ/σ0 = 8%) at a strain of ∼150%. We believe that this conductivity stability came from the formation and maintaining of aligned nanotube structures during the stretching process, which ensures the good tube-tube contacts and the elongation of the FWNT network without losing its conductivity. Such stable conductivity in stretchable fibers will be important for applications in stretchable electronics.

  9. INTEGRATED COI S200 - Hi-NiCalon FIBER WITH AN S200 MATRIX (POLYMER MATRIX COMPOSITE - PMC) / AETB 1

    Science.gov (United States)

    2003-01-01

    INTEGRATED COI S200 - Hi-NiCalon FIBER WITH AN S200 MATRIX (POLYMER MATRIX COMPOSITE - PMC) / AETB 16 (FOAM CORE) / CARBON REINFORCED CYANOESTER (CERAMIC MATRIX COMPOSITE - CMC) HOT STRUCTURE, PANEL 884-1: SAMPLE 1

  10. Carbon/Liquid Crystal Polymer Prepreg for Cryogenic and High-Temp Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — KaZaK Composites proposes to develop a pultrusion process to produce carbon fiber / liquid crystal polymer (LCP) prepreg, a first for this category of materials and...

  11. External reinforcing of fiber concrete constructions by carbon fiber tapes

    OpenAIRE

    S.V. Klyuyev; Yu.V. Guryanov

    2013-01-01

    Strengthening the concrete and reinforced concrete structures with carbon fiber tapes is very actively applied in Europe nowadays. In Russia composites based on carbon fiber have also widely spread recently. The main advantages of these materials for strengthening structures are its high specific strength (strength-weight ratio) and strength-to-density ratio.Experimental studies on strengthening and restoration of the constructions were held. Flexible fiber concrete constructions based on man...

  12. Nanoscale characterization of carbazole-indole copolymers modified carbon fiber surfaces.

    Science.gov (United States)

    Sarac, A Sezai; Serantoni, Marina; Tofail, Syed A M; Cunnane, Vincent J

    2005-10-01

    Polycarbazole, carbazole and indole containing copolymers were electrochemically coated onto carbon fiber. The resulting polymers and copolymers were characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Characterization of the thin polymer films were performed on the polymer-coated surface of the carbon fiber. Therefore, the results obtained could elucidate the relationship between the initial feed monomer ratio, the resulting polymer/copolymer film morphology and the surface structure formed. The thickness increase (in diameter) was 0.3 and 0.9 microm, for two different composition of carbazole/indole on the carbon fiber. The carbon fibers coated with copolymer thin films were from 6.5 to 8.2 microm in diameter (from AFM measurement).

  13. 炭纤维增强聚合物基复合材料的热氧老化机理%Thermo-oxidative aging mechanism of carbon fiber reinforced polymer matrix composites

    Institute of Scientific and Technical Information of China (English)

    樊威; 李嘉禄

    2015-01-01

    从基体、纤维和纤维/基体界面的角度,探讨了炭纤维增强聚合物基复合材料( CFRPMCs)的热氧老化机理。总结了纤维性能、纤维取向、纤维体积含量、织物结构、树脂性能、纤维/基体界面强度等因素对CFRPMCs热氧老化性能的影响规律,并简要分析了目前提高CFRPMCs热氧老化性能的方法。研究指出,立体织物增强的聚合物基复合材料能够很好地克服传统层合复合材料热氧老化后易分层的缺点,采用立体织物来增强聚合物,将会是今后提高CFRPMCs热氧稳定性的一个主要发展方向。%The thermo⁃oxidative aging mechanism of carbon fiber reinforced polymer matrix composites ( CFRPMCs) was dis⁃cussed from the perspective of matrix,fiber and the fiber/matrix interface.The influence of fiber properties,fiber orientation,fiber volume fraction,fabric structure,resin properties and fiber/matrix interface strength on the thermo⁃oxidative aging performance of CFRPMCs was investigated,and the current methods of improving the thermo⁃oxidative stability of CFRPMCs were analyzed. The study indicates that the CFRPMCs reinforced by three⁃dimensional fabrics are good at resisting the delamination as the traditional laminated composites after thermo⁃oxidative aging,and the three⁃dimensional fabric reinforced polymer composites will become an important direction of improving the thermo⁃oxidative stability of the CFRPMCs.

  14. Multi-antibody biosensing with Topas microstructured polymer optical fiber

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Bang, Ole; Hoiby, Poul E.

    We present a Topas based microstructured polymer optical fiber multi-antibody biosensor. This polymer allows localized activation of sensor layers on the inner side of the air holes. This concept is used to create two different sensor sections in the same fiber. Simultaneous detection of two kinds...

  15. Light Diffraction of Aligned Polymer Fibers Periodically Dispersed by Phase Separation of Liquid Crystal and Polymer

    Science.gov (United States)

    Murashige, Takeshi; Fujikake, Hideo; Sato, Hiroto; Kikuchi, Hiroshi; Kurita, Taiichiro; Sato, Fumio

    2004-12-01

    We have confirmed light diffraction of aligned polymer fibers obtained by a phase separation of an anisotropic-phase solution of liquid crystal and polymer. He—Ne laser light passing through the polymer fibers was scattered in the axis vertical to the fibers, and had two peaks of light intensity symmetrical to the center of the transmitting laser spot. The two peaks were found to be caused by light diffraction due to the periodic polymer-fiber dispersion because the peaks corresponded to values calculated by intervals between the fibers. The periodical fiber networks are considered to be formed by anisotropic spinodal decomposition. This effect can be used to measure the dispersion order of the polymer fibers.

  16. Mechanical and Electrical Characterization of Novel Carbon Nano Fiber Ultralow Density Foam

    Science.gov (United States)

    2013-12-01

    instances of such composites are: A study that implanted carbon black, graphite powder and carbon fibers into an insulating polymer matrix and then...determined the effects of applying tensile and compressive stresses found that the resistance changed when stretching the polymer by 40 percent or...sizing. The term sizing refers to an organic mixture that commonly covers the surface of commercial fibers prepared by extrusion or injection

  17. Carbon Fiber Reinforced, Zero CME Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Technical Abstract: This project proposes to develop moisture insensitive, high performance, carbon fiber laminates for future missions. Current space-qualified...

  18. Long fiber polymer composite property calculation in injection molding simulation

    Science.gov (United States)

    Jin, Xiaoshi; Wang, Jin; Han, Sejin

    2013-05-01

    Long fiber filled polymer composite materials have attracted a great attention and usage in recent years. However, the injection and compression molded long fiber composite materials possess complex microstructures that include spatial variations in fiber orientation and length. This paper presents the recent implemented anisotropic rotary diffusion - reduced strain closure (ARD-RSC) model for predicting fiber orientation distribution[1] and a newly developed fiber breakage model[2] for predicting fiber length distribution in injection and compression molding simulation, and Eshelby-Mori-Tanaka model[3,4] with fiber-matrix de-bonding model[5] have been implemented to calculate the long fiber composite property distribution with predicted fiber orientation and fiber length distributions. A validation study on fiber orientation, fiber breakage and mechanical property distributions are given with injection molding process simulation.

  19. Piezoelectric polymer and ceramic ultrafine fibers for piezocomposite films

    OpenAIRE

    Yördem, Sinan Onur; Yordem, Sinan Onur; Papila, Melih; Menceloğlu, Yusuf Z.; Menceloglu, Yusuf Z.; Öğüt, Erdem; Ogut, Erdem; Gülleroğlu, Mert; Gulleroglu, Mert

    2006-01-01

    This paper describes the process development and characterization of Poly(vinylidene fluoride) (PVDF) films and fiber mats and Zinc Oxide (ZnO) fibers as ingredients of a future piezo-composite film. The polymer system PVDF is electroactive and processed here by solution casting and annealing to form active films. Electrospinning of PVDF and Poly(vinyl alcohol)-Zincacetate precursor solutions were also under investigation to produce randomly oriented polymer and ceramic fiber mats, respective...

  20. Fiber-optical accelerometers based on polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings (FBGs) are reported. We have written 3mm FBGs for 1550nm operation, characterized their temperature and strain response, and tested their performance in a prototype accelerometer.......Fiber-optical accelerometers based on polymer optical fiber Bragg gratings (FBGs) are reported. We have written 3mm FBGs for 1550nm operation, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  1. Synergetic Effects of Mechanical Properties on Graphene Nanoplatelet and Multiwalled Carbon Nanotube Hybrids Reinforced Epoxy/Carbon Fiber Composites

    OpenAIRE

    Pin-Ning Wang; Tsung-Han Hsieh; Chin-Lung Chiang; Ming-Yuan Shen

    2015-01-01

    Graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) are novel nanofillers possessing attractive characteristics, including robust compatibility with most polymers, high absolute strength, and cost effectiveness. In this study, an outstanding synergetic effect on the grapheme nanoplatelets (GNPs) and multiwalled carbon nanotubes (CNTs) hybrids were used to reinforce epoxy composite and epoxy/carbon fiber composite laminates to enhance their mechanical properties. The mechanical propertie...

  2. Sensing characteristics of birefringent microstructured polymer optical fiber

    DEFF Research Database (Denmark)

    Szczurowski, Marcin K.; Frazao, Orlando; Baptista, J. M.;

    2011-01-01

    We experimentally studied several sensing characteristics of a birefringent microstructured polymer optical fiber. The fiber exhibits a birefringence of the order 2×10-5 at 1.3 μm because of two small holes adjacent to the core. In this fiber, we measured spectral dependence of phase and group mo...

  3. 聚合物/镀镍碳纤维导电复合材料的研究进展%Research Development of Polymer/Nickel-Coated Carbon Fiber Conductive Composites

    Institute of Scientific and Technical Information of China (English)

    陈彤; 薛平; 贾明印; 韩宇

    2014-01-01

    综述了聚合物/镀镍碳纤维(NiCF)导电复合材料的优点及其导电机理,介绍了该种导电复合材料的几种制备方法,包括单螺杆挤出机法、双螺杆挤出机法、密炼机法和Brabender塑化仪法,并详细地分析和总结了影响聚合物/NiCF导电复合材料导电性的NiCF长度、表面改性与分散、填充量以及加工工艺等因素。%The advantages and conductive mechanism of polymer/nickel-coated carbon fiber conductive composites were reviewed. The several preparation methods of the kind of conductive composites were introduced,which include single-screw extruder,twin-screw extruder,mixer method and Brabender plasti-corder. The effects such as the length,surface treatment and dispersion,addition amounts of the nickel-coated carbon fiber and processing technology on the conductivity of the conductive composites were discussed and summarized.

  4. Manufacturing of Nanocomposite Carbon Fibers and Composite Cylinders

    Science.gov (United States)

    Tan, Seng; Zhou, Jian-guo

    2013-01-01

    Pitch-based nanocomposite carbon fibers were prepared with various percentages of carbon nanofibers (CNFs), and the fibers were used for manufacturing composite structures. Experimental results show that these nanocomposite carbon fibers exhibit improved structural and electrical conductivity properties as compared to unreinforced carbon fibers. Composite panels fabricated from these nanocomposite carbon fibers and an epoxy system also show the same properties transformed from the fibers. Single-fiber testing per ASTM C1557 standard indicates that the nanocomposite carbon fiber has a tensile modulus of 110% higher, and a tensile strength 17.7% times higher, than the conventional carbon fiber manufactured from pitch. Also, the electrical resistance of the carbon fiber carbonized at 900 C was reduced from 4.8 to 2.2 ohm/cm. The manufacturing of the nanocomposite carbon fiber was based on an extrusion, non-solvent process. The precursor fibers were then carbonized and graphitized. The resultant fibers are continuous.

  5. Influence of carbon nano- and micron-sized fibers on structure, mechanical and tribotechnical properties of polymer composites with UHMWPE matrix

    Science.gov (United States)

    Panin, S. V.; Kornienko, L. A.; Aleksenko, V. O.; Ivanova, L. R.; Shilko, S. V.

    2016-11-01

    To compare the efficiency of the solid lubricating and enforcing properties of carbon nano-and microfibers in ultra-high molecular weight polyethylene (UHMWPE) composites their mechanical and tribotechnical characteristics under dry sliding friction and abrasion have been studied. It is shown that under dry sliding friction the wear resistance of the polymer composite "UHMWPE + 0.5 wt % C (nano)" has increased up to 6.6 times, while in the composite "UHMWPE + 5 wt % C (micro)"—by 2.5 times only. At the same time abrasive wear resistance of these composites has increased approximately 2-fold for both types of fillers. The mechanisms of the observed effects are discussed and interpreted.

  6. Photoconductivity of Activated Carbon Fibers

    Science.gov (United States)

    Kuriyama, K.; Dresselhaus, M. S.

    1990-08-01

    The photoconductivity is measured on a high-surface-area disordered carbon material, namely activated carbon fibers, to investigate their electronic properties. Measurements of decay time, recombination kinetics and temperature dependence of the photoconductivity generally reflect the electronic properties of a material. The material studied in this paper is a highly disordered carbon derived from a phenolic precursor, having a huge specific surface area of 1000--2000m{sup 2}/g. Our preliminary thermopower measurements suggest that this carbon material is a p-type semiconductor with an amorphous-like microstructure. The intrinsic electrical conductivity, on the order of 20S/cm at room temperature, increases with increasing temperature in the range 30--290K. In contrast with the intrinsic conductivity, the photoconductivity in vacuum decreases with increasing temperature. The recombination kinetics changes from a monomolecular process at room temperature to a biomolecular process at low temperatures. The observed decay time of the photoconductivity is {approx equal}0.3sec. The magnitude of the photoconductive signal was reduced by a factor of ten when the sample was exposed to air. The intrinsic carrier density and the activation energy for conduction are estimated to be {approx equal}10{sup 21}/cm{sup 3} and {approx equal}20meV, respectively. The majority of the induced photocarriers and of the intrinsic carriers are trapped, resulting in the long decay time of the photoconductivity and the positive temperature dependence of the conductivity.

  7. Electrically conductive, optically transparent polymer/carbon nanotube composites

    Science.gov (United States)

    Connell, John W. (Inventor); Smith, Jr., Joseph G. (Inventor); Harrison, Joycelyn S. (Inventor); Park, Cheol (Inventor); Watson, Kent A. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400-800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior.

  8. The Transport Properties of Activated Carbon Fibers

    Science.gov (United States)

    di Vittorio, S. L.; Dresselhaus, M. S.; Endo, M.; Issi, J-P.; Piraux, L.

    1990-07-01

    The transport properties of activated isotropic pitch-based carbon fibers with surface area 1000 m{sup 2}/g have been investigated. We report preliminary results on the electrical conductivity, the magnetoresistance, the thermal conductivity and the thermopower of these fibers as a function of temperature. Comparisons are made to transport properties of other disordered carbons.

  9. Patterned functional carbon fibers from polyethylene.

    Science.gov (United States)

    Hunt, Marcus A; Saito, Tomonori; Brown, Rebecca H; Kumbhar, Amar S; Naskar, Amit K

    2012-05-08

    Carbon fibers having unique morphologies, from hollow circular to gear-shaped, are produced from a novel melt-processable precursor and method. The resulting carbon fiber exhibits microstructural and topological properties that are dependent on processing conditions, rendering them highly amenable to myriad applications.

  10. Latest progress of carbon-fiber-reinforced polymer energy-storing transtibial prostheses%碳纤维增强复合材料储能小腿假肢的最新进展

    Institute of Scientific and Technical Information of China (English)

    丁国华

    2013-01-01

    BACKGROUND:Carbon-fiber-reinforced polymer energy-storing transtibial prostheses are mature and ideal substitutes for professional disable athletes to increase performance. OBJECTIVE:By discussing the update application and study of the carbon-fiber-reinforced polymer energy-storing transtibial prosthesis and understanding the characteristics of applying transtibial prostheses in different sports program, to provide a useful reference for the design of athletes prostheses. METHODS:A computer-based search of PubMed and VIP databases was performed for articles related to carbon-fiber-reinforced polymer energy-storing transtibial prostheses published from January 1985 to December 2012. The keywords were“CFRP, energy-storing prosthesis, between-knee (transtibial) prosthesis, disable athletes”in English and Chinese, respectively. RESULTS AND CONCLUSION:Currently, we focus on the gait analysis, energy cost and stiffness analysis of athletes who wear carbon-fiber-reinforced polymer energy-storing transtibial prostheses. Studies have demonstrated that carbon-fiber-reinforced polymer energy-storing transtibial prostheses have more advantages over traditional prostheses, but have predominantly disadvantages over able-bodied persons. Thus, there are many difficulties in the clinical application of building carbon-fiber-reinforced polymer energy-storing transtibial prostheses based on the characteristics of athletes’ body status and sports programs.%背景:碳纤维增强复合材料小腿假肢是由碳纤维复合材料设计制作而成,其强度高、质量轻,使假肢功能更完善,尤其是残疾竞技运动员发挥运动能力的理想截肢替代物。  目的:通过探讨由碳纤维复合材料制成的碳纤维增强复合材料小腿假肢在竞技运动小腿假肢的应用和研究进展,了解不同运动项目小腿假肢的应用特点,为设计运动员假肢提供有益借鉴。  方法:以“碳纤维增强复合材料、

  11. Coating of carbon fibers -- The strength of the fibers

    Energy Technology Data Exchange (ETDEWEB)

    Helmer, T. [Alusingen GmbH, Singen (Germany); Peterlik, H.; Kromp, K. [Univ. Wien, Vienna (Austria). Inst. fuer Festkoerperphysik

    1995-01-01

    The 6k carbon fiber Torayca T800H was coated with pyrolytic carbon by a CVD process. Fiber bundles were tested and evaluated. By this procedure, the whole distribution of the failure probability with respect to the fiber strength is obtained in a single experiment. The 50% strength of the fiber bundle, i.e., the strength at which 50% of the fibers in the bundle are broken, is inversely proportional to the square root of the thickness of the coating. By relating the strength to the defect size according to linear-elastic fracture mechanics (LEFM), the probability density function of the defects was derived. It is Weibull-shaped for the uncoated fiber and shows an increasing bimodal shape for the increasing coating thicknesses.

  12. Characterization of electrospun lignin based carbon fibers

    Science.gov (United States)

    Poursorkhabi, Vida; Mohanty, Amar; Misra, Manjusri

    2015-05-01

    The production of lignin fibers has been studied in order to replace the need for petroleum based precursors for carbon fiber production. In addition to its positive environmental effects, it also benefits the economics of the industries which cannot take advantage of carbon fiber properties because of their high price. A large amount of lignin is annually produced as the byproduct of paper and growing cellulosic ethanol industry. Therefore, finding high value applications for this low cost, highly available material is getting more attention. Lignin is a biopolymer making about 15 - 30 % of the plant cell walls and has a high carbon yield upon carbonization. However, its processing is challenging due to its low molecular weight and also variations based on its origin and the method of separation from cellulose. In this study, alkali solutions of organosolv lignin with less than 1 wt/v% of poly (ethylene oxide) and two types of lignin (hardwood and softwood) were electrospun followed by carbonization. Different heating programs for carbonization were tested. The carbonized fibers had a smooth surface with an average diameter of less than 5 µm and the diameter could be controlled by the carbonization process and lignin type. Scanning electron microscopy (SEM) was used to study morphology of the fibers before and after carbonization. Thermal conductivity of a sample with amorphous carbon was 2.31 W/m.K. The electrospun lignin carbon fibers potentially have a large range of application such as in energy storage devices and water or gas purification systems.

  13. Preparation and Characterization of Electrospun Fibers of Poly(methyl methacrylate - Single walled carbon nano-tube Nanocomposites

    Directory of Open Access Journals (Sweden)

    Bibekananda Sundaray, Ph.D.

    2008-12-01

    Full Text Available Electrospinning is a versatile method of preparing polymer nanocmposite fibers. Electrospun nanocomposite fibers of poly(methyl methacrylate and single walled carbon nanotubes were prepared. The fibers were characterized by SEM, TEM, TGA and Raman spectroscopy. These fibers show dramatic improvement in the electrical conductivity compared to the polymer. The temperature dependent electrical resistance measurements show a one dimensional variable range hopping model (1-D VRH type of conduction mechanism operating in these types of systems.

  14. Heat Treated Carbon Fiber Material Selection Database

    Science.gov (United States)

    Effinger, M.; Patel, B.; Koenig, J.

    2008-01-01

    Carbon fibers are used in a variety high temperature applications and materials. However, one limiting factor in their transition into additional applications is an understanding of their functional properties during component processing and function. The requirements on the fibers are governed by the nature of the materials and the environments in which they will be used. The current carbon fiber vendor literature is geared toward the polymeric composite industry and not the ceramic composite industry. Thus, selection of carbon fibers is difficult, since their properties change as a function of heat treatment, processing or component operational temperature, which ever is greatest. To enable proper decisions to be made, a program was established wherein multiple fibers were selected and heat treated at different temperatures. The fibers were then examined for their physical and mechanical properties which are reported herein.

  15. Multifunctional structural supercapacitor composites based on carbon aerogel modified high performance carbon fiber fabric.

    Science.gov (United States)

    Qian, Hui; Kucernak, Anthony R; Greenhalgh, Emile S; Bismarck, Alexander; Shaffer, Milo S P

    2013-07-10

    A novel multifunctional material has been designed to provide excellent mechanical properties while possessing a high electrochemical surface area suitable for electrochemical energy storage: structural carbon fiber fabrics are embedded in a continuous network of carbon aerogel (CAG) to form a coherent but porous monolith. The CAG-modification process was found to be scalable and to be compatible with a range of carbon fiber fabrics with different surface properties. The incorporation of CAG significantly increased the surface area of carbon fiber fabrics, and hence the electrochemical performance, by around 100-fold, resulting in a CAG-normalized specific electrode capacitance of around 62 F g(-1), determined by cyclic voltammetry in an aqueous electrolyte. Using an ionic liquid (IL) electrolyte, the estimated energy density increased from 0.003 to 1 Wh kg(-1), after introducing the CAG into the carbon fiber fabric. 'Proof-of-concept' multifunctional structural supercapacitor devices were fabricated using an IL-modified solid-state polymer electrolyte as a multifunctional matrix to provide both ionic transport and physical support for the primary fibers. Two CAG-impregnated carbon fabrics were sandwiched around an insulating separator to form a functioning structural electrochemical double layer capacitor composite. The CAG-modification not only improved the electrochemical surface area, but also reinforced the polymer matrix surrounding the primary fibers, leading to dramatic improvements in the matrix-dominated composite properties. Increases in in-plane shear strength and modulus, of up to 4.5-fold, were observed, demonstrating that CAG-modified structural carbon fiber fabrics have promise in both pure structural and multifunctional energy storage applications.

  16. Residual stress in high modulus carbon fibers

    Science.gov (United States)

    Chen, K. J.; Diefendorf, R. J.

    1982-01-01

    The modulus and residual strain in carbon fibers are measured by successively electrochemically milling away the fiber surface. Electrochemical etching is found to remove the carbon fiber surface very uniformly, in contrast to air and wet oxidation. The precision of fiber diameter measurements is improved by using a laser diffraction technique instead of optical methods. More precise diameter measurements reveal that past correlations of diameter and fiber modulus are largely measurement artifact. The moduli of most carbon fibers decrease after the outer layers of the fibers are removed. Owing to experimental difficulties, the moduli and strengths of the fibers at their centers are not determined, and moduli are estimated on the basis of microstructure. The calculated residual stresses are found to be insensitive to these moduli estimates as well as the exact form of regression equation used to describe the moduli and residual strain distributions. Axial compressive residual stresses are found to be very high for some higher modulus carbon fibers. It is pointed out that the compressive stress makes the fibers insensitive to surface flaws when loaded in tension but it may initiate failure by buckling when loaded in compression.

  17. Fe2O3-loaded activated carbon fiber/polymer materials and their photocatalytic activity for methylene blue mineralization by combined heterogeneous-homogeneous photocatalytic processes

    Science.gov (United States)

    Kadirova, Zukhra C.; Hojamberdiev, Mirabbos; Katsumata, Ken-Ichi; Isobe, Toshihiro; Matsushita, Nobuhiro; Nakajima, Akira; Okada, Kiyoshi

    2017-04-01

    Fe2O3-supported activated carbon felts (Fe-ACFTs) were prepared by impregnating the felts consisted of activated carbon fibers (ACFs) with either polyester fibers (PS-A20) or polyethylene pulp (PE-W15) in Fe(III) nitrate solution and calcination at 250 °C for 1 h. The prepared Fe-ACFTs with 31-35 wt% Fe were characterized by N2-adsorption, scanning electron microscopy, and X-ray diffraction. The Fe-ACFT(PS-A20) samples with 5-31 wt% Fe were microporous with specific surface areas (SBET) ranging from 750 to 150 m2/g, whereas the Fe-ACFT(PE-W15) samples with 2-35 wt% Fe were mesoporous with SBET ranging from 830 to 320 m2/g. The deposition of iron oxide resulted in a decrease in the SBET and methylene blue (MB) adsorption capacity while increasing the photodegradation of MB. The optimum MB degradation conditions included 0.98 mM oxalic acid, pH = 3, 0.02-0.05 mM MB, and 100 mg/L photocatalyst. The negative impact of MB desorption during the photodegradation reaction was more pronounced for mesoporous PE-W15 samples and can be neglected by adding oxalic acid in cyclic experiments. Almost complete and simultaneous mineralization of oxalate and MB was achieved by the combined heterogeneous-homogeneous photocatalytic processes. The leached Fe ions in aqueous solution [Fe3+]f were measured after 60 min for every cycle and found to be about 2 ppm in all four successive cycles. The developed photocatalytic materials have shown good performance even at low content of iron oxide (2-5 wt% Fe-ACFT). Moreover, it is easy to re-impregnate the ACF when the content of iron oxide is reduced during the cyclic process. Thus, low leaching of Fe ions and possibility of cyclic usage are the advantages of the photocatalytic materials developed in this study.

  18. FIBER ORIENTATION IN INJECTION MOLDED LONG CARBON FIBER THERMOPLASTIC COMPOSITES

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jin; Nguyen, Ba Nghiep; Mathur, Raj N.; Sharma, Bhisham; Sangid, Michael D.; Costa, Franco; Jin, Xiaoshi; Tucker III, Charles L.; Fifield, Leonard S.

    2015-03-23

    A set of edge-gated and center-gated plaques were injection molded with long carbon fiber-reinforced thermoplastic composites, and the fiber orientation was measured at different locations of the plaques. Autodesk Simulation Moldflow Insight (ASMI) software was used to simulate the injection molding of these plaques and to predict the fiber orientation, using the anisotropic rotary diffusion and the reduced strain closure models. The phenomenological parameters of the orientation models were carefully identified by fitting to the measured orientation data. The fiber orientation predictions show very good agreement with the experimental data.

  19. The Development and Molding Process of Carbon Fiber Reinforced Polymer in Large Wind Turbine Blades%大型碳纤维复合材料风机叶片成型工艺与发展

    Institute of Scientific and Technical Information of China (English)

    马祥林; 任婷; 徐卫平

    2011-01-01

    本文介绍了风电叶片的纤维增强材料、基体、结构芯材、胶粘剂及辅助材料,同时重点总结了树脂转移模塑(RTM)成型工艺、模压成型工艺和最新的Flex成型工艺在碳纤维复合材料(CFRP)风电叶片的应用进展。通过结合国内外风电的研究现状,分析了CFRP在风电领域的应用与发展。%This paper discussed the material of wind turbine blades, included fiber reinforced material, matrix, the structure of core material, adhesive and auxiliary materials. Meanwhile, RTM( ResinTransferMolding), moulding technology and the new Reinforced Flex molding process are reviewed, which is researched in the carbon fiber reinforced polymer (CFRP) of wind turbine blades. Application and development of CFRP in wind turbine blades is discussed combined with the research status of wind power at home and abroad.

  20. Real time sensing of structural glass fiber reinforced composites by using embedded PVA - carbon nanotube fibers

    Directory of Open Access Journals (Sweden)

    Marioli-Riga Z.

    2010-06-01

    Full Text Available Polyvinyl alcohol - carbon nanotube (PVA-CNT fibers had been embedded to glass fiber reinforced polymers (GFRP for the structural health monitoring of the composite material. The addition of the conductive PVA-CNT fiber to the nonconductive GFRP material aimed to enhance its sensing ability by means of the electrical resistance measurement method. The test specimen’s response to mechanical load and the in situ PVA-CNT fiber’s electrical resistance measurements were correlated for sensing and damage monitoring purposes. The embedded PVA-CNT fiber worked as a sensor in GFRP coupons in tensile loadings. Sensing ability of the PVA-CNT fibers was also demonstrated on an integral composite structure. PVA-CNT fiber near the fracture area of the structure recorded very high values when essential damage occurred to the structure. A finite element model of the same structure was developed to predict axial strains at locations of the integral composite structure where the fibers were embedded. The predicted FEA strains were correlated with the experimental measurements from the PVA-CNT fibers. Calculated and experimental values were in good agreement, thus enabling PVA-CNT fibers to be used as strain sensors.

  1. Soft capacitor fibers using conductive polymers for electronic textiles

    Science.gov (United States)

    Gu, Jian Feng; Gorgutsa, Stephan; Skorobogatiy, Maksim

    2010-11-01

    A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its cross section the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using the fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometers of fibers can be obtained from a single preform with fiber diameters ranging between 500 and 1000 µm. A typical measured capacitance of our fibers is 60-100 nF m-1 and it is independent of the fiber diameter. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kΩ m L-1, which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials, the absence of liquid electrolyte in the fiber structure, ease of scalability to large production volumes and high capacitance of our fibers make them interesting for various smart textile applications ranging from distributed sensing to energy storage.

  2. Polymer Self-assembly on Carbon Nanotubes

    Science.gov (United States)

    Giulianini, Michele; Motta, Nunzio

    This chapter analyses the poly(3-hexylthiophene) self-assembly on carbon nanotubes and the interaction between the two materials forming a new hybrid nanostructure. The chapter starts with a review of the several studies investigating polymers and biomolecules self-assembled on nanotubes. Then conducting polymers and polythiophenes are briefly introduced. Accordingly, carbon nanotube structure and properties are reported in Sect. 3. The experimental section starts with the bulk characterisation of polymer thin films with the inclusion of uniformly distributed carbon nanotubes. By using volume film analysis techniques (AFM, TEM, UV-Vis and Raman), we show how the polymer's higher degree of order is a direct consequence of interaction with carbon nanotubes. Nevertheless, it is through the use of nanoscale analysis and molecular dynamic simulations that the self-assembly of the polymer on the nanotube surface can be clearly evidenced and characterised. In Sect. 6, the effect of the carbon templating structure on the P3HT organisation on the surface is investigated, showing the chirality-driven polymer assembly on the carbon nanotube surface. The interaction between P3HT and CNTs brings also to charge transfer, with the modification of physical properties for both species. In particular, the alteration of the polymer electronic properties and the modification of the nanotube mechanical structure are a direct consequence of the P3HT π-π stacking on the nanotube surface. Finally, some considerations based on molecular dynamics studies are reported in order to confirm and support the experimental results discussed.

  3. Localized biosensing with Topas microstructured polymer optical fiber.

    Science.gov (United States)

    Emiliyanov, Grigoriy; Jensen, Jesper B; Bang, Ole; Hoiby, Poul E; Pedersen, Lars H; Kjaer, Erik M; Lindvold, Lars

    2007-03-01

    We present what is believed to be the first microstructured polymer optical fiber (mPOF) fabricated from Topas cyclic olefin copolymer, which has attractive material and biochemical properties. This polymer allows for a novel type of fiber-optic biosensor, where localized sensor layers may be activated on the inner side of the air holes in a predetermined section of the mPOF. The concept is demonstrated using a fluorescence-based method for selective detection of fluorophore-labeled antibodies.

  4. Polymer Solar Cells: Solubility Controls Fiber Network Formation.

    Science.gov (United States)

    van Franeker, Jacobus J; Heintges, Gaël H L; Schaefer, Charley; Portale, Giuseppe; Li, Weiwei; Wienk, Martijn M; van der Schoot, Paul; Janssen, René A J

    2015-09-16

    The photoactive layer of polymer solar cells is commonly processed from a four-component solution, containing a semiconducting polymer and a fullerene derivative dissolved in a solvent-cosolvent mixture. The nanoscale dimensions of the polymer-fullerene morphology that is formed upon drying determines the solar cell performance, but the fundamental processes that govern the size of the phase-separated polymer and fullerene domains are poorly understood. Here, we investigate morphology formation of an alternating copolymer of diketopyrrolopyrrole and a thiophene-phenyl-thiophene oligomer (PDPPTPT) with relatively long 2-decyltetradecyl (DT) side chains blended with [6,6]-phenyl-C71-butyric acid methyl ester. During solvent evaporation the polymer crystallizes into a fibrous network. The typical width of these fibers is analyzed by quantification of transmission electron microscopic images, and is mainly determined by the solubility of the polymer in the cosolvent and the molecular weight of the polymer. A higher molecular weight corresponds to a lower solubility and film processing results in a smaller fiber width. Surprisingly, the fiber width is not related to the drying rate or the amount of cosolvent. We have made solar cells with fiber widths ranging from 28 to 68 nm and found an inverse relation between fiber width and photocurrent. Finally, by mixing two cosolvents, we develop a ternary solvent system to tune the fiber width. We propose a model based on nucleation-and-growth which can explain these measurements. Our results show that the width of the semicrystalline polymer fibers is not the result of a frozen dynamical state, but determined by the nucleation induced by the polymer solubility.

  5. Considerable different frequency dependence of dynamic tensile modulus between self-heating (Joule heat) and external heating for polymer--nickel-coated carbon fiber composites.

    Science.gov (United States)

    Zhang, Rong; Bin, Yuezhen; Dong, Enyuan; Matsuo, Masaru

    2014-06-26

    Dynamic tensile moduli of polyethylene--nickel-coated carbon fiber (NiCF) composites with 10 and 4 vol % NiCF contents under electrical field were measured by a homemade instrument in the frequency range of 100--0.01 Hz. The drastic descent of the storage modulus of the composite with 10 vol % was verified in lower frequency range with elevating surface temperature (T(s)) by self-heating (Joule heat). The composite was cut when T(s) was beyond 108 °C. On the other hand, the measurement of the composite with 4 vol % beyond 88 °C was impossible, since T(s) did not elevate because of the disruption of current networks. Incidentally, the dynamic tensile moduli by external heating could be measured up to 130 and 115 °C for 10 and 4 vol %, respectively, but the two composites could be elongated beyond the above temperatures. Such different properties were analyzed in terms of crystal dispersions, electrical treeing, and thermal fluctuation-induced tunneling effect.

  6. Study on the Mechanical Properties of Carbon Nanotube/Polyacrylonitrile Composite Fibers

    Institute of Scientific and Technical Information of China (English)

    李建梅; 王彪; 张玉梅; 王华平; 杨崇倡

    2003-01-01

    The method of preparing the multi-walled carbon nanotubes(MWNTs)-polyacrylonitrile (PAN) composite fibers is described and the effects of draw ratio on the mechanical properties of CNT/PAN fibers have also been discussed.The results show that the degrees of MWNTs dispersion in the polymer matrix have much effect on the mechanical properties.

  7. Release characteristics of selected carbon nanotube polymer composites

    Science.gov (United States)

    Multi-walled carbon nanotubes (MWCNTs) are commonly used in polymer formulations to improve strength, conductivity, and other attributes. A developing concern is the potential for carbon nanotube polymer nanocomposites to release nanoparticles into the environment as the polymer ...

  8. Carbon nanotube polymer composition and devices

    Science.gov (United States)

    Liu, Gao; Johnson, Stephen; Kerr, John B.; Minor, Andrew M.; Mao, Samuel S.

    2011-06-14

    A thin film device and compound having an anode, a cathode, and at least one light emitting layer between the anode and cathode, the at least one light emitting layer having at least one carbon nanotube and a conductive polymer.

  9. Why fibers are better turbulent drag reducing agents than polymers

    Science.gov (United States)

    Boelens, Arnout; Muthukumar, Murugappan

    2016-11-01

    It is typically found in literature that fibers are not as effective as drag reducing agents as polymers. However, for low concentrations, when adding charged polymers to either distilled or salt water, it is found that polymers showing rod-like behavior are better drag reducing agents than polymers showing coil-like behavior. In this study, using hybrid Direct Numerical Simulation with Langevin dynamics, a comparison is performed between polymer and fiber stress tensors in turbulent flow. The stress tensors are found to be similar, suggesting a common drag reducing mechanism in the onset regime. Since fibers do not have an elastic backbone, this must be a viscous effect. Analysis of the viscosity tensor reveals that all terms are negligible, except the off-diagonal shear viscosity associated with rotation. Based on this analysis, we are able to explain why charged polymers showing rod-like behavior are better drag reducing agents than polymers showing coil-like behavior. Additionally, we identify the rotational orientation time as the unifying time scale setting a new time criterion for drag reduction by both flexible polymers and rigid fibers. This research was supported by NSF Grant No. DMR-1404940 and AFOSR Grant No. FA9550-14-1-0164.

  10. Hybrid polymer photonic crystal fiber with integrated chalcogenide glass nanofilms

    DEFF Research Database (Denmark)

    Markos, Christos; Kubat, Irnis; Bang, Ole

    2014-01-01

    The combination of chalcogenide glasses with polymer photonic crystal fibers (PCFs) is a difficult and challenging task due to their different thermo-mechanical material properties. Here we report the first experimental realization of a hybrid polymer-chalcogenide PCF with integrated As2S3 glass ...

  11. Fiber design and realization of point-by-point written fiber Bragg gratings in polymer optical fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Stecher, Matthias; Town, Graham E.;

    2012-01-01

    and realization of a microstructured polymer optical fiber made of PMMA for direct writing of FBGs. The fiber was designed specifically to avoid obstruction of the writing beam by air-holes. The realized fiber has been used to point-by-point write a 5 mm long fourth order FBG with a Bragg wavelength of 1518 nm...

  12. A study of ultra-strength polymer fibers via calorimetry

    Science.gov (United States)

    Egorov, V. M.; Boiko, Yu. M.; Marikhin, V. A.; Myasnikova, L. P.; Radovanova, E. I.

    2016-08-01

    Xerogel reactor powders and supramolecular polyethylene fibers with various degrees of hood have been studied via differential scanning calorimetry. A higher strength of laboratory fibers in comparison with industrial ones is found to be achieved due to a multistage band high-temperature hood that causes the thermodynamic parameters of supramolecular polymer structure.

  13. Carbon fiber resin matrix interphase: effect of carbon fiber surface treatment on composite performance

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, S.; Megerdigian, C.; Papalia, R.

    1985-04-01

    Carbon fibers are supplied by various manufacturers with a predetermined level of surface treatment and matrix compatible sizings. Surface treatment of the carbon fiber increases the active oxygen content, the polarity and the total free surface energy of the fiber surface. This study is directed toward determining the effect of varying carbon fiber surface treatment on the composite performance of thermoset matrix resins. The effect of varying fiber surface treatment on performance of a promising proprietary sizing is also presented. 6 references, 11 figures.

  14. Nano-Fiber Reinforced Enhancements in Composite Polymer Matrices

    Science.gov (United States)

    Chamis, Christos C.

