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Sample records for carbon nanotube materials

  1. Carbon nanotube composite materials

    Energy Technology Data Exchange (ETDEWEB)

    O' Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2015-03-24

    A material consisting essentially of a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes dissolved in a solvent. Un-functionalized carbon nanotube concentrations up to 30 wt % and hydroxylated carbon nanotube concentrations up to 40 wt % can be used with even small concentrations of each (less than 2 wt %) useful in producing enhanced conductivity properties of formed thin films.

  2. Carbon Nanotube Composites: Strongest Engineering Material Ever?

    Science.gov (United States)

    Mayeaux, Brian; Nikolaev, Pavel; Proft, William; Nicholson, Leonard S. (Technical Monitor)

    1999-01-01

    The primary goal of the carbon nanotube project at Johnson Space Center (JSC) is to fabricate structural materials with a much higher strength-to-weight ratio than any engineered material today, Single-wall nanotubes present extraordinary mechanical properties along with new challenges for materials processing. Our project includes nanotube production, characterization, purification, and incorporation into applications studies. Now is the time to move from studying individual nanotubes to applications work. Current research at JSC focuses on structural polymeric materials to attempt to lower the weight of spacecraft necessary for interplanetary missions. These nanoscale fibers present unique new challenges to composites engineers. Preliminary studies show good nanotube dispersion and wetting by the epoxy materials. Results of tensile strength tests will also be reported. Other applications of nanotubes are also of interest for energy storage, gas storage, nanoelectronics, field emission, and biomedical uses.

  3. Carbon nanotube materials from hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, A.C.; Bekkedahl, T.A.; Cahill, A.F. [National Renewable Energy Laboratory, Golden, CO (United States)

    1995-09-01

    The lack of convenient and cost-effective hydrogen storage is a major impediment to wide scale use of hydrogen in the United States energy economy. Improvements in the energy densities of hydrogen storage systems, reductions in cost, and increased compatibility with available and forecasted systems are required before viable hydrogen energy use pathways can be established. Carbon-based hydrogen adsorption materials hold particular promise for meeting and exceeding the U.S. Department of Energy hydrogen storage energy density targets for transportation if concurrent increases in hydrogen storage capacity and carbon density can be achieved. These two goals are normally in conflict for conventional porous materials, but may be reconciled by the design and synthesis of new adsorbent materials with tailored pore size distributions and minimal macroporosity. Carbon nanotubes offer the possibility to explore new designs for adsorbents because they can be fabricated with small size distributions, and naturally tend to self-assemble by van der Waals forces. This year we report heats of adsorption for hydrogen on nanotube materials that are 2 and 3 times greater than for hydrogen on activated carbon. The hydrogen which is most strongly bound to these materials remains on the carbon surface to temperatures greater than 285 K. These results suggest that nanocapillary forces are active in stabilizing hydrogen on the surfaces of carbon nanotubes, and that optimization of the adsorbent will lead to effective storage at higher temperatures. In this paper we will also report on our activities which are targeted at understanding and optimizing the nucleation and growth of single wall nanotubes. These experiments were made possible by the development of a unique feedback control circuit which stabilized the plasma-arc during a synthesis run.

  4. Carbon nanotube materials for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, A.C.; Parilla, P.A.; Jones, K.M.; Riker, G.; Heben, M.J. [National Renewable Energy Lab., Golden, CO (United States)

    1998-08-01

    Carbon single-wall nanotubes (SWNTs) are essentially elongated pores of molecular dimensions and are capable of adsorbing hydrogen at relatively high temperatures and low pressures. This behavior is unique to these materials and indicates that SWNTs are the ideal building block for constructing safe, efficient, and high energy density adsorbents for hydrogen storage applications. In past work the authors developed methods for preparing and opening SWNTs, discovered the unique adsorption properties of these new materials, confirmed that hydrogen is stabilized by physical rather than chemical interactions, measured the strength of interaction to be {approximately} 5 times higher than for adsorption on planar graphite, and performed infrared absorption spectroscopy to determine the chemical nature of the surface terminations before, during, and after oxidation. This year the authors have made significant advances in synthesis and characterization of SWNT materials so that they can now prepare gram quantities of high-purity SWNT samples and measure and control the diameter distribution of the tubes by varying key parameters during synthesis. They have also developed methods which purify nanotubes and cut nanotubes into shorter segments. These capabilities provide a means for opening the tubes which were unreactive to the oxidation methods that successfully opened tubes, and offer a path towards organizing nanotube segments to enable high volumetric hydrogen storage densities. They also performed temperature programmed desorption spectroscopy on high purity carbon nanotube material obtained from collaborator Prof. Patrick Bernier and finished construction of a high precision Seivert`s apparatus which will allow the hydrogen pressure-temperature-composition phase diagrams to be evaluated for SWNT materials.

  5. Graphene-carbon nanotube hybrid materials and use as electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Tour, James M.; Zhu, Yu; Li, Lei; Yan, Zheng; Lin, Jian

    2016-09-27

    Provided are methods of making graphene-carbon nanotube hybrid materials. Such methods generally include: (1) associating a graphene film with a substrate; (2) applying a catalyst and a carbon source to the graphene film; and (3) growing carbon nanotubes on the graphene film. The grown carbon nanotubes become covalently linked to the graphene film through carbon-carbon bonds that are located at one or more junctions between the carbon nanotubes and the graphene film. In addition, the grown carbon nanotubes are in ohmic contact with the graphene film through the carbon-carbon bonds at the one or more junctions. The one or more junctions may include seven-membered carbon rings. Also provided are the formed graphene-carbon nanotube hybrid materials.

  6. Carbon nanotube materials for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, A.C.; Jones, K.M.; Heben, M.J. [National Renewable Energy Lab., Golden, CO (United States)

    1996-10-01

    Hydrogen burns pollution-free and may be produced from renewable energy resources. It is therefore an ideal candidate to replace fossil fuels as an energy carrier. However, the lack of a convenient and cost-effective hydrogen storage system greatly impedes the wide-scale use of hydrogen in both domestic and international markets. Although several hydrogen storage options exist, no approach satisfies all of the efficiency, size, weight, cost and safety requirements for transportation or utility use. A material consisting exclusively of micropores with molecular dimensions could simultaneously meet all of the requirements for transportation use if the interaction energy for hydrogen was sufficiently strong to cause hydrogen adsorption at ambient temperatures. Small diameter ({approx}1 mm) carbon single-wall nanotubes (SWNTs) are elongated micropores of molecular dimensions, and materials composed predominantly of SWNTs may prove to be the ideal adsorbent for ambient temperature storage of hydrogen. Last year the authors reported that hydrogen could be adsorbed on arc-generated soots containing 12{Angstrom} diameter nanotubes at temperatures in excess of 285K. In this past year they have learned that such adsorption does not occur on activated carbon materials, and that the cobalt nanoparticles present in their arc-generated soots are not responsible for the hydrogen which is stable at 285 K. These results indicate that enhanced adsorption forces within the internal cavities of the SWNTs are active in stabilizing hydrogen at elevated temperatures. This enhanced stability could lead to effective hydrogen storage under ambient temperature conditions. In the past year the authors have also demonstrated that single-wall carbon nanotubes in arc-generated soots may be selectively opened by oxidation in H{sub 2}O resulting in improved hydrogen adsorption, and they have estimated experimentally that the amount of hydrogen stored is {approximately}10% of the nanotube weight.

  7. Carbon Nanotubes Filled with Ferromagnetic Materials

    Directory of Open Access Journals (Sweden)

    Albrecht Leonhardt

    2010-08-01

    Full Text Available Carbon nanotubes (CNT filled with ferromagnetic metals like iron, cobalt or nickel are new and very interesting nanostructured materials with a number of unique properties. In this paper we give an overview about different chemical vapor deposition (CVD methods for their synthesis and discuss the influence of selected growth parameters. In addition we evaluate possible growth mechanisms involved in their formation. Moreover we show their identified structural and magnetic properties. On the basis of these properties we present different application possibilities. Some selected examples reveal the high potential of these materials in the field of medicine and nanotechnology.

  8. Functional Materials based on Carbon Nanotubes

    OpenAIRE

    Jung, Adrian Thomas

    2007-01-01

    Carbon nanotubes, no matter if they are single-walled or multi-walled, are an integral component in the vastly growing field of nanotechnology. Since their discovery by TEM and the invention of numerous large-scale production techniques, nanotubes are close to making their way into industrial products. Although many properties and modification processes are still under intensive research, the first real-market applications for carbon nanotubes have already been presented. However, if function...

  9. Covalent Crosslinking of Carbon Nanotube Materials for Improved Tensile Strength

    Science.gov (United States)

    Baker, James S.; Miller, Sandi G.; Williams, Tiffany A.; Meador, Michael A.

    2013-01-01

    Carbon nanotubes have attracted much interest in recent years due to their exceptional mechanical properties. Currently, the tensile properties of bulk carbon nanotube-based materials (yarns, sheets, etc.) fall far short of those of the individual nanotube elements. The premature failure in these materials under tensile load has been attributed to inter-tube sliding, which requires far less force than that needed to fracture individual nanotubes.1,2 In order for nanotube materials to achieve their full potential, methods are needed to restrict this tube-tube shear and increase inter-tube forces.Our group is examining covalent crosslinking between the nanotubes as a means to increase the tensile properties of carbon nanotube materials. We are working with multi-walled carbon nanotube (MWCNT) sheet and yarn materials obtained from commercial sources. Several routes to functionalize the nanotubes have been examined including nitrene, aryl diazonium, and epoxide chemistries. The functional nanotubes were crosslinked through small molecule or polymeric bridges. Additionally, electron beam irradiation induced crosslinking of the non-functional and functional nanotube materials was conducted. For example, a nanotube sheet material containing approximately 3.5 mol amine functional groups exhibited a tensile strength of 75 MPa and a tensile modulus of 1.16 GPa, compared to 49 MPa and 0.57 GPa, respectively, for the as-received material. Electron beam irradiation (2.2x 1017 ecm2) of the same amine-functional sheet material further increased the tensile strength to 120 MPa and the modulus to 2.61 GPa. This represents approximately a 150 increase in tensile strength and a 360 increase in tensile modulus over the as-received material with only a 25 increase in material mass. Once we have optimized the nanotube crosslinking methods, the performance of these materials in polymer matrix composites will be evaluated.

  10. Carbon Nanotubes: Miracle of Materials Science?

    Science.gov (United States)

    Files, Bradley S.; Mayeaux, Brian M.

    1999-01-01

    Article to be sent to Advanced Materials and Processes, journal of ASM International, as attached. This is a news-type technical journal for a large organization of scientists, engineers, salesmen, and managers. The article is quite general, meant to be an introduction to the properties of nanotubes. This is a materials science organization, therefore the article is geared toward using nanotubes for materials uses. Pictures have not been included in this version.