    2009-01-01

    Nano-fibers are used to reinforce polymer matrices to enhance the matrix dependent properties that are subsequently used in conventional structural composites. A quasi isotropic configuration is used in arranging like nano-fibers through the thickness to ascertain equiaxial enhanced matrix behavior. The nano-fiber volume ratios are used to obtain the enhanced matrix strength properties for 0.01,0.03, and 0.05 nano-fiber volume rates. These enhanced nano-fiber matrices are used with conventional fiber volume ratios of 0.3 and 0.5 to obtain the composite properties. Results show that nano-fiber enhanced matrices of higher than 0.3 nano-fiber volume ratio are degrading the composite properties.

  15. 拉挤型CFRP管轴压性能%Buckling behavior of pultruded carbon fiber reinforced polymer pipes under axially compressive load

    Institute of Scientific and Technical Information of China (English)

    南波; 武岳; 孙浩田

    2015-01-01

    The spacecraft skeletal structure is usually made of lightweight, high strength composite CFRP material, whose stability capacity is an important indicator of the structural safety performance. Firstly, pultruded CFRP short pipe compression test was done in this paper, focusing on the stiffness, ultimate strength and microscopic failure mode of carbon fiber reinforced resin matrix. Secondly, based on the Hashin failure criteria and using ANSYS finite element software to do numerical simulation showed that the numerical results from Hashin failure criterion can bet⁃ter predict the ultimate bearing capacity in the failure mode of CFRP composites. Next, the Hashin failure criteria are further compared with experiment by using the arc-length method to do numerical simulation for five types of CFRP slender pipes, rendering the load mid⁃span deflection curve of the whole process, summarizing the character⁃istics of its destruction, and deformation characteristics. The simulation results are in good agreement with experi⁃ment. Based on this, a large number of parameter analyses are evaluated and the experimental results are compared with the numerical analysis result. The relationship curve between stability factor Φ and slenderness ratio λ of the pultruded slender CFRP pipe was derived by the least squares fitting calculation. This research is convenient for the application in engineering practice.%航天器骨架结构通常由轻质高强CFRP(carbon fiber reinforced polymer)复合材料管制成,其稳定承载力成为结构安全性能的一项重要指标。对CFRP短管进行轴压试验,重点研究碳纤维增强复合材料的刚度、极限强度以及细观破坏模式。基于Hashin破坏准则进行二次开发,采用ANSYS有限元软件对试验过程进行了数值模拟,数值结果表明,Hashin破坏准则可以较好地预测CFRP复合材料破坏时的极限承载力。基于Hashin破坏准则,采用

  16. Soft capacitor fibers using conductive polymers for electronic textiles

    CERN Document Server

    Gu, Jian Feng; Skorobogatiy, Maksim

    2010-01-01

    A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its crossection the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometres of fibers can be obtained from a single preform with fiber diameters ranging between 500um -1000um. A typical measured capacitance of our fibers is 60-100 nF/m and it is independent of the fiber diameter. For comparison, a coaxial cable of the comparable dimensions would have only ~0.06nF/m capacitance. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kOhm/L, which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials...

  17. Surface Plasmon Resonance Sensors Based on Polymer Optical Fiber

    Institute of Scientific and Technical Information of China (English)

    Rong-Sheng Zheng; Yong-Hua Lu; Zhi-Guo Xie; Jun Tao; Kai-Qun Lin; Hai Ming

    2008-01-01

    Surface Plasmon Resonance (SPR) is a powerful technique for directly sensing in biological studies, chemical detection and environmental pollution monitoring. In this paper, we present polymer optical fiber application in SPR sensors, including wavelength interrogation surface enhanced Raman scattering SPR sensor and surface enhanced Raman scattering (SERS) probe.Long-period fiber gratings are fabricated on single mode polymer optical fiber (POF) with 120 μm period and 50% duty cycle. The polarization characteristic of this kind of birefringent grating is studied. Theoretical analysis shows it will be advantageous in SPR sensing applications.

  18. Carbon fiber composite molecular sieves

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T.D.; Rogers, M.R.; Williams, A.M.

    1996-06-01

    The removal of CO{sub 2} is of significance in several energy applications. The combustion of fossil fuels, such as coal or natural gas, releases large volumes of CO{sub 2} to the environment. Several options exist to reduce CO{sub 2} emissions, including substitution of nuclear power for fossil fuels, increasing the efficiency of fossil plants and capturing the CO{sub 2} prior to emission to the environment. All of these techniques have the attractive feature of limiting the amount of CO{sub 2} emitted to the atmosphere, but each has economic, technical, or societal limitations. In the production of natural gas, the feed stream from the well frequently contains contaminants and diluents which must be removed before the gas can enter the pipeline distribution system. Notable amongst these diluent gasses is CO{sub 2}, which has no calorific value. Currently, the pipeline specification calls for <2 mol % CO{sub 2} in the gas. Gas separation is thus a relevant technology in the field of energy production. A novel separation system based on a parametric swing process has been developed that utilizes the unique combination of properties exhibited by our carbon fiber composite molecular sieve (CFCMS).

  19. The immobilization of proteins on biodegradable polymer fibers via click chemistry.

    Science.gov (United States)

    Shi, Quan; Chen, Xuesi; Lu, Tiancheng; Jing, Xiabin

    2008-03-01

    A facile and efficient method to immobilize bioactive proteins onto polymeric substrate was established. Testis-specific protease 50 (TSP50) was immobilized on ultrafine biodegradable polymer fibers, i.e., (1) to prepare a propargyl-containing polymer P(LA90-co-MPC10) by introducing propargyl group into a cyclic carbonate monomer (5-methyl-5-propargyloxycarbonyl-1,3-dioxan-2-one, MPC) and copolymerizing it with l-lactide; (2) to electrospin the functionalized polymer into ultrafine fibers; (3) to azidize the TSP50, and (4) to perform the click reaction between the propargyl groups on the fibers and the azido groups on the protein. The TSP50-immobilized fibers can resist non-specific protein adsorptions but preserve specific recognition and combination with anti-TSP50. ELISA tests were carried out by using HRP-goat-anti-mouse-IgG(H+L) as secondary antibody and o-phenylenediamine (OPDA)/H(2)O(2) as substrate to detect the combination of immobilized TSP50 with anti-TSP50. The results showed that anti-TSP50 can be selectively adsorbed from its solution onto the TSP50-immobilized fibers in the presence of BSA of as high as 10(4) times concentration. TSP50 immobilized on the fiber and anti-TSP50 combined to the fiber were also quantitatively determined. Anti-TSP50 can be then eluted off from the fiber when pH changes. The eluted fiber can re-combine anti-TSP50 at an efficiency of 75% compared to the original TSP50-immobilized fiber. Therefore, the TSP50-immobilized fibers can be used in the detection, separation, and purification of anti-TSP50. The "click" method can lead to a universal strategy to protein immobilization.

  20. Characterization of electrospun lignin based carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Poursorkhabi, Vida; Mohanty, Amar; Misra, Manjusri [School of Engineering, Thornbrough Building, University of Guelph, Guelph, N1G 2W1, Ontario (Canada); Bioproducts Discovery and Development Centre, Department of Plant Agriculture, Crop Science Building, University of Guelph, Guelph, N1G 2W1, Ontario (Canada)

    2015-05-22

    The production of lignin fibers has been studied in order to replace the need for petroleum based precursors for carbon fiber production. In addition to its positive environmental effects, it also benefits the economics of the industries which cannot take advantage of carbon fiber properties because of their high price. A large amount of lignin is annually produced as the byproduct of paper and growing cellulosic ethanol industry. Therefore, finding high value applications for this low cost, highly available material is getting more attention. Lignin is a biopolymer making about 15 – 30 % of the plant cell walls and has a high carbon yield upon carbonization. However, its processing is challenging due to its low molecular weight and also variations based on its origin and the method of separation from cellulose. In this study, alkali solutions of organosolv lignin with less than 1 wt/v% of poly (ethylene oxide) and two types of lignin (hardwood and softwood) were electrospun followed by carbonization. Different heating programs for carbonization were tested. The carbonized fibers had a smooth surface with an average diameter of less than 5 µm and the diameter could be controlled by the carbonization process and lignin type. Scanning electron microscopy (SEM) was used to study morphology of the fibers before and after carbonization. Thermal conductivity of a sample with amorphous carbon was 2.31 W/m.K. The electrospun lignin carbon fibers potentially have a large range of application such as in energy storage devices and water or gas purification systems.

  1. Selective intercalation of polymers in carbon nanotubes.

    Science.gov (United States)

    Bazilevsky, Alexander V; Sun, Kexia; Yarin, Alexander L; Megaridis, Constantine M

    2007-07-03

    A room-temperature, open-air method is devised to selectively intercalate relatively low-molecular-weight polymers (approximately 10-100 kDa) from dilute, volatile solutions into open-end, as-grown, wettable carbon nanotubes with 50-100 nm diameters. The method relies on a novel self-sustained diffusion mechanism driving polymers from dilute volatile solutions into carbon nanotubes and concentrating them there. Relatively low-molecular-weight polymers, such as poly(ethylene oxide) (PEO, 600 kDa) and poly(caprolactone) (PCL, 80 kDa), were encapsulated in graphitic nanotubes as confirmed by transmission electron microscopy, which revealed morphologies characteristic of mixtures in nanoconfinements affected by intermolecular forces. Whereas relatively small, flexible polymer molecules can conform to enter these nanotubes, larger macromolecules (approximately 1000 kDa) remain outside. The selective nature of this process is useful for filling nanotubes with polymers and could also be valuable in capping nanotubes.

  2. Bragg Grating Based Sensors in Microstructured Polymer Optical Fibers: Accelerometers and Microphones

    DEFF Research Database (Denmark)

    Stefani, Alessio

    and gluing of polymer to silica fibers are discussed. The realization of gratings in polymer fibers is shown with two different techniques: the UV phase mask technique and the direct writing technique reported here for the first time for polymer fibers. Realization of gratings in PMMA step index fibers...

  3. Effect of electropolymer sizing of carbon fiber on mechanical properties of phenolic resin composites

    Institute of Scientific and Technical Information of China (English)

    LI Jin; FAN Qun; CHEN Zhen-hua; HUANG Kai-bing; CHENG Ying-liang

    2006-01-01

    Carbon fiber/phenolic resin composites were reinforced by the carbon fiber sized with the polymer films of phenol,m-phenylenediamine or acrylic acid,which was electropolymerized by cyclic voltammetry or chronopotentiometry. The contact angles of the sized carbon fibers with deionized water and diiodomethane were measured by the wicking method based on the modified Washburn equation,to show the effects of the different electropolymer film on the surface free energy of the carbon fiber after sizing by the electropolymerization. Compared with the unsized carbon fiber,which has 85.6°of contact angle of water,52.2° of contact angle of diiodomethane,and 33.1 mJ/m2 of surface free energy with 29.3 mJ/m2 of dispersive components (γL) and 3.8 mJ/m2 of polar components (γsp),respectively. It is found that the electropolymer sized carbon fiber tends to reduce the surface energy due to the decrease of dispersive γL with the increase of the polymer film on the surface of the carbon fiber that plays an important role in improving the mechanical properties of carbon/phenolic resin composites. Compared with the phenolic resin composites reinforced by the unsized carbon fiber,the impact,flexural and interlaminar shear strength of the phenolic resin composites were improved by 44 %,68% and 87% when reinforced with the carbon fiber sized by the electropolymer of m-phenylenediamine,66%,100%,and 112% by the electropolymer of phenol,and 20%,80 %,100% by the electropolymer of acrylic acid. The results indicate the skills of electropolymerization may provide a feasible method for the sizing of carbon fiber in a composite system,so as to improve the interfacial performance between the reinforce materials and the matrix and to increase the mechanical properties of the composites.

  4. Microstructure of carbon fiber preform and distribution of pyrolytic carbon by chemical vapor infiltration

    Institute of Scientific and Technical Information of China (English)

    陈建勋; 黄伯云

    2004-01-01

    The carbon/carbon composites were made by chemical vapor infiltration(CVI) with needled felt preform. The distribution of the pyrolytic carbon in the carbon fiber preform was studied by polarized light microscope(PLM) and scanning electronic microscope(SEM). The experimental results indicate that the amount of pyrolytic carbon deposited on the surface of chopped carbon fiber is more than that on the surface of long carbon fiber. The reason is the different porosity between the layer of chopped carbon fiber and long carbon fiber. The carbon precursor gas which passes through the part of chopped carbon fibers decomposes and deposits on the surface of chopped carbon fiber. The pyrolytic carbon on the surface of long carbon fibers is produced by the carbon precursor gas diffusing from the chopped fiber and the Z-d fiber. Uniform pore distribution and porosity in preform are necessary for producing C/C composites with high properties.

  5. Hybrid Carbon Fibers/Carbon Nanotubes Structures for Next Generation Polymeric Composites

    Directory of Open Access Journals (Sweden)

    M. Al-Haik

    2010-01-01

    Full Text Available Pitch-based carbon fibers are commonly used to produce polymeric carbon fiber structural composites. Several investigations have reported different methods for dispersing and subsequently aligning carbon nanotubes (CNTs as a filler to reinforce polymer matrix. The significant difficulty in dispersing CNTs suggested the controlled-growth of CNTs on surfaces where they are needed. Here we compare between two techniques for depositing the catalyst iron used toward growing CNTs on pitch-based carbon fiber surfaces. Electrochemical deposition of iron using pulse voltametry is compared to DC magnetron iron sputtering. Carbon nanostructures growth was performed using a thermal CVD system. Characterization for comparison between both techniques was compared via SEM, TEM, and Raman spectroscopy analysis. It is shown that while both techniques were successful to grow CNTs on the carbon fiber surfaces, iron sputtering technique was capable of producing more uniform distribution of iron catalyst and thus multiwall carbon nanotubes (MWCNTs compared to MWCNTs grown using the electrochemical deposition of iron.

  6. Tunable Polymer Fiber Bragg Grating (FBG) Inscription: Fabrication of Dual-FBG Temperature Compensated Polymer Optical Fiber Strain Sensors

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole

    2012-01-01

    We demonstrate stable wavelength tunable inscription of polymer optical fiber Bragg gratings (FBGs). By straining the fiber during FBG inscription, we linearly tune the center wavelength over 7 nm with less than 1% strain. Above 1% strain, the tuning curve saturates and we show a maximum tuning...... of 12 nm with 2.25% strain. We use this inscription method to fabricate a dual-FBG strain sensor in a poly (methyl methacrylate) single-mode microstructured polymer optical fiber and demonstrate temperature compensated strain sensing around 850 nm....

  7. Carbon Fiber Damage in Accelerator Beam

    CERN Document Server

    Sapinski, M; Guerrero, A; Koopman, J; Métral, E

    2009-01-01

    Carbon fibers are commonly used as moving targets in Beam Wire Scanners. Because of their thermomechanical properties they are very resistant to particle beams. Their strength deteriorates with time due to radiation damage and low-cycle thermal fatigue. In case of high intensity beams this process can accelerate and in extreme cases the fiber is damaged during a single scan. In this work a model describing the fiber temperature, thermionic emission and sublimation is discussed. Results are compared with fiber damage test performed on SPS beam in November 2008. In conclusions the limits of Wire Scanner operation on high intensity beams are drawn.

  8. Properties of Single Mode Polymer Optical Fiber

    Institute of Scientific and Technical Information of China (English)

    YANG Dong-xiao

    2003-01-01

    The density,dynamic modulus,Young's modulus,tensile strength,extension properties,Fourier transform infrared spectrum and differential scanning calorimetry have been measured and discussed for single mode polymethyl-methacrylate optical fiber.The results show that the fiber can provide large strain range for polymeric optical fiber Bragg gratings.

  9. Thermophysical ESEM Characterization of Carbon Fibers

    Science.gov (United States)

    Sue, Jiwoong; Ochoa, Ozden O.; Effinger, Michael R.; Munafo, Paul M. (Technical Monitor)

    2002-01-01

    Coefficients of thermal expansion (CTE) of carbon fibers create residual stresses in aggressive manufacturing and service environments. In this effort, environmental scanning electron microscope (ESEM) is used for in situ observations of a carbon fiber cross-section up to 1000 C in order to evaluate the much neglected transverse CTE. The perimeter of fiber cross-section is calculated with the Scion image processing program from images that were taken at every 100 C increments. CTE values are calculated by linear regression of the strain data based on the perimeter changes. Furthermore, through SEM, WDS and TEM observations, we are in the process of bringing an interactive rationale between CTE, crystallinity and surface roughness of carbon fibers.

  10. Zinc Oxide Nanowire Interphase for Enhanced Lightweight Polymer Fiber Composites

    Science.gov (United States)

    Sodano, Henry A.; Brett, Robert

    2011-01-01

    The objective of this work was to increase the interfacial strength between aramid fiber and epoxy matrix. This was achieved by functionalizing the aramid fiber followed by growth of a layer of ZnO nanowires on the fiber surface such that when embedded into the polymer, the load transfer and bonding area could be substantially enhanced. The functionalization procedure developed here created functional carboxylic acid surface groups that chemically interact with the ZnO and thus greatly enhance the strength of the interface between the fiber and the ZnO.

  11. The development of high precision carbon fiber composite mirror

    Science.gov (United States)

    Xu, Liang; Ding, Jiao-teng; Wang, Yong-jie; Xie, Yong-jie; Ma, Zhen; Fan, Xue-wu

    2016-10-01

    Due to low density, high stiffness, low thermal expansion coefficient, duplicate molding, etc., carbon fiber reinforced polymer (CFRP) is one of the potential materials of the optical mirror. The process developed for Φ300mm high precision CFRP mirror described in this paper. A placement tool used to improve laying accuracy up to ± 0.1°.A special reinforced cell structure designed to increase rigidity and thermal stability. Optical replication process adopted for surface modification of the carbon fiber composite mirror blank. Finally, surface accuracy RMS of Φ300mm CFRP mirror is 0.22μm, surface roughness Ra is about 2nm, and the thermal stability can achieve 13nm /°C from the test result. The research content is of some reference value in the infrared as well as visible light applications.

  12. Development of the experimental procedure to examine the response of carbon fiber-reinforced polymer composites subjected to a high-intensity pulsed electric field and low-velocity impact

    Science.gov (United States)

    Hart, Robert J.; Zhupanska, Olesya I.

    2016-01-01

    A new fully automated experimental setup has been developed to study the response of carbon fiber reinforced polymer (CFRP) composites subjected to a high-intensity pulsed electric field and low-velocity impact. The experimental setup allows for real-time measurements of the pulsed electric current, voltage, impact load, and displacements on the CFRP composite specimens. The setup includes a new custom-built current pulse generator that utilizes a bank of capacitor modules capable of producing a 20 ms current pulse with an amplitude of up to 2500 A. The setup enabled application of the pulsed current and impact load and successfully achieved coordination between the peak of the current pulse and the peak of the impact load. A series of electrical, impact, and coordinated electrical-impact characterization tests were performed on 32-ply IM7/977-3 unidirectional CFRP composites to assess their ability to withstand application of a pulsed electric current and determine the effects of the pulsed current on the impact response. Experimental results revealed that the electrical resistance of CFRP composites decreased with an increase in the electric current magnitude. It was also found that the electrified CFRP specimens withstood higher average impact loads compared to the non-electrified specimens.

  13. Development of the experimental procedure to examine the response of carbon fiber-reinforced polymer composites subjected to a high-intensity pulsed electric field and low-velocity impact.

    Science.gov (United States)

    Hart, Robert J; Zhupanska, Olesya I

    2016-01-01

    A new fully automated experimental setup has been developed to study the response of carbon fiber reinforced polymer (CFRP) composites subjected to a high-intensity pulsed electric field and low-velocity impact. The experimental setup allows for real-time measurements of the pulsed electric current, voltage, impact load, and displacements on the CFRP composite specimens. The setup includes a new custom-built current pulse generator that utilizes a bank of capacitor modules capable of producing a 20 ms current pulse with an amplitude of up to 2500 A. The setup enabled application of the pulsed current and impact load and successfully achieved coordination between the peak of the current pulse and the peak of the impact load. A series of electrical, impact, and coordinated electrical-impact characterization tests were performed on 32-ply IM7/977-3 unidirectional CFRP composites to assess their ability to withstand application of a pulsed electric current and determine the effects of the pulsed current on the impact response. Experimental results revealed that the electrical resistance of CFRP composites decreased with an increase in the electric current magnitude. It was also found that the electrified CFRP specimens withstood higher average impact loads compared to the non-electrified specimens.

  14. Sub percolation threshold carbon nanotube based polyvinylidene fluoride polymer-polymer composites

    Science.gov (United States)

    Jacob, Cedric Antony

    The study of piezoelectric materials has traditionally focused largely on homogeneous crystalline or semi-crystalline materials. This research focuses on the concept of piezoelectric composites using selective microstructural reinforcement in the piezoelectric material to improve the piezoelectric properties. This is done using a polyvinylidene fluoride (PVDF) and carbon nanotube composite as the model system. A multi-tiered engineering approach is taken to understand the material (experimental and computational analyses) and design a composite system which provides an effective platform for future research in piezoelectric improvement. A finite element analysis is used to evaluate the ability of carbon nanotubes to generate a heterogeneous electric field where local improvements in electric field produce an increase in the effective piezoelectric strength. The study finds that weight percent and aspect ratio of the carbon nanotubes are of key importance while formations of percolating networks are detrimental to performance. This motivates investigation into electrospinning into a method of producing sub percolation threshold composites with large carbon nanotube content. However, the electrospun fabrics have too low of a dielectric strength to sustain high strength electric fields. This is studied within the context of high voltage physics and a solution inspired by traditional composites manufacturing is proposed wherein the electrospun fiber mat is used as the fiber reinforcing component of a polymer-polymer composite. This composite is thoroughly analyzed to show that it allows for a high dielectric strength combined with high carbon nanotube content. It is also shown that the PVDF contains the proper crystal structure to allow for piezoelectric properties. Furthermore, the addition of carbon nanotubes greatly improves the strength and stiffness of the composite, as well as affecting the internal electric field response to an applied voltage. These qualities

  15. Flexural retrofitting of reinforced concrete structures using Green Natural Fiber Reinforced Polymer plates

    Science.gov (United States)

    Cervantes, Ignacio

    An experimental study will be carried out to determine the suitability of Green Natural Fiber Reinforced Polymer plates (GNFRP) manufactured with hemp fibers, with the purpose of using them as structural materials for the flexural strengthening of reinforced concrete (RC) beams. Four identical RC beams, 96 inches long, are tested for the investigation, three control beams and one test beam. The first three beams are used as references; one unreinforced, one with one layer of Carbon Fiber Reinforced Polymer (CFRP), one with two layers of CFRP, and one with n layers of the proposed, environmental-friendly, GNFRP plates. The goal is to determine the number of GNFRP layers needed to match the strength reached with one layer of CFRP and once matched, assess if the system is less expensive than CFRP strengthening, if this is the case, this strengthening system could be an alternative to the currently used, expensive CFRP systems.

  16. Direct Writing of Fiber Bragg Grating in Microstructured Polymer Optical Fiber

    DEFF Research Database (Denmark)

    Stefani, Alessio; Stecher, Matthias; Town, G. E.

    2012-01-01

    We report point-by-point laser direct writing of a 1520-nm fiber Bragg grating in a microstructured polymer optical fiber (mPOF). The mPOF is specially designed such that the microstructure does not obstruct the writing beam when properly aligned. A fourth-order grating is inscribed in the m...

  17. Tapering of Polymer Optical Fibers for Compound Parabolic Concentrator Fiber Tip Fabrication

    DEFF Research Database (Denmark)

    Hassan, Hafeez Ul; Fasano, Andrea; Nielsen, Kristian;

    2015-01-01

    We propose a process for Polymer Optical Fiber (POF) Compound Parabolic Compound (CPC) tip manufacturing using a heat and pull fiber tapering technique. The POF, locally heated above its glass transition temperature, is parabolically tapered down in diameter, after which it is cut to the desired...

  18. Time-dependent variation of fiber Bragg grating reflectivity in PMMA-based polymer optical fibers

    DEFF Research Database (Denmark)

    Saez-Rodriguez, D.; Nielsen, Kristian; Bang, Ole;

    2015-01-01

    In this Letter, we investigate the effects of viscoelasticity on both the strength and resonance wavelength of two fiber Bragg gratings (FBGs) inscribed in microstructured polymer optical fiber (mPOF) made of undoped PMMA. Both FBGs were inscribed under a strain of 1% in order to increase...

  19. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete

    OpenAIRE

    Weimin Song; Jian Yin

    2016-01-01

    Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF) and carbon fiber (CF) was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC), carbon fiber reinforced concrete (CFRC) and hybrid fiber reinforced concrete (HFRC) were explored at steel fiber volume fraction 0.5%,...

  20. Ply Orientation of Carbon Fiber Reinforced Aircraft Wing - A Parametric Study

    Directory of Open Access Journals (Sweden)

    Dr. Alice Mathai

    2014-05-01

    Full Text Available In the present day scenario, use of carbon fiber composites has been extended to a large number of aircraft components which includes structural and non-structural components. Carbon fiber reinforced polymer (CFRP is a composite material which consists of laminates having reinforcing fibers (carbon of significant strength embedded in a matrix material. Each lamina can have distinct fiber orientations which may vary from the adjoining lamina. The present study focuses on the effect of the ply orientation on the strength of the panels. The wing of a subsonic aircraft was modeled in the ANSYS software. The performance of wing under the application of loads was studied by varying the orientation of fiber layers. From the study, it was observed that the variation in stress occurs with variation in orientation of fiber layers of CFRP composites.

  1. Studies on natural fiber reinforced polymer matrix composites

    Science.gov (United States)

    Patel, R. H.; Kapatel, P. M.; Machchhar, A. D.; Kapatel, Y. A.

    2016-05-01

    Natural fiber reinforced composites show increasing importance in day to days applications because of their low cost, lightweight, easy availability, non-toxicity, biodegradability and environment friendly nature. But these fibers are hydrophilic in nature. Thus they have very low reactivity and poor compatibility with polymers. To overcome these limitations chemical modifications of the fibers have been carried out. Therefore, in the present work jute fibers have chemically modified by treating with sodium hydroxide (NaOH) solutions. These treated jute fibers have been used to fabricate jute fiber reinforced epoxy composites. Mechanical properties like tensile strength, flexural strength and impact strength have been found out. Alkali treated composites show better properties compare to untreated composites.

  2. Gel Spun PAN/CNT Based Carbon Fibers with Honey-Comb Cross-Section

    Science.gov (United States)

    2013-11-13

    30 37 100 / -50 Could not obtain fiber due to uneven extrusion and dripping of polymer solution 3 15/30 150 60 / 40 37 100 / -50 4 15/30 150 70...on structure, processing, and properties of polymer /CNT composite films and fibers were also conducted. Results of these studies are well documented...Structure, and Properties of Carbon Fibers”, Polymer Reviews, 52, 234-258 (2012). DOI: 10.1080/15583724.2012.705410. 9. Y. Liu, Y. H. Choi, H. G. Chae, P

  3. CO2 Laser Cutting of Glass Fiber Reinforce Polymer Composite

    Science.gov (United States)

    Fatimah, S.; Ishak, M.; Aqida, S. N.

    2012-09-01

    The lamination, matrix properties, fiber orientation, and relative volume fraction of matrix of polymer structure make this polymer hard to process. The cutting of polymer composite using CO2 laser could involve in producing penetration energy in the process. Identification of the dominant factors that significantly affect the cut quality is important. The objective of this experiment is to evaluate the CO2 spot size of beam cutting for Glass Fiber Reinforce Polymer Composite (GFRP). The focal length selected 9.5mm which gave smallest focus spot size according to the cutting requirements. The effect of the focal length on the cut quality was investigated by monitoring the surface profile and focus spot size. The beam parameter has great effect on both the focused spot size and surface quality.

  4. Polymers in Carbon Dots: A Review

    Directory of Open Access Journals (Sweden)

    Yiqun Zhou

    2017-02-01

    Full Text Available Carbon dots (CDs have been widely studied since their discovery in 2004 as a green substitute of the traditional quantum dots due to their excellent photoluminescence (PL and high biocompatibility. Meanwhile, polymers have increasingly become an important component for both synthesis and modification of CDs to provide polymeric matrix and enhance their PL property. Furthermore, critical analysis of composites of CDs and polymers has not been available. Herein, in this review, we summarized the use of polymers in the synthesis and functionalization of CDs, and the applications of these CDs in various fields.

  5. Ceramic fibers from Si-B-C polymer precursors

    Science.gov (United States)

    Riccitiello, S. R.; Hsu, M. S.; Chen, T. S.

    1993-01-01

    Non-oxide ceramics such as silicon carbide (SiC), silicon nitride (Si3N4), and silicon borides (SiB4, SiB6) have thermal stability, oxidation resistance, hardness, and varied electrical properties. All these materials can be prepared in a fiber form from a suitable polymer precursor. The above mentioned fibers, when tested over a temperature range from 25 to 1400 C, experience degradation at elevated temperatures. Past work in ceramic materials has shown that the strength of ceramics containing both carbides and borides is sustained at elevated temperatures, with minimum oxidation. The work presented here describes the formation of ceramic fibers containing both elements, boron and silicon, prepared via the polymer precursor route previously reported by the authors, and discusses the fiber mechanical properties that are retained over the temperature range studied.

  6. Solid catalytic growth mechanism of micro-coiled carbon fibers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Micro-coiled carbon fibers were prepared by catalytic pyrolysisof acetylene with nano-sized nickel powder catalyst using the substrate method. The morphology of micro-coiled carbon fibers was observed through field emission scanning electron microscopy. It was found that the fiber and coil diameter of the obtained micro-coiled carbon fibers is about 500—600 nm and 4—5 μm, respectively. Most of the micro-coiled carbon fibers obtained were regular double carbon coils, but a few irregular ones were also observed. On the basis of the experimental observation, a solid catalytic growth mechanism of micro-coiled carbon fibers was proposed.

  7. Localized biosensing with Topas microstructured Polymer Optical Fiber

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Jensen, Jesper Bo; Bang, Ole

    2007-01-01

    We present what is believed to be the first microstructured polymer optical fiber (mPOF) fabricated from Topas cyclic olefin copolymer, which has attractive material and biochemical properties. This polymer allows for a novel type of fiber-optic biosensor, where localized sensor layers may...... be activated on the inner side of the air holes in a predetermined section of the mPOF. The concept is demonstrated using a fluorescencebased method for selective detection of fluorophore-labeled antibodies. © 2007 Optical Society of America...

  8. Effects of moisture on glass fiber-reinforced polymer composites

    DEFF Research Database (Denmark)

    Alzamora Guzman, Vladimir Joel; Brøndsted, Povl

    2015-01-01

    Glass fiber polymer composites are used in wind turbine blades because of their high-specific strength and stiffness, good fatigue properties, and low cost. The wind industry is moving offshore to satisfy economies of scale with larger turbines. High humidity in this environment degrades mechanical...... performance of wind turbine blades over their lifetime. Here, environmental moisture conditions were simulated by immersing glass fiber-reinforced polymer specimens in salt water for a period of up to 8 years. The mechanical properties of specimens were analyzed before and after immersion to evaluate...

  9. Morphological and mechanical analysis of electrospun shape memory polymer fibers

    Science.gov (United States)

    Budun, Sinem; İşgören, Erkan; Erdem, Ramazan; Yüksek, Metin

    2016-09-01

    Shape memory block co-polymer Polyurethane (PU) fibers were fabricated by electrospinning technique. Four different solution concentrations (5 wt.%, 10 wt.%, 15 wt.% and 20 wt.%) were prepared by using Tetrahydrofuran (THF)/N,N-dimethylformamide (DMF) (50:50, v/v) as solvents, and three different voltages (30 kV, 35 kV and 38.9 kV) were determined for the electrospinning process. Solution properties were explored in terms of viscosity and electrical conductivity. It was observed that as the polymer concentration increased in the solution, the conductivity declined. Morphological characteristics of the obtained fibers were analyzed through Scanning Electron Microscopy (SEM) measurements. Findings indicated that fiber morphology varied especially with polymer concentration and applied voltage. Obtained fiber diameter ranged from 112 ± 34 nm to 2046 ± 654 nm, respectively. DSC analysis presented that chain orientation of the polymer increased after electrospinning process. Shape fixity and shape recovery calculations were realized. The best shape fixity value (92 ± 4%) was obtained for Y10K30 and the highest shape recovery measurement (130 ± 4%) was belonged to Y15K39. Mechanical properties of the electrospun webs were also investigated in both machine and transverse directions. Tensile and elongation values were also affected from fiber diameter distribution and morphological characteristics of the electrospun webs.

  10. The Characteristics and Application of Polymer Optical Fiber

    Institute of Scientific and Technical Information of China (English)

    CAI Bo; JI Xiao-li; ZHANG Chao-can

    2003-01-01

    The recent development of polymer optical fiber (POF) at home and abroad was summarized.The special characteristics of the perfluorinated POF were introduced and its wide potential application was predicted. POF is the most suitable in conjunction network project, especially using with quartz optical fibers . Facing this market opportunity, it is a right choice to unit colleges, research institntions and manufacture corporations to accelerate the imdustrialization of POF.

  11. Coating silicon carbide on carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yuqing; Wang Zuoming; Liu Min; Zhou Benlian; Shi Changxu (Inst. of Metal Research, Shenyang (China))

    1992-01-01

    The deposition of an SiC coating on the surface of carbon fibers improves their oxidation resistance and lowers their reactivity with metals at high temperature. Attention is presently given to the case of CVD SiC deposition with a view to the effects of coating thickness, deposition, and crystal structure. The presence of H(+) and other ions during CVD, as well as of free Si, is noted to decrease fiber strength. 10 refs.

  12. CARBON FIBER COMPOSITES IN HIGH VOLUME

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Charles David [ORNL; Das, Sujit [ORNL; Jeon, Dr. Saeil [Volvo Trucks North America

    2014-01-01

    Vehicle lightweighting represents one of several design approaches that automotive and heavy truck manufacturers are currently evaluating to improve fuel economy, lower emissions, and improve freight efficiency (tons-miles per gallon of fuel). With changes in fuel efficiency and environmental regulations in the area of transportation, the next decade will likely see considerable vehicle lightweighting throughout the ground transportation industry. Greater use of carbon fiber composites and light metals is a key component of that strategy. This paper examines the competition between candidate materials for lightweighting of heavy vehicles and passenger cars. A 53-component, 25 % mass reduction, body-in-white cost analysis is presented for each material class, highlighting the potential cost penalty for each kilogram of mass reduction and then comparing the various material options. Lastly, as the cost of carbon fiber is a major component of the elevated cost of carbon fiber composites, a brief look at the factors that influence that cost is presented.

  13. Analysis of Treatment Methods for Carbon Fiber Reinforced Polymer Composite Wastes%聚合物基碳纤维复合材料废弃物的几种处理方法分析

    Institute of Scientific and Technical Information of China (English)

    张建川

    2011-01-01

    Considered environmental protection,sustainable development,and actual production and applications of carbon fibers(CAs) in our country,the necessity of carbon fiber reinforced polymer composite(CFRP) waste treatment was described in details.According to the category of CFRP wastes,three treatment methods including enginery material recycling,material recycling energy recovery and energy recovery by incinerating CFRP wastes were put forward.And some kinds of the possible treatment projects were evaluated reasonably from three aspects including treatment expenses,environmental impact and substitute use.Comprehensively considering environment impact and economic efficiency,the performance of substitute products,the material recycling energy recovery is the best method in present stage.In addition,in order to push forward the later polymer composite waste treatment work,related suggestion was set forth from both inner factors and external factors.%从环保和可持续发展角度出发,并结合我国碳纤维(CF)生产与使用实际情况,对聚合物基碳纤维复合材料(CFRP)废弃物处理必要性作了较为详尽的阐述。根据CFRP废弃物种类,提出了机械材料再循环法、材料再循环与能量回收法、能量回收焚烧法三种可行处理方法,并从处理费用、环境影响、替代用途三方面对多种处理方案进行了合理评估。综合考虑处理环境影响、经济效益及替代物使用性能等因素,材料再循环与能量回收法为处理CFRP废弃物最合适的方法。此外,为推进其后期处理工作的顺利进行,还从内部、外部因素两方面提出相关建议。

  14. Method for production of polymer and carbon nanofibers from water-soluble polymers.

    Science.gov (United States)

    Spender, Jonathan; Demers, Alexander L; Xie, Xinfeng; Cline, Amos E; Earle, M Alden; Ellis, Lucas D; Neivandt, David J

    2012-07-11

    Nanometer scale carbon fibers (carbon nanofibers) are of great interest to scientists and engineers in fields such as materials science, composite production, and energy storage due to their unique chemical, physical, and mechanical properties. Precursors currently used for production of carbon nanofibers are primarily from nonrenewable resources. Lignin is a renewable natural polymer existing in all high-level plants that is a byproduct of the papermaking process and a potential feedstock for carbon nanofiber production. The work presented here demonstrates a process involving the rapid freezing of an aqueous lignin solution, followed by sublimation of the resultant ice, to form a uniform network comprised of individual interconnected lignin nanofibers. Carbonization of the lignin nanofibers yields a similarly structured carbon nanofiber network. The methodology is not specific to lignin; nanofibers of other water-soluble polymers have been successfully produced. This nanoscale fibrous morphology has not been observed in traditional cryogel processes, due to the relatively slower freezing rates employed compared to those achieved in this study.

  15. SiCO-doped carbon fibers with unique dual superhydrophilicity/superoleophilicity and ductile and capacitance properties.

    Science.gov (United States)

    Lu, Ping; Huang, Qing; Mukherjee, Amiya; Hsieh, You-Lo

    2010-12-01

    Silicon oxycarbide (SiCO) glass-doped carbon fibers with an average diameter of 163 nm were successfully synthesized by electrospinning polymer mixtures of preceramic precursor polyureasilazane (PUS) and carbon precursor polyacrylonitrile (PAN) into fibers then converting to ceramic/carbon hybrid via cross-linking, stabilization, and pyrolysis at temperatures up to 1000 °C. The transformation of PUS/PAN polymer precursors to SiCO/carbon structures was confirmed by EDS and FTIR. Both carbon and SiCO/carbon fibers were amorphous and slightly oxidized. Doping with SiCO enhanced the thermal stability of carbon fibers and acquired new ductile behavior in the SiCO/carbon fibers with significantly improved flexibility and breaking elongation. Furthermore, the SiCO/carbon fibers exhibited dual superhydrophilicity and superoleophilicity with water and decane absorbing capacities of 873 and 608%, respectively. The cyclic voltammetry also showed that SiCO/carbon composite fibers possess better capacitor properties than carbon fibers.

  16. Molecularly Imprinted Polymer Coated on Stainless Steel Fiber

    Institute of Scientific and Technical Information of China (English)

    Hu XiaoGang; Dai GuiMei; Huang JiaJing

    2009-01-01

    @@ With characteristics of specific selectivity,good chemical stability and easy preparation,molecularly imprinted polymer (MIP) has been used as the recognition materials m various fields ~([1,2]).Recently,the application of MIP in the sample pre-treatment techniques such as SPME was attractive ~([3,4]).For analysis of complicated samples,the interference matrix would be reduced obviously with the MIP-coated SPME fiber~([5-7]).Because MIPs were coated on the surface of silica fiber through chemical bonding,those fibers could be used for over 80 times without obvious losing of surface quality and extraction performance of MIP coatings.

  17. DUCTILITY BEHAVIOR FIBER REINFORCED CONCRETE BEAMS STRENGTHENED WITH EXTERNALLY BONDED GLASS FIBER REINFORCED POLYMER LAMINATES

    Directory of Open Access Journals (Sweden)

    Mariappan Mahalingam

    2013-01-01

    Full Text Available The study presents the results of an experimental investigation conducted on Steel Fiber Reinforced Concrete (SFRC beams with externally bonded Glass Fiber Reinforced Polymer (GFRP laminates with a view to study their strength and ductility. A total of ten beams, 150×250 mm in cross-section were tested in the laboratory over an effective span of 2800 mm. Three fiber reinforced concrete beams were used as reference beams. Six fiber reinforced concrete beams were provided with externally bonded GFRP laminates. One concrete beam was left virgin without any fiber reinforcement and external GFRP laminates. All the beams were tested until failure. The variables considered included volume fraction of fiber reinforcement and stiffness of GFRP laminates. The static responses of all the beams were evaluated in terms of strength, stiffness and ductility. The test results show that the beams provided with externally bonded GFRP laminates exhibit improved performance over the beams with internal fiber reinforcement.

  18. Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

    Science.gov (United States)

    Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

    2015-07-21

    Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

  19. Improvement of carbon fiber surface properties using electron beam irradiation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Carbon fiber-reinforced advance composites have been used for struetural applications, mainly on account of their mechanical properties. The main factor for a good mechanical performance of carbon fiber-reinforced composite is the interfacial interaction between its components, which are carbon fiber and polymeric matrix. The aim of this study is to improve the surface properties of the carbon fiber using ionizing radiation from an electron beam to obtain better adhesion properties in the resultant composite. EB radiation was applied on the carbon fiber itself before preparing test specimens for the mechanical tests. Experimental results showed that EB irradiation improved the tensile strength of carbon fiber samples. The maximum value in tensile strength was reached using doses of about 250kGy. After breakage, the morphology aspect of the tensile specimens prepared with irradiated and non-irradiated carbon fibers were evaluated. SEM micrographs showed modifications on the carbon fiber surface.

  20. Characterization of refractive index distribution of polymer optical fiber

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A focusing method is developed to characterize the refractive index profile of polymer optical fiber (POF). Based on the refractive index profile the theoretical bandwidth and the core index exponentα (α > 0) of POF are calculated. The results show that the value of theoretical bandwidth agrees well with the experimental data.

  1. Effect of polymer coating on leakage losses in Bragg fibers.

    Science.gov (United States)

    Uspenskii, Yu A; Uzorin, E E; Vinogradov, A V; Likhachev, M E; Semjonov, S L; Bubnov, M M; Dianov, E M; Jamier, R; Février, S

    2007-05-15

    It is found that the reflection of leaky radiation from the interface between the outer silica cladding and the coating polymer greatly modifies the loss spectrum of Bragg fibers. A simple model that describes this effect is proposed and confirmed by measurement and computation.

  2. Temperature effects on polymer-carbon composite sensors: evaluating the role of polymer molecular weight and carbon loading

    Science.gov (United States)

    Homer, M. L.; Lim, J. R.; Manatt, K.; Kisor, A.; Lara, L.; Jewell, A. D.; Yen, S. -P. S.; Shevade, A. V.; Ryan, M. A.

    2003-01-01

    We report the effect of environmental condtions coupled with varying polymer properties and carbon loadings on the performance of polymer-carbon black composite film, used as sensing medium in the JPL Electronic Nose.

  3. Polymer Optical Fiber Compound Parabolic Concentrator fiber tip based glucose sensor: In-Vitro Testing

    DEFF Research Database (Denmark)

    Hassan, Hafeez Ul; Janting, Jakob; Aasmul, Soren;

    2016-01-01

    We present in-vitro sensing of glucose using a newly developed efficient optical fiber glucose sensor based on a Compound Parabolic Concentrator (CPC) tipped polymer optical fiber (POF). A batch of 9 CPC tipped POF sensors with a 35 mm fiber length is shown to have an enhanced fluorescence pickup...... efficiency with an average increment factor of 1.7 as compared to standard POF sensors with a plane cut fiber tip. Invitro measurements for two glucose concentrations (40 and 400 mg/dL) confirm that the CPC tipped sensors efficiently can detect both glucose concentrations. it sets the footnote at the bottom...

  4. Changes in the Thermal and Dimensional Stability of the Structure of a Polymer Composite After Carbonization

    Science.gov (United States)

    Gaidachuk, V. E.; Kondratiev, A. V.; Chesnokov, A. V.

    2017-01-01

    Based on the theory of reinforcement of polymer composites, approximate relations for the physicomechanical and strength properties of a carbon-carbon composite material are synthesized, which are used to perform a finite-element analysis of the degree and character of changes in the thermal and dimensional stability of its structure after carbonization. Using approximate criteria of structural optimization of carbon-carbon composites ensuring their maximum dimensional stability, a [0/±45/90] package of thermally nonquilibrium layers is investigated and compared with an analogous carbon-fiber-reinforced plastic.

  5. Carbon fiber CVD coating by carbon nanostructured for space materials protection against atomic oxygen

    Science.gov (United States)

    Pastore, Roberto; Bueno Morles, Ramon; Micheli, Davide

    2016-07-01

    adhesion and durability in the environment. Though these coatings are efficient in protecting polymer composites, their application imposes severe constraints. Their thermal expansion coefficients may differ markedly from those of polymer composite substrates: as a result, cracks develop in the coatings on thermal cycling and AO can penetrate through them to the substrate. In addition to the technicalities of forming an effective barrier, such factors as cost, convenience of application and ease of repair are important considerations in the selection of a coating for a particular application. The latter issues drive the aerospace research toward the development of novel light composite materials, like the so called polymer nanocomposites, which are materials with a polymer matrix and a filler with at least one dimension less than 100 nanometers. Current interest in nanocomposites has been generated and maintained because nanoparticle-filled polymers exhibit unique combinations of properties not achievable with traditional composites. These combinations of properties can be achieved because of the small size of the fillers, the large surface area the fillers provide, and in many cases the unique properties of the fillers themselves. In particular, the carbon fiber-based polymeric composite materials are the basic point of interest: the aim of the present study is to find new solution to produce carbon fiber-based composites with even more upgraded performances. One intriguing strategy to tackle such an issue has been picked out in the coupling between the carbon fibers and the carbon nanostructures. That for two main reasons: first, carbon nanostructures have shown fancy potentialities for any kind of technological applications since their discovery, second, the chemical affinity between fiber and nanostructure (made of the same element) should be a likely route to approach the typical problems due to thermo-mechanical compatibility. This work is joined in such framework

  6. 电热作用对碳纤维树脂基复合材料力学性能的影响%Effects of electric thermal effect on mechanical properties of carbon fiber reinforced polymer

    Institute of Scientific and Technical Information of China (English)

    路鹏程; 毕亚芳; 王志平; 张俊; 张国尚

    2016-01-01

    Temperature field variation rule of carbon fiber reinforced polymer (CFRP)was tested by using electric thermal experimental platform for composites,while revealing the influence mechanism of electric thermal effect on the mechanical properties of CFRP from the interfacial shear strength of monofilament tensile fracture,the short beam shear property and shear fracture etc.The results show that electric thermal effect can increase the overall tem-perature of CFRP,and reach steady state temperature at about 4 min.CFRP laminate surface temperature is higher with increasing of the current strength,CFRP’s surface temperature reaches 1 5 1 ℃ when the current strength is 8 A (0.44 A/mm2 );the monofilament tensile and short beam shear strength of the interface with the increasing current strength increase at first and then decrease;when at a low current,the electric thermal effect generates less Joule heat,which can optimize the interface property to improve the interfacial shear strength,when at a high cur-rent,the electric thermal effect’s Joule heat is much higher,which can produce the irreversible damage such as abla-tion on interface and reduce the interfacial bonding property.%采用复合材料电热实验平台,测试碳纤维树脂基复合材料(Carbon Fiber Reinforced Polymer,CFRP)电热作用下温度场变化规律,同时从单丝拉伸断裂界面剪切强度、短梁剪切性能变化和剪切断口等多方面揭示电热作用对CFRP力学性能的影响机制。结果表明:电热作用会使 CFRP 整体温度迅速升高,在约4 min时达到稳态温度,随着电流强度的增大,CFRP层板表面温度越高,当电流强度为8 A(0.44 A/mm2)时,CFRP 的表面温度达到151℃;单丝拉伸和短梁剪切界面强度都随着电流强度增加呈现先增加后降低的趋势;小电流时,电热作用产生较少的焦耳热,优化界面性能,提高界面剪切强度,大电流时,电热作用产生的焦耳热过大,对界面产生烧蚀等

  7. Studies on copper coating on carbon fibers

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The weak interface bonding of metal matrix reinforced by carbon fibers is the central problem of fabricating such composites. Depositing copper coating on carbon fibers is regarded as a feasible method to solve the problem. In this paper, copper coating has been deposited on the fibers through both electroless deposition and electroplating methods. Two kinds of complexing agents and two stabilizing agents are taken during the electroless plating process. The solution is stable, and little extraneous component is absorbed on the surface. After adding additive agents and increasing the concentration of H2SO4 to the acid cupric sulfate electrolyte, the "black core" during usual electroplating process is avoided. The quality of copper coating is analyzed using SEM and XRD, etc.

  8. Structure and Properties of poly (para phynelyne benzobisoxazole) (PBO) /single wall carbon nano tube composite fibers

    Science.gov (United States)

    Kumar, Satish; Zhang, Xiefei; Bhattacharyya, Arup R.; Min, Byung G.; Dang, T. D.; Arnold, F. E.; Vaia, Richard A.; Ramesh, S.; Willis, P. A.; Hauge, R. H.; Smalley, R. E.

    2002-03-01

    The liquid crystalline compositions are prepared by the in-situ polycondensation of diamines and diacid monomers in the presence of single wall carbon nano tubes (SWNT). Processing of the new compositions into fibers provide hybrid materials with improved mechanical properties. The in-situ polymerizations were carried out in polyphosphoric acid (PPA). Carbon nano tubes as high as 10 wt.polymer weight have been utilized. Fiber spinning has been carried out using dry jet wet spinning using a piston driven spinning system and the fiber coagulated in water and subsequently vacuum dried and heat treated in nitrogen at 400oC. Structure and properties of these fibers have been studied. Tensile strength of the composite fibers increased by about 50morphology of these fibers have been studied using X- ray diffraction and scanning electron microscopy.

  9. Formation of thick dielectrophoretic carbon nanotube fibers

    Energy Technology Data Exchange (ETDEWEB)

    Plaado, Margo; Mononen, Robert Matias; Lohmus, Ruenno; Kink, Ilmar; Saal, Kristjan, E-mail: saal@fi.tartu.ee [Institute of Physics, University of Tartu, and Estonian Nanotechnology Competence Centre, 142 Riia Street, 51014 Tartu (Estonia)

    2011-07-29

    The aim of this work was to study the formation process of dielectrophoretic (DEP) carbon nanotube fibers (CNT-fibers) and characterize the fiber properties relevant to their technological applications. The fiber diameter was shown to increase when applied voltage was increased (up to 350 V{sub pp}) and when retraction speed was decreased (down from 400 {mu}m s{sup -1}) in accordance with theoretical expectations. This paper represents the first demonstration of the formation of thick DEP CNT-fibers (up to {approx} 0.4 mm). This is an intriguing result, as it expands the diversity of possible applications of the fibers and facilitates their characterization by analytical methods that require large quantities of the material. The performance of these thick fibers was as follows: a density of {approx} 0.35 g cm{sup -3}, a tensile strength of {approx} 15 MPa, a Young's modulus of {approx} 1 GPa, and an electrical resistivity of {approx} 70 m{Omega} cm.

  10. Sequestration of Single-Walled Carbon Nanotubes in a Polymer

    Science.gov (United States)

    Bley, Richard A.

    2007-01-01

    Sequestration of single-walled carbon nanotubes (SWCNs) in a suitably chosen polymer is under investigation as a means of promoting the dissolution of the nanotubes into epoxies. The purpose of this investigation is to make it possible to utilize SWCNs as the reinforcing fibers in strong, lightweight epoxy-matrix/carbon-fiber composite materials. SWCNs are especially attractive for use as reinforcing fibers because of their stiffness and strength-to-weight ratio: Their Young s modulus has been calculated to be 1.2 TPa, their strength has been calculated to be as much as 100 times that of steel, and their mass density is only one-sixth that of steel. Bare SWCNs cannot be incorporated directly into composite materials of the types envisioned because they are not soluble in epoxies. Heretofore, SWCNS have been rendered soluble by chemically attaching various molecular chains to them, but such chemical attachments compromise their structural integrity. In the method now under investigation, carbon nanotubes are sequestered in molecules of poly(m-phenylenevinylene-co-2,5-dioctyloxy-p-phenylenevinylene) [PmPV]. The strength of the carbon nanotubes is preserved because they are not chemically bonded to the PmPV. This method exploits the tendency of PmPV molecules to wrap themselves around carbon nanotubes: the wrapping occurs partly because there exists a favorable interface between the conjugated face of a nanotube and the conjugated backbone of the polymer and partly because of the helical molecular structure of PmPV. The constituents attached to the polymer backbones (the side chains) render the PmPV-wrapped carbon nanotubes PmPV soluble in organic materials that, in turn, could be used to suspend the carbon nanotubes in epoxy precursors. At present, this method is being optimized: The side chains on the currently available form of PmPV are very nonpolar and unable to react with the epoxy resins and/or hardeners; as a consequence, SWCN/PmPV composites have been

  11. Effect of Anodization on the Graphitization of PANbased Carbon Fibers of PAN-based Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    HE Dongmei; YAO Yinghua; XU Shihai; CAI Qingyun

    2011-01-01

    One-step pretreatment,anodization,is used to activate the polyacrylonitrile (PAN)-based carbon fibers instead of the routine two-step pretreatment,sensitization with SnCl2 and activation with PdCl2 The effect of the anodization pretreatment on the graphitization of PAN-based carbon fibers is investigated as a function of Ni-P catalyst.The PAN-based carbon fibers are anodized in H3PO4 electrolyte resulting in the formation of active sites,which thereby facilitates the following electroless Ni-P coating.Carbon fibers in the presence and absence of Ni-P coatings are heat treated and the structural changes are characterized by X-ray diffraction and Raman spectroscopy,both of which indicate that the graphitization of PAN-based carbon fibers are accelerated by both the anodization treatment and the catalysts Ni-E Using the anodized carbon fibers,the routine two-step pretreatment,sensitization and activation,is not needed.

  12. Manufacturing Energy Intensity and Opportunity Analysis for Fiber-Reinforced Polymer Composites and Other Lightweight Materials

    Energy Technology Data Exchange (ETDEWEB)

    Liddell, Heather; Brueske, Sabine; Carpenter, Alberta; Cresko, Joseph

    2016-09-22

    With their high strength-to-weight ratios, fiber-reinforced polymer (FRP) composites are important materials for lightweighting in structural applications; however, manufacturing challenges such as low process throughput and poor quality control can lead to high costs and variable performance, limiting their use in commercial applications. One of the most significant challenges for advanced composite materials is their high manufacturing energy intensity. This study explored the energy intensities of two lightweight FRP composite materials (glass- and carbon-fiber-reinforced polymers), with three lightweight metals (aluminum, magnesium, and titanium) and structural steel (as a reference material) included for comparison. Energy consumption for current typical and state-of-the-art manufacturing processes were estimated for each material, deconstructing manufacturing process energy use by sub-process and manufacturing pathway in order to better understand the most energy intensive steps. Energy saving opportunities were identified and quantified for each production step based on a review of applied R&D technologies currently under development in order to estimate the practical minimum energy intensity. Results demonstrate that while carbon fiber reinforced polymer (CFRP) composites have the highest current manufacturing energy intensity of all materials considered, the large differences between current typical and state-of-the-art energy intensity levels (the 'current opportunity') and between state-of-the-art and practical minimum energy intensity levels (the 'R&D opportunity') suggest that large-scale energy savings are within reach.

  13. Carbon Fiber Composite Monoliths as Catalyst Supports

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Pickel, Joseph M [ORNL; Blom, Douglas Allen [ORNL; Burchell, Timothy D [ORNL

    2006-01-01

    Carbon fiber composite monoliths are rigid bodies that can be activated to a large surface area, have tunable porosity, and proven performance in gas separation and storage. They are ideal as catalyst supports in applications where a rigid support, with open structure and easy fluid access is desired. We developed a procedure for depositing a dispersed nanoparticulate phase of molybdenum carbide (Mo2C) on carbon composite monoliths in the concentration range of 3 to 15 wt% Mo. The composition and morphology of this phase was characterized using X-ray diffraction and electron microscopy, and a mechanism was suggested for its formation. Molybdenum carbide is known for its catalytic properties that resemble those of platinum group metals, but at a lower cost. The materials obtained are expected to demonstrate catalytic activity in a series of hydrocarbon reactions involving hydrogen transfer. This project demonstrates the potential of carbon fiber composite monoliths as catalyst supports.

  14. Carbon Fiber Composite Monoliths for Catalyst Supports

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Pickel, Joseph M [ORNL; Blom, Douglas Allen [ORNL; Burchell, Timothy D [ORNL

    2006-01-01

    Carbon fiber composite monoliths are rigid bodies that can be activated to a large surface area, have tunable porosity, and proven performance in gas separation and storage. They are ideal as catalyst supports in applications where a rigid support, with open structure and easy fluid access is desired. We developed a procedure for depositing a dispersed nanoparticulate phase of molybdenum carbide (Mo2C) on carbon composite monoliths in the concentration range of 3 to 15 wt% Mo. The composition and morphology of this phase was characterized using X-ray diffraction and electron microscopy, and a mechanism was suggested for its formation. Molybdenum carbide is known for its catalytic properties that resemble those of platinum group metals, but at a lower cost. The materials obtained are expected to demonstrate catalytic activity in a series of hydrocarbon reactions involving hydrogen transfer. This project demonstrates the potential of carbon fiber composite monoliths as catalyst supports.

  15. Morphological and mechanical analysis of electrospun shape memory polymer fibers

    Energy Technology Data Exchange (ETDEWEB)

    Budun, Sinem [Institute of Pure and Applied Science, Marmara University, 34722 Istanbul (Turkey); İşgören, Erkan [Textile Technology, Technical Education Faculty, Marmara University, 34722 Istanbul (Turkey); Erdem, Ramazan, E-mail: ramazanerdem@akdeniz.edu.tr [Textile Technologies, Serik G-S. Sural Vocational School of Higher Education, Akdeniz University, 07500 Antalya (Turkey); Yüksek, Metin [Textile Engineering, Technology Faculty, Marmara University, 34722 Istanbul (Turkey)

    2016-09-01

    Highlights: • Fiber morphology of PU based shape memory fibers varied especially with polymer concentration and applied voltage. • The smallest diameter (381 ± 165 nm) and almost uniform (without bead) fibers were belonged to the sample Y10K30 with a feeding rate of 1 ml/h and an applied voltage of 30 kV at 24.5 cm distance. • All calculated shape fixity results were above 80% and the best value (92 ± 4%) was obtained for Y10K30. • All gained shape recovery results were determined above 100% and the highest measurement (130 ± 4%) was belonged to Y15K39. • The greatest tensile property was obtained for Y10K30 (14.7 ± 3.2 MPa) in machine direction and for Y10K39 (12.9 ± 0.8 MPa) in transverse direction. Y15K39 (411 ± 24%) and Y20K30 (402 ± 34%) possessed the highest elongation results compared with the other electrospun webs. - Abstract: Shape memory block co-polymer Polyurethane (PU) fibers were fabricated by electrospinning technique. Four different solution concentrations (5 wt.%, 10 wt.%, 15 wt.% and 20 wt.%) were prepared by using Tetrahydrofuran (THF)/N,N-dimethylformamide (DMF) (50:50, v/v) as solvents, and three different voltages (30 kV, 35 kV and 38.9 kV) were determined for the electrospinning process. Solution properties were explored in terms of viscosity and electrical conductivity. It was observed that as the polymer concentration increased in the solution, the conductivity declined. Morphological characteristics of the obtained fibers were analyzed through Scanning Electron Microscopy (SEM) measurements. Findings indicated that fiber morphology varied especially with polymer concentration and applied voltage. Obtained fiber diameter ranged from 112 ± 34 nm to 2046 ± 654 nm, respectively. DSC analysis presented that chain orientation of the polymer increased after electrospinning process. Shape fixity and shape recovery calculations were realized. The best shape fixity value (92 ± 4%) was obtained for Y10K30 and the highest shape

  16. RADIATION EFFECTS ON EPOXY/CARBON FIBER COMPOSITE

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, E; Eric Skidmore, E

    2008-12-12

    The Department of Energy Savannah River Site vitrifies nuclear waste incident to defense programs through its Defense Waste Processing Facility (DWPF). The piping in the DWPF seal pot jumper configuration must withstand the stresses during an unlikely but potential deflagration event, and maintain its safety function for a 20-year service life. Carbon fiber-reinforced epoxy composites (CFR) were proposed for protection and reinforcement of piping during such an event. The proposed CFR materials have been ASME-approved (Section XI, Code Case N-589-1) for post-construction maintenance and is DOT-compliant per 49CFR 192 and 195. The proposed carbon fiber/epoxy composite reinforcement system was originally developed for pipeline rehabilitation and post-construction maintenance in petrochemical, refineries, DOT applications and other industries. The effects of ionizing radiation on polymers and organic materials have been studied for many years. The majority of available data are based on traditional exposures to gamma irradiation at high dose rates ({approx}10,000 Gy/hr) allowing high total dose within reasonable test periods and general comparison of different materials exposed at such conditions. However, studies in recent years have shown that degradation of many polymers are sensitive to dose rate, with more severe degradation often observed at similar or even lower total doses when exposed to lower dose rates. This behavior has been primarily attributed to diffusion-limited oxidation which is minimized during very high dose rate exposures. Most test standards for accelerated aging and nuclear qualification of components acknowledge these limitations. The results of testing to determine the radiation resistance and microstructural effects of gamma irradiation exposure on a bisphenol-A based epoxy matrix composite reinforced with carbon fibers are presented. This work provides a foundation for a more extensive evaluation of dose rate effects on advanced epoxy

  17. Theoretical Estimation of Thermal Effects in Drilling of Woven Carbon Fiber Composite

    OpenAIRE

    José Díaz-Álvarez; Alvaro Olmedo; Carlos Santiuste; María Henar Miguélez

    2014-01-01

    Carbon Fiber Reinforced Polymer (CFRPs) composites are extensively used in structural applications due to their attractive properties. Although the components are usually made near net shape, machining processes are needed to achieve dimensional tolerance and assembly requirements. Drilling is a common operation required for further mechanical joining of the components. CFRPs are vulnerable to processing induced damage; mainly delamination, fiber pull-out, and thermal degradation, drilling in...

  18. Carbon Fiber Foam Composites and Methods for Making the Same

    Science.gov (United States)

    Leseman, Zayd Chad (Inventor); Atwater, Mark Andrew (Inventor); Phillips, Jonathan (Inventor)

    2014-01-01

    Exemplary embodiments provide methods and apparatus of forming fibrous carbon foams (FCFs). In one embodiment, FCFs can be formed by flowing a fuel rich gas mixture over a catalytic material and components to be encapsulated in a mold to form composite carbon fibers, each composite carbon fiber having a carbon phase grown to encapsulate the component in situ. The composite carbon fibers can be intertwined with one another to form FCFs having a geometry according to the mold.

  19. Self-healing in single and multiple fiber(s) reinforced polymer composites

    OpenAIRE

    2010-01-01

    You Polymer composites have been attractive medium to introduce the autonomic healing concept into modern day engineering materials. To date, there has been significant research in self-healing polymeric materials including several studies specifically in fiber reinforced polymers. Even though several methods have been suggested in autonomic healing materials, the concept of repair by bleeding of enclosed functional agents has garnered wide attention by the scientific community. A self-...

  20. AN INITIAL EVALUATION OF POLY(VINYLACETYLENE) AS A CARBON-FIBER PRECURSOR

    NARCIS (Netherlands)

    MAVINKURVE, A; VISSER, S; PENNINGS, AJ

    1995-01-01

    Poly(vinylacetylene) obtained by the selective polymerization of monovinylacetylene through the vinyl group has been investigated for its use as an alternative precursor for carbon fibers. The low yield of char obtained on pyrolysis of the polymer in an inert atmosphere was improved dramatically by

  1. Quasi-Carbon Fibers and the Composites

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@The aim of this report is to study the properties of quasi-carbon fibers (QCF) prepared from the PAN fiber precursor by pyrolysis at a temperature between 400℃ and 1200℃. The resistivity of QCF with different heat-treated temperature (HTT) was investigated by a Hall-35 testing system,and the flexural properties of the result composites (QCFC) are also discussed. In addition, the scanning electronic microscope (SEM) was utilized to observe the surface morphology of QCF and the fracture section of QCFC obtained from flexural testing.

  2. Functionalised hybrid materials of conducting polymers with individual wool fibers.

    Science.gov (United States)

    Kelly, Fern M; Johnston, James H; Borrmann, Thomas; Richardson, Michael J

    2008-04-01

    Composites of natural protein materials, such as merino wool, with the conducting polymers polypyrrole (PPy) and polyaniline (PAn) have been successfully synthesised. In doing so, hybrid materials have been produced in which the mechanical strength and flexibility of the fibers is retained whilst also incorporating the desired chemical and electrical properties of the polymer. Scanning electron microscopy shows PPy coatings to comprise individual polymer spheres, approximately 100 to 150 nm in diameter. The average size of the polymer spheres of PAn was observed to be approximately 50 to 100 nm in diameter. These spheres fuse together in a continuous sheet to coat the fibers in their entirety. The reduction of silver ions to silver metal nanoparticles onto the redox active polymer surface has also been successful and thus imparts anti-microbial properties to the hybrid materials. This gives rise to further applications requiring the inhibition of microbial growth. The chemical and physical characterisation of such products has been undertaken through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electrical conductivity, cyclic voltammetry, X-ray photoelectron spectroscopy (XPS) and the testing of their anti-microbial activity.

  3. Intrinsically Conductive Polymer Fibers from Thermoplastic trans-1,4-Polyisoprene.

    Science.gov (United States)

    Han, Peng; Zhang, Xiaohong; Qiao, Jinliang

    2016-05-17

    Herein, we report a new strategy to prepare conductive polymer fibers to overcome the insurmountable weakness of current conductive polymer fibers. First, special thermoplastic polymers are processed into polymer fibers using a conventional melt-spinning process, and then the nonconductive polymer fibers are converted into intrinsically conductive polymer fibers. Using this new strategy, intrinsically conductive polymer fibers have been prepared by melt spinning low-cost thermoplastic trans-1,4-polyisoprene and doping with iodine, which can be as fine as 0.01 mm, and the resistivity can be as low as 10(-2) Ω m. Moreover, it has been found that drawing can improve the orientation of trans-1,4-polyisoprene crystals in the fibers and, thus, the conductivity of the conductive polymer fibers. Therefore, conductive fibers with excellent conductivities can be prepared by large drawing ratios before doping. Such conductive polymer fibers with low cost could be used in textile, clothing, packing, and other fields, which would benefit both industry and daily life. The newly developed method also allows one to produce conductive polymers of any shape besides fibers for antistatic or conductive applications.

  4. Carbon fiber composite molecular sieves

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T.D.; Rogers, M.R. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    Monolithic adsorbents based on isotropic pitch fibers have been developed jointly by ORNL and the University of Kentucky, Center for Applied Energy Research. The monoliths are attractive for gas separation and storage applications because of their unique combination of physical properties and microporous structure. Currently at ORNL the monoliths are produced in billets that are 10 cm in diameter and 25 cm in length. The monolithic adsorbent material is being considered for guard bed applications on a natural gas (NG) powered device. In order for the material to be successful in this application, one must attain a uniform activation to modest micropore volumes throughout the large monoliths currently being produced. Here the authors report the results of a study directed toward attaining uniform activation in these billets.

  5. Fiber design and realization of point-by-point written fiber Bragg gratings in polymer optical fibers

    Science.gov (United States)

    Stefani, Alessio; Stecher, Matthias; Town, Graham E.; Bang, Ole

    2012-04-01

    An increasing interest in making sensors based on fiber Bragg gratings (FBGs) written in polymer optical fibers (POFs) has been seen recently. Mostly microstructured POFs (mPOFs) have been chosen for this purpose because they are easier to fabricate compared, for example, to step index fibers and because they allow to tune the guiding parameters by modifying the microstructure. Now a days the only technique used to write gratings in such fibers is the phase mask technique with UV light illumination. Despite the good results that have been obtained, a limited flexibility on the grating design and the very long times required for the writing of FBGs raise some questions about the possibility of exporting POF FBGs and the sensors based on them from the laboratory bench to the mass production market. The possibility of arbitrary design of fiber Bragg gratings and the very short time required to write the gratings make the point-by-point grating writing technique very interesting and would appear to be able to fill this technological gap. On the other end this technique is hardly applicable for microstructured fibers because of the writing beam being scattered by the air-holes. We report on the design and realization of a microstructured polymer optical fiber made of PMMA for direct writing of FBGs. The fiber was designed specifically to avoid obstruction of the writing beam by air-holes. The realized fiber has been used to point-by-point write a 5 mm long fourth order FBG with a Bragg wavelength of 1518 nm. The grating was inspected under Differential Interferometric Contrast microscope and the reflection spectrum was measured. This is, to the best of our knowledge, the first FBGs written into a mPOF with the point-by-point technique and also the fastest ever written into a polymer optical fiber, with less than 2.5 seconds needed.

  6. Polymer-derived silicon carbide fibers with near-stoichiometric composition and low oxygen content

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, M.D.; Scheiffele, G.W.; Saleem, M.; Staab, G.A.; Morrone, A.A.; Williams, T.J. [Univ. of Florida, Gainesville, FL (United States). Dept. of Materials Science and Engineering

    1995-10-01

    Fine-diameter ({approximately} 10--15 {micro}m), polymer-derived SiC fibers were characterized. The average tensile strength of the fibers was {approximately} 2.8 GPa, although some lots had average strengths exceeding 3.5 GPa. Microstructure observations showed that fibers had fine grain sizes (mostly {approximately} 0.05--0.2 {micro}m), high densities ({approximately} 3.1--3.2 g/cm{sup 3}), and small residual pore sizes ({le} 0.1 {micro}m). Elemental analysis showed that fibers had near-stoichiometric composition. Electron and X-ray diffraction analyses indicated that fibers were primarily beta silicon carbide, with a minor amount of the alpha phase. A small amount of graphitic carbon was detected in some samples using high resolution transmission electron microscopy. The residual oxygen content in the fibers was {le} 0.1 wt%. Fibers exhibited good thermomechanical stability, as heat treatment at 1,800 C for 4 h in argon resulted in only an {approximately} 8% decrease in strength.

  7. New biocomposites based on bioplastic flax fibers and biodegradable polymers.

    Science.gov (United States)

    Wróbel-Kwiatkowska, Magdalena; Czemplik, Magdalena; Kulma, Anna; Zuk, Magdalena; Kaczmar, Jacek; Dymińska, Lucyna; Hanuza, Jerzy; Ptak, Maciej; Szopa, Jan

    2012-01-01

    A new generation of entirely biodegradable and bioactive composites with polylactic acid (PLA) or poly-ε-caprolactone (PCL) as the matrix and bioplastic flax fibers as reinforcement were analyzed. Bioplastic fibers contain polyhydroxybutyrate and were obtained from transgenic flax. Biochemical analysis of fibers revealed presence of several antioxidative compounds of hydrophilic (phenolics) and hydrophobic [cannabidiol (CBD), lutein] nature, indicating their high antioxidant potential. The presence of CBD and lutein in flax fibers is reported for the first time. FTIR analysis showed intermolecular hydrogen bonds between the constituents in composite PLA+flax fibers which were not detected in PCL-based composite. Mechanical analysis of prepared composites revealed improved stiffness and a decrease in tensile strength. The viability of human dermal fibroblasts on the surface of composites made of PLA and transgenic flax fibers was the same as for cells cultured without composites and only slightly lower (to 9%) for PCL-based composites. The amount of platelets and Escherichia coli cells aggregated on the surface of the PLA based composites was significantly lower than for pure polymer. Thus, composites made of PLA and transgenic flax fibers seem to have bacteriostatic, platelet anti-aggregated, and non-cytotoxic effect.

  8. High Sensitivity Polymer Optical Fiber-Bragg-Grating-Based Accelerometer

    DEFF Research Database (Denmark)

    Stefani, Alessio; Andresen, Søren; Yuan, Wu;

    2012-01-01

    We report on the fabrication and characterization of the first accelerometer based on a polymer optical fiber Bragg grating (FBG) for operation at both 850 and 1550 nm. The devices have a flat frequency response over a 1-kHz bandwidth and a resonance frequency of about 3 kHz. The response is linear...... very strong accelerations. We compare with corresponding silica FBG accelerometers and demonstrate that using polymer FBGs improves the sensitivity by more than a factor of four and increases the figure of merit, defined as the sensitivity times the resonance frequency squared....

  9. Applications of micro-SAXS/WAXS to study polymer fibers

    Energy Technology Data Exchange (ETDEWEB)

    Riekel, C. E-mail: riekel@esrf.fr

    2003-01-01

    Instrumentation and selected applications for X-ray microdiffraction experiments on polymer and biopolymer fibers at the European Synchrotron Radiation Facility (ESRF) microfocus beamline are reviewed. Combined SAXS/WAXS experiments can be performed on single fibers with a beam size down to about 5 {mu}m. WAXS experiments can be performed down to about 2 {mu}m and in exceptional cases down to 0.1 {mu}m beam size. The instrumental possibilities are demonstrated for the production line of spider silk.

  10. Selective detection of antibodies in microstructured polymer optical fibers

    DEFF Research Database (Denmark)

    Jensen, Jesper Bo Damm; Hoiby, P.E.; Emiliyanov, Grigoriy Andreev

    2005-01-01

    We demonstrate selective detection of fluorophore labeled antibodies from minute samples probed by a sensor layer of complementary biomolecules immobilized inside the air holes of microstructured Polymer Optical Fiber (mPOF). The fiber core is defined by a ring of 6 air holes and a simple procedure...... was applied to selectively capture either α-streptavidin or α-CRP antibodies inside these air holes. A sensitive and easy-to-use fluorescence method was used for the optical detection. Our results show that mPOF based biosensors can provide reliable and selective antibody detection in ultra small sample...

  11. Selective detection of antibodies in microstructured polymer optical fibers.

    Science.gov (United States)

    Jensen, Jesper; Hoiby, Poul; Emiliyanov, Grigoriy; Bang, Ole; Pedersen, Lars; Bjarklev, Anders

    2005-07-25

    We demonstrate selective detection of fluorophore labeled antibodies from minute samples probed by a sensor layer of complementary biomolecules immobilized inside the air holes of microstructured Polymer Optical Fiber (mPOF). The fiber core is defined by a ring of 6 air holes and a simple procedure was applied to selectively capture either alpha-streptavidin or alpha-CRP antibodies inside these air holes. A sensitive and easy-to-use fluorescence method was used for the optical detection. Our results show that mPOF based biosensors can provide reliable and selective antibody detection in ultra small sample volumes.

  12. Carbon Fiber Damage in Particle Beam

    CERN Document Server

    Dehning, B; Kroyer, T; Meyer, M; Sapinski, M

    2011-01-01

    Carbon fibers are commonly used as moving targets in beam wire scanners. The heating of the fiber due to energy loss of the particles travelling through is simulated with Geant4. The heating induced by the beam electromagnetic field is estimated with ANSYS. The heat transfer and sublimation processes are modelled. Due to the model nonlinearity, a numerical approach based on discretization of the wire movement is used to solve it for particular beams. Radiation damage to the fiber is estimated with SRIM. The model is tested with available SPS and LEP data and a dedicated damage test on the SPS beam is performed followed by a post-mortem analysis of the wire remnants. Predictions for the LHC beams are made.

  13. Fabrication of Microscale Carbon Nanotube Fibers

    Directory of Open Access Journals (Sweden)

    Gengzhi Sun

    2012-01-01

    Full Text Available Carbon nanotubes (CNTs have excellent mechanical, chemical, and electronic properties, but realizing these excellences in practical applications needs to assemble individual CNTs into larger-scale products. Recently, CNT fibers demonstrate the potential of retaining CNT's superior properties at macroscale level. High-performance CNT fibers have been widely obtained by several fabrication approaches. Here in this paper, we review several key spinning techniques including surfactant-based coagulation spinning, liquid-crystal-based solution spinning, spinning from vertical-aligned CNT arrays, and spinning from CNT aerogel. The method, principle, limitations, and recent progress of each technique have been addressed, and the fiber properties and their dependences on spinning parameters are also discussed.

  14. Mechanical properties of carbon fiber/cellulose composite papers modified by hot-melting fibers

    OpenAIRE

    Yunzhou Shi; Biao Wang

    2014-01-01

    Carbon fiber (CF)/cellulose (CLS) composite papers were prepared by papermaking techniques and hot-melting fibers were used for modification. The mechanical properties of the obtained composite papers with different CF, CLS and hot-melting fiber ratios were studied and further discussed. It is observed that, for both CF/CLS composite papers and those modified by hot-melting fibers, the normal stress firstly increases and then declines with the addition of carbon fibers. The results also show ...

  15. Carbon coatings on polymers and their biocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Hubáček, T. [Department of Solid State Engineering, Institute of Chemical Technology, 16628 Prague (Czech Republic); Siegel, J., E-mail: jakub.siegel@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 16628 Prague (Czech Republic); Khalili, R.; Slepičková-Kasálková, N.; Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 16628 Prague (Czech Republic)

    2013-06-15

    In this paper we modified the surface properties of polymer foils (polyethyleneterephthalate (PET) and polytetrafluoroethylene (PTFE)) by flash evaporation of carbon layers (C-layers). Adhesion and proliferation of vascular smooth muscle cells (VSMC) on carbon coated PTFE and PET were studied in vitro. Chemical composition of deposited C-layers was determined by Raman spectroscopy, surface contact angle was measured by goniometry. Surface morphology of carbon coated samples was studied using atomic force microscopy. Electrical properties of deposited C-layers were determined by measuring its sheet resistance. It was found that the carbon deposition leads to a decrease of surface roughness of PTFE and PET and to a significant increase of sample wettability. Electrical resistance and wettability of deposited C-layers depends significantly on both the thickness of C-layer and the type of polymeric substrate used. It was found that maximal stimulation of the VSMC (adhesion and proliferation) on carbon coated polymers depends on the surface roughness and contact angle of cell carriers used.

  16. Temperature sensing of micron scale polymer fibers using fiber Bragg gratings

    KAUST Repository

    Zhou, J.