  11. Carbon nanotube-based functional materials for optical limiting.

    Science.gov (United States)

    Chen, Yu; Lin, Ying; Liu, Ying; Doyle, James; He, Nan; Zhuang, Xiaodong; Bai, Jinrui; Blau, Werner J

    2007-01-01

    Optical limiting is an important application of nonlinear optics, useful for the protection of human eyes, optical elements, and optical sensors from intense laser pulses. An optical limiter is such a device that strongly attenuates high intensity light and potentially damaging light such as focused laser beams, whilst allowing for the high transmission of ambient light. Optical limiting properties of carbon nanotube suspensions, solubilized carbon nanotubes, small molecules doped carbon nanotubes and polymer/carbon nanotube composites have been reviewed. The optical limiting responses of carbon nanotube suspensions are shown to be dominated by nonlinear scattering as a result of thermally induced solvent-bubble formation and sublimation of the nanotubes, while the solubilized carbon nanotubes optically limit through nonlinear absorption mechanism and exhibit significant solution-concentration-dependent optical limiting responses. In the former case the optical limiting results are independent of nanotube concentrations at the same linear transmittance as that of the solubilized systems. Many efforts have been invested into the research of polymer/carbon nanotube composites in an attempt to allow for the fabrication of films required for the use of nanotubes in a real optical limiting application. The higher carbon nanotube content samples block the incident light more effectively at higher incident energy densities or intensities. The optical limiting mechanism of these composite materials is quite complicated. Besides nonlinear scattering contribution to the optical limiting, there may also be other contributions e.g., nonlinear absorption, nonlinear refraction, electronic absorption and others to the optical limiting. Further improvements in the optical limiting efficiency of the composites and in the dispersion and alignment properties of carbon nanotubes in the polymer matrix could be realized by variation of both nanostructured guest and polymer host, and by

  12. Electromagnetic characteristics of carbon nanotube film materials

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2015-08-01

    Full Text Available Carbon nanotube (CNT possesses remarkable electrical conductivity, which shows great potential for the application as electromagnetic shielding material. This paper aims to characterize the electromagnetic parameters of a high CNT loading film by using waveguide method. The effects of layer number of CNT laminate, CNT alignment and resin impregnation on the electromagnetic characteristics were analyzed. It is shown that CNT film exhibits anisotropic electromagnetic characteristic. Pristine CNT film shows higher real part of complex permittivity, conductivity and shielding effectiveness when the polarized direction of incident wave is perpendicular to the winding direction of CNT film. For the CNT film laminates, complex permittivity increases with increasing layer number, and correspondingly, shielding effectiveness decreases. The five-layer CNT film shows extraordinary shielding performance with shielding effectiveness ranging from 67 dB to 78 dB in X-band. Stretching process induces the alignment of CNTs. When aligned direction of CNTs is parallel to the electric field, CNT film shows negative permittivity and higher conductivity. Moreover, resin impregnation into CNT film leads to the decrease of conductivity and shielding effectiveness. This research will contribute to the structural design for the application of CNT film as electromagnetic shielding materials.

  13. Obtaining New Dental Materials Reinforced with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    I.V. Zaporotskova

    2014-07-01

    Full Text Available The article seeks to explore the change of strength properties of composite polymer material on the basis of fast-hardening dental plastic "Carbogen", when reinforcing its coal-native nanotubes. Were discussed peculiarities of composition of Carboante, ways of creation of polymeric composition deposits by doping their carbon nanotubes, the results of measuring the strength characteristic characteristics obtained new polymer materials. On the basis of the analysis of the practical and the theoretical-sky research, conclusions were drawn on the feasibility of a new filling material with the use of carbon nanotubes with unique strength characteristics and use of their in dentistry.

  14. Improved Composites Using Crosslinked, Surface-Modified Carbon Nanotube Materials

    Science.gov (United States)

    Baker, James Stewart

    2014-01-01

    Individual carbon nanotubes (CNTs) exhibit exceptional tensile strength and stiffness; however, these properties have not translated well to the macroscopic scale. Premature failure of bulk CNT materials under tensile loading occurs due to the relatively weak frictional forces between adjacent CNTs, leading to poor load transfer through the material. When used in polymer matrix composites (PMCs), the weak nanotube-matrix interaction leads to the CNTs providing less than optimal reinforcement.Our group is examining the use of covalent crosslinking and surface modification as a means to improve the tensile properties of PMCs containing carbon nanotubes. Sheet material comprised of unaligned multi-walled carbon nanotubes (MWCNT) was used as a drop-in replacement for carbon fiber in the composites. A variety of post-processing methods have been examined for covalently crosslinking the CNTs to overcome the weak inter-nanotube shear interactions, resulting in improved tensile strength and modulus for the bulk sheet material. Residual functional groups from the crosslinking chemistry may have the added benefit of improving the nanotube-matrix interaction. Composites prepared using these crosslinked, surface-modified nanotube sheet materials exhibit superior tensile properties to composites using the as received CNT sheet material.

  15. Carbon nanotubes grown on bulk materials and methods for fabrication

    Science.gov (United States)

    Menchhofer, Paul A.; Montgomery, Frederick C.; Baker, Frederick S.

    2011-11-08

    Disclosed are structures formed as bulk support media having carbon nanotubes formed therewith. The bulk support media may comprise fibers or particles and the fibers or particles may be formed from such materials as quartz, carbon, or activated carbon. Metal catalyst species are formed adjacent the surfaces of the bulk support material, and carbon nanotubes are grown adjacent the surfaces of the metal catalyst species. Methods employ metal salt solutions that may comprise iron salts such as iron chloride, aluminum salts such as aluminum chloride, or nickel salts such as nickel chloride. Carbon nanotubes may be separated from the carbon-based bulk support media and the metal catalyst species by using concentrated acids to oxidize the carbon-based bulk support media and the metal catalyst species.

  16. Carbon nanotube prepared from carbon monoxide by CVD method and its application as electrode materials

    Institute of Scientific and Technical Information of China (English)

    AN Yuliang; YUAN Xia; CHENG Shinan; GEN Xin

    2006-01-01

    Carbon nanotubes with larger inner diameter were synthesized by the chemical vapor deposition of carbon monoxide (CO) on iron catalyst using H2S as promoting agent.It is found that the structure and morphology of carbon nanotubes can be tailored, to some degree, by varying the experimental conditions such as precursor components and process parameters.The results show that the presence of H2S may play key role for growing Y-branched carbon nanotubes.The products were characterized by SEM, TEM, and Raman spectroscopy, respectively.Furthermore, the obtained carbon nanotubes were explored as electrode materials for supercapacitor.

  17. Exposure to Carbon Nanotube Material: Assessment of Nanotube Cytotoxicity Using Human Keratinocyte Cells

    Science.gov (United States)

    Shvedova, Anna A.; Castranova, Vincent; Kisin, Elena R.; Schwegler-Berry, Diane; Murray, Ashley R.; Gandelsman, Vadim Z.; Maynard, Andrew; Baron, Paul

    2003-01-01

    Carbon nanotubes are new members of carbon allotropes similar to fullerenes and graphite. Because of their unique electrical, mechanical, and thermal properties, carbon nanotubes are important for novel applications in the electronics, aerospace, and computer industries. Exposure to graphite and carbon materials has been associated with increased incidence of skin diseases, such as carbon fiber dermatitis, hyperkeratosis, and naevi. We investigated adverse effects of single-wall carbon nanotubes (SWCNT) using a cell culture of immortalized human epidermal keratinocytes (HaCaT). After 18 h of exposure of HaCaT to SWCNT, oxidative stress and cellular toxicity were indicated by formation of free radicals, accumulation of peroxidative products, antioxidant depletion, and loss of cell viability. Exposure to SWCNT also resulted in ultrastructural and morphological changes in cultured skin cells. These data indicate that dermal exposure to unrefined SWCNT may lead to dermal toxicity due to accelerated oxidative stress in the skin of exposed workers.

  18. Material and structural instabilities of single-wall carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    J. Wu; K. C. Hwang; J. Song; Y. Huang

    2008-01-01

    The nonlinear atomistic interactions usually involve softening behavior. Instability resulting directly from this softening are called the material instability, while those unrelated to this softening are called the structural instability. We use the finite-deformation shell theory based on the interatomic potential to show that the tension instability of single-wall carbon nanotubes is the material instability, while the compression and torsion instabilities are structural instability.

  19. Advanced materials based on carbon nanotube arrays, yarns and papers

    Science.gov (United States)

    Bradford, Phlip David

    Carbon nanotubes have hundreds of potential applications but require innovative processing techniques to manipulate the microscopic carbon dust into useful devices and products. This thesis describes efforts to process carbon nanotubes (CNTs) using novel methods with the goals of: (1) improving the properties of energy absorbing and composite carbon nanotube materials and (2) increasing understanding of fundamental structure-property relationships within these materials. Millimeter long CNTs, in the form of arrays, yarns and papers, were used to produce energy absorbing foams and high volume fraction CNT composites. Vertically aligned CNT arrays were grown on silicon substrates using chemical vapor deposition (CVD) of ethylene gas over iron nano-particles. The low density, millimeter thick arrays were tested under compression as energy absorbing foams. With additional CVD processing steps, it was possible to tune the compressive properties of the arrays. After the longest treatment, the compressive strength of the arrays was increased by a factor of 35 with a density increase of only six fold, while also imparting recovery from compression to the array. Microscopy revealed that the post-synthesis CVD treatment increased the number of CNT walls through an epitaxial type radial growth on the surface of the as-grown tubes. The increase in tube radius and mutual support between nanotubes explained the increases in compressive strength while an increase in nanotube roughness was proposed as the morphological change responsible for recovery in the array. Carbon nanotube yarns were used as the raw material for macroscopic textile preforms with a multi-level hierarchical carbon nanotube (CNT) structure: nanotubes, bundles, spun single yarns, plied yarns and 3-D braids. In prior tensile tests, composites produced from the 3-D braids exhibited unusual mechanical behavior effects. The proposed physical hypotheses explained those effects by molecular level interactions and

  20. Carbon nanotube nanoelectrode arrays

    Science.gov (United States)

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  1. Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials

    CERN Document Server

    Levitsky, Igor A; Karachevtsev, Victor A

    2012-01-01

    Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials describes physical, optical and spectroscopic properties of the emerging class of nanocomposites formed from carbon nanotubes (CNTs)  interfacing with organic and inorganic materials. The three main chapters detail novel trends in  photophysics related to the interaction of  light with various carbon nanotube composites from relatively simple CNT/small molecule assemblies to complex hybrids such as CNT/Si and CNT/DNA nanostructures.   The latest experimental results are followed up with detailed discussions and scientific and technological perspectives to provide a through coverage of major topics including: ·   Light harvesting, energy conversion, photoinduced charge separation  and transport  in CNT based nanohybrids · CNT/polymer composites exhibiting photoactuation; and ·         Optical  spectroscopy  and structure of CNT/DNA complexes. Including original data and a short review of recent research, Phot...

  2. Single-walled Carbon Nanotubes as Electrode Materials for Supercapacitors

    Institute of Scientific and Technical Information of China (English)

    XU Bina; WU Feng; WANG Fang; CHEN Shi; CAO Gao-Ping; YANG Yu-Sheng

    2006-01-01

    Large-scale synthesized single-walled carbon nanotubes (SWNT) prepared by electric arc discharge method and a mixture of NiO and Y2O3 as catalyst have been used as electrode materials for supercapacitors. N2 adsorption/desorption measurement shows that the SWNT is a microporous and mesoporous material with specific surface area 435 m2g1.Thespecific capacitance of the nitric acid treated SWNT in aqueous electrolyte reaches as high as 105 F/g, which is a combination of electric double layer capacitance and pseudocapacitance. The SWNT-based capacitors also have good charge/discharge reversibility and cycling perdurability.