    2015-07-02

    Highly conductive polymer fibers are key components in the design of multifunctional textiles. Measuring the voltage/temperature relationships of these fibers is very challenging due to their very small diameters, making it impossible to rely on classical temperature sensing techniques. These fibers are also so fragile that they cannot withstand any perturbation from external measurement systems. We propose here, a non-contact temperature measurement technique based on fiber Bragg gratings (FBGs). The heat exchange is carefully controlled between the probed fibers and the sensing FBG by promoting radiation and convective heat transfer rather than conduction, which is known to be poorly controlled. We demonstrate our technique on a highly conductive Poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS)-based fiber. A non-phenomenological model of the sensing system based on meaningful physical parameters is validated towards experimental observations. The technique reliably measures the temperature of the polymer fibers when subjected to electrical loading. © 2015 IOP Publishing Ltd.

  17. Strength and Deformation of Axially Loaded Fiber-Reinforced Polymer Sheet Confined Concrete Columns

    Institute of Scientific and Technical Information of China (English)

    李静; 钱稼茹; 蒋剑彪

    2004-01-01

    Experimental results of 29 axially loaded fiber-reinforced polymer sheet (FS) confined concrete columns and two reference plain concrete columns are introduced. Twenty four column specimens were confined with carbon fiber sheet (CFS) and five column specimens were hybrid confined with both CFS and glass fiber sheet (GFS). The influence of aspect ratio, FS material, initial axial force ratio, and FS confinement degree on the strength and deformation of columns were studied. Based on the experimental results, the equations of complete stress-strain curve of CFS confined concrete are proposed. These equations are suitable for the nonlinear analysis of square and rectangular section columns. Suggestions of applying FS to confine concrete columns are presented.

  18. Light transmission for polymer fibers using skew and meridional rays

    Science.gov (United States)

    Tekelioglu, Murat

    This dissertation is concerned with the development of a light transmission model for polymer optical fibers having application in hybrid solar lighting (HSL) systems. Conceptually, the HSL system consists of a solar collector/receiver that focuses concentrated visible solar light onto a polymer optical fiber (up to 10-m-long) that transports the solar light to an interior space. For this study, the polymer optical fiber is a large-core (0.2-40 mm diameter) plastic optical fiber (POF) comprised of various lengths of straight and bent sections. Although there has been extensive research on the transmission of monochromatic light through optical fibers for the communications industry, there are relatively few publications for visible light transmission through POFs. These publications were critically reviewed in this research. It is shown that the light transmission can be described with either skew or meridional rays. For each ray type, the HSL system light transmission was determined as a function of fiber geometrical properties (core and cladding radii, bend radius, bend angle, and fiber length) and optical properties (core and clad refractive indices, absorption and scattering coefficients, core-clad rms roughness height, and core-clad interface defects loss coefficient). To do this, first, models were developed for separate straight and bent sections for multiple skew and meridional rays. Second, the straight and bent models were combined into a FORTRAN simulation program for an arbitrary fiber with a combination of arbitrary straight and bent sections. The input condition of the rays (arrangement of rays, incident angle, and intensity profile) is user-defined. Third, the simulation results were experimentally validated using two different POFs, twelve configurations of straight and bent fiber subsystems, and two ray types. These experimental comparisons show that the transmission model using meridional rays is slightly better than that with the skew rays. But

  19. Carbon nanotube and graphene nanoribbon-coated conductive Kevlar fibers.

    Science.gov (United States)

    Xiang, Changsheng; Lu, Wei; Zhu, Yu; Sun, Zhengzong; Yan, Zheng; Hwang, Chi-Chau; Tour, James M

    2012-01-01

    Conductive carbon material-coated Kevlar fibers were fabricated through layer-by-layer spray coating. Polyurethane was used as the interlayer between the Kevlar fiber and carbon materials to bind the carbon materials to the Kevlar fiber. Strongly adhering single-walled carbon nanotube coatings yielded a durable conductivity of 65 S/cm without significant mechanical degradation. In addition, the properties remained stable after bending or water washing cycles. The coated fibers were analyzed using scanning electron microcopy and a knot test. The as-produced fiber had a knot efficiency of 23%, which is more than four times higher than that of carbon fibers. The spray-coating of graphene nanoribbons onto Kevlar fibers was also investigated. These flexible coated-Kevlar fibers have the potential to be used for conductive wires in wearable electronics and battery-heated armors.

  20. Carbon fiber-reinforced carbon as a potential implant material.

    Science.gov (United States)

    Adams, D; Williams, D F; Hill, J

    1978-01-01

    A carbon fiber-reinforced carbon is being evaluated as a promising implant material. In a unidirectional composite, high strengths (1200 MN/m2 longitudinal flexural strength) and high modulus (140 GN/m2 flexural modulus) may be obtained with an interlaminar shear strength of 18 MN/m2. Alternatively, layers of fibers may be laid in two directions to give more isotopic properties. The compatibility of the material with bone has been studied by implanting specimens in holes drilled in rat femora. For a period of up to 8 weeks, a thin layer of fibrous tissue bridged the gap between bone and implant; but this tissue mineralizes and by 10 weeks, bone can be observed adjacent to the implant, giving firm fixation. Potential applications include endosseous dental implants where a greater strength in the neck than that provided by unreinforced carbon would be advantageous.

  1. Mechanical Properties of Heat-treated Carbon Fibers

    Science.gov (United States)

    Effinger, Michael R.; Patel, Bhavesh; Koenig, John; Cuneo, Jaques; Neveux, Michael G.; Demos, Chrystoph G.

    2004-01-01

    Carbon fibers are selected for ceramic matrix composites (CMC) are based on their as-fabricated properties or on "that is what we have always done" technical culture while citing cost and availability when there are others with similar cost and availability. However, the information is not available for proper selection of carbon fibers since heat-treated properties are not known for the fibers on the market currently. Heat-treating changes the fiber's properties. Therefore, an effort was undertaken to establish fiber properties on 19 different types of fibers from six different manufactures for both PAN and pitch fibers. Heat-treating has been done at three different temperatures.

  2. 3D Viscoelastic Finite Element Modelling of Polymer Flow in the Fiber Drawing Process for Microstructured Polymer Optical Fiber Fabrication

    DEFF Research Database (Denmark)

    Fasano, Andrea; Rasmussen, Henrik K.; Marín, J. M. R.

    2015-01-01

    the numerical modelling of mPOF drawing has mainly beenbased on principles, such as generalized Newtonian fluid dynamics, which are not able to cope with the elasticcomponent in polymer flow. In the present work, we employ the K-BKZ constitutive equation, a non-linearsingle-integral model that combines both...... modelling of the fiber drawingprocess using a fully three-dimensional and time-dependent finite element method, giving significant insightinto this widely spread mPOF production technique. Our computational predictions are physically based on theviscoelastic fluid dynamics of polymers. Until now...

  3. Viscoelastic limit of polymer optical fibers: characterization of the dynamic response

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Scott Wu; Andresen, S.;

    2011-01-01

    Characterization of polymer optical fibers (POFs) in terms of dynamic behavior is important for many sensors applications for which this type of fibers offers big advantages. We report measurements of the Young’s modulus on microstructured and step index polymer optical fibers and their comparison...

  4. Aligned and Electrospun Piezoelectric Polymer Fiber Assembly and Scaffold

    Science.gov (United States)

    Scott-Carnell, Lisa A. (Inventor); Siochi, Emilie J. (Inventor); Holloway, Nancy M. (Inventor); Leong, Kam W. (Inventor); Kulangara, Karina (Inventor)

    2015-01-01

    A scaffold assembly and related methods of manufacturing and/or using the scaffold for stem cell culture and tissue engineering applications are disclosed which at least partially mimic a native biological environment by providing biochemical, topographical, mechanical and electrical cues by using an electroactive material. The assembly includes at least one layer of substantially aligned, electrospun polymer fiber having an operative connection for individual voltage application. A method of cell tissue engineering and/or stem cell differentiation uses the assembly seeded with a sample of cells suspended in cell culture media, incubates and applies voltage to one or more layers, and thus produces cells and/or a tissue construct. In another aspect, the invention provides a method of manufacturing the assembly including the steps of providing a first pre-electroded substrate surface; electrospinning a first substantially aligned polymer fiber layer onto the first surface; providing a second pre-electroded substrate surface; electrospinning a second substantially aligned polymer fiber layer onto the second surface; and, retaining together the layered surfaces with a clamp and/or an adhesive compound.

  5. Property and Shape Modulation of Carbon Fibers Using Lasers.

    Science.gov (United States)

    Blaker, Jonny J; Anthony, David B; Tang, Guang; Shamsuddin, Siti-Ros; Kalinka, Gerhard; Weinrich, Malte; Abdolvand, Amin; Shaffer, Milo S P; Bismarck, Alexander

    2016-06-29

    An exciting challenge is to create unduloid-reinforcing fibers with tailored dimensions to produce synthetic composites with improved toughness and increased ductility. Continuous carbon fibers, the state-of-the-art reinforcement for structural composites, were modified via controlled laser irradiation to result in expanded outwardly tapered regions, as well as fibers with Q-tip (cotton-bud) end shapes. A pulsed laser treatment was used to introduce damage at the single carbon fiber level, creating expanded regions at predetermined points along the lengths of continuous carbon fibers, while maintaining much of their stiffness. The range of produced shapes was quantified and correlated to single fiber tensile properties. Mapped Raman spectroscopy was used to elucidate the local compositional and structural changes. Irradiation conditions were adjusted to create a swollen weakened region, such that fiber failure occurred in the laser treated region producing two fiber ends with outwardly tapered ends. Loading the tapered fibers allows for viscoelastic energy dissipation during fiber pull-out by enhanced friction as the fibers plough through a matrix. In these tapered fibers, diameters were locally increased up to 53%, forming outward taper angles of up to 1.8°. The tensile strength and strain to failure of the modified fibers were significantly reduced, by 75% and 55%, respectively, ensuring localization of the break in the expanded region; however, the fiber stiffness was only reduced by 17%. Using harsher irradiation conditions, carbon fibers were completely cut, resulting in cotton-bud fiber end shapes. Single fiber pull-out tests performed using these fibers revealed a 6.75-fold increase in work of pull-out compared to pristine carbon fibers. Controlled laser irradiation is a route to modify the shape of continuous carbon fibers along their lengths, as well as to cut them into controlled lengths leaving tapered or cotton-bud shapes.

  6. Fiber-reinforced polymer concrete: Property improvement by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Martinez B, G. [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados, Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Km. 12 Carretera Toluca-Atlacomulco, San Cayetano 50200, Estado de Mexico (Mexico); Brostow, W. [Laboratory of Advanced Polymers and Optimized Materials, Department of Materials Science and Engineering, University of North Texas, Denton TX 76203-5310 (United States)], e-mail: gonzomartinez02@yahoo.com.mx

    2009-07-01

    Polymer concrete (PC) is a particulate composite in which a thermoset resin forms a polymeric matrix and binds inorganic aggregates (dispersed particles of strengthening phases). This in contrast to Portland cement concrete (PCC) in which the binding is a result of interaction of cement with water. Adding polymeric materials to the concrete one can obtain high compressive and flexural strength, high impact and abrasion resistance, lower weight and lower costs. Moreover, PC is a very good repair material for structure elements damaged by trapping water inside the structure and by acid attacks which take place in the PCC. In the present chapter we discuss uses of polymer concrete and the importance of using gamma radiation as a novel technology for manufacturing fiber-reinforced polymer concrete. Our technology is different from the costly and time consuming current procedures such as chemical attack or thermal treatment. (Author)

  7. Control of self organization in conjugated polymer fibers.

    Science.gov (United States)

    Chuangchote, Surawut; Fujita, Michiyasu; Sagawa, Takashi; Sakaguchi, Hiroshi; Yoshikawa, Susumu

    2010-11-01

    We propose new strategy to facilitate the fabrication of conjugated polymer fiber with higher oriented structures, which focused on electrospinning of a blend solution of regioregular poly(3-hexylthiophene) (rr-P3HT) and poly(vinyl pyrrolidone) (PVP). SEM observation revealed that the blend system forms homogeneous composite nanofibers. This system exhibits the specific feature of strong interchain contribution of P3HT from UV-vis absorption, fluorescence spectroscopic, XRD, and photoelectron spectrometric (for HOMO levels) investigations. We also demonstrate the removal of the PVP component from the P3HT/PVP composite fibers through the selective extraction and such strong interchain stacking of pristine P3HT fiber mat can be remarkably maintained.

  8. Flexural analysis of palm fiber reinforced hybrid polymer matrix composite

    Science.gov (United States)

    Venkatachalam, G.; Gautham Shankar, A.; Raghav, Dasarath; Santhosh Kiran, R.; Mahesh, Bhargav; Kumar, Krishna

    2015-07-01

    Uncertainty in availability of fossil fuels in the future and global warming increased the need for more environment friendly materials. In this work, an attempt is made to fabricate a hybrid polymer matrix composite. The blend is a mixture of General Purpose Resin and Cashew Nut Shell Liquid, a natural resin extracted from cashew plant. Palm fiber, which has high strength, is used as reinforcement material. The fiber is treated with alkali (NaOH) solution to increase its strength and adhesiveness. Parametric study of flexure strength is carried out by varying alkali concentration, duration of alkali treatment and fiber volume. Taguchi L9 Orthogonal array is followed in the design of experiments procedure for simplification. With the help of ANOVA technique, regression equations are obtained which gives the level of influence of each parameter on the flexure strength of the composite.

  9. THE MECHANICAL BEHAVIOR EXPERIMENT AND ANALYSIS OF CONTINUOUS BEAMS STRENGTHENED WITH CARBON FIBER REINFORCED POLYMER SHEETS%碳纤维布加固连续梁力学性能试验及分析

    Institute of Scientific and Technical Information of China (English)

    程东辉; 王天峰; 易亚敏

    2011-01-01

    为了开展碳纤维布加固钢筋混凝土连续梁受力性能的研究工作,对3根两跨采用碳纤维布加固的钢筋混凝土连续梁进行三分点加载的受力性能试验研究,获得加固状态下钢筋混凝土连续梁正截面承载力、裂缝分布及开展、中支座塑性铰区分布长度等试验实测值和荷载-挠度曲线及内力重分布关系曲线。试验研究表明:钢筋混凝土连续梁在加固状态下的破坏呈现中支座纵向受力钢筋先屈服,跨中纵向受力钢筋后屈服,碳纤维布被拉断的形式;试验梁加载过程中有明显的内力重分布,承载力极限状态下内力重分布幅度超过50%;由于跨中碳纤维布的存在约束了连续梁的变形,从而导致中支座控制截面附近塑性区域分布长度比普通钢筋混凝土连续梁有所减小。%In order to study the mechanical behavior of concrete continuous beams strengthened with CFRP sheets, 3 two-span continuous beams were fabricated, and strengthened with CFRP sheets at each span. The test of loading on two-point was completed, from which the bearing capacity, cracks distribution, the test value of the length of plastic hinge region, curves of load-deformation and curves of internal force redistribution were obtained. The test results showed that the failure of concrete continuous beams strengthened with CFRP sheets was characterized by longtitudinal reinforcement yielded in intermediate support sections, then the longtitudinal reinforcement yielded in the middle span sections, at last carbon fiber polymer sheets were pulled off. The internal force redistribution appeared apparently in beams during loading process and the redistribution rate was over 50% in the state of ultimate bearing capacity. As CFRP confined the deflection of beams,the length of the plastic hinge region near the sections of intermediate support was reduced as compared to ordinary continuous reinforced beams.

  10. Waste polyvinylchloride derived pitch as a precursor to develop carbon fibers and activated carbon fibers.

    Science.gov (United States)

    Qiao, W M; Yoon, S H; Mochida, I; Yang, J H

    2007-01-01

    Polyvinylchloride (PVC) was successfully recycled through the solvent extraction from waste pipe with an extraction yield of ca. 86%. The extracted PVC was pyrolyzed by a two-stage process (260 and 410 degrees C) to obtain free-chlorine PVC based pitch through an effective removal of chlorine from PVC during the heat-treatment. As-prepared pitch (softening point: 220 degrees C) was spun, stabilized, carbonized into carbon fibers (CFs), and further activated into activated carbon fibers (ACFs) in a flow of CO2. As-prepared CFs show comparable mechanical properties to commercial CFs, whose maximum tensile strength and modulus are 862 MPa and 62 GPa, respectively. The resultant ACFs exhibit a high surface area of 1200 m2/g, narrow pore size distribution and a low oxygen content of 3%. The study provides an effective insight to recycle PVC from waste PVC and develop a carbon precursor for high performance carbon materials such as CFs and ACFs.

  11. Nondestructive testing of externally reinforced structures for seismic retrofitting using flax fiber reinforced polymer (FFRP) composites

    Science.gov (United States)

    Ibarra-Castanedo, C.; Sfarra, S.; Paoletti, D.; Bendada, A.; Maldague, X.

    2013-05-01

    Natural fibers constitute an interesting alternative to synthetic fibers, e.g. glass and carbon, for the production of composites due to their environmental and economic advantages. The strength of natural fiber composites is on average lower compared to their synthetic counterparts. Nevertheless, natural fibers such as flax, among other bast fibers (jute, kenaf, ramie and hemp), are serious candidates for seismic retrofitting applications given that their mechanical properties are more suitable for dynamic loads. Strengthening of structures is performed by impregnating flax fiber reinforced polymers (FFRP) fabrics with epoxy resin and applying them to the component of interest, increasing in this way the load and deformation capacities of the building, while preserving its stiffness and dynamic properties. The reinforced areas are however prompt to debonding if the fabrics are not mounted properly. Nondestructive testing is therefore required to verify that the fabric is uniformly installed and that there are no air gaps or foreign materials that could instigate debonding. In this work, the use of active infrared thermography was investigated for the assessment of (1) a laboratory specimen reinforced with FFRP and containing several artificial defects; and (2) an actual FFRP retrofitted masonry wall in the Faculty of Engineering of the University of L'Aquila (Italy) that was seriously affected by the 2009 earthquake. Thermographic data was processed by advanced signal processing techniques, and post-processed by computing the watershed lines to locate suspected areas. Results coming from the academic specimen were compared to digital speckle photography and holographic interferometry images.

  12. Circumventing the mechanochemical origins of strength loss in the synthesis of hierarchical carbon fibers.

    Science.gov (United States)

    Steiner, Stephen A; Li, Richard; Wardle, Brian L

    2013-06-12

    Hierarchical carbon fibers (CFs) sheathed with radial arrays of carbon nanotubes (CNTs) are promising candidates for improving the intra- and interlaminar properties of advanced fiber-reinforced composites (e.g., graphite/epoxy) and for high-surface-area electrodes for battery and supercapacitor architectures. While CVD growth of CNTs on CFs has been previously shown to improve the apparent shear strength between fibers and polymer matrices (up to 60%), this has to date been achieved only at the expense of significant reductions in tensile strength (~30-50%) and stiffness (~10-20%) of the underlying fiber. Here we demonstrate two approaches for growing aligned and unaligned CNTs on CFs that enable preservation of fiber strength and stiffness. We observe that CVD-induced reduction of fiber strength and stiffness is primarily attributable to mechanochemical reorganization of the underlying fiber when heated untensioned above ~550 °C in both hydrocarbon-containing and inert atmospheres. We show that tensioning fibers to ≥12% of tensile strength during CVD enables aligned CNT growth while simultaneously preserving fiber strength and stiffness even at growth temperatures >700 °C. We also show that CNT growth employing CO2/acetylene at 480 °C without tensioning-below the identified critical strength-loss temperature-preserves fiber strength. These results highlight previously unidentified mechanisms underlying synthesis of hierarchical CFs and demonstrate scalable, facile methods for doing so.

  13. Effect of Hybrid Surface Modifications on Tensile Properties of Polyacrylonitrile- and Pitch-Based Carbon Fibers

    Science.gov (United States)

    Naito, Kimiyoshi

    2016-05-01

    Recent interest has emerged in techniques that modify the surfaces of carbon fibers, such as carbon nanotube (CNT) grafting or polymer coating. Hybridization of these surface modifications has the potential to generate highly tunable, high-performance materials. In this study, the mechanical properties of surface-modified polyacrylonitrile (PAN)-based and pitch-based carbon fibers were investigated. Single-filament tensile tests were performed for fibers modified by CNT grafting, dipped polyimide coating, high-temperature vapor deposition polymerized polyimide coating, grafting-dipping hybridization, and grafting-vapor deposition hybridization. The Weibull statistical distributions of the tensile strengths of the surface-modified PAN- and pitch-based carbon fibers were examined. All surface modifications, especially hybrid modifications, improved the tensile strengths and Weibull moduli of the carbon fibers. The results exhibited a linear relationship between the Weibull modulus and average tensile strength on a log-log scale for all surface-modified PAN- and pitch-based carbon fibers.

  14. Influence of fiber type, fiber mat orientation, and process time on the properties of a wood fiber/polymer composite

    DEFF Research Database (Denmark)

    Plackett, David; Torgilsson, R.; Løgstrup Andersen, T.

    2002-01-01

    A rapid press consolidation technique was used to produce composites from two types of air-laid wood fiber mat, incorporating either mechanically refined or bleached chemi-thermomechanically refined Norway Spruce [Picea abies (L.) Karst] and a bicomponent polymer fiber. The manufacturing technique...... involved pre-compression, contact heating to the process temperature under vacuum and then rapid transfer to the press for consolidation and cooling. Composites were tested to determine response to water or water vapor, porosity, fiber volume fraction and tensile properties. The composites absorbed water...... by the polymer matrix had been maximized within a five-minute heating time. Results also indicated that had been maximized within a five-minute heating time. Results also indicated that porosity was not the key determinant of tensile properties in the composites....

  15. Study on an Improved Phosphate Cement Binder for the Development of Fiber-Reinforced Inorganic Polymer Composites

    Directory of Open Access Journals (Sweden)

    Zhu Ding

    2014-11-01

    Full Text Available Magnesium phosphate cement (MPC has been proven to be a very good repair material for deteriorated concrete structures. It has excellent adhesion performance, leading to high bonding strength with old concrete substrates. This paper presents an experimental study into the properties of MPC binder as the matrix of carbon fiber sheets to form fiber-reinforced inorganic polymer (FRIP composites. The physical and mechanical performance of the fresh mixed and the hardened MPC paste, the bond strength of carbon fiber sheets in the MPC matrix, the tensile strength of the carbon FRIP composites and the microstructure of the MPC matrix and fiber-reinforced MPC composites were investigated. The test results showed that the improved MPC binder is well suited for developing FRIP composites, which can be a promising alternative to externally-bonded fiber-reinforced polymer (FRP composites for the strengthening of concrete structures. Through the present study, an in-depth understanding of the behavior of fiber-reinforced inorganic MPC composites has been achieved.

  16. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Weimin Song

    2016-08-01

    Full Text Available Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF and carbon fiber (CF was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC, carbon fiber reinforced concrete (CFRC and hybrid fiber reinforced concrete (HFRC were explored at steel fiber volume fraction 0.5%, 1%, 1.5% and carbon fiber 0.1%, 0.2%, 0.3%. Results showed that the addition of steel fiber and carbon fiber can increase the compressive strength. SF, CF and the hybridization between them could increase the compressive toughness significantly. The impact test results showed that as the volume of fiber increased, the impact number of the first visible crack and the ultimate failure also increased. The improvement of toughness mainly lay in improving the crack resistance after the first crack. Based on the test results, the positive hybrid effect of steel fiber and carbon fiber existed in hybrid fiber reinforced concrete. The relationship between the compressive toughness and impact toughness was also explored.

  17. Plateau-Rayleigh Instability Morphology Evolution (PRIME): From Electrospun Core-Shell Polymer Fibers to Polymer Microbowls.

    Science.gov (United States)

    Chiu, Yu-Jing; Tseng, Hsiao-Fan; Lo, Yu-Ching; Wu, Bo-Hao; Chen, Jiun-Tai

    2017-03-01

    Electrospun core-shell fibers have great potentials in many areas, such as tissue engineering, drug delivery, and organic solar cells. Although many core-shell fibers have been prepared and studied, the morphology transformation of core-shell fibers have been rarely studied. In this work, the morphology evolution of electrospun core-shell polymer fibers driven by the Plateau-Rayleigh instability is investigated. Polystyrene/poly(methyl methacrylate) (PS/PMMA) core-shell fibers are first prepared by using blend solutions and a single axial electrospinning setup. After PS/PMMA core-shell fibers are annealed on a PS film, the fibers undulate and sink into the polymer film, forming core-shell hemispheres. The evolution process, which can be observed in situ by optical microscopy, is mainly driven by achieving lower surface and interfacial energies. The morphologies of the transformed structures can be confirmed by a selective removal technique, and polymer microbowls can be obtained.

  18. Rapid Development of Carbon Fiber Industry in Jilin

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In recent years, Jilin Carbon Fiber Industrial Zone in Liaoning Province has seen a rapid development, forming a complete industrial chain from precursor to carbonization, and then to products. Along with the promotion of a large number of carbon fiber in

  19. Basalt fiber reinforced polymer composites: Processing and properties

    Science.gov (United States)

    Liu, Qiang

    A high efficiency rig was designed and built for in-plane permeability measurement of fabric materials. A new data derivation procedure to acquire the flow fluid pattern in the experiment was developed. The measurement results of the in-plane permeability for basalt twill 31 fabric material showed that a high correlation exists between the two principal permeability values for this fabric at 35% fiber volume fraction. This may be the most important scientific contribution made in this thesis. The results from radial measurements corresponded quite well with those from Unidirectional (UD) measurements, which is a well-established technique. No significant differences in mechanical properties were found between basalt fabric reinforced polymer composites and glass composites reinforced by a fabric of similar weave pattern. Aging results indicate that the interfacial region in basalt composites may be more vulnerable to environmental damage than that in glass composites. However, the basalt/epoxy interface may have been more durable than the glass/epoxy interface in tension-tension fatigue because the basalt composites have significantly longer fatigue life. In this thesis, chapter I reviews the literature on fiber reinforced polymer composites, with concentration on permeability measurement, mechanical properties and durability. Chapter II discusses the design of the new rig for in-plane permeability measurement, the new derivation procedure for monitoring of the fluid flow pattern, and the permeability measurement results. Chapter III compares the mechanical properties and durability between basalt fiber and glass fiber reinforced polymer composites. Lastly, chapter IV gives some suggestions and recommendations for future work.

  20. Natural Fiber-Reinforced Hybrid Polymer Nanocomposites: Effect of Fiber Mixing and Nanoclay on Physical, Mechanical, and Biodegradable Properties

    Directory of Open Access Journals (Sweden)

    Md. Saiful Islam

    2015-01-01

    Full Text Available Combining two kinds of fibers is a potential way to improve the essential properties of natural fiber-reinforced hybrid polymer composites. Biocomposites produced from natural resources are experiencing an increase in interest due to their high demand in the market for manufacturing, in addition to environmental and sustainability issues. In this study, natural fiber-reinforced hybrid polymer nanocomposites were prepared from coir fiber, wood fiber, polypropylene, and montmorillonite nanoclay using a hot press technique. The effects of fiber mixing and montmorillonite on their physico-mechanical and biodegradable properties were subsequently investigated. Before being used, both the wood and the coir fibers were alkali-treated to reduce their hydrophilicity. The mechanical properties of the fabricated composites were measured using a universal tensile testing machine and found to be enhanced after fiber mixing and nanoclay incorporation. Fourier transform infrared spectra indicated that the characteristic peaks of the composites shifted after fiber mixing. A new peak around 470 cm-1 was observed in the case of the nanocomposites, which confirmed the interaction between the fiber, polymer, and montmorillonite (MMT. Scanning electron microscopic analysis revealed that MMT strongly improved the adhesion and compatibility between the fiber and polymer matrix. The combining of fibers improved the biodegradability and water absorption properties, while MMT addition had the reverse effect on the same properties of the composites.

  1. Narrow Bandwidth 850-nm Fiber Bragg Gratings in Few-Mode Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Stefani, Alessio; Yuan, Wu; Markos, Christos;

    2011-01-01

    We report on the inscription and characterization of narrow bandwidth fiber Bragg gratings (FBGs) with 850-nm resonance wavelength in polymer optical fibers (POFs). We use two fibers: an in-house fabricated microstructured POF (mPOF) with relative hole size of 0.5 and a commercial step-index POF......, which supports six modes at 850 nm. The gratings have been written with the phase-mask technique and a 325-nm HeCd laser. The mPOF grating has a full-width at half-maximum (FWHM) bandwidth of 0.29 nm and the step-index POF has a bandwidth of 0.17 nm. For both fibers, the static tensile strain...

  2. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Among the...

  3. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Included among...

  4. Arrayed Lensed Fibers Collectively Fabricated Utilizing UV-Curable Fluorinated Polymer

    Institute of Scientific and Technical Information of China (English)

    Kyung-Rok; Kim; Manjung; Han; Selee; Chang; K.; Oh

    2003-01-01

    A novel fabrication method for lensed fiber array has been proposed utilizing UV-curable fluorinated polymer, whose refractive index is matched to fused silica. The structure is composed of three segments; single mode fiber, coreless silica fiber and UV-curable polymer lens-tip. Flexible control of the curvature of lens-tip was realized by control of deposited volume of the liquid polymer and free-space interconnection performances are characterized.

  5. Effects of carbon nanoparticles on properties of thermoset polymer systems

    Science.gov (United States)

    Movva, Siva Subramanyam

    Polymer nanocomposites are novel materials in which at least one of the dimensions of the reinforcing material is on the order of 100 nm or less. While thermoplastic nanocomposites have been studied very widely, there are fewer studies concerning the effect of nanoparticles on thermoset systems. Low temperature cure thermoset systems are very important for many important applications. In this study, the processing, mechanical and thermal properties and reaction kinetics of carbon nanofiber (CNF) and/or carbon nanotubes (CNT) reinforced low temperature vinyl ester and epoxy nanocomposites were studied. In the first part, the processing challenge of incorporating CNFs into conventional fiber reinforced composites made by Vacuum infusion resin transfer molding (VARTM) was addressed by a new technique. The CNFs are pre-bound on the long fiber mats, instead of mixing them in the polymer resin, thereby eliminating several processing drawbacks. The resulting hybrid nanocomposites showed significant improvements in tensile, flexural and thermal properties. The effect of CNFs on the mold filling in VARTM was also studied and shown to follow the Darcy's law. In the second part, the effect of CNFs on the low temperature cure kinetics of vinyl ester and epoxy resins is studied using a thermal analysis technique, namely Differential scanning calorimetry (DSC). The effect of CNFs on the free radical polymerization of vinyl esters was found to be very complex as the CNFs interact with the various curing ingredients in the formulation. Specifically, the interaction effects of CNFs and the inhibitor were studied and a reaction mechanism was proposed to explain the observed phenomenon. The effect of surface modification of the carbon nanoparticles on the cure kinetics of wind-blade epoxy was studied. The surface functionalization reduced the activation energy of the epoxy reaction and was found to have an acceleration effect on the cure kinetics of epoxy resin at room temperature

  6. Guiding mode in elliptical core microstructured polymer optical fiber

    Institute of Scientific and Technical Information of China (English)

    Yani Zhang; Liyong Ren; Kang Li; Hanyi Wang; Wei Zhao; Lili Wang; Runcai Miao; Maryanne C. J. Large; Martijn A. van Eijkelenborg

    2007-01-01

    A kind of microstructured polymer optical fiber with elliptical core has been fabricated by adopting insitu chemical polymerization technology and the secondary sleeving draw-stretching technique. Microscope photography demonstrates the clear hole-structure retained in the fiber. Though the holes distortion is visible, initial laser experiment indicates that light can be strongly confined in the elliptical core region,and the mode field is split obviously and presents the multi-mode characteristic. Numerical modeling is carried out for the real fiber with the measured parameters, including the external diameter of 150μm, the average holes diameter of 3.3μm, and the averageole spacing of .3μm by using full-vector plane wave method. The guided mode fields of the numerical simulation are consistent with the experiment result.This fiber shows the strong multi-mode and weak birefringence in the visible and near-infrared band, and has possibility for achieving the fiber mode convertors, mode selective couplers and so on.

  7. Guiding mode in elliptical core microstructured polymer optical fiber

    Science.gov (United States)

    Zhang, Yani; Ren, Liyong; Li, Kang; Wang, Hanyi; Zhao, Wei; Wang, Lili; Miao, Runcai; Large, Maryanne C. J.; van Eijkelenborg, Martijn A.

    2007-04-01

    A kind of microstructured polymer optical fiber with elliptical core has been fabricated by adopting in-situ chemical polymerization technology and the secondary sleeving draw-stretching technique. Microscope photography demonstrates the clear hole-structure retained in the fiber. Though the holes distortion is visible, initial laser experiment indicates that light can be strongly confined in the elliptical core region, and the mode field is split obviously and presents the multi-mode characteristic. Numerical modeling is carried out for the real fiber with the measured parameters, including the external diameter of 150 microns, the average holes diameter of 3.3 microns, and the average hole spacing of 6.3 microns by using full-vector plane wave method. The guided mode fields of the numerical simulation are consistent with the experiment result. This fiber shows the strong multi-mode and weak birefringence in the visible and near-infrared band, and has possibility for achieving the fiber mode convertors, mode selective couplers and so on.

  8. Influence of photoactive additive on growth of polymer microelements on the top of optical fiber

    Science.gov (United States)

    Fokina, M. I.; Burunkova, J. E.; Denisuk, I. Y.

    2007-06-01

    Kinetics of polymer microelements growing on the top of optical fiber with use of different photoactive additives (Rodamine B, Coumarin) was studied. Consequently, the technological principles of production of polymer self-adjoint microelements were founded

  9. Designed amyloid fibers as materials for selective carbon dioxide capture.

    Science.gov (United States)

    Li, Dan; Furukawa, Hiroyasu; Deng, Hexiang; Liu, Cong; Yaghi, Omar M; Eisenberg, David S

    2014-01-07

    New materials capable of binding carbon dioxide are essential for addressing climate change. Here, we demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture. Solid-state NMR proves that amyloid fibers containing alkylamine groups reversibly bind carbon dioxide via carbamate formation. Thermodynamic and kinetic capture-and-release tests show the carbamate formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence of water, in both a natural amyloid and designed amyloids having increased carbon dioxide capacity. Heating to 100 °C regenerates the material. These results demonstrate the potential of amyloid fibers for environmental carbon dioxide capture.

  10. Alumina Coating on Carbon Fibers by Sol-Gel Method

    OpenAIRE

    2006-01-01

    Alumina precursor film was coated on carbon fibers by a sol-gel method using aluminum alkoxide solution. The optimum coating condition for the concentration of alumina alkoxide and silane coupling agent was determined to uniformly coat alumina precursor on carbon fibers. Alumina precursor converted to alumina ceramics by heating at 750℃. SEM and EPMA showed that alumina ceramics was uniformly coated on carbon fibers. The thickness of alumina layer increased with increasing coating times. The ...

  11. Carbon Fiber Morphology. 2. Expanded Wide-Angle X-Ray Diffraction Studies of Carbon Fibers

    Science.gov (United States)

    1991-02-01

    X- Ray Diffraction," JPS. Polym. Phys. Ed., 16, 939 (1978). 17. Rosalind E. Franklin , "The Structure of Graphitic Carbons," Acta Cryst., 4, 253 (1951...18. Rosalind E. Franklin , "The Interpretation of Diffuse X-ray Diagrams of Carbon," Acta CrL, 3, 107 (1950). 19. K. Jain and A. S. Abhiraman...been generally mentioned much earlier by Franklin [17,18]. Jain and Abhiraman [19] demonstrated that these corrections can make significant differences

  12. Tensile strain and temperature characterization of FBGs in preannealed Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Andresen, Søren;

    2010-01-01

    Our thermal and tensile strain experiments show that fiber Bragg gratings (FBGs) in preannealed polymer optical fibers (POFs) can offer more stable performance and extend the operating temperature and strain range without hysteresis.......Our thermal and tensile strain experiments show that fiber Bragg gratings (FBGs) in preannealed polymer optical fibers (POFs) can offer more stable performance and extend the operating temperature and strain range without hysteresis....

  13. Voltammetric detection of biological molecules using chopped carbon fiber.

    Science.gov (United States)

    Sugawara, Kazuharu; Yugami, Asako; Kojima, Akira

    2010-01-01

    Voltammetric detection of biological molecules was carried out using chopped carbon fibers produced from carbon fiber reinforced plastics that are biocompatible and inexpensive. Because chopped carbon fibers normally are covered with a sizing agent, they are difficult to use as an electrode. However, when the surface of a chopped carbon fiber was treated with ethanol and hydrochloric acid, it became conductive. To evaluate the functioning of chopped carbon fibers, voltammetric measurements of [Fe(CN)(6)](3-) were carried out. Redoxes of FAD, ascorbic acid and NADH as biomolecules were recorded using cyclic voltammetry. The sizing agents used to bundle the fibers were epoxy, polyamide and polyurethane resins. The peak currents were the greatest when using the chopped carbon fibers that were created with epoxy resins. When the electrode response of the chopped carbon fibers was compared with that of a glassy carbon electrode, the peak currents and the reversibility of the electrode reaction were sufficient. Therefore, the chopped carbon fibers will be useful as disposable electrodes for the sensing of biomolecules.

  14. Continuous nanoscale carbon fibers with superior mechanical strength.

    Science.gov (United States)

    Liu, Jie; Yue, Zhongren; Fong, Hao

    2009-03-01

    Continuous nanoscale carbon fibers can be developed by stabilization and carbonization of highly aligned and extensively stretched electrospun polyacrylonitrile copolymer nanofiber precursor under optimal tension. These carbon fibers, with diameters of tens of nanometers, are expected to possess a superior mechanical strength that is unlikely to be achieved through conventional approaches. This is because i) the innovative precursor, with a fiber diameter approximately 100 times smaller than that of conventional counterparts, possesses an extremely high degree of macromolecular orientation and a significantly reduced amount of structural imperfections, and ii) the ultrasmall fiber diameter also effectively prevents the formation of structural inhomogeneity, particularly sheath/core structures during stabilization and carbonization.

  15. Polarization dependence of laser interaction with carbon fibers and CFRP.

    Science.gov (United States)

    Freitag, Christian; Weber, Rudolf; Graf, Thomas

    2014-01-27

    A key factor for laser materials processing is the absorptivity of the material at the laser wavelength, which determines the fraction of the laser energy that is coupled into the material. Based on the Fresnel equations, a theoretical model is used to determine the absorptivity for carbon fiber fabrics and carbon fiber reinforced plastics (CFRP). The surface of each carbon fiber is considered as multiple layers of concentric cylinders of graphite. With this the optical properties of carbon fibers and their composites can be estimated from the well-known optical properties of graphite.

  16. Engineered Polymer Composites Through Electrospun Nanofiber Coating of Fiber Tows

    Science.gov (United States)

    Kohlman, Lee W.; Bakis, Charles; Williams, Tiffany S.; Johnston, James C.; Kuczmarski, Maria A.; Roberts, Gary D.

    2014-01-01

    Composite materials offer significant weight savings in many aerospace applications. The toughness of the interface of fibers crossing at different angles often determines failure of composite components. A method for toughening the interface in fabric and filament wound components using directly electrospun thermoplastic nanofiber on carbon fiber tow is presented. The method was first demonstrated with limited trials, and then was scaled up to a continuous lab scale process. Filament wound tubes were fabricated and tested using unmodified baseline towpreg material and nanofiber coated towpreg.