  3. Multilayer Electroactive Polymer Composite Material Comprising Carbon Nanotubes

    Science.gov (United States)

    Ounaies, Zoubeida (Inventor); Park, Cheol (Inventor); Harrison, Joycelyn S. (Inventor); Holloway, Nancy M. (Inventor); Draughon, Gregory K. (Inventor)

    2009-01-01

    An electroactive material comprises multiple layers of electroactive composite with each layer having unique dielectric, electrical and mechanical properties that define an electromechanical operation thereof when affected by an external stimulus. For example, each layer can be (i) a 2-phase composite made from a polymer with polarizable moieties and an effective amount of carbon nanotubes incorporated in the polymer for a predetermined electromechanical operation, or (ii) a 3-phase composite having the elements of the 2-phase composite and further including a third component of micro-sized to nano-sized particles of an electroactive ceramic incorporated in the polymer matrix.

  4. Computational Nanotechnology of Materials, Electronics and Machines: Carbon Nanotubes

    Science.gov (United States)

    Srivastava, Deepak

    2001-01-01

    This report presents the goals and research of the Integrated Product Team (IPT) on Devices and Nanotechnology. NASA's needs for this technology are discussed and then related to the research focus of the team. The two areas of focus for technique development are: 1) large scale classical molecular dynamics on a shared memory architecture machine; and 2) quantum molecular dynamics methodology. The areas of focus for research are: 1) nanomechanics/materials; 2) carbon based electronics; 3) BxCyNz composite nanotubes and junctions; 4) nano mechano-electronics; and 5) nano mechano-chemistry.

  5. Chemically modified carbon nanotubes as material enhanced laser desorption ionisation (MELDI) material in protein profiling

    International Nuclear Information System (INIS)

    Biomarkers play a potential role in the early detection and diagnosis of a disease. Our aim is to derivatize carbon nanotubes for exploration of the differences in human body fluids e.g. serum, through matrix assisted laser desorption ionisation/time of flight mass spectrometry (MALDI/TOF-MS) that can be related to disease and subsequently to be employed in the biomarker discovery process. This application we termed as the material enhanced laser desorption ionisation (MELDI). The versatility of this technology is meant to increase the amount of information from biological samples on the protein level, which will have a major impact to serve the cause of diagnostic markers. Serum peptides and proteins are immobilized on derivatized carbon nanotubes, which function as binding material. Protein-loaded suspension is placed on a stainless steel target or buckypaper on aluminum target for direct analysis with MALDI-MS. The elution method to wash the bound proteins from carbon nanotubes was employed to compare with the direct analysis procedure. Elution is carried out by MALDI matrix solution to get them out of the entangled nanotubes, which are difficult to desorb by laser due to the complex nanotube structures. The advantage of these optimized methods compared to the conventional screening methods is the improved sensitivity, selectivity and the short analysis time without prior albumin and immunoglobulin depletion. The comparison of similarly modified diamond and carbon nanotubes exhibit differences in their nature to bind the proteins out of serum due to the differences in their physical characteristics. Infrared (IR) spectroscopy provided hint for the presence of tertiary amine peak at the crucial chemical step of iminodiacetic acid addition to acid chloride functionality on carbon nanotubes. Atomic absorption spectroscopy (AAS) was utilized to quantitatively measure the copper capacity of these derivatized carbon nanotubes which is a direct measure of capacity of

  6. Chemically modified carbon nanotubes as material enhanced laser desorption ionisation (MELDI) material in protein profiling

    Energy Technology Data Exchange (ETDEWEB)

    Najam-ul-Haq, M. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria); Rainer, M. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria); Schwarzenauer, T. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria); Huck, C.W. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria)]. E-mail: christian.w.huck@uibk.ac.at; Bonn, G.K. [Institute of Analytical Chemistry and Radiochemistry, Leopold-Franzens University, Innrain 52a, A-6020 Innsbruck (Austria)

    2006-03-02

    Biomarkers play a potential role in the early detection and diagnosis of a disease. Our aim is to derivatize carbon nanotubes for exploration of the differences in human body fluids e.g. serum, through matrix assisted laser desorption ionisation/time of flight mass spectrometry (MALDI/TOF-MS) that can be related to disease and subsequently to be employed in the biomarker discovery process. This application we termed as the material enhanced laser desorption ionisation (MELDI). The versatility of this technology is meant to increase the amount of information from biological samples on the protein level, which will have a major impact to serve the cause of diagnostic markers. Serum peptides and proteins are immobilized on derivatized carbon nanotubes, which function as binding material. Protein-loaded suspension is placed on a stainless steel target or buckypaper on aluminum target for direct analysis with MALDI-MS. The elution method to wash the bound proteins from carbon nanotubes was employed to compare with the direct analysis procedure. Elution is carried out by MALDI matrix solution to get them out of the entangled nanotubes, which are difficult to desorb by laser due to the complex nanotube structures. The advantage of these optimized methods compared to the conventional screening methods is the improved sensitivity, selectivity and the short analysis time without prior albumin and immunoglobulin depletion. The comparison of similarly modified diamond and carbon nanotubes exhibit differences in their nature to bind the proteins out of serum due to the differences in their physical characteristics. Infrared (IR) spectroscopy provided hint for the presence of tertiary amine peak at the crucial chemical step of iminodiacetic acid addition to acid chloride functionality on carbon nanotubes. Atomic absorption spectroscopy (AAS) was utilized to quantitatively measure the copper capacity of these derivatized carbon nanotubes which is a direct measure of capacity of

  7. Hot extruded carbon nanotube reinforced aluminum matrix composite materials

    Science.gov (United States)

    Kwon, Hansang; Leparoux, Marc

    2012-10-01

    Carbon nanotube (CNT) reinforced aluminum (Al) matrix composite materials were successfully fabricated by mechanical ball milling followed by powder hot extrusion processes. Microstructural analysis revealed that the CNTs were well dispersed at the boundaries and were aligned with the extrusion direction in the composites obtained. Although only a small quantity of CNTs were added to the composite (1 vol%), the Vickers hardness and the tensile strength were significantly enhanced, with an up to three-fold increase relative to that of pure Al. From the fractography of the extruded Al-CNT composite, several shapes were observed in the fracture surface, and this unique morphology is discussed based on the strengthening mechanism. The damage in the CNTs was investigated with Raman spectroscopy. However, the Al-CNT composite materials were not only strengthened by the addition of CNTs but also enhanced by several synergistic effects. The nanoindentation stress-strain curve was successfully constructed by setting the effective zero-load and zero-displacement points and was compared with the tensile stress-strain curve. The yield strengths of the Al-CNT composites from the nanoindentation and tensile tests were compared and discussed. We believe that the yield strength can be predicted using a simple nanoindentation stress/strain curve and that this method will be useful for materials that are difficult to machine, such as complex ceramics.

  8. Hot extruded carbon nanotube reinforced aluminum matrix composite materials

    International Nuclear Information System (INIS)

    Carbon nanotube (CNT) reinforced aluminum (Al) matrix composite materials were successfully fabricated by mechanical ball milling followed by powder hot extrusion processes. Microstructural analysis revealed that the CNTs were well dispersed at the boundaries and were aligned with the extrusion direction in the composites obtained. Although only a small quantity of CNTs were added to the composite (1 vol%), the Vickers hardness and the tensile strength were significantly enhanced, with an up to three-fold increase relative to that of pure Al. From the fractography of the extruded Al–CNT composite, several shapes were observed in the fracture surface, and this unique morphology is discussed based on the strengthening mechanism. The damage in the CNTs was investigated with Raman spectroscopy. However, the Al–CNT composite materials were not only strengthened by the addition of CNTs but also enhanced by several synergistic effects. The nanoindentation stress–strain curve was successfully constructed by setting the effective zero-load and zero-displacement points and was compared with the tensile stress–strain curve. The yield strengths of the Al–CNT composites from the nanoindentation and tensile tests were compared and discussed. We believe that the yield strength can be predicted using a simple nanoindentation stress/strain curve and that this method will be useful for materials that are difficult to machine, such as complex ceramics. (paper)

  9. Carbon nanotube reservoirs for self-healing materials

    Energy Technology Data Exchange (ETDEWEB)

    Lanzara, G [Department of Aeronautics and Astronautics, Stanford University (United States); Yoon, Y [Defense Acquisition Program Administration (DAPA) (Korea, Republic of); Liu, H; Peng, S [Department of Mechanical Engineering, Stanford University (United States); Lee, W-I, E-mail: glanzara@stanford.ed [Department of Mechanical and Aerospace Engineering, Seoul National University (Korea, Republic of)

    2009-08-19

    A novel nanoreservoir made of carbon nanotubes (CNTs) is proposed for realizing tougher and automated self-healing materials. The advantages of the approach are that CNTs have the potential to play the role of reinforcing elements prior to and after sealing a crack and that the number of voids is reduced after the material and the CNTs themselves are healed. The focus of this paper is on investigating the feasibility of using CNTs as a nanoreservoir by analyzing the dynamics of a fluid flowing out of a ruptured single-walled CNT (SWNT), where the fluid resembles an organic healing agent. With this in mind the escaping mechanism of organic molecules stored inside a cracked SWNT was investigated through a molecular dynamics study. The study shows that, when a SWNT wall suffers the formation of a crack, a certain amount of organic molecules, stored inside the SWNT, escape into space in a few picoseconds. This phenomenon is found to depend on the temperature and on the size of the cracks. The results of this study indicate that CNTs have the potential to be successfully used to realize the next generation of stronger, lighter and self-healing materials.

  10. EPR characterisation of platinum nanoparticle functionalised carbon nanotube hybrid materials.

    Science.gov (United States)

    Dennany, Lynn; Sherrell, Peter; Chen, Jun; Innis, Peter C; Wallace, Gordon G; Minett, Andrew I

    2010-04-28

    The use of nanostructured carbon materials as electrodes for energy storage and conversion is an expanding area of research in recent years. Herein, platinum nanoparticles have been deposited onto both multi-walled and single-walled carbon nanotubes (CNTs) via a microwave assisted polyol reduction method. This interaction has been probed with electron paramagnetic resonance (EPR) and Raman spectroscopies to elucidate the charge/electron transfer interactions between the Pt nanoparticles and the CNTs. Observed shifts in the g factors of the CNTs are indicative of such an electronic interaction, strongly suggesting the covalent attachment of the nanoparticles to the carboxylic groups on the CNTs, formed during the microwave-assisted reduction process. The Pt decorated CNTs show a dramatic increase in electrochemical behaviour in terms of high reversible capacity and relatively stable cycle performance compared to unmodified CNTs increasing their applicability in energy storage devices. For instance, significant increases in the electrochemical double layer capacitance are observed for the CNT-NP composite electrode. PMID:20379504

  11. Field-Flow Fractionation of Carbon Nanotubes and Related Materials

    Energy Technology Data Exchange (ETDEWEB)

    John P. Selegue

    2011-11-17

    During the grant period, we carried out FFF studies of carbonaceous soot, single-walled and multi-walled carbon nanotubes, carbon nano-onions and polyoxometallates. FFF alone does not provide enough information to fully characterize samples, so our suite of characterization techniques grew to include light scattering (especially Photon Correlation Spectroscopy), scanning and transmission electron microscopy, thermogravimetric analysis and spectroscopic methods. We developed convenient techniques to deposit and examine minute FFF fractions by electron microscopy. In collaboration with Arthur Cammers (University of Kentucky), we used Flow Field-Flow Fractionation (Fl-FFF) to monitor the solution-phase growth of keplerates, a class of polyoxometallate (POM) nanoparticles. We monitored the evolution of Mo-POM nanostructures over the course of weeks by by using flow field-flow fractionation and corroborated the nanoparticle structures by using transmission electron microscopy (TEM). Total molybdenum in the solution and precipitate phases was monitored by using inductively coupled plasma analyses, and total Mo-POM concentration by following the UV-visible spectra of the solution phase. We observe crystallization-driven formation of (Mo132) keplerate and solution phase-driven evolution of structurally related nanoscopic species (3-60 nm). FFF analyses of other classes of materials were less successful. Attempts to analyze platelets of layered materials, including exfoliated graphite (graphene) and TaS2 and MoS2, were disappointing. We were not able to optimize flow conditions for the layered materials. The metal sulfides react with the aqueous carrier liquid and settle out of suspension quickly because of their high density.

  12. Single-walled carbon nanotube networks in conductive composite materials.

    Science.gov (United States)

    Bârsan, Oana A; Hoffmann, Günter G; van der Ven, Leo G J; de With, G Bert

    2014-01-01

    Electrically conductive composite materials can be used for a wide range of applications because they combine the advantages of a specific polymeric material (e.g., thermal and mechanical properties) with the electrical properties of conductive filler particles. However, the overall electrical behaviour of these composite materials is usually much below the potential of the conductive fillers, mainly because by mixing two different components, new interfaces and interphases are created, changing the properties and behaviours of both. Our goal is to characterize and understand the nature and influence of these interfaces on the electrical properties of composite materials. We have improved a technique based on the use of sodium carboxymethyl cellulose (CMC) to disperse single-walled carbon nanotubes (SWCNTs) in water, followed by coating glass substrates, and drying and removing the CMC with a nitric acid treatment. We used electron microscopy and atomic force microscopy techniques to characterize the SWCNT films, and developed an in situ resistance measurement technique to analyse the influence of both the individual components and the mixture of an epoxy/amine system on the electrical behaviour of the SWCNTs. The results showed that impregnating a SWCNT network with a polymer is not the only factor that affects the film resistance; air exposure, temperature, physical and chemical properties of the individual polymer components, and also the formation of a polymeric network, can all have an influence on the macroscopic electrical properties of the initial SWCNT network. These results emphasize the importance of understanding the effects that each of the components can have on each other before trying to prepare an efficient polymer composite material. PMID:25430670

  13. Comparison of Properties of Polymer Composite Materials Reinforced with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Zygoń P.

    2015-04-01

    Full Text Available Carbon nanotubes because of their high mechanical, optical or electrical properties, have found use as semiconducting materials constituting the reinforcing phase in composite materials. The paper presents the results of the studies on the mechanical properties of polymer composites reinforced with carbon nanotubes (CNT. Three-point bending tests were carried out on the composites. The density of each obtained composite was determined as well as the surface roughness and the resistivity at room temperature.

  14. Carbon nanotube-reinforced composites as structural materials for microactuators in microelectromechanical systems

    International Nuclear Information System (INIS)

    Nanocomposites are a promising new class of structural materials for the mechanical components of microelectromechanical systems (MEMS). This paper presents a detailed theoretical investigation of the utility of carbon nanotube-reinforced composites for designing actuators with low stiffness and high natural frequencies of vibration. The actuators are modelled as beams of solid rectangular cross-section consisting of an isotropic matrix reinforced with transversely isotropic carbon nanotubes. Three different types of nanotube reinforcements are considered: single-walled carbon nanotubes (SWNTs), multi-walled carbon nanotubes (MWNTs) and arrays of SWNTs. The effects of nanotube aspect ratio, dispersion, alignment and volume fraction on the elastic modulus and longitudinal wave velocity are analysed by recourse to the Eshelby-Mori-Tanaka theory. The calculated bounds on Young's modulus and wave velocity capture the trend of the experimental results reported in the literature. Polymer-matrix nanocomposites reinforced with aligned, dispersed SWNTs are identified as excellent candidates for microactuators and microresonators, with properties rivalling those of monolithic metallic and ceramic structures used in the current generation of MEMS. A qualitative comparison between the state-of-the-art in nanocomposite manufacturing technology and the predicted upper bound on Young's modulus and longitudinal wave velocity highlights the enormous improvements needed in materials processing and micromachining to harness the full potential of carbon nanotube-reinforced composites for microactuator applications. These results have immediate and significant implications for the use of nanotube composites in MEMS

  15. Applications of Carbon Nanotubes

    Science.gov (United States)

    Ajayan, Pulickel M.; Zhou, Otto Z.

    Carbon nanotubes have attracted the fancy of many scientists worldwide. The small dimensions, strength and the remarkable physical properties of these structures make them a very unique material with a whole range of promising applications. In this review we describe some of the important materials science applications of carbon nanotubes. Specifically we discuss the electronic and electrochemical applications of nanotubes, nanotubes as mechanical reinforcements in high performance composites, nanotube-based field emitters, and their use as nanoprobes in metrology and biological and chemical investigations, and as templates for the creation of other nanostructures. Electronic properties and device applications of nanotubes are treated elsewhere in the book. The challenges that ensue in realizing some of these applications are also discussed from the point of view of manufacturing, processing, and cost considerations.

  16. Conditions for forming composite carbon nanotube-diamond like carbon material that retain the good properties of both materials

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Wei, E-mail: wei.ren@helsinki.fi; Avchaciov, Konstantin; Nordlund, Kai [Department of Physics, University of Helsinki, P.O. Box 43, FIN-00014 Helsinki (Finland); Iyer, Ajai; Koskinen, Jari [Department of Materials Science and Engineering, School of Chemical Technology, Aalto University, P.O. Box 16200, 00076 Espoo (Finland); Kaskela, Antti; Kauppinen, Esko I. [NanoMaterials Group, Department of Applied Physics, Aalto University School of Science, P.O. Box 15100, 00076 Aalto (Finland)

    2015-11-21

    Carbon nanotubes are of wide interest due to their excellent properties such as tensile strength and electrical and thermal conductivity, but are not, when placed alone on a substrate, well resistant to mechanical wear. Diamond-like carbon (DLC), on the other hand, is widely used in applications due to its very good wear resistance. Combining the two materials could provide a very durable pure carbon nanomaterial enabling to benefit from the best properties of both carbon allotropes. However, the synthesis of high-quality diamond-like carbon uses energetic plasmas, which can damage the nanotubes. From previous works it is neither clear whether the quality of the tubes remains good after DLC deposition, nor whether the DLC above the tubes retains the high sp{sup 3} bonding fraction. In this work, we use experiments and classical molecular dynamics simulations to study the mechanisms of DLC formation on various carbon nanotube compositions. The results show that high-sp{sup 3}-content DLC can be formed provided the deposition conditions allow for sidewards pressure to form from a substrate close beneath the tubes. Under optimal DLC formation energies of around 40–70 eV, the top two nanotube atom layers are fully destroyed by the plasma deposition, but layers below this can retain their structural integrity.

  17. Conditions for forming composite carbon nanotube-diamond like carbon material that retain the good properties of both materials

    International Nuclear Information System (INIS)

    Carbon nanotubes are of wide interest due to their excellent properties such as tensile strength and electrical and thermal conductivity, but are not, when placed alone on a substrate, well resistant to mechanical wear. Diamond-like carbon (DLC), on the other hand, is widely used in applications due to its very good wear resistance. Combining the two materials could provide a very durable pure carbon nanomaterial enabling to benefit from the best properties of both carbon allotropes. However, the synthesis of high-quality diamond-like carbon uses energetic plasmas, which can damage the nanotubes. From previous works it is neither clear whether the quality of the tubes remains good after DLC deposition, nor whether the DLC above the tubes retains the high sp3 bonding fraction. In this work, we use experiments and classical molecular dynamics simulations to study the mechanisms of DLC formation on various carbon nanotube compositions. The results show that high-sp3-content DLC can be formed provided the deposition conditions allow for sidewards pressure to form from a substrate close beneath the tubes. Under optimal DLC formation energies of around 40–70 eV, the top two nanotube atom layers are fully destroyed by the plasma deposition, but layers below this can retain their structural integrity

  18. Nanoscale High Energetic Materials: A Polymeric Nitrogen Chain N8 Confined inside a Carbon Nanotube

    Science.gov (United States)

    Abou-Rachid, Hakima; Hu, Anguang; Timoshevskii, Vladimir; Song, Yanfeng; Lussier, Louis-Simon

    2008-05-01

    We present a theoretical study of a new hybrid material, nanostructured polymeric nitrogen, where a polymeric nitrogen chain is encapsulated in a carbon nanotube. The electronic and structural properties of the new system are studied by means of ab initio electronic structure and molecular dynamics calculations. Finite temperature simulations demonstrate the stability of this nitrogen phase at ambient pressure and room temperature using carbon nanotube confinement. This nanostructured confinement may open a new path towards stabilizing polynitrogen or polymeric nitrogen at ambient conditions.

  19. Synthesis of nano-carbon (nanotubes, nanofibres, graphene) materials

    Indian Academy of Sciences (India)

    Kalpana Awasthi; Rajesh Kumar; Himanshu Raghubanshi; Seema Awasthi; Ratnesh Pandey; Devinder Singh; T P Yadav; O N Srivastava

    2011-07-01

    In the present study, we report the synthesis of carbon nanotubes (CNTs) using a new natural precursor: castor oil. The CNTs were synthesized by spray pyrolysis of castor oil–ferrocene solution at 850°C under an Ar atmosphere. We also report the synthesis of carbon nitrogen (C–N) nanotubes using castor oil–ferrocene–ammonia precursor. The as-grown CNTs and C–N nanotubes were characterized through scanning and transmission electron microscopic techniques. Graphitic nanofibres (GNFs) were synthesized by thermal decomposition of acetylene (C2H2) gas using Ni catalyst at 600°C. As-grown GNFs reveal both planar and helical morphology. We have investigated the structural and electrical properties of multi-walled CNTs (MWNTs)–polymer (polyacrylamide (PAM)) composites. The MWNTs–PAM composites were prepared using as purified, with ball milling and functionalized MWNTs by solution cast technique and characterized through SEM. A comparative study has been made on the electrical property of these MWNTs–PAM composites with different MWNTs loadings. It is shown that the ball milling and functionalization of MWNTs improves the dispersion of MWNTs into the polymer matrix. Enhanced electrical conductivity was observed for the MWNTs–PAM composites. Graphene samples were prepared by thermal exfoliation of graphite oxide. XRD analysis confirms the formation of graphene.

  20. Transparent and Electrically Conductive Carbon Nanotube-Polymer Nanocomposite Materials for Electrostatic Charge Dissipation

    Science.gov (United States)

    Dervishi, E.; Biris, A. S.; Biris, A. R.; Lupu, D.; Trigwell, S.; Miller, D. W.; Schmitt, T.; Buzatu, D. A.; Wilkes, J. G.

    2006-01-01

    In recent years, nanocomposite materials have been extensively studied because of their superior electrical, magnetic, and optical properties and large number of possible applications that range from nano-electronics, specialty coatings, electromagnetic shielding, and drug delivery. The aim of the present work is to study the electrical and optical properties of carbon nanotube(CNT)-polymer nanocomposite materials for electrostatic charge dissipation. Single and multi-wall carbon nanotubes were grown by catalytic chemical vapor deposition (CCVD) on metal/metal oxide catalytic systems using acetylene or other hydrocarbon feedstocks. After the purification process, in which amorphous carbon and non-carbon impurities were removed, the nanotubes were functionalized with carboxylic acid groups in order to achieve a good dispersion in water and various other solvents. The carbon nanostructures were analyzed, both before and after functionalization by several analytical techniques, including microscopy, Raman spectroscopy, and X-Ray photoelectron spectroscopy. Solvent dispersed nanotubes were mixed (1 to 7 wt %) into acrylic polymers by sonication and allowed to dry into 25 micron thick films. The electrical and optical properties of the films were analyzed as a function of the nanotubes' concentration. A reduction in electrical resistivity, up to six orders of magnitude, was measured as the nanotubes' concentration in the polymeric films increased, while optical transparency remained 85 % or higher relative to acrylic films without nanotubes.