  17. Reinforcement of RC structure by carbon fibers

    Directory of Open Access Journals (Sweden)

    Kissi B.

    2016-01-01

    Full Text Available In recent years, rehabilitation has been the subject of extensive research due to the increased spending on building maintenance work and restoration of built works. In all cases, it is essential to carry out methods of reinforcement or maintenance of structural elements, following an inspection analysis and methodology of a correct diagnosis. This research focuses on the calculation of the necessary reinforcement sections of carbon fiber for structural elements with reinforced concrete in order to improve their load bearing capacity and rigidity. The different results obtained reveal a considerable gain in resistance and deformation capacity of reinforced sections without significant increase in the weight of the rehabilitated elements.

  18. Investigations into polymer and carbon nanomaterial separations

    Science.gov (United States)

    Owens, Cherie Nicole

    The work of this thesis follows a common theme of research focused on innovative separation science. Polyhydroxyalkanoates are biodegradable polyesters produced by bacteria that can have a wide distribution in molecular weight and monomer composition. This large distribution often leads to unpredictable physical properties making commercial applications challenging. To improve polymer homogeneity and obtain samples with a clear set of physical characteristics, poly-3-hydroxyvalerate-co-3-hydroxybutyrate copolymers were fractionated using gradient polymer elution chromatography (GPEC) with carefully optimized gradients. The resulting fractions were analyzed using Size Exclusion Chromatography (SEC) and NMR. As the percentage of “good” solvent was increased in the mobile phase, the polymers eluted with decreasing percentage of 3-hydroxyvalerate and increasing molecular weight, which indicates the importance of precipitation/redissolution in the separation. As such, GPEC is an excellent choice to provide polyhydroxyalkanoate samples with a narrower distribution in composition than the original bulk copolymer. Additionally, the critical condition was found for 3-hydroxybutyrate to erase its effects on retention of the copolymer. Copolymer samples were then separated using Liquid Chromatography at the Critical Condition (LCCC) and it was determined that poly(3-hydroxvalerate-co-3-hydroxybutyrate) is a statistically random copolymer. The second project uses ultra-thin layer chromatography (UTLC) to study the performance and behavior of polyhydroxybutyrate (P3HB) as a chromatographic substrate. One specific polyhydroxyalkanoate, polyhydroxybutyrate, is a liquid crystalline polymer that can be electrospun. Electrospinning involves the formation of nanofibers though the application of an electric potential to a polymer solution. Precisely controlled optimization of electrospinning parameters was conducted to achieve the smallest diameter PHA nanofibers to date to

  19. Photoluminescent carbon dots from 1,4-addition polymers.

    Science.gov (United States)

    Jiang, Zhiqiang; Nolan, Andrew; Walton, Jeffrey G A; Lilienkampf, Annamaria; Zhang, Rong; Bradley, Mark

    2014-08-25

    Photoluminescent carbon dots were synthesised directly by thermopyrolysis of 1,4-addition polymers, allowing precise control of their properties. The effect of polymer composition on the properties of the carbon dots was investigated by TEM, IR, XPS, elemental analysis and fluorescence analysis, with carbon dots synthesised from nitrogen-containing polymers showing the highest fluorescence. The carbon dots with high nitrogen content were observed to have strong fluorescence in the visible region, and culture with cells showed that the carbon dots were non-cytotoxic and readily taken up by three different cell lines.

  20. Deformation Resistance Effect of PAN-based Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    ZHENG Lixia; LI Zhuoqiu; SONG Xianhui; LU Yong

    2009-01-01

    The deformation resistance effect of polyacrylonitrile(PAN)-based carbon fibers was investigated,and the variatipn law of electrical resistivity under tensile stress was analyzed.The results show that the gauge factor(fractional change in resistance per unit strain)of PAN-based carbon fibers is 1.38,which is lower than that of the commonly-used resistance strain gauge.These may due to that the electrical resistivity of carbon fibers decreases under tensile stress.In addition when the carbon fibers are stretched,the change of its resistance is caused by fiber physical dimension and the change of electric resistivity,and mainly caused by the change of physical dimension.The mechanical properties of carbon fiber monofilament were also measured.

  1. Biodegradation of pitch-based high performance carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T. (Yamaguchi Univ., Yamaguchi, (Japan). Faculty of Education)

    1992-09-10

    Although carbon fibers are widely used in various purposes because of their excellent mechanical properties, their behavior under biodegradation by microorganisms has not been elucidated. To elucidate the process of biodegradation of carbon fibers is important for understanding thoroughly the durability and the functionality of the fibers. In this article, a study has been made on biodegradation of pitch-based high performance carbon fibers by microorganisms. The fiber which was degraded has been examined with a scanning electron microscope. Aspergillus flavus has broken surface areas of high performance carbon fibers in 60 days and the fibril structure under the surface layer of the fiber has been exfoliated by degradation. The fibrils on the second layer have been 100-110nm wide. The fibrils have been in line nearly parallel to the fiber axis. The above carbon fibers are carbon type, but in case of graphite type high performance carbon fibers, its broken areas have not been shown and they have shown much stronger resistance against microbial attacks. 11 refs., 8 figs., 2 tabs.

  2. Modification of the Interfacial Interaction between Carbon Fiber and Epoxy with Carbon Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Kejing Yu

    2016-05-01

    Full Text Available The mechanical properties of the hybrid materials and epoxy and carbon fiber (CF composites were improved significantly as compared to the CF composites made from unmodified epoxy. The reasons could be attributed to the strong interfacial interaction between the CF and the epoxy composites for the existence of carbon nanomaterials. The microstructure and dispersion of carbon nanomaterials were characterized by transmission electron microscopy (TEM and optical microscopy (OM. The results showed that the dispersion of the hybrid materials in the polymer was superior to other carbon nanomaterials. The high viscosity and shear stress characterized by a rheometer and the high interfacial friction and damping behavior characterized by dynamic mechanical analysis (DMA indicated that the strong interfacial interaction was greatly improved between fibers and epoxy composites. Remarkably, the tensile tests presented that the CF composites with hybrid materials and epoxy composites have a better reinforcing and toughening effect on CF, which further verified the strong interfacial interaction between epoxy and CF for special structural hybrid materials.

  3. High-stability polymer optical fiber with Rhodamine-doped cladding for fiber light systems

    Science.gov (United States)

    Jaramillo-Ochoa, L.; Narro-García, R.; Ocampo, M. A.; Quintero-Torres, R.

    2016-09-01

    In this work, the photodegradation of a polymer optical fiber with Rhodamine doped cladding as a function of illumination time and excitation intensity is presented. To show the effect of photodegradation on different bulk geometries and environments, the photodegradation from a dye doped preform and a PMMA thick film is also evaluated. The reversible and the irreversible degradation of the florescent material were quantified under an established excitation scheme. To this purpose, a four-level system to model the photodegradation rates and its relation with the population of the states is presented and it is used to justify a possible underlying mechanism. The obtained results suggest an increase of one order of magnitude in the stability (lifetime) of the polymer optical fiber with respect to the preform or the thick film geometry stability.

  4. [INVITED] New advances in polymer fiber Bragg gratings

    Science.gov (United States)

    Nogueira, Rogério; Oliveira, Ricardo; Bilro, Lúcia; Heidarialamdarloo, Jamshid

    2016-04-01

    During the last years, fiber Bragg gratings (FBGs) written in polymer optical fibers (POFs) have been pointed as an interesting alternative to silica FBGs for applications in sensors and in optical access networks. In order to use such components in real applications, the manipulation of POFs, as well as the increase of quality in the production of FBGs has to be achieved. In this article some of the recent advances regarding these two aspects are reported and include recent developments to produce smooth POFs end face with high quality, benefiting the current splicing process and the inscription of high quality FBGs in a few seconds. Furthermore, additional characterizations to strain, temperature, pressure, and humidity are also shown.

  5. Polymer microstructured fibers for guiding of THz radiation

    DEFF Research Database (Denmark)

    Nielsen, Kristian; Bang, Ole; Jepsen, Peter Uhd

    2010-01-01

    THz radiation, including low-loss transport of THz signals [1] between high-speed devices, integrated components for manipulation of THz light [2], such as power splitters, polarization management, and frequency filters, and confinement of the electric field of a THz signal in a small volume, enabling...... spectroscopic investigations of minute sample quantities [3]. In this presentation we will describe our current efforts in the development, fabrication and characterization of a class of THz waveguides and components based on microstructured polymer optical fibers (mPOF’s) [4] designed for the THz frequency...... fibers and components is carried out by THz time-domain spectroscopy, where the amplitude and phase of the transmitted signal through the sample is compared to a reference signal. In this manner we can characterize both loss and dispersion of the waveguide. In addition, near-field measurements across...

  6. Isothermal and hygrothermal agings of hybrid glass fiber/carbon fiber composite

    Science.gov (United States)

    Barjasteh, Ehsan

    New applications of fiber-reinforced polymer composites (FRPCs) are arising in non-traditional sectors of industry, such as civil infrastructure, automotive, and power distribution. For example, composites are being used in place of steel to support high-voltage overhead conductors. In this application, conductive strands of aluminum are wrapped around a solid composite rod comprised of unidirectional carbon and glass fibers in an epoxy matrix, which is commercially called ACCC conductor. Composite-core conductors such as these are expected to eventually replace conventional steel-reinforced conductors because of the reduced sag at high temperatures, lower weight, higher ampacity, and reduced line losses. Despite the considerable advantages in mechanical performance, long-term durability of composite conductors is a major concern, as overhead conductors are expected to retain properties (with minimal maintenance) over a service life that spans multiple decades. These concerns stem from the uncertain effects of long-term environmental exposure, which includes temperature, moisture, radiation, and aggressive chemicals, all of which can be exacerbated by cyclic loads. In general, the mechanical and physical properties of polymer composites are adversely affected by such environmental factors. Consequently, the ability to forecast changes in material properties as a function of environmental exposure, particularly bulk mechanical properties, which are affected by the integrity of fiber-matrix interfaces, is required to design for extended service lives. Polymer composites are susceptible to oxidative degradation at high temperatures approaching but not quite reaching the glass transition temperature ( Tg). Although the fibers are stable at such temperatures, the matrix and especially the fiber-matrix interface can undergo degradation that affects the physical and mechanical properties of the structure over time. Therefore, as a first step, the thermal aging of an

  7. Coupling losses in perfluorinated multi-core polymer optical fibers.

    Science.gov (United States)

    Durana, Gaizka; Aldabaldetreku, Gotzon; Zubia, Joseba; Arrue, Jon; Tanaka, Chikafumi

    2008-05-26

    The aim of the present paper is to provide a comprehensive analysis of coupling losses in perfluorinated (PF) multi-core polymer optical fibers (MC-POFs), which consist of groups of 127 graded-index cores. In our analysis we take into account geometrical, longitudinal, transverse, and angular misalignments. We perform several experimental measurements and computer simulations in order to calculate the coupling losses for a PF MC-POF prototype. Based on these results, we propose several hints of practical interest to the manufacturer which would allow an appropriate connector design in order to handle conveniently the coupling losses incurred when connectorizing two PF MC-POFs.

  8. Electrospun Fibers of Enteric Polymer for Controlled Drug Delivery

    Directory of Open Access Journals (Sweden)

    Fábia F. P. da Costa

    2015-01-01

    Full Text Available The production of electrospun fibers of enteric polymer for controlled delivery of drugs represents a simple and low cost procedure with promising advantages relative to the longer therapeutic window provided by cylindrical geometry in association with intrinsic properties of pH-dependent drug carriers. In this work, we have explored the incorporation of additives (block copolymers of poly(ethylene-b-poly(ethylene oxide into matrix of Eudragit L-100 and the effective action of hybrid composites on delivery of nifedipine, providing improvement in the overall process of controlled release of loaded drug.

  9. Processing and characterization of natural cellulose fibers/thermoset polymer composites.

    Science.gov (United States)

    Thakur, Vijay Kumar; Thakur, Manju Kumari

    2014-08-30

    Recently natural cellulose fibers from different biorenewable resources have attracted the considerable attraction of research community all around the globe owing to their unique intrinsic properties such as biodegradability, easy availability, environmental friendliness, flexibility, easy processing and impressive physico-mechanical properties. Natural cellulose fibers based materials are finding their applications in a number of fields ranging from automotive to biomedical. Natural cellulose fibers have been frequently used as the reinforcement component in polymers to add the specific properties in the final product. A variety of cellulose fibers based polymer composite materials have been developed using various synthetic strategies. Seeing the immense advantages of cellulose fibers, in this article we discuss the processing of biorenewable natural cellulose fibers; chemical functionalization of cellulose fibers; synthesis of polymer resins; different strategies to prepare cellulose based green polymer composites, and diverse applications of natural cellulose fibers/polymer composite materials. The article provides an in depth analysis and comprehensive knowledge to the beginners in the field of natural cellulose fibers/polymer composites. The prime aim of this review article is to demonstrate the recent development and emerging applications of natural cellulose fibers and their polymer materials.

  10. Structural Behavior of Concrete Beams Reinforced with Basalt Fiber Reinforced Polymer (BFRP) Bars

    Science.gov (United States)

    Ovitigala, Thilan

    The main challenge for civil engineers is to provide sustainable, environmentally friendly and financially feasible structures to the society. Finding new materials such as fiber reinforced polymer (FRP) material that can fulfill the above requirements is a must. FRP material was expensive and it was limited to niche markets such as space shuttles and air industry in the 1960s. Over the time, it became cheaper and spread to other industries such as sporting goods in the 1980-1990, and then towards the infrastructure industry. Design and construction guidelines are available for carbon fiber reinforced polymer (CFRP), aramid fiber reinforced polymer (AFRP) and glass fiber reinforced polymer (GFRP) and they are currently used in structural applications. Since FRP is linear elastic brittle material, design guidelines for the steel reinforcement are not valid for FRP materials. Corrosion of steel reinforcement affects the durability of the concrete structures. FRP reinforcement is identified as an alternative to steel reinforcement in corrosive environments. Although basalt fiber reinforced polymer (BFRP) has many advantages over other FRP materials, but limited studies have been done. These studies didn't include larger BFRP bar diameters that are mostly used in practice. Therefore, larger beam sizes with larger BFRP reinforcement bar diameters are needed to investigate the flexural and shear behavior of BFRP reinforced concrete beams. Also, shear behavior of BFRP reinforced concrete beams was not yet studied. Experimental testing of mechanical properties and bond strength of BFRP bars and flexural and shear behavior of BFRP reinforced concrete beams are needed to include BFRP reinforcement bars in the design codes. This study mainly focuses on the use of BFRP bars as internal reinforcement. The test results of the mechanical properties of BFRP reinforcement bars, the bond strength of BFRP reinforcement bars, and the flexural and shear behavior of concrete beams

  11. Carbon nanotube-polymer composites manufacture, properties, and applications

    CERN Document Server

    Grady, Brian P

    2011-01-01

    The accessible compendium of polymers in carbon nanotubes (CNTs) Carbon nanotubes (CNTs)-extremely thin tubes only a few nanometers in diameter but able to attain lengths thousands of times greater-are prime candidates for use in the development of polymer composite materials. Bringing together thousands of disparate research works, Carbon Nanotube-Polymer Composites: Manufacture, Properties, and Applications covers CNT-polymers from synthesis to potential applications, presenting the basic science and engineering of this dynamic and complex area in an accessible, readable way. Desi

  12. Friction and wear behavior of carbon fiber reinforced brake materials

    Institute of Scientific and Technical Information of China (English)

    Du-qing CHENG; Xue-tao WANG; Jian ZHU; Dong-bua QIU; Xiu-wei CHENG; Qing-feng GUAN

    2009-01-01

    A new composite brake material was fabri-cated with metallic powders, barium sulphate and modified phenolic resin as the matrix and carbon fiber as the reinforced material. The friction, wear and fade character-istics of this composite were determined using a D-MS friction material testing machine. The surface structure of carbon fiber reinforced friction materials was analyzed by scanning electronic microscopy (SEM). Glass fiber-reinforced and asbestos fiber-reinforced composites with the same matrix were also fabricated for comparison. The carbon fiber-reinforced friction materials (CFRFM) shows lower wear rate than those of glass fiber- and asbestos fiber-reinforced composites in the temperature range of 100℃-300℃. It is interesting that the frictional coefficient of the carbon fiber-reinforced friction materials increases as frictional temperature increases from 100℃ to 300℃, while the frictional coefficients of the other two composites decrease during the increasing temperatures. Based on the SEM observation, the wear mechanism of CFRFM at low temperatures included fiber thinning and pull-out. At high temperature, the phenolic matrix was degraded and more pull-out enhanced fiber was demonstrated. The properties of carbon fiber may be the main reason that the CFRFM possess excellent tribological performances.

  13. Fabrication of sisal fibers/epoxy composites with liquid crystals polymer grafted on sisal fibers

    Science.gov (United States)

    Luo, Q. Y.; Lu, S. R.; Song, L. F.; Li, Y. Q.

    2016-07-01

    In this word, microcrystalline cellulose fibers (MCFs), extracted from sisal fibers, were treated with function end-group hyperbranched liquid crystals (HLP). This work brought some insights into the successful surface modification in epoxy composite with HLP. The HLP-MCFs/epoxy composites are studied systematically. The HLP - MCFs/epoxy composites were studied by Fourier transform infrared spectroscopy (FT-IR), polarizing microscope (POM), X-ray photoelectron spectroscopy (XPS) and mechanical properties analysis. The results reveal that the reinforcement of EP composites was carried out by adding HLP-MCFs. In particular, with 1.0 wt% filler loading, the flexural strength, tensile strength, impact strength and flexural modulus of the HLP-MCFs/EP composites were increased by 60%, 69%, 130%, and 192%, respectively. It anticipates that our current work exploits more efficient methods to overcome the few nature fiber/polymer (NPC) adhesion in the interface region and provides implications for the engineering applications of the development of NPC.

  14. Processing and Characterization of Basalt Fiber Reinforced Ceramic Composites for High Temperature Applications Using Polymer Precursors

    Science.gov (United States)

    Cox, Sarah B.; Lui, Donovan; Gou, Jihua

    2014-01-01

    The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Ceramics can take much higher temperatures, but they are difficult to produce and form in bulk volumes. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, allowing a shape to be formed and cured and then to be pyrolized in order to obtain a ceramic with the associated thermal and mechanical properties. The two PDCs used in this development are polysiloxane and polycarbosilane. Polysiloxanes contain a silicon oxycarbide backbone when pyrolized up to 1000C. Polycarbosilane, an organosilicon polymer, contain a silicon-carbon backbone; around 1200C, beta-SiC begins to crystallize. The use of basalt in structural and high temperature applications has been under development for over 50 years, yet there has been little published research on the incorporation of basalt fibers as a reinforcement in composites. Basalt is a naturally occurring material found in volcanic rock. Continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material. Thermal and mechanical testing includes oxyacetylene torch testing and three point bend testing.

  15. Preparation and Properties of Polymer/Vermiculite Hybrid Superabsorbent Reinforced by Fiber for Enhanced Oil Recovery

    Directory of Open Access Journals (Sweden)

    Fayang Jin

    2014-01-01

    Full Text Available A series of polymer/clay hybrid superabsorbent composites (SACFs comprising acrylamide, acrylic acid, sodium 2-acrylamido-tetradecyl sulfonate, fiber, and vermiculite by in situ intercalation and exfoliated method was successfully synthesized. The structure of SACFs was characterized by IR, SXRD, and SEM measurements. Much notable absorbency for SACF-2 was observed compared to that for SACF-1 in the absence of hydrophobic group in the high cationic solution due to the alkyl carbon chain and sulfonic acid group of hydrophobic moistures protecting the cations from attacking the carboxylate groups. What is more, high temperature fiber which acts as bridge connection for the polymeric network structure enhanced both toughness and strength for SACF-4 in the harsh conditions. At the total dissolved substance of 212000 mg/L for Tarim Basin injected water and the temperature of 120°C, desired absorbency as well as water retaining property for SACF-4 was observed during the long period of thermal ageing. Core flooding experiments demonstrated that SACFs could migrate as amoeba in the porous medium and accumulated in the narrow channel to adjust injection profile, promoting the subsequent water diverting into the unswept zones. Finally, characteristic parameters for SACFs calculated from flooding experiment further confirmed these polymer/clay hybrid composites reinforced by fiber would have robust application in the mature oilfield for profile control.

  16. Interlaminar fracture in carbon fiber/thermoplastic composites

    Science.gov (United States)

    Hinkley, J. A.; Bascom, W. D.; Allred, R. E.

    1990-01-01

    The surfaces of commercial carbon fibers are generally chemically cleaned or oxidized and then coated with an oligomeric sizing to optimize their adhesion to epoxy matrix resins. Evidence from fractography, from embedded fiber testing and from fracture energies suggests that these standard treatments are relatively ineffective for thermoplastic matrices. This evidence is reviewed and model thermoplastic composites (polyphenylene oxide/high strain carbon fibers) are used to demonstrate how differences in adhesion can lead to a twofold change in interlaminar fracture toughness. The potential for improved adhesion via plasma modification of fiber surfaces is discussed. Finally, a surprising case of fiber-catalyzed resin degradation is described.

  17. Characterization and Oxidation Behavior of Rayon-Derived Carbon Fibers

    Science.gov (United States)

    Jacobson, Nathan; Hull, David

    2010-01-01

    Rayon-derived fibers are the central constituent of reinforced carbon/ carbon (RCC) composites. Optical, scanning electron, and transmission electron microscopy were used to characterize the as-fabricated fibers and the fibers after oxidation. Oxidation rates were measured with weight loss techniques in air and oxygen. The as-received fibers are approximately 10 micron in diameter and characterized by grooves or crenulations around the edges. Below 800 C, in the reaction-controlled region, preferential attack began in the crenulations and appeared to occur down fissures in the fibers.

  18. Electrically Conductive, Optically Transparent Polymer/Carbon Nanotube Composites and Process for Preparation Thereof

    Science.gov (United States)

    Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Harrison, Joycelyn S. (Inventor); Park, Cheol (Inventor); Watson, Kent A. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400-800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior.

  19. 基于连续碳纤维/树脂智能材料的梁结构应变模态表征%Strain modal characterization of beams using continuous carbon fiber/polymer smart composite

    Institute of Scientific and Technical Information of China (English)

    朱四荣; 周志勇; 吕泳; 郑华升; 李卓球

    2013-01-01

    研制了一种具有动态传感功能的碳纤维/树脂智能层,可用于结构的应变模态诊断.通过不同加载频率下的单向拉伸实验揭示了这种智能材料对低频动态载荷的响应能力,并理论分析了动态响应误差的影响因素.在此基础上将碳纤维/环氧树脂智能层连续敷设于悬臂梁结构表面代替传统的点式应变片,进行应变模态测试.测试结果表明,碳纤维/环氧树脂智能层可以较精确地反映结构的前三阶固有频率,并较好地表征结构的前三阶应变模态振型.对悬臂梁局部附加质量后重新进行了模态试验,结果表明:附加质量后,智能层反映的结构固有频率显著下降;同时,在附加质量所在的节点位置,智能层反映的应变模态振型有突变产生,说明智能层所表征的应变模态对结构物性参数变化具有识别能力,采用智能层与采用应变片的实验结果一致.此外,基于碳纤维/树脂智能层的可覆盖性,采用有限的测点全面捕捉了结构的应变模态信息,并在测试中通过在可疑区域内逐步增加测点,实现了结构物性参数变化的定位.%A carbon fiber/polymer smart layer able to sense dynamic strain was developed to perform structural strain modal diagnosis.The sensitivity of such a smart material to dynamic load at low frequency was revealed by the tension tests conducted with different frequencies,and the influencing factors on the error of the dynamic response were analyzed theoretically.The smart layer was continuously laid on a cantilever beam and took place of traditional strain gauges to test its strain modals.The test results indicate that the smart layer is able to exactly present the natural frequencies and the strain modal shapes of the first three orders for the beam.The test was conducted again on the beam with added mass.It is found that the added mass leads to the decrease of the natural frequencies and induces mutations on the smart

  20. 碳纤维布与钢板粘结复合材料徐变性能试验研究%Experimental research on creep of steel plates bonded by carbon fiber reinforced polymer

    Institute of Scientific and Technical Information of China (English)

    卢亦焱; 张学朋; 唐志宇

    2011-01-01

    通过碳纤维布(CFRP)与钢板复合材料的徐变试验,分析了CFRP材料徐变与时间的关系,研究了加荷幅值、CFRP截面面积、初始应变等因素对其徐变性能的影响,揭示了CFRP材料徐变机理;通过徐变前后复合材料试件基本力学性能试验,研究了CFRP徐变对复合材料力学性能的影响;定性分析了徐变对复合加固混凝土梁的影响。研究表明:CFRP与钢板复合材料在40%极限荷载持续作用下,CFRP材料徐变值为初始应变的10%左右,且前期发展较快,100 h发展至70%左右,后期变缓;试件中CFRP材料的徐变值随着加载幅值、初始应变的升高而有所增大,但CFRP宽度对其影响不大;CFRP徐变后复合材料试件的屈服荷载、极限荷载和弹性模量均下降,且呈现徐变值越大,下降幅度越大的变化趋势;CFRP材料的徐变会引起复合材料加固构件截面应力重分布,导致CFRP应力减小、加固效果减弱。%The creep experiment on steel plates bonded by carbon fiber reinforced polymer was conducted to investigate the long-term properties of the composite material.The relationship between creep and time was analyzed,and the influential factors such as the stress amplitude,area of the CFRP,initial strain were also studied by the creep experiment which revealed the mechanism of creep of CFRP.The effect of the mechanical performance of the composite material was explained by the test of basic mechanical property before and after creep procedure.Through the theoretical analysis of mechanical behavior of the structure strengthened by composite material the influence of creep was discussed qualitatively.It is found that the ultimate creep is about ten percent of the initial strain under the constant load of 40% of the ultimate load,and the creep develops faster in the early period which can reach 70% of the ultimate creep in 100 hours.The creep of the CFRP increases with the increase of stress amplitude and initial

  1. Computational modeling of ring textures in mesophase carbon fibers

    Directory of Open Access Journals (Sweden)

    de Andrade Lima Luiz Rogério Pinho

    2003-01-01

    Full Text Available Carbon fibers are widely used in many industrial applications due the fact of their excellent properties. Carbonaceous mesophases are liquid crystalline precursor materials that can be spun into high performance carbon fibers using the melt spinning process, which is a flow cascade consisting of pressure driven flow-converging die flow-free surface extensional spinline flow that modifies the precursor molecular orientation structure. Carbon fiber property optimization requires a better understanding of the principles that control the structure development during the fiber formation processes and the rheological processing properties. This paper presents the elastic and continuum theory of liquid crystalsand computer simulations of structure formation for pressure-driven flow of carbonaceous liquid crystalline precursors used in the industrial carbon fiber spinning process. The simulations results capture the formation of characteristic fiber macro-textures and provide new knowledge on the role of viscous and elastic effects in the spinning process.

  2. Surface State of Carbon Fibers Modified by Electrochemical Oxidation

    Institute of Scientific and Technical Information of China (English)

    Yunxia GUO; Jie LIU; Jieying LIANG

    2005-01-01

    Surface of polyacrylonitrile (PAN)-based carbon fibers was modified by electrochemical oxidation. The modification effect on carbon fibers surface was explored using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Results showed that on the modified surface of carbon fibers, the carbon contents decreased by 9.7% and the oxygen and nitrogen contents increased by 53.8% and 7.5 times, respectively. The surface roughness and the hydroxyl and carbonyl contents also increased. The surface orientation index was reduced by 1.5%which decreased tensile strength of carbon fibers by 8.1%, and the microcrystalline dimension also decreased which increased the active sites of carbon fiber surface by 78%. The physical and chemical properties of carbon fibers surface were modified through the electrochemical oxidative method, which improved the cohesiveness between the fibers and resin matrix and increased the interlaminar shear strength (ILSS) of carbon fibers reinforced epoxy composite (CFRP) over 20%.

  3. Nano-Textured Fiber Coatings for Energy Absorbing Polymer Matrix Composite Materials

    Science.gov (United States)

    2004-12-01

    NANO-TEXTURED FIBER COATINGS FOR ENERGY ABSORBING POLYMER MATRIX COMPOSITE MATERIALS R. E. Jensen and S. H. McKnight Army Research Laboratory...Textured Fiber Coatings For Energy Absorbing Polymer Matrix Composite Materials 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6

  4. Instability and morphology of polymer solutions coating a fiber

    CERN Document Server

    Boulogne, François; Giorgiutti-Dauphiné, Frédérique

    2013-01-01

    We report an experimental study on the dynamics of a thin film of polymer solution coating a vertical fiber. The liquid film has first a constant thickness and then undergoes the Rayleigh-Plateau instability which leads to the formation of sequences of drops, separated by a thin film, moving down at a constant velocity. Different polymer solutions are used, i.e. xanthan solutions and polyacrylamide (PAAm) solutions. These solutions both exhibit shear-rate dependence of the viscosity, but for PAAm solutions, there are strong normal stresses in addition of the shear-thinning effect. We characterize experimentally and separately the effects of these two non-Newtonian properties on the flow on the fiber. Thus, in the flat film observed before the emergence of the drops, only shear-thinning effect plays a role and tends to thin the film compared to the Newtonian case. The effect of the non-Newtonian rheology on the Rayleigh-Plateau instability is then investigated through the measurements of the growth rate and th...

  5. Selective Serial Multi-Antibody Biosensing with TOPAS Microstructured Polymer Optical Fibers

    DEFF Research Database (Denmark)

    Emiliyanov, Grigoriy Andreev; Høiby, Poul E.; Pedersen, Lars H.

    2013-01-01

    We have developed a fluorescence-based fiber-optical biosensor, which can selectively detect different antibodies in serial at preselected positions inside a single piece of fiber. The fiber is a microstructured polymer optical fiber fabricated from TOPAS cyclic olefin copolymer, which allows...... for UV activation of localized sensor layers inside the holes of the fiber. Serial fluorescence-based selective sensing of Cy3-labelled α-streptavidin and Cy5-labelled α-CRP antibodies is demonstrated....

  6. Selective Serial Multi-Antibody Biosensing with TOPAS Microstructured Polymer Optical Fibers

    Directory of Open Access Journals (Sweden)

    Lars H. Pedersen

    2013-03-01

    Full Text Available We have developed a fluorescence-based fiber-optical biosensor, which can selectively detect different antibodies in serial at preselected positions inside a single piece of fiber. The fiber is a microstructured polymer optical fiber fabricated from TOPAS cyclic olefin copolymer, which allows for UV activation of localized sensor layers inside the holes of the fiber. Serial fluorescence-based selective sensing of Cy3-labelled α-streptavidin and Cy5-labelled α-CRP antibodies is demonstrated.

  7. Selective serial multi-antibody biosensing with TOPAS microstructured polymer optical fibers.

    Science.gov (United States)

    Emiliyanov, Grigoriy; Høiby, Poul E; Pedersen, Lars H; Bang, Ole

    2013-03-08

    We have developed a fluorescence-based fiber-optical biosensor, which can selectively detect different antibodies in serial at preselected positions inside a single piece of fiber. The fiber is a microstructured polymer optical fiber fabricated from TOPAS cyclic olefin copolymer, which allows for UV activation of localized sensor layers inside the holes of the fiber. Serial fluorescence-based selective sensing of Cy3-labelled α-streptavidin and Cy5-labelled α-CRP antibodies is demonstrated.

  8. Increased sensitivity in fiber-based spectroscopy using carbon-coated fiber.

    Science.gov (United States)

    Sudirman, Aziza; Norin, Lars; Margulis, Walter

    2012-12-17

    Carbon-coated optical fibers are used here for reducing the luminescence background created by the primary-coating and thus increase the sensitivity of fiber-based spectroscopy systems. The 2-3 orders of magnitude signal-to-noise ratio improvement with standard telecom fibers is sufficient to allow for their use as Raman probes in the identification of organic solvents.

  9. Improved thermoplastic composite by alignment of vapor-grown carbon fiber

    Science.gov (United States)

    Kuriger, Rex Jerrald

    2000-10-01

    Vapor grown carbon fiber (VGCF) is a new and inexpensive carbon fiber produced by vapor deposition of hydrocarbons on metal catalysts. Unlike continuous conventional PAN or pitch-derived carbon fibers, VGCF is discontinuous with diameters of about 200 nanometers and lengths ranging from 10 to 200 micrometers. The microscopic size and random entanglement of the fibers create several problems when processing VGCF composites. It is particularly difficult to disperse the entangled fibers in the matrix and orient them along a preferred axis to provide directional reinforcement. This work introduces a technique to produce an improved polymeric composite by alignment of vapor grown carbon nano-fibers in a polypropylene matrix. A twin-screw extruder was used to shear mix and disperse the fibers in the polymer matrix. The composite mixtures were extruded through a converging-annular die that generates flow-induced fiber alignment along the extrusion direction. The effect that the various extrusion conditions have on the bulk properties of the extrudate was investigated. It was found that the extrusion process is strongly dependent on the fiber content of the composite. The extrusion pressure increased and the flow rate decreased with fiber volume fraction. The tensile strength and modulus for the composite samples varied with extrusion temperature and screw speed, and the void content increased with fiber volume fraction. It was shown that fiber alignment could be improved by increasing the residence time in the die channel and was verified using x-ray diffraction. The mechanical properties of the aligned samples increased with fiber content. Also, the tensile strength improved with greater fiber orientation; however, more fiber alignment had little affect on the modulus. To better predict the strength of these partially aligned fiber composites, an experimental and theoretical approach was introduced. The experimental data correspond reasonably well when compared with the

  10. Preliminary experimental study of a carbon fiber array cathode

    Science.gov (United States)

    Li, An-kun; Fan, Yu-wei

    2016-08-01

    The preliminary experimental results of a carbon fiber array cathode for the magnetically insulated transmission line oscillator (MILO) operations are reported. When the diode voltage and diode current were 480 kV and 44 kA, respectively, high-power microwaves with a peak power of about 3 GW and a pulse duration of about 60 ns were obtained in a MILO device with the carbon fiber array cathode. The preliminary experimental results show that the shot-to-shot reproducibility of the diode current and the microwave power is stable until 700 shots. No obvious damage or deterioration can be observed in the carbon fiber surface morphology after 700 shots. Moreover, the cathode performance has no observable deterioration after 700 shots. In conclusion, the maintain-free lifetime of the carbon fiber array cathode is more than 700 shots. In this way, this carbon fiber array cathode offers a potential replacement for the existing velvet cathode.

  11. Enhanced thermal conductance of polymer composites through embeddingaligned carbon nanofibers

    Directory of Open Access Journals (Sweden)

    Dale K. Hensley

    2016-07-01

    Full Text Available The focus of this work is to find a more efficient method of enhancing the thermal conductance of polymer thin films. This work compares polymer thin films embedded with randomly oriented carbon nanotubes to those with vertically aligned carbon nanofibers. Thin films embedded with carbon nanofibers demonstrated a similar thermal conductance between 40–60 μm and a higher thermal conductance between 25–40 μm than films embedded with carbon nanotubes with similar volume fractions even though carbon nanotubes have a higher thermal conductivity than carbon nanofibers.

  12. DSC Study on the Polyacrylonitrile Precursors for Carbon Fibers

    Institute of Scientific and Technical Information of China (English)

    Wangxi ZHANG; Musen LI

    2005-01-01

    Different polyacrylonitrile (PAN) precursor fibers that displayed various thermal properties were studied by using differential scanning calorimetry (DSC). Results showed that some commercial PAN precursor fibers displayed double separated peaks and these fibers were of high quality because of their process stability during their conversion to carbon fibers of high performance. Some fabrication processes, such as spinning, drawing, could not apparently change the DSC features of a PAN precursor fiber. It was concluded that the thermal properties of a PAN precursor fiber was mainly determined from its comonomer content type and compositions.

  13. Smart Cellulose Fibers Coated with Carbon Nanotube Networks

    OpenAIRE

    Haisong Qi; Jianwen Liu; Edith Mäder

    2014-01-01

    Smart multi-walled carbon nanotube (MWCNT)-coated cellulose fibers with a unique sensing ability were manufactured by a simple dip coating process. The formation of electrically-conducting MWCNT networks on cellulose mono- and multi-filament fiber surfaces was confirmed by electrical resistance measurements and visualized by scanning electron microscopy. The interaction between MWCNT networks and cellulose fiber was investigated by Raman spectroscopy. The piezoresistivity of these fibers fo...

  14. Morphological analysis of polymers on hair fibers by SEM and AFM

    Directory of Open Access Journals (Sweden)

    Valéria Fernandes Monteiro

    2003-12-01

    Full Text Available The polyquaternium 7® polymer is widely used in cosmetic formulations. Morphologic alterations in hair fibers were observed after the application of the polyquaternium 7® polymer, using SEM and AFM. Continuous applications of this product indicated that it accumulates on the fibers, improving the aspect of the hair surface. Quantitative analysis of the images obtained by AFM was undertaken. The data obtained for the hair surface roughness indicates that the fibers treated with the polymer presented higher roughness than the untreated hair fibers.

  15. Fiber-optical microphones and accelerometers based on polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole

    2010-01-01

    Polymer optical fibers (POFs) are ideal for applications as the sensing element in fiber-optical microphones and accelerometers based on fiber Bragg gratings (FBGs) due to their reduced Young’s Modulus of 3.2GPa, compared to 72GPa of Silica. To maximize the sensitivity and the dynamic range...... of the device the outer diameter and the length of the sensing fiber segment should be as small as possible. To this end we have fabricated 3mm FBGs in single-mode step-index POFs of diameter 115 micron, using 325nm UV writing and a phase-mask technique. 6mm POF sections with FBGs in the center have been glued...... to standard Silica SMF28 fibers. These POF FBGs have been characterized in terms of temperature and strain to find operating regimes with no hysteresis. Commercial fast wavelength interrogators (KHz) are shown to be able to track the thin POF FBGs and they are finally applied in a prototype accelerometer...

  16. Cost effective optical coupling for polymer optical fiber communication

    Science.gov (United States)

    Chandrappan, Jayakrishnan; Zhang, Jing; Mohan, Ramkumar V.; Gomez, Philbert Oliver; Aung, Than Aye; Xiao, Yongfei; Ramana, Pamidighantam V.; Lau, John Hon Shing; Kwong, Dim Lee

    2008-02-01

    Polymer Optical Fiber (POF) optical modules are gaining momentum due to their applications in short distance communications. POFs offer more flexibility for plug and play applications and provide cost advantages. They also offer significant weight advantage in automotive and avionic networks. One of the most interesting field of application is home networking. Low cost optical components are required, since cost is a major concern in local and home networks. In this publication, a fast and easy to install, low cost solution for efficient light coupling in and out of Step Index- POF is explored. The efficient coupling of light from a large core POF to a small area detector is the major challenge faced. We simulated direct coupling, lens coupling and bend losses for step index POF using ZEMAX R optical simulation software. Simulations show that a lensed fiber tip particularly at the receiver side improves the coupling efficiency. The design is optimized for 85% coupling efficiency and explored the low cost fabrication method to implement it in the system level. The two methods followed for lens fabrication is described here in detail. The fabricated fiber lenses are characterized using a beam analyzer. The fabrication process was reiterated to optimize the lens performance. It is observed that, the fabricated lenses converge the POF output spot size by one fourth, there by enabling a higher coupling efficiency. This low cost method proves to be highly efficient and effective optical coupling scheme in POF communications.