  1. Carbon nanotubes, a megatrend in materials engineering with good application prospects; Carbon Nanotubes. Megatrend der Werkstofftechnologie mit aussichtsreichen Anwendungsperspektiven

    Energy Technology Data Exchange (ETDEWEB)

    Hoffschulz, Holger [Bayer Technology Services GmbH, Leverkusen (Germany). Process Technology - Innovation Management; Krueger, Peter [Bayer MaterialScience AG (Germany). Business Unit Coatings, Adhesives and Specialities

    2009-10-15

    Carbon nanotubes (CNT) are an international megatrend with fascinating perspectives. CNTs can improve the mechanical, electronic and thermal properties of materials significantly and have the potential to produce novel materials and products that cannot be achieved with conventional technologies. In Germany, a close-meshed research association has been founded by about 80 renowned partners of science, small business and industry to generate a basis for a leading market for this material. The initiative will bridge the gap between innovative technology and practical applications. In 18 projects, innovative applications will be developed in the fields of energy, environment, mobility, and lightweight construction. (orig.) [German] Carbon Nanotubes (CNT) sind weltweit ein Megatrend der Werkstofftechnologie mit faszinierenden Perspektiven. CNTs koennen dazu beitragen, die mechanischen, elektronischen und thermischen Eigenschaften von Werkstoffen grundlegend zu verbessern und haben das Potenzial, voellig neue Werkstoffe und Produkte hervorzubringen, die mit bisheriger Technologie nicht realisierbar sind. In Deutschland hat sich kuerzlich ein eng vernetzter Forschungsverbund mit rund 80 namhaften Partnern aus Wissenschaft, Mittelstand und Grossindustrie zusammen gefunden, um die Basis fuer einen Leitmarkt fuer diesen Werkstoff zu legen. Die Initiative schlaegt eine Bruecke zwischen wegweisender Technologie und praxisnahen Anwendungen und entwickelt in 18 Projekten innovative Applikationen auf den Gebieten Energie/Umwelt, Mobilitaet sowie Leichtbau. (orig.)

  2. Synthesis, alignment, growth mechanism and functional properties of carbon nanotubes and their hybrid materials with inorganic and biomaterials

    OpenAIRE

    Joshi, Ravi

    2010-01-01

    The present work comprises a novel method for selective growth of carbon nanotubes, study of their growth mechanism as well as synthesis and application of their various hybrid materials. An experimental setup is established to grow carbon nanotubes using water assisted chemical vapor deposition method. Various growth parameters were scrutinized carefully and a growth mechanism is put forth for the same method. A new methodology to prepare different hybrid materials of aligned carbon nanotube...

  3. Nanostructured composites based on carbon nanotubes and epoxy resin for use as radar absorbing materials

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Valdirene Aparecida [Instituto Tecnologico de Aeronautica (ITA), Sao Jose dos Campos, SP (Brazil); Folgueras, Luiza de Castro; Candido, Geraldo Mauricio; Paula, Adriano Luiz de; Rezende, Mirabel Cerqueira, E-mail: mirabelmcr@iae.cta.br [Instituto de Aeronautica e Espaco (IAE), Sao Jose dos Campos, SP (Brazil). Div. de Materiais; Costa, Michelle Leali [Universidade Estadual Paulista Julio de Mesquita Filho (DMT/UNESP), Guaratingueta, SP (Brazil). Dept. de Materiais e Tecnologia

    2013-07-01

    Nanostructured polymer composites have opened up new perspectives for multifunctional materials. In particular, carbon nanotubes (CNTs) present potential applications in order to improve mechanical and electrical performance in composites with aerospace application. The combination of epoxy resin with multi walled carbon nanotubes results in a new functional material with enhanced electromagnetic properties. The objective of this work was the processing of radar absorbing materials based on formulations containing different quantities of carbon nanotubes in an epoxy resin matrix. To reach this objective the adequate concentration of CNTs in the resin matrix was determined. The processed structures were characterized by scanning electron microscopy, rheology, thermal and reflectivity in the frequency range of 8.2 to 12.4 GHz analyses. The microwave attenuation was up to 99.7%, using only 0.5% (w/w) of CNT, showing that these materials present advantages in performance associated with low additive concentrations (author)

  4. Properties of carbon nanotube-dispersed Sr-hydroxyapatite injectable material for bone defects

    OpenAIRE

    Raucci, M. G.; Alvarez-Perez, M.; Giugliano, D.; Zeppetelli, S.; Ambrosio, L.

    2016-01-01

    This study concerns the synthesis of gel materials based on carbon nanotubes dispersed strontium-modified hydroxyapatite (Sr-HA) at different compositions obtained by sol–gel technology and their influence on human-bone-marrow-derived mesenchymal stem cells. Furthermore, an evaluation of the influence of nanotubes and Strontium on physico-chemical, morphological, rheological and biological properties of hydroxyapatite gel was also performed. Morphological analysis (scanning electron microscop...

  5. Carbon nanotube macroelectronics

    Science.gov (United States)

    Zhang, Jialu

    In this dissertation, I discuss the application of carbon nanotubes in macroelectronis. Due to the extraordinary electrical properties such as high intrinsic carrier mobility and current-carrying capacity, single wall carbon nanotubes are very desirable for thin-film transistor (TFT) applications such as flat panel display, transparent electronics, as well as flexible and stretchable electronics. Compared with other popular channel material for TFTs, namely amorphous silicon, polycrystalline silicon and organic materials, nanotube thin-films have the advantages of low-temperature processing compatibility, transparency, and flexibility, as well as high device performance. In order to demonstrate scalable, practical carbon nanotube macroelectroncis, I have developed a platform to fabricate high-density, uniform separated nanotube based thin-film transistors. In addition, many other essential analysis as well as technology components, such as nanotube film density control, purity and diameter dependent semiconducting nanotube electrical performance study, air-stable n-type transistor fabrication, and CMOS integration platform have also been demonstrated. On the basis of the above achievement, I have further demonstrated various kinds of applications including AMOLED display electronics, PMOS and CMOS logic circuits, flexible and transparent electronics. The dissertation is structured as follows. First, chapter 1 gives a brief introduction to the electronic properties of carbon nanotubes, which serves as the background knowledge for the following chapters. In chapter 2, I will present our approach of fabricating wafer-scale uniform semiconducting carbon nanotube thin-film transistors and demonstrate their application in display electronics and logic circuits. Following that, more detailed information about carbon nanotube thin-film transistor based active matrix organic light-emitting diode (AMOLED) displays is discussed in chapter 3. And in chapter 4, a technology to

  6. Nanotube composite carbon fibers

    Science.gov (United States)

    Andrews, R.; Jacques, D.; Rao, A. M.; Rantell, T.; Derbyshire, F.; Chen, Y.; Chen, J.; Haddon, R. C.

    1999-08-01

    Single walled carbon nanotubes (SWNTs) were dispersed in isotropic petroleum pitch matrices to form nanotube composite carbon fibers with enhanced mechanical and electrical properties. We find that the tensile strength, modulus, and electrical conductivity of a pitch composite fiber with 5 wt % loading of purified SWNTs are enhanced by ˜90%, ˜150%, and 340% respectively, as compared to the corresponding values in unmodified isotropic pitch fibers. These results serve to highlight the potential that exits for developing a spectrum of material properties through the selection of the matrix, nanotube dispersion, alignment, and interfacial bonding.

  7. Development of a Taste Sensor Based on a Carbon Nanotube-Polymer Composite Material

    Science.gov (United States)

    Hirata, Takamichi; Takagi, Keisuke; Akiya, Masahiro

    2007-04-01

    A taste sensor consisting of a back-gate type field effect transistor (FET) chip based on carbon nanotube compound materials [poly(ethylene glycol) (PEG)-grafted single-walled carbon nanotubes (PEG-SWNTs)] was developed. The results of impedance measurements for five tastes (sourness, saltiness, bitterness, sweetness, and umami), are shown much difference for specific tastes which are difficult to identify by using Langmuir-Blodgett (LB) film. Moreover, the sensor is able to distinguish most of the experimental taste materials with a short response time (˜60 s).

  8. Morphology, structure and Raman scattering of carbon nanotubes produced by using mesoporous materials

    Institute of Scientific and Technical Information of China (English)

    解思深; 李文治; 王超英; 徐丽雯; 张昊; 张云; 钱露茜

    1997-01-01

    Carbon nanotubes were prepared by chemical vapor deposition (CVD) of hydrocarbon gas on various substrates.The effect of substrates on the growth,morphology and structure of carbon nanotubes were investigated.Aligned carbon nanotubes with high density and purity were achieved by CVD on mesoporous silica substrate.The Raman scattering of aligned carbon nanotubes was carried out,and the dependence of the phonon properties on the mi-crostructure of the nanotubes has been discussed.

  9. Carbon nanotube solar cells.

    Directory of Open Access Journals (Sweden)

    Colin Klinger

    Full Text Available We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabricate using a spray-paint technique. We observe that cells with a lower concentration of carbon nanotubes on the active semiconducting electrode perform better than cells with a higher concentration of nanotubes. This effect is contrary to the expectation that a larger number of nanotubes would lead to more photoconversion and therefore more power generation. We attribute this to the presence of metallic nanotubes that provide a short for photo-excited electrons, bypassing the load. We demonstrate optimization strategies that improve cell efficiency by orders of magnitude. Once it is possible to make semiconducting-only carbon nanotube films, that may provide the greatest efficiency improvement.

  10. Computational Nanotechnology of Molecular Materials, Electronics, and Actuators with Carbon Nanotubes and Fullerenes

    Science.gov (United States)

    Srivastava, Deepak; Menon, Madhu; Cho, Kyeongjae; Biegel, Bryan (Technical Monitor)

    2001-01-01

    The role of computational nanotechnology in developing next generation of multifunctional materials, molecular scale electronic and computing devices, sensors, actuators, and machines is described through a brief review of enabling computational techniques and few recent examples derived from computer simulations of carbon nanotube based molecular nanotechnology.

  11. Properties of carbon nanotube-dispersed Sr-hydroxyapatite injectable material for bone defects

    Science.gov (United States)

    Raucci, M. G.; Alvarez-Perez, M.; Giugliano, D.; Zeppetelli, S.; Ambrosio, L.