  17. Inductive wireless sensor-actuator node for structural health monitoring of fiber reinforced polymers by means of Lamb-waves

    Science.gov (United States)

    Focke, Oliver; Salas, Mariugenia; Herrmann, Axel S.; Lang, Walter

    2015-03-01

    Wireless excitation of Piezo-Wafer-Active-Sensors (PWAS) was achieved using Low-frequency coils produced via Tailored-Fiber-Placement. Carbon Fiber Reinforced Polymer behaves as conductor and depending on the frequency it shields radio waves; this effect is rising at high-frequency. A high permeability material was placed under the highfrequency antenna and re-tuning was performed to improve the quality of transmission. In this manner sensor responses were successfully transmitted wirelessly by analog amplitude modulation. The signals were evaluated to verify the functionality in presence of defects like delamination or holes. Generated power was confirmed to be enough to excite the actuator.

  18. Development of multifunctional fiber reinforced polymer composites through ZnO nanowire arrays

    Science.gov (United States)

    Malakooti, Mohammad H.; Patterson, Brendan A.; Hwang, Hyun-Sik; Sodano, Henry A.

    2016-04-01

    Piezoelectric nanowires, in particular zinc oxide (ZnO) nanowires, have been vastly used in the fabrication of electromechanical devices to convert wasted mechanical energy into useful electrical energy. Over recent years, the growth of vertically aligned ZnO nanowires on various structural fibers has led to the development of fiber-based nanostructured energy harvesting devices. However, the development of more realistic energy harvesters that are capable of continuous power generation requires a sufficient mechanical strength to withstand typical structural loading conditions. Yet, a durable, multifunctional material system has not been developed thoroughly enough to generate electrical power without deteriorating the mechanical performance. Here, a hybrid composite energy harvester is fabricated in a hierarchical design that provides both efficient power generating capabilities while enhancing the structural properties of the fiber reinforced polymer composite. Through a simple and low-cost process, a modified aramid fabric with vertically aligned ZnO nanowires grown on the fiber surface is embedded between woven carbon fabrics, which serve as the structural reinforcement as well as the top and the bottom electrodes of the nanowire arrays. The performance of the developed multifunctional composite is characterized through direct vibration excitation and tensile strength examination.

  19. RADIATION EFFECTS ON EPOXY CARBON FIBER COMPOSITE

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, E

    2008-05-30

    Carbon fiber-reinforced bisphenol-A epoxy matrix composite was evaluated for gamma radiation resistance. The composite was exposed to total gamma doses of 50, 100, and 200 Mrad. Irradiated and baseline samples were tested for tensile strength, hardness and evaluated using FTIR (Fourier transform infrared) spectroscopy and DSC (differential scanning calorimetry) for structural changes. Scanning electron microscopy was used to evaluate microstructural behavior. Mechanical testing of the composite bars revealed no apparent change in modulus, strain to failure, or fracture strength after exposures. However, testing of only the epoxy matrix revealed changes in hardness, thermal properties, and FTIR results with increasing gamma irradiation. The results suggest the epoxy within the composite can be affected by exposure to gamma irradiation.

  20. Graphene quantum dots derived from carbon fibers.

    Science.gov (United States)

    Peng, Juan; Gao, Wei; Gupta, Bipin Kumar; Liu, Zheng; Romero-Aburto, Rebeca; Ge, Liehui; Song, Li; Alemany, Lawrence B; Zhan, Xiaobo; Gao, Guanhui; Vithayathil, Sajna Antony; Kaipparettu, Benny Abraham; Marti, Angel A; Hayashi, Takuya; Zhu, Jun-Jie; Ajayan, Pulickel M

    2012-02-08

    Graphene quantum dots (GQDs), which are edge-bound nanometer-size graphene pieces, have fascinating optical and electronic properties. These have been synthesized either by nanolithography or from starting materials such as graphene oxide (GO) by the chemical breakdown of their extended planar structure, both of which are multistep tedious processes. Here, we report that during the acid treatment and chemical exfoliation of traditional pitch-based carbon fibers, that are both cheap and commercially available, the stacked graphitic submicrometer domains of the fibers are easily broken down, leading to the creation of GQDs with different size distribution in scalable amounts. The as-produced GQDs, in the size range of 1-4 nm, show two-dimensional morphology, most of which present zigzag edge structure, and are 1-3 atomic layers thick. The photoluminescence of the GQDs can be tailored through varying the size of the GQDs by changing process parameters. Due to the luminescence stability, nanosecond lifetime, biocompatibility, low toxicity, and high water solubility, these GQDs are demonstrated to be excellent probes for high contrast bioimaging and biosensing applications.

  1. Controlled chemical stabilization of polyvinyl precursor fiber, and high strength carbon fiber produced therefrom

    Science.gov (United States)

    Naskar, Amit K.

    2016-12-27

    Method for the preparation of carbon fiber, which comprises: (i) immersing functionalized polyvinyl precursor fiber into a liquid solution having a boiling point of at least 60.degree. C.; (ii) heating the liquid solution to a first temperature of at least 25.degree. C. at which the functionalized precursor fiber engages in an elimination-addition equilibrium while a tension of at least 0.1 MPa is applied to the fiber; (iii) gradually raising the first temperature to a final temperature that is at least 20.degree. C. above the first temperature and up to the boiling point of the liquid solution for sufficient time to convert the functionalized precursor fiber to a pre-carbonized fiber; and (iv) subjecting the pre-carbonized fiber produced according to step (iii) to high temperature carbonization conditions to produce the final carbon fiber. Articles and devices containing the fibers, including woven and non-woven mats or paper forms of the fibers, are also described.

  2. Carbon nanotubes on carbon fibers: Synthesis, structures and properties

    Science.gov (United States)

    Zhang, Qiuhong

    The interface between carbon fibers (CFs) and the resin matrix in traditional high performance composites is characterized by a large discontinuity in mechanical, electrical, and thermal properties which can cause inefficient energy transfer. Due to the exceptional properties of carbon nanotubes (CNTs), their growth at the surface of carbon fibers is a promising approach to controlling interfacial interactions and achieving the enhanced bulk properties. However, the reactive conditions used to grow carbon nanotubes also have the potential to introduce defects that can degrade the mechanical properties of the carbon fiber (CF) substrate. In this study, using thermal chemical vapor deposition (CVD) method, high density multi-wall carbon nanotubes have been successfully synthesized directly on PAN-based CF surface without significantly compromising tensile properties. The influence of CVD growth conditions on the single CF tensile properties and carbon nanotube (CNT) morphology was investigated. The experimental results revealed that under high temperature growth conditions, the tensile strength of CF was greatly decreased at the beginning of CNT growth process with the largest decrease observed for sized CFs. However, the tensile strength of unsized CFs with CNT was approximately the same as the initial CF at lower growth temperature. The interfacial shear strength of CNT coated CF (CNT/CF) in epoxy was studied by means of the single-fiber fragmentation test. Results of the test indicate an improvement in interfacial shear strength with the addition of a CNT coating. This improvement can most likely be attributed to an increase in the interphase yield strength as well as an improvement in interfacial adhesion due to the presence of the nanotubes. CNT/CF also offers promise as stress and strain sensors in CF reinforced composite materials. This study investigates fundamental mechanical and electrical properties of CNT/CF using nanoindentation method by designed

  3. Highly photosensitive polymethyl methacrylate microstructured polymer optical fiber with doped core

    DEFF Research Database (Denmark)

    Sáez-Rodríguez, D.; Nielsen, Kristian; Rasmussen, Henrik K.

    2013-01-01

    In this Letter, we report the fabrication of a highly photosensitive, microstructured polymer optical fiber using benzyl dimethyl ketal as a dopant, as well as the inscription of a fiber Bragg grating in the fiber. A refractive index change in the core of at least 3.2×10−4 has been achieved...

  4. Novel method of polymer/low-melting-point metal alloy/light metal fiber composite fabrication

    Directory of Open Access Journals (Sweden)

    J. Park

    2016-07-01

    Full Text Available A novel method of polymer/low-melting-point metal alloy (LMA/light metal fiber composite fabrication is proposed to solve problems of polymer/metal composites. The first step is mixing light metal particles with LMA at a temperature above the melting point of the LMA. The second step is cold extrusion of the LMA/light metal particles to fabricate LMA/light metal fibers. Thus, the LMA/light metal fibers with a density of ~4.5 g/cm3 were obtained. The last step is compounding a polymer with the LMA/light metal fibers at the processing temperature of the polymer above the melting points of the LMA. The effects of the length and the cross-sectional shape of light metal fiber on the morphology of the LMA/light metal fibers in the polymer matrix were studied, as were electrical conductivities and mechanical properties of the composites. As the length and/or the cross-sectional aspect ratio of the fibers was increased, the domains of LMA/light metal fibers formed more networks so that the electrical conductivity increased, and specific surface area of the domains increased so that notched Izod impact strength was improved. Thus, the polymer/LMA/light metal fiber composites were fabricated without degrading processability even at 60 vol% loading and the electrical conductivities over 103 S/cm were achieved.

  5. Strengthening reinforced concrete beams using prestressed glass fiber-reinforced polymer-Part Ⅰ: Experimental study

    Institute of Scientific and Technical Information of China (English)

    HUANG Yue-lin; WU Jong-hwei; YEN Tsong; HUNG Chien-hsing; LIN Yiching

    2005-01-01

    This work is aimed at studying the strengthening of reinforced concrete (R. C.) beams using prestressed glass fiber-reinforced polymer (PGFRP). Carbon fiber-reinforced polymer (CFRP) has recently become popular for use as repair or rehabilitation material for deteriorated R. C. structures, but because CFRP material is very stiff, the difference in CFRP sheet and concrete material properties is not favorable for transferring the prestress from CFRP sheets to R. C. members. Glass fiber-reinforced polymer (GFRP) sheets with Modulus of Elasticity quite close to that of concrete was chosen in this study. The load-carrying capacities (ultimate loads) and the deflections of strengthened R. C. beams using GFRP and PGFRP sheets were tested and compared. T- and ⊥-shaped beams were used as the under-strengthened and over-strengthened beams. The GFRP sheets were prestressed to one-half their tensile capacities before being bonded to the T- and l-shaped R. C. beams. The prestressed tension in the PGFRP sheets caused cambers in the R. C. beams without cracks on the tensile faces. The PGFRP sheets also enhanced the load-carrying capacity. The test results indicated that T-shaped beams with GFRP sheets increased in load-carrying capacity by 55% while the same beams with PGFRP sheets could increase load-carrying capacity by 100%. The ⊥-shaped beams with GFRP sheets could increase load-carrying capacity by 97% while the same beams with PGFRP sheets could increase the loading-carrying capacity by 117%. Under the same external loads, beams with GFRP sheets underwent larger deflections than beams with PGFRP sheets. While GFRP sheets strengthen R. C. beams, PGFRP sheets decrease the beams' ductility, especially for the over-strengthened beams (⊥-shaped beams).

  6. CARBON-FIBRE-REINFORCED POLYMER PARTS EFFECT ON SPACECRAFT OPTOELECTRONIC MODULE LENS SCATTERING

    Directory of Open Access Journals (Sweden)

    S. S. Kolasha

    2016-01-01

    Full Text Available Spacecraft optoelectronic modules traditionally have aluminum alloy or titanium alloy casing which substantial weight increases fuel consumption required to put them into orbit and, consequently, total cost of the project. Carbon fiber reinforced polymer based composite constructive materials is an efficient solution that allows reducing weight and dimensions of large optoelectronic modules 1,5–3 times and the coefficient of linear thermal expansion 15–20 times if compared with metals. Optical characteristic is a crucial feature of carbon-fibre-reinforced polymer that determines composite material interaction with electromagnetic emission within the optical range. This work was intended to develop a method to evaluate Carbon fiber reinforced polymer optoelectronic modules casing effect on lens scattering by computer simulation with Zemax application software package. Degrees of scattered, reflected and absorbed radiant flux effect on imaging quality are described here. The work included experimental study in order to determine bidirectional reflectance distribution function by goniometric method for LUP-0.1 carbon fabric check test pieces of EDT-69U epoxy binder with EPOFLEX-0.4 glue layer and 5056-3.5-23-A aluminium honeycomb filler. The scattered emission was registered within a hemisphere above the check test piece surface. Optical detection direction was determined with zenith (0º < θ < 90º and azimuth (0º < φ < 180º angles with 10° increment. The check test piece surface was proved to scatter emission within a narrow angle range (approximately 20° with clear directivity. Carbon fiber reinforced polymers was found to feature integrated reflectance coefficient 3 to 4 times greater than special coatings do. 

  7. COPPER/CARBON CORE SHELL NANOPARTICLES AS ADDITIVE FOR NATURAL FIBER/WOOD PLASTIC BLENDS

    Directory of Open Access Journals (Sweden)

    Qinglin Wu,

    2012-06-01

    Full Text Available Copper/carbon core/shell nanoparticles (CCCSNs recently have been introduced as an industrial material. In this paper, composites based on high density polyethylene (HDPE, bamboo fiber, CCCSNs, and coupling agent (MAPE were prepared by melt compounding. The influence of CCCSN content on the resulting composites’ mechanical, biological resistance, and thermal properties was investigated. It was found that CCCSNs within the carbon black matrix were processed well with bamboo fiber-plastic blends through mixing and injection molding. The materials enhanced composite strength and modulus-related properties. Composites with CCCSNs and natural fibers reduced heat capacity and thermal diffusivity. Composites with CCCSN materials also enhanced termite and mold performance. Thus, the material can be used as additive for plastics and other polymers to modify strength properties, biological resistance (e.g., mold and stain, and thermal conductivity properties.

  8. The formation of web-like connection among electrospun chitosan/PVA fiber network by the reinforcement of ellipsoidal calcium carbonate.

    Science.gov (United States)

    Sambudi, Nonni Soraya; Kim, Minjeong G; Park, Seung Bin

    2016-03-01

    The electrospun fibers consist of backbone fibers and nano-branch network are synthesized by loading of ellipsoidal calcium carbonate in the mixture of chitosan/poly(vinyl alcohol) (PVA) followed by electrospinning. The synthesized ellipsoidal calcium carbonate is in submicron size (730.7±152.4 nm for long axis and 212.6±51.3 nm for short axis). The electrospun backbone fibers experience an increasing in diameter by loading of calcium carbonate from 71.5±23.4 nm to 281.9±51.2 nm. The diameters of branch fibers in the web-network range from 15 nm to 65 nm with most distributions of fibers are in 30-35 nm. Calcium carbonate acts as reinforcing agent to improve the mechanical properties of fibers. The optimum value of Young's modulus is found at the incorporation of 3 wt.% of calcium carbonate in chitosan/PVA fibers, which is enhanced from 15.7±3 MPa to 432.4±94.3 MPa. On the other hand, the ultimate stress of fibers experiences a decrease. This result shows that the fiber network undergoes changes from flexible to more stiff by the inclusion of calcium carbonate. The thermal analysis results show that the crystallinity of polymer is changed by the existence of calcium carbonate in the fiber network. The immersion of fibers in simulated body fluid (SBF) results in the formation of apatite on the surface of fibers.

  9. Studies on Carbon-Fly Ash Composites with Chopped PANOX Fibers

    Directory of Open Access Journals (Sweden)

    Rakesh V. Patel

    2013-01-01

    Full Text Available Chemical analysis and morphological studies of fly ash reveals the complex chemical constituents present as spherical particles with diameter of less than 25 μm. The constituents of fly ash are silica, alumina, iron oxide, titanium dioxide, calcium and magnesium oxide, and other trace elements. The use of thermosetting as well thermoplastic polymer matrix has been made by several workers to develop polymer matrix fly ash particulate composites by using the hard and abrasive properties of fly ash and lightweight of polymers. Such composites have poor mechanical strength, fracture toughness, and thermal stability. To overcome these shortcomings, in carbonaceous matrix, the carbon fibers were added as additional reinforcement along with the fly ash. The composites were developed with two different methods known as Dry method and Wet method. The processing parameters such as temperature and pressure were optimized in establishing the carbon matrix. Physical, thermal, and mechanical characteristics were studied. The microstructures of composites show good compatibility between fly ash and fibers with the carbon matrix. These composites have higher strength, thermal stability, and toughness as compared to polymer matrix fly ash particulate composites.

  10. Activated Carbon Fibers For Gas Storage

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, Timothy D [ORNL; Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL

    2017-01-01

    The advantages of Activated Carbon Fibers (ACF) over Granular Activated Carbon (GAC) are reviewed and their relationship to ACF structure and texture are discussed. These advantages make ACF very attractive for gas storage applications. Both adsorbed natural gas (ANG) and hydrogen gas adsorption performance are discussed. The predicted and actual structure and performance of lignin-derived ACF is reviewed. The manufacture and performance of ACF derived monolith for potential automotive natural gas (NG) storage applications is reported Future trends for ACF for gas storage are considered to be positive. The recent improvements in NG extraction coupled with the widespread availability of NG wells means a relatively inexpensive and abundant NG supply in the foreseeable future. This has rekindled interest in NG powered vehicles. The advantages and benefit of ANG compared to compressed NG offer the promise of accelerated use of ANG as a commuter vehicle fuel. It is to be hoped the current cost hurdle of ACF can be overcome opening ANG applications that take advantage of the favorable properties of ACF versus GAC. Lastly, suggestions are made regarding the direction of future work.

  11. A single carbon fiber microelectrode with branching carbon nanotubes for bioelectrochemical processes.

    Science.gov (United States)

    Zhao, Xueyan; Lu, Xin; Tze, William T Y; Wang, Ping

    2010-06-15

    Carbon fiber electrodes are greatly promising for microelectronic applications including high performance biosensors, miniaturized transmitters, and energy storage and generation devices. For biosensor applications, one drawback of using carbon fiber microelectrodes, especially single fiber electrodes, is the weak electronic signals, a consequence of low surface area of fibers, which ultimately limit the sensitivity of the sensors. In this paper, we report a novel single fiber microelectrode with branched carbon nanotubes for enhanced sensing performance. The fiber microelectrode was prepared from carbonization of cellulose fibers. Upon introduction of carbon nanotubes, the carbon fibers exhibited a significant increase in the specific surface area from carbon nanotubes enhanced the redox reactions on surfaces of the electrode by reducing the oxidation potential of NAD(H) from 0.8 to 0.55 V. The single carbon fiber with branched nanotubes was also examined for the detection of glycerol, and the results showed linear responding signals in a concentration range of 40-250 microM. These results are comparable to the properties of fossil-based carbon materials, and thus our cellulose-based carbon electrodes provide a potentially sustainable alternative in bioelectrochemical applications.

  12. Carbon Nanofibers (CNFs) Surface Modification to Fabricate Carbon Nanofibers_Nanopaper Integrated Polymer Composite Material.

    Science.gov (United States)

    Jiang, Jianjun; Zhao, Ziwei; Deng, Chao; Liu, Fa; Li, Dejia; Fang, Liangchao; Zhang, Dan; Castro Jose M; Chen, Feng; Lee, L James

    2016-06-01

    Carbon Nanofibers (CNFs) have shown great potential to improve the physical and mechanical properties of conventional Fiber Reinforced Polymer Composites (FRPCs) surface. Excellent dispersion CNFs into water or polymer matrix was very crucial to get good quality CNFs enhanced FRPCs. Because of the hydrophobic properties of CNFs, we apply the reversible switching principles to transfer the hydrophobic surface into hydrophilic surface by growing polyaniline nanograss on the surface of CNFs which was carried out in hydrochloric acid condition. Incorporating CNFs into FRPCs as a surface layer named CNFs Nanopaper to increase the erosion resistance and electrical conductivity in this research which was very important in the wind energy field. In order to get high quality dispersed CNFs suspension, a sonication unit was used to detangle and uniform disperse the functionalized CNFs. A filter with vacuum pressure used to filter the suspension of CNFs onto Carbon veil to make CNFs Nanopaper. Vacuum Aided Resin Transfer Modeling (VARTM) process was used to fabricate Nano-enhanced FRPCs samples. In order to characterize the mechanical properties, three point bending experiment was measured. The flexural strength capacity and deformation resistance and behavior were compared and analyzed. In this paper, we discussed the methods used and provided experimental parameter and experimental results.

  13. Performance of Sprayed Fiber Reinforced Polymer Strengthened Timber Beams

    Directory of Open Access Journals (Sweden)

    S. Talukdar

    2010-01-01

    Full Text Available A study was carried out to investigate the use of Sprayed Fiber Reinforced Polymer (SFRP for retrofit of timber beams. A total of 10-full scale specimens were tested. Two different timber preservatives and two different bonding agents were investigated. Strengthening was characterized using load deflection diagrams. Results indicate that it is possible to enhance load-carrying capacity and energy absorption characteristics using the technique of SFRP. Of the two types of preservatives investigated, the technique appears to be more effective for the case of creosote-treated specimens, where up to a 51% improvement in load-carrying capacity and a 460% increase in the energy absorption capacity were noted. Effectiveness of the bonding agent used was dependent on the type of preservative the specimen had been treated with.

  14. Tapered Polymer Fiber Sensors for Reinforced Concrete Beam Vibration Detection

    Directory of Open Access Journals (Sweden)

    Dong Luo

    2016-12-01

    Full Text Available In this study, tapered polymer fiber sensors (TPFSs have been employed to detect the vibration of a reinforced concrete beam (RC beam. The sensing principle was based on transmission modes theory. The natural frequency of an RC beam was theoretically analyzed. Experiments were carried out with sensors mounted on the surface or embedded in the RC beam. Vibration detection results agreed well with Kistler accelerometers. The experimental results found that both the accelerometer and TPFS detected the natural frequency function of a vibrated RC beam well. The mode shapes of the RC beam were also found by using the TPFSs. The proposed vibration detection method provides a cost-comparable solution for a structural health monitoring (SHM system in civil engineering.

  15. Multigigabit short-reach communication over microstructured polymer optical fiber

    Science.gov (United States)

    Surkova, Galina; Kruglov, Roman; Lwin, Richard; Leon-Saval, Sergio G.; Argyros, Alexander; Poisel, Hans; Zadorin, Anatoly

    2017-03-01

    In contrast to conventional polymer optical fibers (POF) microstructured POF (mPOF) provide an additional opportunity to control the optical properties of the propagating signals. A particular arrangement of the air holes allows to reduce the number of waveguide modes and thus overcome the bandwidth limitation which is inherent for step-index POF. In this paper we report on the implementation of a 50 m data transmission link based on mPOF with a single ring of holes and a core diameter of 180 μm. A bit rate of 7 Gb/s was achieved at a bit-error ratio (BER) of 10-3 employing on-off keying modulation technique and an offline-processed symbol-spaced decision feedback equalizer. Discrete multitone modulation provided a bit rate of 8.07 Gb/s at BER of 10-3.

  16. Durability Studies on Confined Concrete using Fiber Reinforced Polymer

    Science.gov (United States)

    Ponmalar, V.; Gettu, R.

    2014-06-01

    In this study, 24 concrete cylinders with a notch at the centre were prepared. Among them six cylinders were wrapped using single and double layers of fiber reinforced polymer; six cylinders were coated with epoxy resin; the remaining cylinders were used as a control. The cylinders were exposed to wet and dry cycling and acid (3 % H2SO4) solution for the period of 120 days. Two different concrete strengths M30 and M50 were considered for the study. It is found that the strength, ductility and failure mode of wrapped cylinders depend on number of layers and the nature of exposure conditions. It was noticed that the damage due to wet and dry cycling and acid attack was severe in control specimen than the epoxy coated and wrapped cylinders.

  17. Tapered Polymer Fiber Sensors for Reinforced Concrete Beam Vibration Detection.

    Science.gov (United States)

    Luo, Dong; Ibrahim, Zainah; Ma, Jianxun; Ismail, Zubaidah; Iseley, David Thomas

    2016-12-16

    In this study, tapered polymer fiber sensors (TPFSs) have been employed to detect the vibration of a reinforced concrete beam (RC beam). The sensing principle was based on transmission modes theory. The natural frequency of an RC beam was theoretically analyzed. Experiments were carried out with sensors mounted on the surface or embedded in the RC beam. Vibration detection results agreed well with Kistler accelerometers. The experimental results found that both the accelerometer and TPFS detected the natural frequency function of a vibrated RC beam well. The mode shapes of the RC beam were also found by using the TPFSs. The proposed vibration detection method provides a cost-comparable solution for a structural health monitoring (SHM) system in civil engineering.

  18. A comprehensive analysis of scattering in polymer optical fibers.

    Science.gov (United States)

    Aldabaldetreku, Gotzon; Bikandi, Iñaki; Illarramendi, María Asunción; Durana, Gaizka; Zubia, Joseba

    2010-11-22

    The aim of this paper is to investigate the properties of the inhomogeneities that give rise to light scattering in polymer optical fibers (POFs). We perform several measurements in two commercial POFs of identical characteristics: these measurements, based on the side-illumination technique, consist in the detection of the total amount of scattered light guided along a POF sample under different launching conditions and in the acquisition of the corresponding near- and far-field patterns. We carry out complementary computer simulations considering inhomogeneities of different sizes at different positions inside the POF. The comparison of these simulated results with the experimental measurements will provide us with valuable information about the size and placement of the most influential inhomogeneities.

  19. [Carbon fiber-reinforced plastics as implant materials].

    Science.gov (United States)

    Bader, R; Steinhauser, E; Rechl, H; Siebels, W; Mittelmeier, W; Gradinger, R

    2003-01-01

    Carbon fiber-reinforced plastics have been used clinically as an implant material for different applications for over 20 years.A review of technical basics of the composite materials (carbon fibers and matrix systems), fields of application,advantages (e.g., postoperative visualization without distortion in computed and magnetic resonance tomography), and disadvantages with use as an implant material is given. The question of the biocompatibility of carbon fiber-reinforced plastics is discussed on the basis of experimental and clinical studies. Selected implant systems made of carbon composite materials for treatments in orthopedic surgery such as joint replacement, tumor surgery, and spinal operations are presented and assessed. Present applications for carbon fiber reinforced plastics are seen in the field of spinal surgery, both as cages for interbody fusion and vertebral body replacement.

  20. Discussion of Balanced Relative Compression Height ξb (ρb)in Strengthened Beam with Carbon Fiber - Reinforced Polymer Sheets%碳纤维加固钢筋混凝土梁的界限相对受压区高度研究

    Institute of Scientific and Technical Information of China (English)

    江世永; 飞渭; 李迎涛; 彭飞飞; 杜文龙; 王跃文

    2002-01-01

    根据材料的本构关系及平截面假定,结合预应力加固的概念推导出了碳纤维加固钢筋混凝土梁时的三种不同的界限受压区高度,并给出了界限状态下钢筋、混凝土、碳纤维片材的相应应力.%Based on the stress - strain relationship and principle of co - deformation,this paper analyses the balanced relative compression height ξb (ρb) of strengthened beam with Carbon Fiber - Reinforced Polymer(CFRP) sheets, and presents the concept of balanced section. Based on this concept, the method of deciding balanced relative compression height is proposed.

  1. Increasing the Tensile Property of Unidirectional Carbon/Carbon Composites by Grafting Carbon Nanotubes onto Carbon Fibers by Electrophoretic Deposition

    Institute of Scientific and Technical Information of China (English)

    Qiang Song; Kezhi Li; Hejun Li; Qiangang Fu

    2013-01-01

    Although in-situ growing carbon nanotubes (CNTs) on carbon fibers could greatly increase the matrix-dominated mechanical properties of carbon/carbon composites (C/Cs),it always decreased the tensile strength of carbon fibers.In this work,CNTs were introduced into unidirectional carbon fiber (CF) preforms by electrophoretic deposition (EPD) and they were used to reinforce C/Cs.Effects of the content of CNTs introduced by EPD on tensile property of unidirectional C/Cs were investigated.Results demonstrated that EPD could be used as a simple and efficient method to fabricate carbon nanotube reinforced C/Cs (CNT-C/Cs) with excellent tensile strength,which pays a meaningful way to maximize the global performance of CNT-C/Cs.

  2. Effect of the mechanical deformation on the electrical properties of the polymer/CNT fiber

    Science.gov (United States)

    Cho, Hyun Woo; Sung, Bong June; Nano-Bio Computational Chemistry Laboratory Team

    2014-03-01

    We elucidate the effect of the mechanical deformation on the electrical properties of the polymer/CNT fiber. The conductive polymer fiber has drawn a great attention for its potential application to a stretchable electronics such as wearable devices and artificial muscles, etc. However, the electrical conductivity of the polymer-based stretchable electronics decreases significantly during the deformation, which may limit the applicability of the polymer/CNT fiber for the stretchable electronics. Moreover, its physical origin for the decrease in electrical conductivity has not been explained clearly. In this work, we employ a coarse-grained model for the polymer/CNT fiber, and we calculate the electric conductivity using global tunneling network (GTN) model. We show that the electric conductivity decreases during the elongation of the polymer/CNT fiber. We also find using critical path approximation (CPA) that the structure of the electrical network of the CNTs changes collectively during the elongation of the fiber, which is strongly responsible for the reduction of the electrical conductivity of the polymer/CNT fiber.

  3. High-resolution NMR spectra of n-alkanes penetrating into carbon fibers and of protons in carbon fibers.

    Science.gov (United States)

    Yamazaki, Yuya; Kobayashi, Nobuaki; Nikki, Kunio; Kuwahara, Daisuke

    2008-08-01

    We present a simple NMR method for microscopically exploring the local environment in carbon fibers. The method utilizes n-alkanes as probe molecules, where the n-alkanes penetrate carbon fibers of interest. The high-resolution (1)H NMR spectra for a mixture of a carbon fiber and n-alkanes acquired by this method show a shift of the resonance line, which is due to the local structure of the fiber. The utility of this method is discussed on the basis of the (1)H NMR spectra obtained. In addition, the (1)H distribution and the local motion in the structure of the carbon fiber are revealed in view of the (1)H NMR spectra.

  4. Electrical Conductivity of the Carbon Fiber Conductive Concrete

    Institute of Scientific and Technical Information of China (English)

    HOU Zuofu; LI Zhuoqiu; WANG Jianjun

    2007-01-01

    This paper discussed two methods to enhance the electrical conductivity of the carbon fiber(CF) electrically conductive concrete. The increase in the content of stone and the amount of water used to dissolve the methylcellulose and marinate the carbon fibers can decrease the electrical resistivity of the electrically conductive concrete effectively. Based on these two methods, the minimum CF content of the CF electrically conductive concrete for deicing or snow-melting application and the optimal ratio of the amount of water to dissolve the methylcellulose and marinate the carbon fibers were obtained.

  5. Characteristics of Resistivity-temperature for Carbon Fiber Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The resistance response to temperature change of carbon fiber reinforced cement-based composites (CFRC) is reported, which shows some outstanding phenomena of positive temperature coefficient (PTC) of resistance and negative temperature coefficient (NTC) of resistance during the temperature rising.The influences of carbon fiber, cement-based matrix and thermal cycles on the characteristics of temperature-resistivity for the system were also discussed.Because of the special characteristics for temperature resistivity, carbon fiber cement based composites can be useful in structure with the function of alarm for fire.

  6. Self-healing nanocomposite using shape memory polymer and carbon nanotubes

    Science.gov (United States)

    Liu, Yingtao; Rajadas, Abhishek; Chattopadhyay, Aditi

    2013-04-01

    Carbon fiber reinforced composites are used in a wide range of applications in aerospace, mechanical, and civil structures. Due to the nature of material, most damage in composites, such as delaminations, are always barely visible to the naked eye, which makes it difficult to detect and repair. The investigation of biological systems has inspired the development and characterization of self-healing composites. This paper presents the development of a new type of self-healing material in order to impede damage progression and conduct in-situ damage repair in composite structures. Carbon nanotubes, which are highly conductive materials, are mixed with shape memory polymer to develop self-healing capability. The developed polymeric material is applied to carbon fiber reinforced composites to automatically heal the delamination between different layers. The carbon fiber reinforced composite laminates are manufactured using high pressure molding techniques. Tensile loading is applied to double cantilever beam specimens using an MTS hydraulic test frame. A direct current power source is used to generate heat within the damaged area. The application of thermal energy leads to re-crosslinking in shape memory polymers. Experimental results showed that the developed composite materials are capable of healing the matrix cracks and delaminations in the bonded areas of the test specimens. The developed self-healing material has the potential to be used as a novel structural material in mechanical, civil, aerospace applications.

  7. Carbon Fiber and Tungsten Disulfide Nanoscale Architectures for Armor Applications

    Science.gov (United States)

    2012-06-01

    carbon nanotubes are usually only microns in length, it is possible to spin the fibers into a yarn that maintains much of the theoretical strength of the...4 a. Carbon Nanotubes and Nanofibers ..........................................4 b. Tungsten Disulfide...7 II. CARBON NANOFIBER AND WS2 NANOPARTICLE SYNTHESIS AND CHARACTERIZATION METHODS

  8. Oxidation of Carbon Fibers in Water Vapor Studied

    Science.gov (United States)

    Opila, Elizabeth J.

    2003-01-01

    T-300 carbon fibers (BP Amoco Chemicals, Greenville, SC) are a common reinforcement for silicon carbide composite materials, and carbon-fiber-reinforced silicon carbide composites (C/SiC) are proposed for use in space propulsion applications. It has been shown that the time to failure for C/SiC in stressed oxidation tests is directly correlated with the fiber oxidation rate (ref. 1). To date, most of the testing of these fibers and composites has been conducted in oxygen or air environments; however, many components for space propulsion, such as turbopumps, combustors, and thrusters, are expected to operate in hydrogen and water vapor (H2/H2O) environments with very low oxygen contents. The oxidation rate of carbon fibers in conditions representative of space propulsion environments is, therefore, critical for predicting component lifetimes for real applications. This report describes experimental results that demonstrate that, under some conditions, lower oxidation rates of carbon fibers are observed in water vapor and H2/H2O environments than are found in oxygen or air. At the NASA Glenn Research Center, the weight loss of the fibers was studied as a function of water pressure, temperature, and gas velocity. The rate of carbon fiber oxidation was determined, and the reaction mechanism was identified.

  9. Interactions between the glass fiber coating and oxidized carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ku-Herrera, J.J., E-mail: jesuskuh@live.com.mx [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburná de Hidalgo. C.P., 97200 Mérida, Yucatán (Mexico); Avilés, F., E-mail: faviles@cicy.mx [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburná de Hidalgo. C.P., 97200 Mérida, Yucatán (Mexico); Nistal, A. [Instituto de Cerámica y Vidrio (ICV-CSIC), Kelsen 5, 28049 Madrid (Spain); Cauich-Rodríguez, J.V. [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburná de Hidalgo. C.P., 97200 Mérida, Yucatán (Mexico); Rubio, F.; Rubio, J. [Instituto de Cerámica y Vidrio (ICV-CSIC), Kelsen 5, 28049 Madrid (Spain); Bartolo-Pérez, P. [Departamento de Física Aplicada, Cinvestav, Unidad Mérida, C.P., 97310 Mérida, Yucatán (Mexico)

    2015-03-01

    Graphical abstract: - Highlights: • Oxidized multiwall carbon nanotubes (MWCNTs) were deposited onto E-glass fibers. • The role of the fiber coating on the deposition of MWCNTs on the fibers is studied. • A rather homogeneous deposition of MWCNTs is achieved if the coating is maintained. • Multiple oxygen-containing groups were found in the analysis of the fiber coating. • Evidence of chemical interaction between MWCNTs and the fiber coating was found. - Abstract: Chemically oxidized multiwall carbon nanotubes (MWCNTs) were deposited onto commercial E-glass fibers using a dipping procedure assisted by ultrasonic dispersion. In order to investigate the role of the fiber coating (known as “sizing”), MWCNTs were deposited on the surface of as-received E-glass fibers preserving the proprietary coating as well as onto glass fibers which had the coating deliberately removed. Scanning electron microscopy and Raman spectroscopy were used to assess the distribution of MWCNTs onto the fibers. A rather homogeneous coverage with high density of MWCNTs onto the glass fibers is achieved when the fiber coating is maintained. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance (NMR) analyses of the chemical composition of the glass fiber coating suggest that such coating is a complex mixture with multiple oxygen-containing functional groups such as hydroxyl, carbonyl and epoxy. FTIR and XPS of MWCNTs over the glass fibers and of a mixture of MWCNTs and fiber coating provided evidence that the hydroxyl and carboxyl groups of the oxidized MWCNTs react with the oxygen-containing functional groups of the glass fiber coating, forming hydrogen bonding and through epoxy ring opening. Hydrogen bonding and ester formation between the functional groups of the MWCNTs and the silane contained in the coating are also possible.

  10. The Tensile Behavior of High-Strength Carbon Fibers.

    Science.gov (United States)

    Langston, Tye

    2016-08-01

    Carbon fibers exhibit exceptional properties such as high stiffness and specific strength, making them excellent reinforcements for composite materials. However, it is difficult to directly measure their tensile properties and estimates are often obtained by tensioning fiber bundles or composites. While these macro scale tests are informative for composite design, their results differ from that of direct testing of individual fibers. Furthermore, carbon filament strength also depends on other variables, including the test length, actual fiber diameter, and material flaw distribution. Single fiber tensile testing was performed on high-strength carbon fibers to determine the load and strain at failure. Scanning electron microscopy was also conducted to evaluate the fiber surface morphology and precisely measure each fiber's diameter. Fiber strength was found to depend on the test gage length and in an effort to better understand the overall expected performance of these fibers at various lengths, statistical weak link scaling was performed. In addition, the true Young's modulus was also determined by taking the system compliance into account. It was found that all properties (tensile strength, strain to failure, and Young's modulus) matched very well with the manufacturers' reported values at 20 mm gage lengths, but deviated significantly at other lengths.

  11. Carbon nanotubes filled polymer composites: A comprehensive study on improving dispersion, network formation and electrical conductivity

    Science.gov (United States)

    Chakravarthi, Divya Kannan

    In this dissertation, we determine how the dispersion, network formation and alignment of carbon nanotubes in polymer nanocomposites affect the electrical properties of two different polymer composite systems: high temperature bismaleimide (BMI) and polyethylene. The knowledge gained from this study will facilitate optimization of the above mentioned parameters, which would further enhance the electrical properties of polymer nanocomposites. BMI carbon fiber composites filled with nickel-coated single walled carbon nanotubes (Ni-SWNTs) were processed using high temperature vacuum assisted resin transfer molding (VARTM) to study the effect of lightning strike mitigation. Coating the SWNTs with nickel resulted in enhanced dispersions confirmed by atomic force microscopy (AFM) and dynamic light scattering (DLS). An improved interface between the carbon fiber and Ni-SWNTs resulted in better surface coverage on the carbon plies. These hybrid composites were tested for Zone 2A lightning strike mitigation. The electrical resistivity of the composite system was reduced by ten orders of magnitude with the addition of 4 weight percent Ni-SWNTs (calculated with respect to the weight of a single carbon ply). The Ni-SWNTs - filled composites showed a reduced amount of damage to simulated lightning strike compared to their unfilled counterparts indicated by the minimal carbon fiber pull out. Methods to reduce the electrical resistivity of 10 weight percent SWNTs --- medium density polyethylene (MDPE) composites were studied. The composites processed by hot coagulation method were subjected to low DC electric fields (10 V) at polymer melt temperatures to study the effect of viscosity, nanotube welding, dispersion and, resultant changes in electrical resistivity. The electrical resistivity of the composites was reduced by two orders of magnitude compared to 10 wt% CNT-MDPE baseline. For effective alignment of SWNTs, a new process called Electric field Vacuum Spray was devised to

  12. A Polymer Optical Fiber Fuel Level Sensor: Application to Paramotoring and Powered Paragliding

    OpenAIRE

    David Sánchez Montero; Carmen Vázquez; Pedro Contreras Lallana

    2012-01-01

    A low-cost intensity-based polymer optical fiber (POF) sensor for fuel level measurements in paramotoring and powered paragliding is presented, exploiting the advantages of the optical fiber sensing technology. Experimental results demonstrate that the best option can be performed by stripping the fiber at the desired discrete points to measure the fuel level as well as with a gauge-shape fiber bending. The prototype has a good linearity, better than 4% full scale (F.S.), and sensitivity arou...