    2016-01-01

    This study concerns the synthesis of gel materials based on carbon nanotubes dispersed strontium-modified hydroxyapatite (Sr-HA) at different compositions obtained by sol–gel technology and their influence on human-bone-marrow-derived mesenchymal stem cells. Furthermore, an evaluation of the influence of nanotubes and Strontium on physico-chemical, morphological, rheological and biological properties of hydroxyapatite gel was also performed. Morphological analysis (scanning electron microscopy) shows a homogeneous distribution of modified nanotubes in the ceramic matrix improving the bioactive properties of materials. The biological investigations proved that Sr-HA/carbon nanotube gel containing 0–20 mol (%) of Sr showed no toxic effect and promote the expression of early and late markers of osteogenic differentiation in cell culture performed in basal medium without osteogenic factors. Finally, the SrHA/carbon nanotube gels could have a good potential application as filler in bone repair and regeneration and may be used in the osteoporotic disease treatment. PMID:26816652

  12. Nanoscale Electrochemistry of sp(2) Carbon Materials: From Graphite and Graphene to Carbon Nanotubes.

    Science.gov (United States)

    Unwin, Patrick R; Güell, Aleix G; Zhang, Guohui

    2016-09-20

    Carbon materials have a long history of use as electrodes in electrochemistry, from (bio)electroanalysis to applications in energy technologies, such as batteries and fuel cells. With the advent of new forms of nanocarbon, particularly, carbon nanotubes and graphene, carbon electrode materials have taken on even greater significance for electrochemical studies, both in their own right and as components and supports in an array of functional composites. With the increasing prominence of carbon nanomaterials in electrochemistry comes a need to critically evaluate the experimental framework from which a microscopic understanding of electrochemical processes is best developed. This Account advocates the use of emerging electrochemical imaging techniques and confined electrochemical cell formats that have considerable potential to reveal major new perspectives on the intrinsic electrochemical activity of carbon materials, with unprecedented detail and spatial resolution. These techniques allow particular features on a surface to be targeted and models of structure-activity to be developed and tested on a wide range of length scales and time scales. When high resolution electrochemical imaging data are combined with information from other microscopy and spectroscopy techniques applied to the same area of an electrode surface, in a correlative-electrochemical microscopy approach, highly resolved and unambiguous pictures of electrode activity are revealed that provide new views of the electrochemical properties of carbon materials. With a focus on major sp(2) carbon materials, graphite, graphene, and single walled carbon nanotubes (SWNTs), this Account summarizes recent advances that have changed understanding of interfacial electrochemistry at carbon electrodes including: (i) Unequivocal evidence for the high activity of the basal surface of highly oriented pyrolytic graphite (HOPG), which is at least as active as noble metal electrodes (e.g., platinum) for outer

  13. Optical Kerr effect exhibited by carbon nanotubes and carbon/metal nanohybrid materials

    Science.gov (United States)

    Torres-Torres, C.; Mercado-Zúñiga, C.; Martínez-González, C. L.; Martínez-Gutiérrez, H.; Rebollo, N. R.; Trejo-Valdez, M.; Vargas-García, J. R.; Torres-Martínez, R.

    2015-09-01

    Structural modification of carbon nanotubes in combination with metallic nanoparticles is reported. An enhancement in the nonlinear optical refraction of multi-wall carbon nanotubes by the incorporation of platinum nanoparticles was observed. Comparative results were analyzed taking into account the participation of single-wall carbon nanotubes that originate a decrease in the nonlinear optical response of the multi-wall carbon nanotubes integrating a thin film. A Nd:YAG laser system featuring 532 nm wavelength with 4 ns pulse duration in a two-wave mixing experiment was employed for exploring the studied optical nonlinearities of the samples. The contribution of optical processes to mechanical characteristics dependent on high optical irradiance in carbon nanotubes was described. A variation in the mass density associated to the optically irradiated tubes allowed us to calculate the change in Young's modulus in a thin film configuration. The estimation of an opto-mechanical phenomenon was based on the evaluation of the nonlinearity of index responsible for the optical Kerr effect. According to Raman and optical evaluations, the inclusion of metallic nanoparticles in carbon structures results in a modification of surface that also gives origin to noticeable optical Kerr nonlinearities. Potential applications for developing laser-induced controlled opto-mechanical nanohybrid systems can be contemplated.

  14. Preparation of carbon nanotube composite material with metal matrix by electroplating

    Institute of Scientific and Technical Information of China (English)

    AN Bai-gang; LI Li-xiang; Li Hong-xi

    2005-01-01

    It is demonstrated that the nickel can be deposited directly on the surface of carbon nanotubes without pre-sensitization by Sn2+ and Pd2+ in a watt bath containing suspended nanotubes by electroplating. The nickel is deposited as spherical nanoparticle on the nanotubes. By increasing reaction time, the carbon nanotube is fully coated with nickel. A probable model, which represents the formation process of carbon nanotube-nickel composites by electroplating, is presented. The results show that this method is efficient and simple for preparing carbon nanotube-metal composite.

  15. Enhanced rate performance of multiwalled carbon nanotube encrusted olivine type composite cathode material using polyol technique

    Science.gov (United States)

    Muruganantham, R.; Sivakumar, M.; Subadevi, R.

    2015-12-01

    Olivine type multi-walled carbon nanotube encrusted LiFePO4/C composites have been prepared using economic and energy efficient simple polyol technique without any subsequent heat treatment. The prepared material has an olivine type orthorhombic phase. Also, the iron oxidation state is 2+, which is identified by X-ray diffraction and X-ray photoelectron spectroscopy. It is possible to attain the discharge capacity almost close to theoretical capacity of LiFePO4 as in high temperature methods with ∼100% coulombic efficiency. The specific surface area has been increased upon encrusting multi walled carbon nano tube on LiFePO4/C, which results in enhanced reversible capacity upto 166 mAh g-1 at C/10. Also, it exhibits 89 mAh g-1 even at 30 C rate. This is due to the formation of conductive networks by carbon nanotube, and excellent attachment of LiFePO4/C composite particles on multi-walled carbon nanotube, which induced the kinetics during intercalation/deintercalation process. Multi-walled carbon nanotube acts as the electro-conductive filler on the LiFePO4 surface. The direct addition of MWCNT would result better performances than blending the MWCNT with LiFePO4/C.

  16. Advanced materials from natural materials: synthesis of aligned carbon nanotubes on wollastonites.

    Science.gov (United States)

    Zhao, Meng-Qiang; Zhang, Qiang; Huang, Jia-Qi; Nie, Jing-Qi; Wei, Fei

    2010-04-26

    The growth of carbon nanotubes (CNTs) on natural materials is a low-cost, environmentally benign, and materials-saving method for the large-scale production of CNTs. Directly building 3D CNT architectures on natural materials is a key issue for obtaining advanced materials with high added value. We report the fabrication of aligned CNT arrays on fibrous natural wollastonite. Strongly dispersed iron particles with small sizes were produced on a planar surface of soaked fibrous wollastonite by a reduction process. These particles then catalyzed the decomposition of ethylene, leading to the synchronous growth of CNTs to form leaf- and brush-like wollastonite/CNT hybrids. The as-obtained hybrids could be further transformed into porous SiO(2)/CNT hybrids by reaction with hydrochloric acid. Further treatment with hydrofluoric acid resulted in aligned CNT arrays, with purities as high as 98.7 %. The presented work is very promising for the fabrication of advanced materials with unique structures and properties that can be used as fillers, catalyst supports, or energy-absorbing materials. PMID:20183856

  17. Carbon Nanotube Solar Cells

    OpenAIRE

    Klinger, Colin; Patel, Yogeshwari; Postma, Henk W. Ch.

    2012-01-01

    We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabr...

  18. Carbon nanotube production over MCM-41 type catalytic materials via CVD method

    OpenAIRE

    Nalbant, Aslı; Nalbant, Asli; YÜRÜM, YUDA; Yurum, Yuda

    2010-01-01

    We investigate the effects of mesoporous catalyst synthesis methods over carbon nanotube (CNT) production. Metal incorporated mesoporous catalysts were synthesized by two different microwave assisted synthesis methods. In the first method, MCM-41 mesoporous materials were synthesized with microwave radiation and then metal was impregnated into these as-synthesized MCM-41 samples. In the second method metal was added into the raw materials directly and then the mixture was treated in the mi...

  19. Preparation and electrochemical performance of polyaniline-based carbon nanotubes as electrode material for supercapacitor

    International Nuclear Information System (INIS)

    Nitrogen-containing carbon nanotubes (CNTs) with open end and low specific surface area were prepared via the carbonization of polyaniline (PANI) nanotubes synthesized by a rapidly mixed reaction. On the basis of analyzing the morphologies and structures of the original and carbonized PANI nanotubes, the electrochemical properties of PANI-based CNTs obtained at different temperatures as electrode materials for supercapacitors using 30 wt.% aqueous solution of KOH as electrolyte were investigated by galvanostatic charge/discharge and cyclic voltammetry. It was found that the carbonized PANI nanotubes at 700 oC exhibit high specific capacitance of 163 F g-1 at a current density of 0.1 A g-1 and excellent rate capability in KOH solution. Using X-ray photoelectron spectroscopy measurement the nitrogen state and content in PANI-CNTs were analysed, which could play important roles for the enhancement of electrochemical performance. When the appropriate content of nitrogen is present, the presence of pyrrole or pyridone and quaternary nitrogen is beneficial for the improvement of electron mobility and the wettability of electrode.

  20. Comparing graphene, carbon nanotubes, and superfine powdered activated carbon as adsorptive coating materials for microfiltration membranes.

    Science.gov (United States)

    Ellerie, Jaclyn R; Apul, Onur G; Karanfil, Tanju; Ladner, David A

    2013-10-15

    Multi-walled carbon nanotubes (MWCNTs), nano-graphene platelets (NGPs), and superfine powdered activated carbon (S-PAC) were comparatively evaluated for their applicability as adsorptive coatings on microfiltration membranes. The objective was to determine which materials were capable of contaminant removal while causing minimal flux reduction. Methylene blue and atrazine were the model contaminants. When applied as membrane coatings, MWCNTs had minimal retention capabilities for the model contaminants, and S-PAC had the fastest removal. The membrane coating approach was also compared with a stirred vessel configuration, in which the adsorbent was added to a stirred flask preceding the membrane cell. Direct application of the adsorbent to the membrane constituted a greater initial reduction in permeate concentrations of the model contaminants than with the stirred flask setup. All adsorbents except S-PAC showed flux reductions less than 5% after application as thin-layer membrane coatings, and flux recovery after membrane backwashing was greater than 90% for all materials and masses tested. PMID:23911830

  1. Hybrid Composite of Polyaniline Containing Carbon Nanotube

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Carbon nanotube-polyaniline hybrid material was synthesized by emulsion polymerization in-situ. The morphology of hybrid material was studied by TEM and X-ray diffraction. The conductivity of nanocomposite increases with the increasing of carbon nanotube content because of the new conductivity passageways formed by carbon nanotubes.

  2. Carbon nanotube quantum dots

    NARCIS (Netherlands)

    Sapmaz, S.

    2006-01-01

    Low temperature electron transport measurements on individual single wall carbon nanotubes are described in this thesis. Carbon nanotubes are small hollow cylinders made entirely out of carbon atoms. At low temperatures (below ~10 K) finite length nanotubes form quantum dots. Because of its small si

  3. Thermostability, Photoluminescence, and Electrical Properties of Reduced Graphene Oxide–Carbon Nanotube Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Fuchi Liu

    2013-01-01

    Full Text Available Reduced graphene oxide–carbon nanotube (RGO–CNT hybrid materials were prepared by a simple catalyst-free route. The thermostability, photoluminescence (PL and electrical properties of RGO–CNTs were investigated systematically. The results revealed that compared to RGO, RGO–CNTs showed multicolor PL, and higher thermostability and conductivity. The RGO–CNTs therefore have important potential applications in the fields of photonic and electrical devices.