  13. Active fiber polymer cladding temperature measurement under conditions of laser generation and amplification

    Science.gov (United States)

    Sypin, V. E.; Prusakov, K. Y.; Ryabushkin, O. A.

    2016-04-01

    Polymer cladding temperature of active fiber in lasing regime is important parameter as it allows determination of fiber core temperature that in turn effects laser generation and amplification efficiency. Besides polymer cladding has much lower temperature damage threshold comparing to fused silica. For example, 200 degrees Kelvin overheating of the polymer cladding can result in fiber degradation. In present paper we introduce novel and simple method for precise temperature measurement of active fibers cladding under conditions of laser generation and amplification. Dependence of longitudinal temperature distribution along active fibers on optical pump power can be determined. This method employs measurement of temperature dependent electrical resistance of the metal wire being in thermal contact with fiber polymer cladding. The wire is reeled on the active fiber segment. Under lasing or amplification conditions the polymer cladding of the active fiber is heated together with coiled metal wire resulting in its electrical resistance change. By measuring resistance variation one can determine the temperature of the given fiber section.

  14. Matrimid® derived carbon molecular sieve hollow fiber membranes for ethylene/ethane separation

    KAUST Repository

    Xu, Liren

    2011-09-01

    Carbon molecular sieve (CMS) membranes have shown promising separation performance compared to conventional polymeric membranes. Translating the very attractive separation properties from dense films to hollow fibers is important for applying CMS materials in realistic gas separations. The very challenging ethylene/ethane separation is the primary target of this work. Matrimid® derived CMS hollow fiber membranes have been investigated in this work. Resultant CMS fiber showed interesting separation performance for several gas pairs, especially high selectivity for C2H4/C2H6. Our comparative study between dense film and hollow fiber revealed very similar selectivity for both configurations; however, a significant difference exists in the effective separation layer thickness between precursor fibers and their resultant CMS fibers. SEM results showed that the deviation was essentially due to the collapse of the porous substructure of the precursor fiber. Polymer chain flexibility (relatively low glass transition temperature (Tg) for Matrimid® relative to actual CMS formation) appears to be the fundamental cause of substructure collapse. This collapse phenomenon must be addressed in all cases involving intense heat-treatment near or above Tg. We also found that the defect-free property of the precursor fiber was not a simple predictor of CMS fiber performance. Even some precursor fibers with Knudsen diffusion selectivity could be transformed into highly selective CMS fibers for the Matrimid® precursor. To overcome the permeance loss problem caused by substructure collapse, several engineering approaches were considered. Mixed gas permeation results under realistic conditions demonstrate the excellent performance of CMS hollow fiber membrane for the challenging ethylene/ethane separation. © 2011 Elsevier B.V.

  15. Effect of fabric structure and polymer matrix on flexural strength, interlaminar shear stress, and energy dissipation of glass fiber-reinforced polymer composites

    Science.gov (United States)

    We report the effect of glass fiber structure and the epoxy polymer system on the flexural strength, interlaminar shear stress (ILSS), and energy absorption properties of glass fiber-reinforced polymer (GFRP) composites. Four different GFRP composites were fabricated from two glass fiber textiles of...

  16. Interferometric microstructured polymer optical fiber ultrasound sensor for optoacoustic endoscopic imaging in biomedical applications

    DEFF Research Database (Denmark)

    Gallego, Daniel; Sáez-Rodríguez, David; Webb, David

    2014-01-01

    to conventional piezoelectric transducers. These kind of sensors, made of biocompatible polymers, are good candidates for the sensing element in an optoacoustic endoscope because of its high sensitivity, its shape and its non-brittle and non-electric nature. The acoustic sensitivity of the intrinsic fiber optic......We report a characterization of the acoustic sensitivity of microstructured polymer optical fiber interferometric sensors at ultrasonic frequencies from 100kHz to 10MHz. The use of wide-band ultrasonic fiber optic sensors in biomedical ultrasonic and optoacoustic applications is an open alternative...... interferometric sensors depends strongly of the material which is composed of. In this work we compare experimentally the intrinsic ultrasonic sensitivities of a PMMA mPOF with other three optical fibers: a singlemode silica optical fiber, a single-mode polymer optical fiber and a multimode graded...

  17. Direct Imaging of Deformation and Disorder in Extended-Chain Polymer Fibers

    Science.gov (United States)

    1991-03-01

    Lenhert, T. J. Resch, and W. W. Adams, "Molecular Packing and Crystalline Order in Polybenzobisoxazole and Polybenzobisthiazole Fibers ", in...WL-TR-91-4011 AiAh 1A0 DIRECT IMAGING OF DEFORMATION AND DISORDER IN EXTENDED-CHAIN POLYMER FIBERS David C. Martin Department of Polymer Science and...Deformation and Disorder in Extended-Chain Polymer Fibers 12. PERSONAL AUTHOR(S) David C. Martin 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year

  18. STUDY OF DEPENDENCE OF POLYETHYLENE AND CARBON FIBERS COMPOSITES PROPERNIES ON SURFACE CHARACTERISTICS OF FIBER AND TYPE OF SAMPLES

    Directory of Open Access Journals (Sweden)

    Petukhova E. S.

    2015-06-01

    Full Text Available PE2NT11 and chopped carbon fibers and PE2NT11 and modified carbon fibers composites were investigated. It was shown that the mechanical properties depend on the surface characteristics of fibers. It was found that laboratory and tube samples have some difference in mechanical properties that connected with specific distribution of fibers in samples

  19. STUDY OF DEPENDENCE OF POLYETHYLENE AND CARBON FIBERS COMPOSITES PROPERNIES ON SURFACE CHARACTERISTICS OF FIBER AND TYPE OF SAMPLES

    OpenAIRE

    Petukhova E. S.

    2015-01-01

    PE2NT11 and chopped carbon fibers and PE2NT11 and modified carbon fibers composites were investigated. It was shown that the mechanical properties depend on the surface characteristics of fibers. It was found that laboratory and tube samples have some difference in mechanical properties that connected with specific distribution of fibers in samples

  20. Polymer-functionalized single-walled carbon nanotubes as a novel sol-gel solid-phase micro-extraction coated fiber for determination of poly-brominated diphenyl ethers in water samples with gas chromatography-electron capture detection.

    Science.gov (United States)

    Zhang, Weiya; Sun, Yin; Wu, Caiying; Xing, Jun; Li, Jianying

    2009-04-15

    Single-walled carbon nanotubes (SWNTs) were functionalized with a hydroxyl-terminated silicone oil (TSO-OH). It is synthesized by the reactions of carbonyl chloride groups on the surface of SWNTs and hydroxyl groups of silicone oil (TSO-OH). The functionalized product SWNTs-TSO-OH was first used as precursor and selective stationary phase to prepare the sol-gel derived poly(SWNTs-TSO-OH) solid-phase microextraction (SPME) fiber for determination of polybrominated diphenyl ethers (PBDEs) in water samples. The possible major reaction of the sol-gel coating process was discussed and confirmed by IR spectra, Raman spectroscopy, and scanning electron microscopy. Some parameters of SPME fiber for the determination of PBDEs were investigated by headspace SPME/gas chromatography with electron-capture detection (HS-SPME/GC-ECD). Compared with the commercial SPME fiber, the new coated fiber showed higher extraction efficiency to PBDEs, better thermal stability (over 340 degrees C), and longer life span (over 200 times). All of these advantages are mainly due to the incorporation of SWNTs, which enhanced the pi-pi interaction with PBDEs and increased the surface area of extraction in contact with the sample. Moreover, the sol-gel coating technology additionally provided the porous structure of the 3-D silica network and the strong chemical binding provided which also will improve the extraction efficiency. Under optimized conditions, the method detection limits for seven PBDEs were 0.08-0.8 ng/L (S/N = 3) and the precision (RSD, n = 5) was 2.2-7.5% at the 50 ng/L level. The linearity of the developed method is in the range of 5-500 ng/L with coefficients of correlation greater than 0.995. The developed method was successfully applied for the analysis of trace PBDEs in reservoir water and wastewater samples. The recoveries obtained at spiking 50 ng/L were between 74% and 109% (n = 5) for PBDEs in water samples.

  1. Autonomic healing of carbon fiber/epoxy interfaces.

    Science.gov (United States)

    Jones, Amanda R; Cintora, Alicia; White, Scott R; Sottos, Nancy R

    2014-05-14

    A maximum of 91% recovery of interfacial shear strength (IFSS) is achieved for carbon fiber/epoxy interfaces functionalized with capsules containing reactive epoxy resin and ethyl phenyl acetate (EPA). We find a binder is necessary to improve the retention of capsules on the carbon fiber surface. Two different methods for applying the binder to the carbon fiber surface are investigated. Healing efficiency is assessed by recovery of IFSS of a single functionalized fiber embedded in a microdroplet of epoxy. Debonding of the fiber/matrix interface ruptures the capsules, releasing resin and EPA solvent into the crack plane. The solvent swells the matrix, initiating transport of residual amine functionality from the matrix for further curing with the epoxy resin delivered to the crack plane. The two binder protocols produce comparable results, both yielding higher recovery of IFSS than samples prepared without a binder.

  2. Enhancement of Adhesive Strength of Ultrahigh Molecular Weight Polyethylene Fibers Prepared by Polar Polymer Implantation

    Institute of Scientific and Technical Information of China (English)

    YU Jun-rong; YANG Xin-ge; HU Zu-ming; LIU Zhao-feng

    2007-01-01

    A new technique was proposed to enhance the adhesive strength of ultrahigh molecular weight polyethylene (UHMWPE) fibers. Polar polymer was implanted into UHMWPE gel fibers during extracting process and can then be trapped en the surface of the fibers after subsequent ultra-drawing. The physical and chemical changes in the fiber structure were examined with scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The mechanical and interfacial adhesion properties of UHMWPE fibers were investigated with tensile testing. The results showed that there wee polar groups on the surface of pretreated UHMWPE fiber. The interracial shear strength of UHMWPE fibers with epoxy resin was greatly improved without socrificing the excellent mechanical properties of fibers. After pretreated with ethylene/vinyl acetate copolymer (EVA), the shear strength of the interface between fiber and epoxy resin increased from 1.06 to 2.49 MPa, while the integrated mechanical properties of the pretreated UHMWPE fibers ware still optimal.

  3. Influence of Carbon Fiber Contents on the Temperature Sensibility of CFRC Road Material

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The relationship between the electrical resistivity of carbon fiber reinforced concrete(CFRC) containing different carbon fiber contents and temperature was studied.it is found that carbon fiber contents influence greatly on the temperature sensibility of CFRC road material.Only with a certain amount of carbon fiber can CFRC show a sensitive and stable temperature sensibility.

  4. Thermo-oxidative stability studies of PMR-15 polymer matrix composites reinforced with various fibers

    Science.gov (United States)

    Bowles, Kenneth J.

    1990-01-01

    An experimental study was conducted to measure the thermo-oxidative stability of PMR-15 polymer matrix composites reinforced with various fibers and to observe differences in the way they degrade in air. The fibers that were studied included graphite and the thermally stable Nicalon and Nextel ceramic fibers. Weight loss rates for the different composites were assessed as a function of mechanical properties, specimen geometry, fiber sizing, and interfacial bond strength. Differences were observed in rates of weight loss, matrix cracking, geometry dependency, and fiber-sizing effects. It was shown that Celion 6000 fiber-reinforced composites do not exhibit a straight-line Arrhenius relationship at temperatures above 316 C.

  5. Free-standing membrane polymer laser on the end of an optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Tianrui, E-mail: trzhai@bjut.edu.cn, E-mail: zhangxinping@bjut.edu.cn; Li, Songtao; Hu, Yujie; Wang, Yimeng; Wang, Li; Zhang, Xinping, E-mail: trzhai@bjut.edu.cn, E-mail: zhangxinping@bjut.edu.cn [Institute of Information Photonics Technology and College of Applied Sciences, Beijing University of Technology, Beijing 100124 (China); Chen, Li [Department of Mathematics and Physics, North China Electric Power University, Hebei 071000 (China)

    2016-01-25

    One- and two-dimensional distributed feedback cavities were constructed on free-standing polymer membranes using spin-coating and lift-off techniques. Low threshold lasing was generated through feedback amplification when the 290-nm membrane device was optically pumped, which was attributed to the strong confinement mechanism provided by the active waveguide layer without a substrate. The free-standing membrane polymer laser is flexible and can be transplanted. Single- and dual-wavelength fiber lasers were achieved by directly attaching the membrane polymer laser on the optical fiber end face. This technique provides potential to fabricate polymer lasers on surfaces with arbitrary shapes.

  6. Experimental Study on Electric Properties of Carbon Fiber Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    According to the phenomenon that the physical properties have a great effect on the electric capability of carbon fiber reinforced concrete, the author researched the relationship between DC resistance of carbon fiber reinforced concrete and curing age using the two-probe method. Then the effect of insulative area,location and quantity on DC resistance of carbon fiber reinforced concrete was investigated at different curing age with analysis of hydration. The results suggest that DC resistance increases greatly with its curing age, which illustrates the relationship like Gaussian curve. In every curing ages the electric capability of carbon fiber reinforced concrete weakenes with the increase of insulative area. In same curing ages, section and insulative area, the more the quantity of insulation, the stronger the conductibility. The insulative location in optimal position can only result in optimal conductibility.

  7. Effect of carbon fiber on calcium phosphate bone cement

    Institute of Scientific and Technical Information of China (English)

    戴红莲; 王欣宇; 黄健; 闫玉华; 李世普

    2004-01-01

    The calcium phosphate cement (α-TCP/TTCP) was reinforced with oxidation-treated carbon fibers. The effect of aspect ratio and content of carbon fiber on the compression strength and bending strength of the hardened body was discussed. The results show that the reinforcing effect is optimal as the aspect ratio is 375 and the additive amount is 0.3% (mass fraction). Under this condition, the compressive strength is increased by 55% (maximum 63.46 MPa), and the bending strength is nearly increased by 100% (maximum 11.95 MPa), respectively. However, if the additive quantity and aspect ratio are too high, the effect of the carbon fibers is limited because it can not be dispersed uniformly in the hardened body. The biological evaluation indicates that the calcium phosphate cement reinforced by carbon fibers has good biocompatibility.

  8. Functionalized Cellulose: PET Polymer Fibers with Zeolites for Detoxification Against Nerve Agents%Functionalized Cellulose:PET Polymer Fibers with Zeolites for Detoxification Against Nerve Agents

    Institute of Scientific and Technical Information of China (English)

    Agarwal Satya R; Sundarrajan Subramanian; Ramakrishna Seeram

    2012-01-01

    Presently activated carbon is used as an adsorptive material for chemical and biological warfare agents.It possess excellent surface properties such as large surface area,fire-resistance and plenty availability,but has disadvantages such as its heavy weight,low breathability (after adsorption of moisture) and disposal.In this paper,we propose to utilize novel electrospun polymeric nanostructures having zeolites as catalyst materials.In this respective,the electrospun polymer nanofibers would serve as the best possible substitutes to activated carbon based protective clothing applications.This is the first in the literature that reports the integration of these types of catalysts with nanofiberous membranes.Electrospinning of cellulose/polyethylene terephthalate (PET) blend nanofibers has been carried out.Zeolite catalysts (Linde Type A and Mordenite) for the detoxification of nerve agent stimulant-paraoxon,were prepared due to their relative simplicity of synthesis.The catalysts were then coated onto nanofiber membranes and their morphology was confirmed using SEM.This is the first report on the coating of nanofibers with zeolites and their successful demonstration against nerve agent stimulant.The UV absorption spectra clearly show the detoxification ability of the functionalized fibers and their potential to be used in textiles for protection and decontamination.

  9. Hydrogen adsorption properties of polymer-derived nanoporous SiC{sub x} fibers

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Zengyong; He, Rongan; Zhang, Xiaobin; Cheng, Haifeng; Li, Xiaodong; Wang, Yingde [State Key Laboratory of Advanced Ceramic Fibers and Composites, National University of Defense Technology, Changsha 410073 (China)

    2010-04-15

    In an effort to prepare new hydrogen storage materials, we successfully obtained three types of polymer-derived nanoporous SiC{sub x} (x = 5-7) fibers, whose specific surface areas (SSAs) are larger than 580 m{sup 2}/g. Their hydrogen adsorption properties were studied with a comparison of multi-walled carbon nanotubes (MWCNTs). The results reveal that micropores play a predominant role in hydrogen adsorptions at 77 K and at pressures below 0.5 MPa, and mesopores begin to take greater effect when the pressure increases beyond 0.5 MPa. The maximum hydrogen storage capacity (HSC), 0.33 wt% at 302 K and 4 MPa, was achieved for SiC{sub x}-KN fibers with SSA of 990 m{sup 2}/g, while the HSC of the MWCNTs is 0.09 wt% at the same conditions. For these new materials, this work demonstrates that small pore size, large micropore volume and large SSA are all beneficial for the high hydrogen uptake. It can also be deduced from the work that the HSC of the SiC{sub x} fibers could be further increased if the crystallinity and the composition are better controlled. (author)

  10. UV-cured adhesives for carbon fiber composite applications

    Science.gov (United States)

    Lu, Hsiao-Chun

    Carbon fiber composite materials are increasingly used in automobile, marine, and aerospace industries due to their unique properties, including high strength, high stiffness and low weight. However, due to their brittle characteristic, these structures are prone to physical damage, such as a bird strike or impact damage. Once the structure is damaged, it is important to have fast and reliable temporary repair until the permanent repair or replacement can take place. In this dissertation, UV-based adhesives were used to provide a bonding strength for temporary repair. Adhesively bonded patch repair is an efficient and effective method for temporary repair. In this study, precured patches (hard patches) and dry fabric patches with laminating resins (soft patches) were performed. UV-based epoxy adhesives were applied to both patch repair systems. For precured patch repair, the bonding strengths were investigated under different surface treatments for bonding area and different adhesives thicknesses. The shear stresses of different UV exposure times and curing times were tested. Besides, the large patch repair was investigated as well. For soft patch repair, the hand wet lay-up was applied due to high viscosity of UV resins. A modified single lap shear testing (ASTM D5868) was applied to determine the shear stress. The large patches used fiber glass instead of carbon fiber to prove the possibility of repair with UV epoxy resin by hand wet lay-up process. The hand lay-up procedure was applied and assisted by vacuum pressure to eliminate the air bubbles and consolidate the patches. To enhance the bonding strength and effective soft patch repair, vacuum assisted resin transferring molding (VaRTM) is the better option. However, only low viscosity resins can be operated by VaRTM. Hence, new UV-based adhesives were formulated. The new UV-based adhesives included photoinitiator (PI), epoxy and different solvents. Solvents were used to compound the photoinitiator into epoxy

  11. Deposition of carbon nanotubes onto aramid fibers using as-received and chemically modified fibers

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Uicab, O. [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburna de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Avilés, F., E-mail: faviles@cicy.mx [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburna de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Gonzalez-Chi, P.I; Canché-Escamilla, G.; Duarte-Aranda, S. [Centro de Investigación Científica de Yucatán A.C., Unidad de Materiales, Calle 43 No.130, Col. Chuburna de Hidalgo, C.P. 97200 Mérida, Yucatán (Mexico); Yazdani-Pedram, M. [Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, S. Livingstone 1007, Independencia, Santiago (Chile); Toro, P. [Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Av. Beauchef 850, Santiago (Chile); Gamboa, F. [Centro de Investigacion y de Estudios Avanzados del IPN, Unidad Mérida, Depto. de Física Aplicada, Km. 6 Antigua Carretera a Progreso, 97310 Mérida, Yucatán (Mexico); Mazo, M.A.; Nistal, A.; Rubio, J. [Instituto de Cerámica y Vidrio (ICV-CSIC), Kelsen 5, 28049 Madrid (Spain)

    2016-11-01

    Highlights: • The surface of aramid fibers was functionalized by two acid treatments. • The treatment based on HNO{sub 3}/H{sub 2}SO{sub 4} reduced the mechanical properties of the fibers. • CNTs were deposited on the aramid fibers, reaching electrical conductivity. • Homogeneous CNT distribution was achieved by using pristine fibers or chlorosulfonic acid. - Abstract: Multiwall carbon nanotubes (MWCNTs) oxidized by an acid treatment were deposited on the surface of as-received commercial aramid fibers containing a surface coating (“sizing”), and fibers modified by either a chlorosulfonic treatment or a mixture of nitric and sulfuric acids. The surface of the aramid fiber activated by the chemical treatments presents increasing density of CO, COOH and OH functional groups. However, these chemical treatments reduced the tensile mechanical properties of the fibers, especially when the nitric and sulfuric acid mixture was used. Characterization of the MWCNTs deposited on the fiber surface was conducted by scanning electron microscopy, Raman spectroscopy mapping and X-ray photoelectron spectroscopy. These characterizations showed higher areal concentration and more homogeneous distribution of MWCNTs over the aramid fibers for as-received fibers and for those modified with chlorosulfonic acid, suggesting the existence of interaction between the oxidized MWCNTs and the fiber coating. The electrical resistance of the MWCNT-modified aramid yarns comprising ∼1000 individual fibers was in the order of MΩ/cm, which renders multifunctional properties.

  12. Carbon-fiber composite molecular sieves for gas separation

    Energy Technology Data Exchange (ETDEWEB)

    Jagtoyen, M.; Derbyshire, F.; Kimber, G.; Fei, Y.Q. [Univ. of Kentucky Center for Applied Energy Research, Lexington, KY (United States)

    1995-08-01

    The progress of research in the development of novel, rigid, monolithic adsorbent carbon fiber composites is described. Carbon fiber composites are produced at ORNL and activated at the CAER using steam or CO{sub 2} under different conditions, with the aims of producing a uniform degree of activation through the material, and of closely controlling pore structure and adsorptive properties The principal focus of the work to date has been to produce materials with narrow porosity for use in gas separations.

  13. Chronic in vivo stability assessment of carbon fiber microelectrode arrays

    Science.gov (United States)

    Patel, Paras R.; Zhang, Huanan; Robbins, Matthew T.; Nofar, Justin B.; Marshall, Shaun P.; Kobylarek, Michael J.; Kozai, Takashi D. Y.; Kotov, Nicholas A.; Chestek, Cynthia A.

    2016-12-01

    Objective. Individual carbon fiber microelectrodes can record unit activity in both acute and semi-chronic (∼1 month) implants. Additionally, new methods have been developed to insert a 16 channel array of carbon fiber microelectrodes. Before assessing the in vivo long-term viability of these arrays, accelerated soak tests were carried out to determine the most stable site coating material. Next, a multi-animal, multi-month, chronic implantation study was carried out with carbon fiber microelectrode arrays and silicon electrodes. Approach. Carbon fibers were first functionalized with one of two different formulations of PEDOT and subjected to accelerated aging in a heated water bath. After determining the best PEDOT formula to use, carbon fiber arrays were chronically implanted in rat motor cortex. Some rodents were also implanted with a single silicon electrode, while others received both. At the end of the study a subset of animals were perfused and the brain tissue sliced. Tissue sections were stained for astrocytes, microglia, and neurons. The local reactive responses were assessed using qualitative and quantitative methods. Main results. Electrophysiology recordings showed the carbon fibers detecting unit activity for at least 3 months with average amplitudes of ∼200 μV. Histology analysis showed the carbon fiber arrays with a minimal to non-existent glial scarring response with no adverse effects on neuronal density. Silicon electrodes showed large glial scarring that impacted neuronal counts. Significance. This study has validated the use of carbon fiber microelectrode arrays as a chronic neural recording technology. These electrodes have demonstrated the ability to detect single units with high amplitude over 3 months, and show the potential to record for even longer periods. In addition, the minimal reactive response should hold stable indefinitely, as any response by the immune system may reach a steady state after 12 weeks.

  14. Nanowire modified carbon fibers for enhanced electrical energy storage

    Science.gov (United States)

    Shuvo, Mohammad Arif Ishtiaque; (Bill) Tseng, Tzu-Liang; Ashiqur Rahaman Khan, Md.; Karim, Hasanul; Morton, Philip; Delfin, Diego; Lin, Yirong

    2013-09-01

    The study of electrochemical super-capacitors has become one of the most attractive topics in both academia and industry as energy storage devices because of their high power density, long life cycles, and high charge/discharge efficiency. Recently, there has been increasing interest in the development of multifunctional structural energy storage devices such as structural super-capacitors for applications in aerospace, automobiles, and portable electronics. These multifunctional structural super-capacitors provide structures combining energy storage and load bearing functionalities, leading to material systems with reduced volume and/or weight. Due to their superior materials properties, carbon fiber composites have been widely used in structural applications for aerospace and automotive industries. Besides, carbon fiber has good electrical conductivity which will provide lower equivalent series resistance; therefore, it can be an excellent candidate for structural energy storage applications. Hence, this paper is focused on performing a pilot study for using nanowire/carbon fiber hybrids as building materials for structural energy storage materials; aiming at enhancing the charge/discharge rate and energy density. This hybrid material combines the high specific surface area of carbon fiber and pseudo-capacitive effect of metal oxide nanowires, which were grown hydrothermally in an aligned fashion on carbon fibers. The aligned nanowire array could provide a higher specific surface area that leads to high electrode-electrolyte contact area thus fast ion diffusion rates. Scanning Electron Microscopy and X-Ray Diffraction measurements are used for the initial characterization of this nanowire/carbon fiber hybrid material system. Electrochemical testing is performed using a potentio-galvanostat. The results show that gold sputtered nanowire carbon fiber hybrid provides 65.9% higher energy density than bare carbon fiber cloth as super-capacitor.

  15. Ultrafine microporous and mesoporous activated carbon fibers from alkali lignin

    OpenAIRE

    2013-01-01

    A facile and sustainable approach has been successfully devised to fabricate ultrafine (100-500 nm) highly porous activated carbon fibers (ACFs) by electrospinning of aqueous solutions of predominantly alkali lignin (low sulfonate content) followed by simultaneous carbonization and activation at 850 °C under N2. Incorporating a polyethylene oxide (PEO) carrier with only up to one ninth of lignin not only enabled efficient electrospinning into fibers but also retained fibrous structures during...

  16. ADSORPTION OF DYES ON ACTIVATED CARBON FIBERS

    Institute of Scientific and Technical Information of China (English)

    ChenShuixia; WuChangqing; 等

    1998-01-01

    The adsorption behavior of dyes on a variety of sisal based activated carbon fibers (SACF) has been studied in this paper. The results show that this kind of ACF has excellent adsorption capacities for some organic (dye) molecules.SACF can remove nearly all methylene blue,crystal violet,bromophenol blue and Eriochrome blue black R from water after static adsorption for 24h. at 30℃. The adsorption amounts can reach more than 400mg/g when adding 50 mg SACF into 50 ml dye solution.Under the same conditions,the adsorption amounts of xylenol orange fluorescein and Eriochrome black T wree lower.On the other hand,the adsorption amounts change along with the characteristics of adsorbents.The SACFs activated above 840℃,which have higher specific surface areas and wider pore radii,have higher adsorption amounts for the dyes.The researching results also show that the adsorption rates of dyes onto SACFs decrease by the order of methylene blue,Eriochrome blue black R and crystal violet.

  17. Growth of Graphene Nanoribbons and Carbon Onions from Polymer

    Institute of Scientific and Technical Information of China (English)

    GUO Xiao-Song; LU Bing-An; XIE Er-Qing

    2011-01-01

    Graphene nanoribbons and carbon onions are directly prepared by electron beam irradiation of polyacrylonitrile and expanded polystyrene nanofibers,respectively.By controlling the irradiation process in a high resolution transmission electron microscope,the number of layers of the graphene nanoribbons,as well as the dimension of the carbon onions,can be controlled.It is found that the initial diameter of the nanofiber has a strong effect on the final results.A mechanism is proposed to explain the transformation of polymer nanofibers to carbon nanostructures under electron beam irradiation.This supposes that the polymer nanofibers are first carbonized and then graphitized as a result of the high energy electrons.According to the mechanism,it is believed that all polymer nanofibers could be carbonized and then converted to graphene nanoribbons by proper electron beam irradiation.

  18. Preparation of Electrospun Polymer Fibers Using a Copper Wire Electrode in a Capillary Tube

    Science.gov (United States)

    Shinbo, Kazunari; Onozuka, Shintaro; Hoshino, Rikiya; Mizuno, Yoshinori; Ohdaira, Yasuo; Baba, Akira; Kato, Keizo; Kaneko, Futao

    2010-04-01

    Polymer fibers were prepared by an electrospinning method utilizing a copper wire electrode in a capillary tube. The morphology of electrospun poly(vinyl alcohol) (PVA) fibers was observed, and was found to be dependent on the wire electrode tip position in the capillary tube, the concentration of the polymer solution, the distance between the electrodes, and the applied voltage. By using the wire electrode, the experimental setup is simple and the distance between the electrodes and the applied voltage can be easily reduced. Furthermore, the preparation of poly(3-hexylthiophene) (P3HT) fibers was carried out. P3HT fibers were successfully prepared by mixing poly(ethylene oxide) (PEO) in P3HT solution. Orientation control was also carried out by depositing the fibers on a rotating collector electrode, and the alignment of the P3HT:PEO fibers was confirmed. Anisotropy of the optical absorption spectra was also observed for the aligned fibers.

  19. Multiscale characterization of chemical–mechanical interactions between polymer fibers and cementitious matrix

    Energy Technology Data Exchange (ETDEWEB)

    Hernández-Cruz, Daniel; Hargis, Craig W.; Bae, Sungchul; Itty, Pierre A.; Meral, Cagla; Dominowski, Jolee; Radler, Michael J.; Kilcoyne, David A.; Monteiro, Paulo J. M.

    2014-04-01

    Together with a series of mechanical tests, the interactions and potential bonding between polymeric fibers and cementitious materials were studied using scanning transmission X-ray microscopy (STXM) and microtomography (lCT). Experimental results showed that these techniques have great potential to characterize the polymer fiber-hydrated cement-paste matrix interface, as well as differentiating the chemistry of the two components of a bi-polymer (hybrid) fiber the polypropylene core and the ethylene acrylic acid copolymer sheath. Similarly, chemical interactions between the hybrid fiber and the cement hydration products were observed, indicating the chemical bonding between the sheath and the hardened cement paste matrix. Microtomography allowed visualization of the performance of the samples, and the distribution and orientation of the two types of fiber in mortar. Beam flexure tests confirmed improved tensile strength of mixes containing hybrid fibers, and expansion bar tests showed similar reductions in expansion for the polypropylene and hybrid fiber mortar bars.

  20. Tensile Properties of Polyimide Composites Incorporating Carbon Nanotubes-Grafted and Polyimide-Coated Carbon Fibers

    Science.gov (United States)

    Naito, Kimiyoshi

    2014-09-01

    The tensile properties and fracture behavior of polyimide composite bundles incorporating carbon nanotubes-grafted (CNT-grafted) and polyimide-coated (PI-coated) high-tensile-strength polyacrylonitrile (PAN)-based (T1000GB), and high-modulus pitch-based (K13D) carbon fibers were investigated. The CNT were grown on the surface of the carbon fibers by chemical vapor deposition. The pyromellitic dianhydride/4,4'-oxydianiline PI nanolayer coating was deposited on the surface of the carbon fiber by high-temperature vapor deposition polymerization. The results clearly demonstrate that CNT grafting and PI coating were effective for improving the Weibull modulus of T1000GB PAN-based and K13D pitch-based carbon fiber bundle composites. In addition, the average tensile strength of the PI-coated T1000GB carbon fiber bundle composites was also higher than that of the as-received carbon fiber bundle composites, while the average tensile strength of the CNT-grafted T1000GB, K13D, and the PI-coated K13D carbon fiber bundle composites was similar to that of the as-received carbon fiber bundle composites.

  1. Carbon fiber enhanced bioelectricity generation in soil microbial fuel cells.

    Science.gov (United States)

    Li, Xiaojing; Wang, Xin; Zhao, Qian; Wan, Lili; Li, Yongtao; Zhou, Qixing

    2016-11-15

    The soil microbial fuel cell (MFC) is a promising biotechnology for the bioelectricity recovery as well as the remediation of organics contaminated soil. However, the electricity production and the remediation efficiency of soil MFC are seriously limited by the tremendous internal resistance of soil. Conductive carbon fiber was mixed with petroleum hydrocarbons contaminated soil and significantly enhanced the performance of soil MFC. The maximum current density, the maximum power density and the accumulated charge output of MFC mixed carbon fiber (MC) were 10, 22 and 16 times as high as those of closed circuit control due to the carbon fiber productively assisted the anode to collect the electron. The internal resistance of MC reduced by 58%, 83% of which owed to the charge transfer resistance, resulting in a high efficiency of electron transfer from soil to anode. The degradation rates of total petroleum hydrocarbons enhanced by 100% and 329% compared to closed and opened circuit controls without the carbon fiber respectively. The effective range of remediation and the bioelectricity recovery was extended from 6 to 20cm with the same area of air-cathode. The mixed carbon fiber apparently enhanced the bioelectricity generation and the remediation efficiency of soil MFC by means of promoting the electron transfer rate from soil to anode. The use of conductively functional materials (e.g. carbon fiber) is very meaningful for the remediation and bioelectricity recovery in the bioelectrochemical remediation.

  2. Carbon Nanotube-Conducting Polymer Composites Based Solar Cells

    Institute of Scientific and Technical Information of China (English)

    Prakash; R.Somani; M.Umeno

    2007-01-01

    1 Results Combination of carbon nanotubes (CN) with polymers is important for application towards value added composites,solar cells,fuel cells etc.Especially interesting is the combination of CN with π-conjugated polymers because of the potential interaction between the highly delocalized π-electrons of the CN and the π-electrons correlated with the lattice of polymer skeleton.Efficient exciton dissociation due to electron transfer from the photoexcited polymer to CN is of interest for photovoltaic app...

  3. Interlaminar Shear Property of Modified Glass Fiber reinforced Polymer with Different MWCNTs

    Institute of Scientific and Technical Information of China (English)

    Sun Lili; Zhao Yan; Duan Yuexin; Zhang Zuoguang

    2008-01-01

    The intcrlaminar shear property of composites remains a serious concern in application. In this article, five different multiwalled carbon nanotubes (MWCNTs) are tried to improve the interlaminar shear property of composites, including two MWCNTs (MWCNTs-A and MWCNTs-B) different with diameters and lengths, an orientated MWCNTs (MWCNTs-C), a film-shaped MWCNTs-A (MWCNTs-D), and a surface-treated MWCNTs-B (MWCNTs-E). The interlaminar shear strength (ILSS) of the composites, filled with one of the above-mentioned materials as a constituent is investigated. The best ILSS increases by 8.16% from 24.5 MPa to 26.5 MPa with MWCNTs-E. In addition, the dispersion of MWCNTs in a glass fiber-reinforced polymer (GFRP) is researched by a scanning electron microscopy (SEM) in association with the ILSS results.

  4. An Investigation of the Electrochemical Behavior of Graphite Fiber-Polymer Composites.

    Science.gov (United States)

    1982-04-01

    The factors influencing the use and stability of graphite fiber polymer matrix composite electrodes have been determined. Several possible uses of these electrodes have been examined for scientific feasibility.

  5. Peapod-like composite with nickel phosphide nanoparticles encapsulated in carbon fibers as enhanced anode for li-ion batteries.

    Science.gov (United States)

    Zhang, Huijuan; Feng, Yangyang; Zhang, Yan; Fang, Ling; Li, Wenxiang; Liu, Qing; Wu, Kai; Wang, Yu

    2014-07-01

    Herein, we introduce a peapod-like composite with Ni12 P5 nanoparticles encapsulated in carbon fibers as the enhanced anode in Li-ion batteries for the first time. In the synthesis, NiNH4 PO4 ⋅H2 O nanorods act as precursors and sacrificial templates, and glucose molecules serve as the green carbon source. With the aid of hydrogen bonding between the precursor and carbon source, a polymer layer is hydrothermally formed and then rationally converted into carbon fibers upon inert calcination at elevated temperatures. Meanwhile, NiNH4 PO4 ⋅H2 O nanorods simultaneously turn into Ni12 P5 nanoparticles encapsulated in carbon fibers by undergoing a decomposition and reduction process induced by high temperature and the carbon fibers. The obtained composite performs excellently as a Li-ion batteries anode relative to pure-phase materials. Specific capacity can reach 600 m Ah g(-1) over 200 cycles, which is much higher than that of isolated graphitized carbon or phosphides, and reasonably believed to originate from the synergistic effect based on the combination of Ni12 P5 nanoparticles and carbon fibers. Due to the benignity, sustainability, low cost, and abundance of raw materials of the peapod-like composite, numerous potential applications, in fields such as optoelectronics, electronics, specific catalysis, gas sensing, and biotechnology can be envisaged.

  6. Pre-treatment of multi-walled carbon nanotubes for polyetherimide mixed matrix hollow fiber membranes.

    Science.gov (United States)

    Goh, P S; Ng, B C; Ismail, A F; Aziz, M; Hayashi, Y

    2012-11-15

    Mixed matrix hollow fibers composed of multi-walled carbon nanotubes (MWCNTs) and polyetherimide (PEI) were fabricated. Pre-treatment of MWCNTs was carried out prior to the incorporation into the polymer matrix using a simple and feasible two stages approach that involved dry air oxidation and surfactant dispersion. The characterizations of the surface treated MWCNTs using TEM and Raman spectroscopy have evidenced the effectiveness of dry air oxidation in eliminating undesired amorphous carbon and metal catalyst while surfactant dispersion using Triton X100 has suppressed the agglomeration of MWCNTs. The resultant mixed matrix hollow fibers were applied for O(2)/N(2) pure gas separation. Interestingly, it was found that removal of disordered amorphous carbons and metal particles has allowed the hollow structures to be more accessible for the fast and smooth transport of gas molecules, hence resulted in noticeable improvement in the gas separation properties. The composite hollow fibers embedded with the surface modified MWCNTs showed increase in permeability as much as 60% while maintaining the selectivity of the O(2)/N(2) gas pair. This study highlights the necessity to establish an appropriate pre-treatment approach for MWCNTs in order to fully utilize the beneficial transport properties of this material in mixed matrix polymer nanocomposite for gas separation.