  4. Thermostability, Photoluminescence, and Electrical Properties of Reduced Graphene Oxide–Carbon Nanotube Hybrid Materials

    OpenAIRE

    Fuchi Liu; Yong Cao; Mingdong Yi; Linghai Xie; Wei Huang; Nujiang Tang; Wei Zhong; Youwei Du

    2013-01-01

    Reduced graphene oxide–carbon nanotube (RGO–CNT) hybrid materials were prepared by a simple catalyst-free route. The thermostability, photoluminescence (PL) and electrical properties of RGO–CNTs were investigated systematically. The results revealed that compared to RGO, RGO–CNTs showed multicolor PL, and higher thermostability and conductivity. The RGO–CNTs therefore have important potential applications in the fields of photonic and electrical devices.

  5. Potential of Carbon Nanotube Reinforced Cement Composites as Concrete Repair Material

    OpenAIRE

    Tanvir Manzur; Nur Yazdani; Md. Abul Bashar Emon

    2016-01-01

    Carbon nanotubes (CNTs) are a virtually ideal reinforcing agent due to extremely high aspect ratios and ultra high strengths. It is evident from contemporary research that utilization of CNT in producing new cement-based composite materials has a great potential. Consequently, possible practical application of CNT reinforced cementitious composites has immense prospect in the field of applied nanotechnology within construction industry. Several repair, retrofit, and strengthening techniques a...

  6. Evaluation for cell affinity of the composite material containing carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    KANG Shizhao; WAN Yuqing; YAN Huijuan; BEI Jianzhong; WANG Chen; WANG Shenguo; WANG Chunru; WAN Lijun; BAI Chunli

    2004-01-01

    The composite material of poly-(L-lactide) (PLLA) and carbon nanotubes (CNTs) were prepared. Its surface morphologies and property were worked out by using atomic force microscopy (AFM) and contact angle measurement. Moreover, the prime cytocompatibility was used to investigate the biocompatibility of the composite material containing CNTs and the effects of CNTs on one aspect of cell function, cell affinity. The results obtained indicate that the composite material of PLLA and CNTs possesses good biocompatibility for both the 3T3 fibroblasts and Oct-1 osteoblast-like cells. The addition of CNTs will greatly affect cell affinity of the material, which may be disadvantage for the cell adhesion.

  7. Plumbing carbon nanotubes

    Science.gov (United States)

    Jin, Chuanhong; Suenaga, Kazu; Iijima, Sumio

    2008-01-01

    Since their discovery, the possibility of connecting carbon nanotubes together like water pipes has been an intriguing prospect for these hollow nanostructures. The serial joining of carbon nanotubes in a controlled manner offers a promising approach for the bottom-up engineering of nanotube structures-from simply increasing their aspect ratio to making integrated carbon nanotube devices. To date, however, there have been few reports of the joining of two different carbon nanotubes. Here we demonstrate that a Joule heating process, and associated electro-migration effects, can be used to connect two carbon nanotubes that have the same (or similar) diameters. More generally, with the assistance of a tungsten metal particle, this technique can be used to seamlessly join any two carbon nanotubes-regardless of their diameters-to form new nanotube structures.

  8. Enhanced Photovoltaic Performance with Carbon Nanotubes Incorporating into Hole Transport Materials for Perovskite Solar Cells

    Science.gov (United States)

    Wang, Junxia; Li, Jingling; Xu, Xueqing; Xu, Gang; Shen, Honglie

    2016-10-01

    In an attempt to further enhance the photovoltaic performance of perovskite solar cells (PSCs) fabricated by spray deposition under ambient conditions, carbon nanotubes (CNTs) are introduced for incorporation into hole transport materials (HTM). The effect of CNT category and length on the efficiency of the perovskite solar cell for incorporation into HTM is investigated. The enhanced photovoltaic performance is achieved in multi-walled carbon nanotubes (MWCNTs) with the shortest length. The efficiency of acid-treated MWCNT-based cells is improved compared to that of purified MWCNTs due to the better dispersibility and the π-π interaction between the -COOH group and spiro-OMeTAD. As the volume ratio of the spiro-OMeTAD and spiro/MWCNTs mixture is 2:2 or 3:1, the highest power conversion efficiency (PCE) of PSCs containing MWCNTs reaches 8.7% with the enhanced short-circuit current density ( J sc) and open-circuit voltage ( V oc).

  9. Enhanced Photovoltaic Performance with Carbon Nanotubes Incorporating into Hole Transport Materials for Perovskite Solar Cells

    Science.gov (United States)

    Wang, Junxia; Li, Jingling; Xu, Xueqing; Xu, Gang; Shen, Honglie

    2016-06-01

    In an attempt to further enhance the photovoltaic performance of perovskite solar cells (PSCs) fabricated by spray deposition under ambient conditions, carbon nanotubes (CNTs) are introduced for incorporation into hole transport materials (HTM). The effect of CNT category and length on the efficiency of the perovskite solar cell for incorporation into HTM is investigated. The enhanced photovoltaic performance is achieved in multi-walled carbon nanotubes (MWCNTs) with the shortest length. The efficiency of acid-treated MWCNT-based cells is improved compared to that of purified MWCNTs due to the better dispersibility and the π-π interaction between the -COOH group and spiro-OMeTAD. As the volume ratio of the spiro-OMeTAD and spiro/MWCNTs mixture is 2:2 or 3:1, the highest power conversion efficiency (PCE) of PSCs containing MWCNTs reaches 8.7% with the enhanced short-circuit current density (J sc) and open-circuit voltage (V oc).

  10. Carbon nanotubes, phthalocyanines and porphyrins: attractive hybrid materials for electrocatalysis and electroanalysis.

    Science.gov (United States)

    Zagal, José H; Griveau, Sophie; Ozoemena, Kenneth I; Nyokong, Tebello; Bedioui, Fethi

    2009-04-01

    The manuscript discusses different ways of forming hybrid materials between single (SWCNT) or multi (MWCNT) walled carbon nanotubes and biomimetic compounds such as metalloporphyrins, metallophthalocyanines and other MN4 complexes. The hybrid materials are employed for electrocatalysis of reactions such as oxygen and hydrogen peroxide reduction, nitric oxide oxidation, oxidation of thiols and other pollutants. Methods of characterizing the hybrid materials such as cyclic voltammetry (CV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electrochemical microscopy (SECM) are discussed.

  11. ANALYSIS OF MATERIAL MECHANICAL PROPERTIES FOR SINGLE-WALLED CARBON NANOTUBES

    Institute of Scientific and Technical Information of China (English)

    Fu Yiming; Xu Xiaoxian

    2005-01-01

    Abstract The carbon-carbon bond between two nearest-neighboring atoms is modeled as a beam and the single-walled carbon nanotubes are treated as the space frame structures in order to analyze the mechanical properties of carbon nanotubes. Based on the theory of TersoffBrenner force field, the energy relationships between the carbon-carbon bond and the beam model are obtained, and the stiffness parameters of the beam are determined. By applying the present model, the Young's moduli of the single-walled carbon nanotubes with different tube diameters are determined. And the present results are compared with available data.

  12. Enhanced Carbon Nanotube Ultracapacitors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation utilizes carbon nanotubes (CNTs) coated with pseudo-capacitive MnO2 material as nano-composite electrode and ionic electrolyte for the...

  13. NASA-JSC Protocol for the Characterization of Single Wall Carbon Nanotube Material Quality

    Science.gov (United States)

    Arepalli, Sivaram; Nikolaev, Pasha; Gorelik, Olga; Hadjiev, Victor; Holmes, William; Devivar, Rodrigo; Files, Bradley; Yowell, Leonard

    2010-01-01

    It is well known that the raw as well as purified single wall carbon nanotube (SWCNT) material always contain certain amount of impurities of varying composition (mostly metal catalyst and non-tubular carbon). Particular purification method also creates defects and/or functional groups in the SWCNT material and therefore affects the its dispersability in solvents (important to subsequent application development). A number of analytical characterization tools have been used successfully in the past years to assess various properties of nanotube materials, but lack of standards makes it difficult to compare these measurements across the board. In this work we report the protocol developed at NASA-JSC which standardizes measurements using TEM, SEM, TGA, Raman and UV-Vis-NIR absorption techniques. Numerical measures are established for parameters such as metal content, homogeneity, thermal stability and dispersability, to allow easy comparison of SWCNT materials. We will also report on the recent progress in quantitative measurement of non-tubular carbon impurities and a possible purity standard for SWCNT materials.

  14. Multifunctional Material Structures Based on Laser-Etched Carbon Nanotube Arrays

    Directory of Open Access Journals (Sweden)

    Aline Emplit

    2014-09-01

    Full Text Available High-power electronics in the transportation and aerospace sectors need size and weight reduction. Multifunctional and multistructured materials are currently being developed to couple electromagnetic (EM and thermal properties, i.e., shielding against electromagnetic impulsions, and thermal management across the thermal interface material (TIM. In this work, we investigate laser-machined patterned carbon nanotube (CNT micro-brushes as an alternative to metallic structures for driving simultaneously EM and heat propagation. The thermal and electromagnetic response of the CNT array is expected to be sensitive to the micro-structured pattern etched in the CNT brush.

  15. Engineering a novel material: Nanometric titanium carbide particles in a matrix of carbon nanotubes

    CERN Document Server

    BADIE, Sylvain

    2015-01-01

    New physics studies at ISOLDE are motivated by new beams available, especially beams of exotic nuclei located at the frontier of the nuclear chart. Such beams are often short lived (in the order of milliseconds) and decay before they can be extracted from the target material, where typical diffusion times are in the order of seconds or more. Novel nanostructured and nanocomposite target materials have been developed to increase the release efficiency by reducing the diffusion paths and so the diffusion times, allowing ISOLDE to deliver new and more intense beams of exotic nuclei. 35Ca (25 ms half-life) was attempted by developing a titanium carbide and carbon black nanocomposite, but such isotope could not be extracted. A different production method with different precursors - titanium oxide and multiwall carbon nanotubes - is here proposed and expected to yield a target material which will increase the release rates of such isotope. A novel material, very porous, consisting of titanium carbide particles disp...

  16. Damping Property of a Cement-Based Material Containing Carbon Nanotube

    OpenAIRE

    Wei-Wen Li; Wei-Ming Ji; Yi Liu; Feng Xing; Yu-Kai Liu

    2015-01-01

    This study aimed to explore the damping property of a cement-based material with carbon nanotube (CNT). In the study, the cement composites with different contents of CNT (0 wt%, 0.033 wt%, 0.066 wt%, and 0.1 wt%) were investigated. Logarithmic Decrement method and Dynamic Mechanical Analysis (DMA) method were utilized to study the damping property of CNT/cement composite. The influences of CNT on pore size distribution and microstructure of composite were analyzed by Mercury Intrusion Porosi...

  17. Controlling the Electrostatic Discharge Ignition Sensitivity of Composite Energetic Materials Using Carbon Nanotube Additives

    Energy Technology Data Exchange (ETDEWEB)

    Kade H. Poper; Eric S. Collins; Michelle L. Pantoya; Michael Daniels

    2014-10-01

    Powder energetic materials are highly sensitive to electrostatic discharge (ESD) ignition. This study shows that small concentrations of carbon nanotubes (CNT) added to the highly reactive mixture of aluminum and copper oxide (Al + CuO) significantly reduces ESD ignition sensitivity. CNT act as a conduit for electric energy, bypassing energy buildup and desensitizing the mixture to ESD ignition. The lowest CNT concentration needed to desensitize ignition is 3.8 vol.% corresponding to percolation corresponding to an electrical conductivity of 0.04 S/cm. Conversely, added CNT increased Al + CuO thermal ignition sensitivity to a hot wire igniter.