  7. Quasi-Static Indentation Analysis of Carbon-Fiber Laminates.

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, Timothy [Sandia National Lab. (SNL-CA), Livermore, CA (United States); English, Shawn Allen [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Nelson, Stacy Michelle [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2015-12-01

    A series of quasi - static indentation experiments are conducted on carbon fiber reinforced polymer laminates with a systematic variation of thicknesses and fixture boundary conditions. Different deformation mechanisms and their resulting damage mechanisms are activated b y changing the thickn ess and boundary conditions. The quasi - static indentation experiments have been shown to achieve damage mechanisms similar to impact and penetration, however without strain rate effects. The low rate allows for the detailed analysis on the load response. Moreover, interrupted tests allow for the incremental analysis of various damage mechanisms and pr ogressions. The experimentally tested specimens are non - destructively evaluated (NDE) with optical imaging, ultrasonics and computed tomography. The load displacement responses and the NDE are then utilized in numerical simulations for the purpose of model validation and vetting. The accompanying numerical simulation work serves two purposes. First, the results further reveal the time sequence of events and the meaning behind load dro ps not clear from NDE . Second, the simulations demonstrate insufficiencies in the code and can then direct future efforts for development.

  8. CARBONIZED STARCH MICROCELLULAR FOAM-CELLULOSE FIBER COMPOSITE STRUCTURES

    Directory of Open Access Journals (Sweden)

    Andrew R. Rutledge

    2008-11-01

    Full Text Available The production of microporous carbon foams from renewable starch microcellular foam-fiber (SMCF-Fiber composites is described. Carbon foams are used in applications such as thermal insulation, battery electrodes, filters, fuel cells, and medical devices. SMCF-Fiber compos-ites were created from an aquagel. The water in the aquagel was exchanged with ethanol and then dried and carbonized. Higher amylose content starches and fiber contents of up to 4% improved the processability of the foam. The SMCF structure revealed agglomerates of swollen starch granules connected by a web of starch with pores in the 50-200 nanometer range. Heating the SMCF-fiber in a nitrogen atmosphere to temperatures between 350-700˚C produced carbon foams with a three-dimensional closed cell foam structure with cell diameters around 50 microns and pore walls around 1-3 microns. The stress versus strain compression data for carbonized samples displayed a linear elastic region and a plateau indicative of brittle crushing, typical of an elastic-brittle foam. The carbon foam products from these renew-able precursors are promising carbon structures with moderate strength and low density.

  9. Carbon fiber dispersion models used for risk analysis calculations

    Science.gov (United States)

    1979-01-01

    For evaluating the downwind, ground level exposure contours from carbon fiber dispersion, two fiber release scenarios were chosen. The first is the fire and explosion release in which all of the fibers are released instantaneously. This model applies to accident scenarios where an explosion follows a short-duration fire in the aftermath of the accident. The second is the plume release scenario in which the total mass of fibers is released into the fire plume. This model applies to aircraft accidents where only a fire results. These models are described in detail.

  10. The Carbon Nanotube Fibers for Optoelectric Conversion and Energy Storage

    Directory of Open Access Journals (Sweden)

    Yongfeng Luo

    2014-01-01

    Full Text Available This review summarizes recent studies on carbon nanotube (CNT fibers for weavable device of optoelectric conversion and energy storage. The intrinsic properties of individual CNTs make the CNT fibers ideal candidates for optoelectric conversion and energy storage. Many potential applications such as solar cell, supercapacitor, and lithium ion battery have been envisaged. The recent advancement in CNT fibers for optoelectric conversion and energy storage and the current challenge including low energy conversion efficiency and low stability and future direction of the energy fiber have been finally summarized in this paper.

  11. Conductive polymer combined silk fiber bundle for bioelectrical signal recording.

    Directory of Open Access Journals (Sweden)

    Shingo Tsukada

    Full Text Available Electrode materials for recording biomedical signals, such as electrocardiography (ECG, electroencephalography (EEG and evoked potentials data, are expected to be soft, hydrophilic and electroconductive to minimize the stress imposed on living tissue, especially during long-term monitoring. We have developed and characterized string-shaped electrodes made from conductive polymer with silk fiber bundles (thread, which offer a new biocompatible stress free interface with living tissue in both wet and dry conditions.An electroconductive polyelectrolyte, poly(3,4-ethylenedioxythiophene-poly(styrenesulfonate (PEDOT-PSS was electrochemically combined with silk thread made from natural Bombyx mori. The polymer composite 280 µm thread exhibited a conductivity of 0.00117 S/cm (which corresponds to a DC resistance of 2.62 Mohm/cm. The addition of glycerol to the PEDOT-PSS silk thread improved the conductivity to 0.102 S/cm (20.6 kohm/cm. The wettability of PEDOT-PSS was controlled with glycerol, which improved its durability in water and washing cycles. The glycerol treated PEDOT-PSS silk thread showed a tensile strength of 1000 cN in both wet and dry states. Without using any electrolytes, pastes or solutions, the thread directly collects electrical signals from living tissue and transmits them through metal cables. ECG, EEG, and sensory evoked potential (SEP signals were recorded from experimental animals by using this thread placed on the skin. PEDOT-PSS silk glycerol composite thread offers a new class of biocompatible electrodes in the field of biomedical and health promotion that does not induce stress in the subjects.

  12. Titanium Implant Osseointegration Problems with Alternate Solutions Using Epoxy/Carbon-Fiber-Reinforced Composite.

    Science.gov (United States)

    Petersen, Richard C

    2014-12-01

    The aim of the article is to present recent developments in material research with bisphenyl-polymer/carbon-fiber-reinforced composite that have produced highly influential results toward improving upon current titanium bone implant clinical osseointegration success. Titanium is now the standard intra-oral tooth root/bone implant material with biocompatible interface relationships that confer potential osseointegration. Titanium produces a TiO2 oxide surface layer reactively that can provide chemical bonding through various electron interactions as a possible explanation for biocompatibility. Nevertheless, titanium alloy implants produce corrosion particles and fail by mechanisms generally related to surface interaction on bone to promote an inflammation with fibrous aseptic loosening or infection that can require implant removal. Further, lowered oxygen concentrations from poor vasculature at a foreign metal surface interface promote a build-up of host-cell-related electrons as free radicals and proton acid that can encourage infection and inflammation to greatly influence implant failure. To provide improved osseointegration many different coating processes and alternate polymer matrix composite (PMC) solutions have been considered that supply new designing potential to possibly overcome problems with titanium bone implants. Now for important consideration, PMCs have decisive biofunctional fabrication possibilities while maintaining mechanical properties from addition of high-strengthening varied fiber-reinforcement and complex fillers/additives to include hydroxyapatite or antimicrobial incorporation through thermoset polymers that cure at low temperatures. Topics/issues reviewed in this manuscript include titanium corrosion, implant infection, coatings and the new epoxy/carbon-fiber implant results discussing osseointegration with biocompatibility related to nonpolar molecular attractions with secondary bonding, carbon fiber in vivo properties, electrical

  13. Titanium Implant Osseointegration Problems with Alternate Solutions Using Epoxy/Carbon-Fiber-Reinforced Composite

    Directory of Open Access Journals (Sweden)

    Richard C. Petersen

    2014-12-01

    Full Text Available The aim of the article is to present recent developments in material research with bisphenyl-polymer/carbon-fiber-reinforced composite that have produced highly influential results toward improving upon current titanium bone implant clinical osseointegration success. Titanium is now the standard intra-oral tooth root/bone implant material with biocompatible interface relationships that confer potential osseointegration. Titanium produces a TiO2 oxide surface layer reactively that can provide chemical bonding through various electron interactions as a possible explanation for biocompatibility. Nevertheless, titanium alloy implants produce corrosion particles and fail by mechanisms generally related to surface interaction on bone to promote an inflammation with fibrous aseptic loosening or infection that can require implant removal. Further, lowered oxygen concentrations from poor vasculature at a foreign metal surface interface promote a build-up of host-cell-related electrons as free radicals and proton acid that can encourage infection and inflammation to greatly influence implant failure. To provide improved osseointegration many different coating processes and alternate polymer matrix composite (PMC solutions have been considered that supply new designing potential to possibly overcome problems with titanium bone implants. Now for important consideration, PMCs have decisive biofunctional fabrication possibilities while maintaining mechanical properties from addition of high-strengthening varied fiber-reinforcement and complex fillers/additives to include hydroxyapatite or antimicrobial incorporation through thermoset polymers that cure at low temperatures. Topics/issues reviewed in this manuscript include titanium corrosion, implant infection, coatings and the new epoxy/carbon-fiber implant results discussing osseointegration with biocompatibility related to nonpolar molecular attractions with secondary bonding, carbon fiber in vivo

  14. Influence of carbon nanotubes coatings onto carbon fiber by oxidative treatments combined with electrophoretic deposition on interfacial properties of carbon fiber composite

    Science.gov (United States)

    Deng, Chao; Jiang, Jianjun; Liu, Fa; Fang, Liangchao; Wang, Junbiao; Li, Dejia; Wu, Jianjun

    2015-12-01

    To improve the interfacial performance of carbon fiber (CF) and epoxy resin, carbon nanotubes (CNTs) coatings were utilized to achieve this purpose through coating onto CF by the treatment with hydrogen peroxide and concentrated nitric acid combined with electrophoretic deposition (EPD) process. The influence of electrophoretically deposited CNTs coatings on the surface properties of CFs were investigated by Fourier transform infrared spectrometer, atomic force microscopy, scanning electron microscopy and dynamic contact angle analysis. The results indicated that the deposition of carbon nanotubes introduced some polar groups to carbon fiber surfaces, enhanced surface roughness and changed surface morphologies of carbon fibers. Surface wettability of carbon fibers may be significantly improved by increasing surface free energy of the fibers due to the deposition of CNTs. The thickness and density of the coatings increases with the introduction of pretreatment of the CF during the EPD process. Short beam shear test was performed to examine the effect of carbon fiber functionalization on mechanical properties of the carbon fiber/epoxy resin composites. The interfacial adhesion of CNTs/CF reinforced epoxy composites showed obvious enhancement of interlaminar shear strength by 60.2% and scanning electron microscope photographs showed that the failure mode of composites was changed after the carbon fibers were coated with CNTs.

  15. Mechanical properties of carbon fiber composites for environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, R.; Grulke, E. [Univ. of Kentucky, Lexington, KY (United States)

    1996-10-01

    Activated carbon fiber composites show great promise as fixed-bed catalytic reactors for use in environmental applications such as flue gas clean-up and ground water decontamination. A novel manufacturing process produces low density composites from chopped carbon fibers and binders. These composites have high permeability, can be activated to have high surface area, and have many potential environmental applications. This paper reports the mechanical and flow properties of these low density composites. Three point flexural strength tests were used to measure composite yield strength and flexural moduli. Composites containing over 10 pph binder had an adequate yield strength of about 200 psi at activations up to 40% weight loss. The composites were anisotropic, having along-fiber to cross-fiber yield strength ratios between 1.2 and 2.0. The friction factor for flow through the composites can be correlated using the fiber Reynolds number, and is affected by the composite bulk density.

  16. Multiscale carbon nanotube-carbon fiber reinforcement for advanced epoxy composites.

    Science.gov (United States)

    Bekyarova, E; Thostenson, E T; Yu, A; Kim, H; Gao, J; Tang, J; Hahn, H T; Chou, T-W; Itkis, M E; Haddon, R C

    2007-03-27

    We report an approach to the development of advanced structural composites based on engineered multiscale carbon nanotube-carbon fiber reinforcement. Electrophoresis was utilized for the selective deposition of multi- and single-walled carbon nanotubes (CNTs) on woven carbon fabric. The CNT-coated carbon fabric panels were subsequently infiltrated with epoxy resin using vacuum-assisted resin transfer molding (VARTM) to fabricate multiscale hybrid composites in which the nanotubes were completely integrated into the fiber bundles and reinforced the matrix-rich regions. The carbon nanotube/carbon fabric/epoxy composites showed approximately 30% enhancement of the interlaminar shear strength as compared to that of carbon fiber/epoxy composites without carbon nanotubes and demonstrate significantly improved out-of-plane electrical conductivity.

  17. Resistance Responses of Carbon Fiber Cement to Cycled Compressive Stresses

    Institute of Scientific and Technical Information of China (English)

    SHUI Zhonghe; LI Chao; LIAO Weidong

    2005-01-01

    The stress-resistance relationship of carbon fiber cement was studicd. Attention has been paid to explore the improvement of the stress-resistance sensitivity under cycled stress restriction. The prismy carbon fiber cement sensors were pre-fabricated. The factors such as contents of carbon fibers, silica fume, dispersant and the w/ c were taken into account. The electrical resistance variations with the dynamic and static loads were simulated using a strain-controlled test machine. The test results show that there is an optimal fiber content, with which the compression-sensitivity achieves a high level. The addition of silica fume can improve the sensitivity. Urder the optimal test conditions, the measured resistances can greatly correspond with the changes of the load.

  18. Adsorption Properties of Lignin-derived Activated Carbon Fibers (LACF)

    Energy Technology Data Exchange (ETDEWEB)

    Contescu, Cristian I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gallego, Nidia C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Thibaud-Erkey, Catherine [United Technologies Research Center (UTRC), East Hartford, CT (United States); Karra, Reddy [United Technologies Research Center (UTRC), East Hartford, CT (United States)

    2016-04-01

    The object of this CRADA project between Oak Ridge National Laboratory (ORNL) and United Technologies Research Center (UTRC) is the characterization of lignin-derived activated carbon fibers (LACF) and determination of their adsorption properties for volatile organic compounds (VOC). Carbon fibers from lignin raw materials were manufactured at Oak Ridge National Laboratory (ORNL) using the technology previously developed at ORNL. These fibers were physically activated at ORNL using various activation conditions, and their surface area and pore-size distribution were characterized by gas adsorption. Based on these properties, ORNL did down-select five differently activated LACF materials that were delivered to UTRC for measurement of VOC adsorption properties. UTRC used standard techniques based on breakthrough curves to measure and determine the adsorption properties of indoor air pollutants (IAP) - namely formaldehyde and carbon dioxide - and to verify the extent of saturated fiber regenerability by thermal treatments. The results are summarized as follows: (1) ORNL demonstrated that physical activation of lignin-derived carbon fibers can be tailored to obtain LACF with surface areas and pore size distributions matching the properties of activated carbon fibers obtained from more expensive, fossil-fuel precursors; (2) UTRC investigated the LACF potential for use in air cleaning applications currently pursued by UTRC, such as building ventilation, and demonstrated their regenerability for CO2 and formaldehyde, (3) Both partners agree that LACF have potential for possible use in air cleaning applications.

  19. Single mode step-index polymer optical fiber for humidity insensitive high temperature fiber Bragg grating sensors

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Fasano, Andrea; Stefani, Alessio;

    2016-01-01

    We have fabricated the first single-mode step-index and humidity insensitive polymer optical fiber operating in the 850 nm wavelength ranges. The step-index preform is fabricated using injection molding, which is an efficient method for cost effective, flexible and fast preparation of the fiber...... preform. The fabricated single-mode step-index (SI) polymer optical fiber (POF) has a 4.8µm core made from TOPAS grade 5013S-04 with a glass transition temperature of 134°C and a 150 µm cladding made from ZEONEX grade 480R with a glass transition temperature of 138°C. The key advantages of the proposed...... SIPOF are low water absorption, high operating temperature and chemical inertness to acids and bases and many polar solvents as compared to the conventional poly-methyl-methacrylate (PMMA) and polystyrene based POFs. In addition, the fiber Bragg grating writing time is short compared to microstructured...

  20. Aminosilane-grafted polymer/silica hollow fiber adsorbents for CO₂ capture from flue gas.

    Science.gov (United States)

    Rezaei, Fateme; Lively, Ryan P; Labreche, Ying; Chen, Grace; Fan, Yanfang; Koros, William J; Jones, Christopher W

    2013-05-01

    Amine/silica/polymer composite hollow fiber adsorbents are produced using a novel reactive post-spinning infusion technique, and the obtained fibers are shown to capture CO2 from simulated flue gas. The post-spinning infusion technique allows for functionalization of polymer/silica hollow fibers with different types of amines during the solvent exchange step after fiber spinning. The post-spinning infusion of 3-aminopropyltrimethoxysilane (APS) into mesoporous silica/cellulose acetate hollow fibers is demonstrated here, and the materials are compared with hollow fibers infused with poly(ethyleneimine) (PEI). This approach results in silica/polymer composite fibers with good amine distribution and accessibility, as well as adequate porosity retained within the fibers to facilitate rapid mass transfer and adsorption kinetics. The CO2 adsorption capacities for the APS-infused hollow fibers are shown to be comparable to those of amine powders with similar amine loadings. In contrast, fibers that are spun with presynthesized, amine-loaded mesoporous silica powders show negligible CO2 uptake and low amine loadings because of loss of amines from the silica materials during the fiber spinning process. Aminosilica powders are shown to be more hydrophilic than the corresponding amine containing composite hollow fibers, the bare polymer as well as silica support. Both the PEI-infused and APS-infused fibers demonstrate reduced CO2 adsorption upon elevating the temperature from 35 to 80 °C, in accordance with thermodynamics, whereas PEI-infused powders show increased CO2 uptake over that temperature range because of competing diffusional and thermodynamic effects. The CO2 adsorption kinetics as probed via TGA show that the APS-infused hollow fiber adsorbents have more rapid uptake kinetics than their aminosilica powder analogues. The adsorption performance of the functionalized hollow fibers is also assessed in CO2 breakthrough experiments. The breakthrough results show a

  1. Hansen solubility parameters for a carbon fiber/epoxy composite

    DEFF Research Database (Denmark)

    Launay, Helene; Hansen, Charles M.; Almdal, Kristoffer

    2007-01-01

    In this study, the physical affinity between an epoxy matrix and oxidized, unsized carbon fibers has been evaluated using Hansen solubility (cohesion) parameters (HSP). A strong physical compatibility has been shown, since their respective HSP are close. The use of a glassy carbon substrate...

  2. Electrochemical intercalation of lithium into carbons using a solid polymer electrolyte

    Science.gov (United States)

    Zaghib, K.; Choquette, Y.; Guerfi, A.; Simoneau, M.; Bélanger, A.; Gauthier, M.

    A study of the electrochemical performance of carbon materials from different types was carried out on true solid polymer-based poly(ethylene oxide) (PEO) with LiTFSI for application as the negative electrode in lithium ion solid-state batteries (LISSBs) at 60 °C. The reversible and irreversible capacity depend strongly on the crystallinity, the form of carbon and the impurities. A comparison of particle versus fiber was done when we investigated the charge/discharge characteristics with different current densities. The galvanostatic curves show high reversibility of the lithium—carbon in solid polymer electrolyte. The kinetics of electrochemical intercalation of lithium into carbon was studied by impedance spectroscopy especially for evaluating the diffusion coefficient in different origins of carbon. The degree of ionization of lithium was investigated by using solid-state 7Li nuclear magnetic resonance spectroscopy when the electrode is fully intercalated or doped down to 0 V. The chemical shift of 7Li NMR in lithium intercalation or doping in the carbons was classified in two ranges, 42 ppm and 9 ppm. 7Li NMR suggests the carbon with a 42 ppm range is the best choice for LISSBs.

  3. Electrochemical intercalation of lithium into carbons using a solid polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Zaghib, K.; Choquette, Y.; Guerfi, A.; Simoneau, M.; Belanger, A.; Gauthier, M. [Institut de Recherche d`Hydro-Quebec, Varennes (Canada)

    1997-10-01

    A study of the electrochemical performance of carbon materials from different types was carried out on true solid polymer-based poly(ethylene oxide) (PEO) with LiTFSI for application as the negative electrode in lithium ion solid-state batteries (LISSBs) at 60 C. The reversible and irreversible capacity depend strongly on the crystallinity, the form of carbon and the impurities. A comparison of particle versus fiber was done when we investigated the charge/discharge characteristics with different current densities. The galvanostatic curves show high reversibility of the lithium-carbon in solid polymer electrolyte. The kinetics of electrochemical intercalation of lithium into carbon was studied by impedance spectroscopy especially for evaluating the diffusion coefficient in different origins of carbon. The degree of ionization of lithium was investigated by using solid-state {sup 7}Li nuclear magnetic resonance spectroscopy when the electrode is fully intercalated or doped down to 0 V. The chemical shift of {sup 7}Li NMR in lithium intercalation or doping in the carbons was classified in two ranges, 42 ppm and 9 ppm. {sup 7}Li NMR suggests the carbon with a 42 ppm range is the best choice for LISSBs. (orig.)

  4. Polymer Selection Approach for Commonly and Uncommonly Used Natural Fibers Under Uncertainty Environments

    Science.gov (United States)

    AL-Oqla, Faris M.; Sapuan, S. M.

    2015-07-01

    Factors like awareness of the scarcity of non-renewable natural resources, high petroleum prices, and demands for environmental sustainability, as well as reducing the amount of environmental pollution, have led to a renewed interest in natural fiber reinforced polymer composites as a potential bio-based material type. The best polymer matrix type in view of the wide range of conflicting criteria to form a polymeric-based composite material suitable for sustainable industry under an uncertainty environment has still not been sufficiently determined. This work introduces a selection model to evaluate the available polymers for natural fibers to enhance the industrial sustainability theme. The model built was developed to evaluate various polymer types and to determine their relative merits taking account of various conflicting criteria for both commonly used and uncommonly used natural fibers utilizing the analytical hierarchy process technique. It was found that the choice of the best polymer type for a certain fiber type depends strongly on the polymers' intrinsic desirable conflicting characteristics. Polymers evaluations are illustrated for different technical criteria in order to facilitate the polymer selection process for various industrial applications with high confidence levels.

  5. THz waveguides, devices and hybrid polymer-chalcogenide photonic crystal fibers

    DEFF Research Database (Denmark)

    Bao, Hualong; Markos, Christos; Nielsen, Kristian;

    2014-01-01

    In this contribution, we review our recent activities in the design, fabrication and characterization of polymer THz waveguides. Besides the THz waveguides, we finally will also briefly show some of our initial results on a novel hybrid polymer photonic crystal fiber with integrated chalcogenide...

  6. Designing microstructured polymer optical fibers for cascaded quadratic soliton compression of femtosecond pulses

    DEFF Research Database (Denmark)

    Bache, Morten

    2009-01-01

    The dispersion of index-guiding microstructured polymer optical fibers is calculated for second-harmonic generation. The quadratic nonlinearity is assumed to come from poling of the polymer, which in this study is chosen to be the cyclic olefin copolymer Topas. We found a very large phase mismatch...

  7. Fibers coated with molecularly imprinted polymers for solid-phase microextraction

    NARCIS (Netherlands)

    Koster, E.H M; Crescenzi, C; den Hoedt, W; Ensing, K; de Jong, G.J.

    2001-01-01

    The simplicity and flexibility of solid-phase microextraction have been combined with the selectivity of molecularly imprinted polymers (MIPs), Silica fibers were coated reproducible with a 75-mum layer of methacrylate polymer either nonimprinted or imprinted with clenbuterol to compare their extrac

  8. Improved thermal and strain performance of annealed polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bache, Morten;

    2011-01-01

    We report on a detailed study of the inscription and characterization of fiber Bragg gratings (FBGs) in commercial step index polymer optical fibers (POFs). Through the growth dynamics of the gratings, we identify the effect of UV-induced heating during the grating inscription. We found that FBGs...

  9. Design and construction of a carbon fiber gondola for the SPIDER balloon-borne telescope

    CERN Document Server

    Soler, J D; Amiri, M; Benton, S J; Bock, J J; Bond, J R; Bryan, S A; Chiang, C; Contaldi, C C; Crill, B P; Doré, O P; Farhang, M; Filippini, J P; Fissel, L M; Fraisse, A A; Gambrel, A E; Gandilo, N N; Golwala, S; Gudmundsson, J E; Halpern, M; Hasselfield, M; Hilton, G C; Holmes, W A; Hristov, V V; Irwin, K D; Jones, W C; Kermish, Z D; Kuo, C L; MacTavish, C J; Mason, P V; Megerian, K G; Moncelsi, L; Nagy, J M; Netterfield, C B; O'Brient, R; Rahlin, A S; Reintsema, C D; Ruhl, J E; Runyan, M C; Shariff, J A; Trangsrud, A; Tucker, C; Tucker, R S; Turner, A D; Weber, A C; Wiebe, D V; Young, E Y

    2014-01-01

    We introduce the light-weight carbon fiber and aluminum gondola designed for the SPIDER balloon-borne telescope. SPIDER is designed to measure the polarization of the Cosmic Microwave Background radiation with unprecedented sensitivity and control of systematics in search of the imprint of inflation: a period of exponential expansion in the early Universe. The requirements of this balloon-borne instrument put tight constrains on the mass budget of the payload. The SPIDER gondola is designed to house the experiment and guarantee its operational and structural integrity during its balloon-borne flight, while using less than 10% of the total mass of the payload. We present a construction method for the gondola based on carbon fiber reinforced polymer tubes with aluminum inserts and aluminum multi-tube joints. We describe the validation of the model through Finite Element Analysis and mechanical tests.

  10. The effect of exfoliated graphite on carbon fiber reinforced composites for cryogenic applications

    Science.gov (United States)

    McLaughlin, Adam Michael

    It is desirable to lighten cryogenic fuel tanks through the use of composites for the development of a reusable single stage launch vehicle. Conventional composites fall victim to microcracking due to the cyclic loading and temperature change experienced during launch and re-entry conditions. Also, the strength of a composite is generally limited by the properties of the matrix. The introduction of the nanoplatelet, exfoliated graphite or graphene, to the matrix shows promise of increasing both the microcracking resistivity and the mechanical characteristics. Several carbon fiber composite plates were manufactured with varying concentrations of graphene and tested under both room and cryogenic conditions to characterize graphene's effect on the composite. Results from tensile and fracture testing indicate that the ideal concentration of graphene in our carbon fiber reinforced polymer composites for cryogenic applications is 0.08% mass graphene.

  11. [Raman spectra of carbon fibers during electrochemical treatment].

    Science.gov (United States)

    Zhang, Min; Zhu, Bo; Wang, Cheng-guo; Wei, Han-xing

    2010-01-01

    Laser Raman spectroscopy was employed to characterize the microstructure variations of polyacrylonitrile-based carbon fibers during electrochemical treatment, and the characteristics of first-order Raman spectra of carbon fibers with different treatment time were investigated in the present paper. The results indicate that the Raman spectra of the carbon fibers can be fitted into four bands, named as D (or D1) band, G band, D2 band and D3 band, respectively. The Raman parameters to characterize surface microstructure variations of carbon fibers mainly include R(I(D2)) / I(G), area ratio of D band and G band), I(D2) / I(G) (area ratio of D2 band and G band), I(D3) / I(G) (area ratio of D3 band and G band), and I(D(S))/ I(G) (area ratio of all the disordered structure and G band). The peak separation between D band and G band becomes large after electrochemical treatment. R increases, which indicates that the surface disordered degree of carbon fibers increases. I(D3) / I(G) increases, which is caused by organic molecules, fragments or functional groups; decreases which is caused by the break of the aliphatic structures. With increasing treatment time, I(D(S)) / I(G) increases continuously, and the change trend of l(D(S)) / I(G) is consistent with that of R value, which can be used to comprehensively explain the variation of the surface structure of carbon fibers. So, the variety rules of the structure of carbon fibers can be investigated by laser Raman spectroscopy during electrochemical treatment.

  12. E-beam-Cure Fabrication of Polymer Fiber/Matrix Composites for Multifunctional Radiation Shielding

    Science.gov (United States)

    Wilson, John W.; Jensen, Brian J.; Thibeault, Sheila A.; Hou, Tan-Hung; Saether, Erik; Glaessgen, Edward H.; Humes, Donald H.; Chang, Chie K.; Badavi, Francis F.; Kiefer, Rrichard L.; Adams, Dan O.

    2004-01-01

    Aliphatic polymers were identified as optimum radiation polymeric shielding materials for building multifunctional structural elements. Conceptual damage-tolerant configurations of polyolefins have been proposed but many issues on the manufacture remain. In the present paper, we will investigate fabrication technologies with e-beam curing for inclusion of high-strength aliphatic polymer fibers into a highly cross-linked polyolefin matrix. A second stage of development is the fabrication methods for applying face sheets to aliphatic polymer closed-cell foams.

  13. Hierarchical composite structures prepared by electrophoretic deposition of carbon nanotubes onto glass fibers.

    Science.gov (United States)

    An, Qi; Rider, Andrew N; Thostenson, Erik T

    2013-03-01

    Carbon nanotube/glass fiber hierarchical composite structures have been produced using an electrophoretic deposition (EPD) approach for integrating the carbon nanotubes (CNTs) into unidirectional E-glass fabric, followed by infusion of an epoxy polymer matrix. The resulting composites show a hierarchical structure, where the structural glass fibers, which have diameters in micrometer range, are coated with CNTs having diameters around 10-20 nm. The stable aqueous dispersions of CNTs were produced using a novel ozonolysis and ultrasonication technique that results in dispersion and functionalization in a single step. Ozone-oxidized CNTs were then chemically reacted with a polyethyleneimine (PEI) dendrimer to enable cathodic EPD and promote adhesion between the CNTs and the glass-fiber substrate. Deposition onto the fabric was accomplished by placing the fabric in front of the cathode and applying a direct current (DC) field. Microscopic characterization shows the integration of CNTs throughout the thickness of the glass fabric, where individual fibers are coated with CNTs and a thin film of CNTs also forms on the fabric surfaces. Within the composite, networks of CNTs span between adjacent fibers, and the resulting composites exhibit good electrical conductivity and considerable increases in the interlaminar shear strength, relative to fiber composites without integrated CNTs. Mechanical, chemical and morphological characterization of the coated fiber surfaces reveal interface/interphase modification resulting from the coating is responsible for the improved mechanical and electrical properties. The CNT-coated glass-fiber laminates also exhibited clear changes in electrical resistance as a function of applied shear strain and enables self-sensing of the transition between elastic and plastic load regions.

  14. [Raman spectra of PAN-based carbon fibers during graphitization].

    Science.gov (United States)

    Li, Dong-Feng; Wang, Hao-Jing; Wang, Xin-Kui

    2007-11-01

    Laser Raman spectroscopy was employed to characterize the structure of PAN-based carbon fibers during graphitization (2 000-3 000 degrees C), and the spectra of the surface and the cross section of the fibers were compared. The results show that the Raman spectra of the fibers after graphitization can be separated as three bands (D, G and D'). The degree of disorder of the fibers can be measured by Raman spectra parameter, such as the full-widths at half maximum (FWHM) of D and G bands, Raman shift of G band, and the integrated intensity ratio in the form of R(I(D) I(G)). Further investigation demonstrated that the FWHM of D and G bands, Raman shift of G band and the value of R decrease with increasing heat treatment temperature (HTT). The D band can be seen and the value of R is 0.19 even after being heat treated at 3 000 V, indicting that the fibers still have disordered carbons. In addition, the value of R is linearly related to the reciprocal of the basal plane length of the crystallites (L(a)). The spectra of the surface and the cross-section of the fibers after graphitization show obvious difference. So the degree of graphitization and preferred orientation of carbon fibers can be quantitatively characterized by laser Raman spectroscopy.

  15. Use of Carbon Fiber Composite Molecular Sieves for Air Separation

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Frederick S [ORNL; Contescu, Cristian I [ORNL; Gallego, Nidia C [ORNL; Burchell, Timothy D [ORNL

    2005-09-01

    A novel adsorbent material, 'carbon fiber composite molecular sieve' (CFCMS), has been developed by the Oak Ridge National Laboratory. Its features include high surface area, large pore volume, and a rigid, permeable carbon structure that exhibits significant electrical conductivity. The unique combination of high adsorptive capacity, permeability, good mechanical properties, and electrical conductivity represents an enabling technology for the development of novel gas separation and purification systems. In this context, it is proposed that a fast-cycle air separation process that exploits a kinetic separation of oxygen and nitrogen should be possible using a CFCMS material coupled with electrical swing adsorption (ESA). The adsorption of O{sub 2}, N{sub 2}, and CO{sub 2} on activated carbon fibers was investigated using static and dynamic techniques. Molecular sieving effects in the activated carbon fiber were highlighted by the adsorption of CO{sub 2}, a more sensitive probe molecule for the presence of microporosity in adsorbents. The kinetic studies revealed that O2 was more rapidly adsorbed on the carbon fiber than N{sub 2}, and with higher uptake under equilibrium conditions, providing the fiber contained a high proportion of very narrow micropores. The work indicated that CFCMS is capable of separating O{sub 2} and N{sub 2} from air on the basis of the different diffusion rates of the two molecules in the micropore network of the activated carbon fibers comprising the composite material. In response to recent enquires from several potential users of CFCMS materials, attention has been given to the development of a viable continuous process for the commercial production of CFCMS material. As part of this effort, work was implemented on characterizing the performance of lignin-based activated carbon fiber, a potentially lower cost fiber than the pitch-based fibers used for CFCMS production to date. Similarly, to address engineering issues

  16. Semiempirical Methodology for Estimating the Service Life of Concrete Deck Panels Strengthened with Fiber-Reinforced Polymer

    Directory of Open Access Journals (Sweden)

    Eon-Kyoung Kim

    2014-01-01

    Full Text Available Deterioration of concrete bridge decks affects their durability, safety, and function. It is therefore necessary to conduct structural rehabilitation of damaged concrete decks by strengthening them with fiber-reinforced polymer. Of the recent studies on the strengthened structures, most have focused on static behavior; only a few studies have investigated fatigue behavior. Accurate analysis of fatigue in concrete deck performance requires a more realistic simulated moving load. This study developed a theoretical live-load model to reflect the effect of moving vehicle loads, based on a statistical approach to the measurement of real traffic loads over various time periods in Korea. It assessed the fatigue life and strengthening effect of bridge decks strengthened with either carbon fiber sheets or grid carbon fiber polymer plastic using probabilistic and reliability analyses. It used extrapolations and simulations to derive maximum load effects for time periods ranging from 1 day to 75 years. Limited fatigue tests were conducted and probabilistic and reliability analyses were carried out on the strengthened concrete bridge deck specimens to predict the extended fatigue life. Analysis results indicated that strengthened concrete decks provide sufficient resistance against increasing truck loads during the service life of a bridge.

  17. A Review on Natural Fiber Reinforced Polymer Composite and Its Applications

    Directory of Open Access Journals (Sweden)

    Layth Mohammed

    2015-01-01

    Full Text Available Natural fibers are getting attention from researchers and academician to utilize in polymer composites due to their ecofriendly nature and sustainability. The aim of this review article is to provide a comprehensive review of the foremost appropriate as well as widely used natural fiber reinforced polymer composites (NFPCs and their applications. In addition, it presents summary of various surface treatments applied to natural fibers and their effect on NFPCs properties. The properties of NFPCs vary with fiber type and fiber source as well as fiber structure. The effects of various chemical treatments on the mechanical and thermal properties of natural fibers reinforcements thermosetting and thermoplastics composites were studied. A number of drawbacks of NFPCs like higher water absorption, inferior fire resistance, and lower mechanical properties limited its applications. Impacts of chemical treatment on the water absorption, tribology, viscoelastic behavior, relaxation behavior, energy absorption flames retardancy, and biodegradability properties of NFPCs were also highlighted. The applications of NFPCs in automobile and construction industry and other applications are demonstrated. It concluded that chemical treatment of the natural fiber improved adhesion between the fiber surface and the polymer matrix which ultimately enhanced physicomechanical and thermochemical properties of the NFPCs.

  18. Exploring a novel multifunctional agent to improve the dispersion of short aramid fiber in polymer matrix

    Directory of Open Access Journals (Sweden)

    K. Naskar

    2012-04-01

    Full Text Available Composites based on resorcinol formaldehyde latex (RFL coated aramid short fiber and a polyolefin based thermoplastic elastomer, namely ethylene octene copolymer (EOC were prepared by melt mixing technique. The effects of both fiber loading and its length on the mechanical and thermal characteristics of the composite under natural and sheared conditions were investigated. Both the low strain modulus and Young’s modulus were increased as a function of fiber loading and length. However, thermal stability of the composite was found to enhance with increase in fiber loading and was independent of fiber length. Due to poor interfacial interaction between the fiber and the matrix and the formation of fiber aggregation especially with 6 mm fiber at high loading, the elongation and toughness of the composite were found to decrease drastically. In order to solve this problem, a maleic anhydride adducted polybutadiene (MA-g-PB was applied on the aramid fiber. The improvements in tensile strength, elongation at break, toughness to stiffness balance and a good quality of fiber dispersion especially with 6 mm short fiber were achieved. These results indicate the potential use of maleic anhydride adducted PB as a multifunctional interface modifying coupling agent for the aramid short fiber reinforced polymers to enhance the mechanical properties as well as fiber dispersion. FTIR analyses of the treated fiber and SEM analyses of the tensile fractured surfaces of the composite strongly support and explain these results.

  19. Fiber-optic liquid level monitoring system using microstructured polymer fiber Bragg grating array sensors: performance analysis

    DEFF Research Database (Denmark)

    Marques, C. A. F.; Pospori, A.; Saez-Rodriguez, D.

    2015-01-01

    A highly sensitive liquid level monitoring system based on microstructured polymer optical fiber Bragg grating (mPOFBG) array sensors is reported for the first time. The configuration is based on five mPOFBGs inscribed in the same fiber in the 850 nm spectral region, showing the potential...... of the sensor is found to be 98 pm/cm of water, enhanced by more than a factor of 9 when compared to an equivalent sensor based on a silica fiber around 1550 nm. The temperature sensitivity is studied and a multi-sensor arrangement proposed, which has the potential to provide level readings independent...

  20. A comparative study of carbon fiber-based microelectrodes for the measurement of nitric oxide in brain tissue.

    Science.gov (United States)

    Santos, Ricardo M; Lourenço, Cátia F; Piedade, Ana P; Andrews, Rodney; Pomerleau, François; Huettl, Peter; Gerhardt, Greg A; Laranjinha, João; Barbosa, Rui M

    2008-12-01

    The measurement of Nitric oxide (NO) in real-time has been a major concern due to the involvement of this ubiquitous free radical modulator in several physiological and pathological pathways in tissues. Here we performed a study aiming at evaluating different types of carbon fibers, namely Textron, Amoco, Courtaulds and carbon nanotubes (University of Kentucky) covered with Nafion/o-phenylenediamine (o-PD) for NO measurement in terms of sensitivity, LOD, response time and selectivity against major potential interferents in the brain (ascorbate, nitrite and dopamine). The results indicate that, as compared with the other carbon fibers and nanotubes, Textron carbon fiber microelectrodes coated with two layers of Nafion and o-PD exhibited better characteristics for NO measurement as they are highly selective against ascorbate (>30,000:1), nitrite (>2000:1) and dopamine (>80:1). These coated Textron microelectrodes showed an average sensitivity of 341+/-120pA/microM and a detection limit of 16+/-11nM. The better performance of the Textron fibers is likely related to a stronger adhesion or more uniform coating of the Nafion and o-PD polymers to the fiber surface. In addition, the background current of the Textron carbon fibers is low, contributing to the excellent signal-to-noise for detection of NO.