  18. STRUCTURE AND PROPERTIES OF COMPOSITE MATERIAL BASED ON GYPSUM BINDER AND CARBON NANOTUBES

    Directory of Open Access Journals (Sweden)

    CHUMAK Anastasia Gennadievna

    2013-04-01

    Full Text Available The aim of this work is to carry out a number of studies in the area of nanomodi­fication of gypsum binder matrix and to investigate the influence of multilayer carbon nanotubes on the structure, physical and mechanical properties of obtained compos­ites. The study of the gypsum binders structure formation mechanisms with the use of nanoadditives makes it possible to control the production processes of gypsum materi­als and articles with the given set of properties. The main tasks of the binder nanomodification are: even distribution of carbon nanostructures over the whole volume of material and provision of stability for the nanodimensional modifier during production process of the construction composite.

  19. Effects of bimetallic catalysts on synthesis of nitrogen-doped carbon nanotubes as nanoscale energetic materials

    Institute of Scientific and Technical Information of China (English)

    Hao Liu; Yong Zhang; Ruying Li; Xueliang Sun; Hakima Abou-Rachid

    2011-01-01

    Well aligned nitrogen-doped carbon nanotubes (CNx-NTs),as energetic materials,are synthesized on a silicon substrate by aerosol-assisted chemical vapor deposition.Tungsten (W) and molybdenum (Mo) metals are respectively introduced to combine with iron (Fe) to act as a bimetallic co-catalyst layer.Correlations between the composition and shape of the co-catalyst and morphology,size,growth rate and nitrogen doping amount of the synthesized CNx-NTs are investigated by secondary and backscattered electron imaging in a field emission scanning electron microscope (FESEM) and X-ray photoelectron spectrometer (XPS).Compared to pure iron catalyst.W-Fe co-catalyst can result in lower growth rate,larger diameter and wider size distribution of the CNx-NTs; while incorporation of molybdenum into the iron catalyst layer can reduce the diameter and size distribution of the nanotubes.Compared to the sole iron catalyst,Fe-W catalyst impedes nitrogen doping while Fe-Mo catalyst promotes the incorporation of nitrogen into the nanotubes.The present work indicates that CNx-NTs with modulated size,growth rate and nitrogen doping concentration are expected to be synthesized by tuning the size and composition of co-catalysts,which may find great potential in producing CNx-NTs with controlled structure and properties.

  20. Fast Synthesis of Multilayer Carbon Nanotubes from Camphor Oil as an Energy Storage Material

    Directory of Open Access Journals (Sweden)

    Amin TermehYousefi

    2014-01-01

    Full Text Available Among the wide range of renewable energy sources, the ever-increasing demand for electricity storage represents an emerging challenge. Utilizing carbon nanotubes (CNTs for energy storage is closely being scrutinized due to the promising performance on top of their extraordinary features. In this work, well-aligned multilayer carbon nanotubes were successfully synthesized on a porous silicon (PSi substrate in a fast process using renewable natural essential oil via chemical vapor deposition (CVD. Considering the influx of vaporized multilayer vertical carbon nanotubes (MVCNTs to the PSi, the diameter distribution increased as the flow rate decreased in the reactor. Raman spectroscopy results indicated that the crystalline quality of the carbon nanotubes structure exhibits no major variation despite changes in the flow rate. Fourier transform infrared (FT-IR spectra confirmed the hexagonal structure of the carbon nanotubes because of the presence of a peak corresponding to the carbon double bond. Field emission scanning electron microscopy (FESEM images showed multilayer nanotubes, each with different diameters with long and straight multiwall tubes. Moreover, the temperature programmed desorption (TPD method has been used to analyze the hydrogen storage properties of MVCNTs, which indicates that hydrogen adsorption sites exist on the synthesized multilayer CNTs.

  1. Preparation of Ni(OH)2-graphene sheet-carbon nanotube composite as electrode material for supercapacitors

    International Nuclear Information System (INIS)

    Highlights: • CNT is introduced into graphene to prevent restacking by solvothermal reaction. • Ethanol as a low cost and green solvent is used in solvothermal reaction. • Ni(OH)2 nanosheets were chemically precipitated into GS-CNT to increase the capacitance. - Abstract: Ni(OH)2-graphene sheet-carbon nanotube composite was prepared for supercapacitance materials through a simple two-step process involving solvothermal synthesis of graphene sheet-carbon nanotube composite in ethanol and chemical precipitation of Ni(OH)2. According to N2 adsorption/desorption analysis, the Brunauer–Emmett–Teller surface area of graphene sheet-carbon nanotube composite (109.07 m2 g−1) was larger than that of pure graphene sheets (32.06 m2 g−1), indicating that the added carbon nanotubes (15 wt.%) could prevent graphene sheets from restacking in the solvothermal reaction. The results of field emission scanning electron microscopy and transmission electron microscopy showed that Ni(OH)2 nanosheets were uniformly loaded into the three-dimensional interconnected network of graphene sheet-carbon nanotube composite. The microstructure enhanced the rate capability and utilization of Ni(OH)2. The specific capacitance of Ni(OH)2-graphene sheet-carbon nanotube composite was 1170.38 F g−1 at a current density of 0.2 A g−1 in the 6 mol L−1 KOH solution, higher than those provided by pure Ni(OH)2 (953.67 Fg−1) and graphene sheets (178.25 F g−1). After 20 cycles at each current density (0.2, 0.4, 0.6, 0.8, 1.0 and 1.2 A g−1), the capacitance of Ni(OH)2-graphene sheet-carbon nanotube composite decreased 26.96% of initial capacitance compared to 74.52% for pure Ni(OH)2

  2. Studies of Carbon Nanotubes

    Science.gov (United States)

    Caneba, Gerard T.

    2005-01-01

    The fellowship experience for this summer for 2004 pertains to carbon nanotube coatings for various space-related applications. They involve the following projects: (a) EMI protection films from HiPco-polymers, and (b) Thermal protection nanosilica materials. EMI protection films are targeted to be eventually applied onto casings of laptop computers. These coatings are composites of electrically-conductive SWNTs and compatible polymers. The substrate polymer will be polycarbonate, since computer housings are typically made of carbon composites of this type of polymer. A new experimental copolymer was used last year to generate electrically-conductive and thermal films with HiPco at 50/50 wt/wt composition. This will be one of the possible formulations. Reference films will be base polycarbonate and neat HiPco onto polycarbonate films. Other coating materials that will be tried will be based on HiPco composites with commercial enamels (polyurethane, acrylic, polyester), which could be compatible with the polycarbonate substrate. Nanosilica fibers are planned for possible use as thermal protection tiles on the shuttle orbiter. Right now, microscale silica is used. Going to the nanoscale will increase the surface-volume-per-unit-area of radiative heat dissipation. Nanoscale carbon fibers/nanotubes can be used as templates for the generation of nanosilica. A sol-gel operation is employed for this purpose.

  3. Carbon Nanotube Enhanced Aerospace Composite Materials A New Generation of Multifunctional Hybrid Structural Composites

    CERN Document Server

    Kostopoulos, V

    2013-01-01

    The well documented increase in the use of high performance composites as structural materials in aerospace components is continuously raising the demands in terms of dynamic performance, structural integrity, reliable life monitoring systems and adaptive actuating abilities. Current technologies address the above issues separately; material property tailoring and custom design practices aim to the enhancement of dynamic and damage tolerance characteristics, whereas life monitoring and actuation is performed with embedded sensors that may be detrimental to the structural integrity of the component. This publication explores the unique properties of carbon nanotubes (CNT) as an additive in the matrix of Fibre Reinforced Plastics (FRP), for producing structural composites with improved mechanical performance as well as sensing/actuating capabilities. The successful combination of the CNT properties and existing sensing actuating technologies leads to the realization of a multifunctional FRP structure. The curre...

  4. Organic modification of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The organic modification of carbon nanotubes is a novel research field being developed recently. In this article, the history and newest progress of organic modification of carbon nanotubes are reviewed from two aspects:organic covalent modification and organic noncovalent modification of carbon nanotubes. The preparation and properties of organic modified carbon nanotubes are discussed in detail. In addition, the prospective development of organic modification of carbon nanotubes is suggested.

  5. Synthesis and characterization of SnO-carbon nanotube composite as anode material for lithium-ion batteries

    International Nuclear Information System (INIS)

    SnO-carbon nanotube composite was synthesized by a sol-gel method. The electrochemical behavior of the composite using an anode active material in lithium-ion batteries was investigated. It was found that the composite showed enhanced anode performance compared with the unsupported SnO or carbon nanotube (CNT). The capacity fade of the composite electrode was reduced over unsupported SnO or CNT. We attribute the results to the conductivity and ductility of the CNT matrix, and the high dispersion of SnO

  6. Hybrid Multi-Walled Carbon Nanotube TiO2 Electrode Material for Next Generation Energy Storage Devices

    CERN Document Server

    Marler, Sydney

    2016-01-01

    Current supercapacitors present several distinct limitations that severely inhibit the efficiency, power, and electrical capacitance of energy storage devices. Supercapacitors present an exciting prospect that has countless applications in renewable energy storage and modern day electronic devices. In recent years the exciting development of carbon nanotubes (CNTs) has presented an advantage in electrode development. CNTs, however beneficial for their increased electrode surface area, have severe limitations regarding conductivity and electrode density. Creating a nanocomposite hybrid out of a transition metal-oxide and carbon nanotube array would help the current limitations of the modern supercapacitor. TiO2 was chosen for its common occurrence in everyday materials and promising capacitance levels. A multi-walled carbon nanotube array was grown on a SiO2 precursor via CCVD. The transition metal oxide was then deposited via RF Sputtering methods to a MWCNT array. Recharge tests and characterization were con...

  7. Functionalized polypropylenes as efficient dispersing agents for carbon nanotubes in a polypropylene matrix; application to electromagnetic interference (EMI) absorber materials

    OpenAIRE

    Thomassin, Jean-Michel; Huynen, Isabelle; Jérôme, Robert; Detrembleur, Christophe

    2010-01-01

    Carbon nanotubes (CNTs) have been dispersed within polypropylene with the purpose to prepare electromagnetic interference (EMI) absorbers. In order to limit the reflectivity of the electromagnetic waves at the interface of the materials while achieving good absorbing properties, the CNTs concentration must be kept low (

  8. Different Technical Applications of Carbon Nanotubes

    OpenAIRE

    Abdalla, S; Al-Marzouki, F.; Ahmed A. Al-Ghamdi; Abdel-Daiem, A.

    2015-01-01

    Carbon nanotubes have been of great interest because of their simplicity and ease of synthesis. The novel properties of nanostructured carbon nanotubes such as high surface area, good stiffness, and resilience have been explored in many engineering applications. Research on carbon nanotubes have shown the application in the field of energy storage, hydrogen storage, electrochemical supercapacitor, field-emitting devices, transistors, nanoprobes and sensors, composite material, templates, etc....

  9. Self-Consistent Physical Properties of Carbon Nanotubes in Composite Materials

    Science.gov (United States)

    Pipes, R. B.; Frankland, S. J. V.; Hubert, P.; Saether, E.

    2002-12-01

    A set of relationships is developed for selected physical properties of single-walled carbon nanotubes (SWCN) and their hexagonal arrays as a function of nanotube size in terms of the chiral vector integer pair, (n,m). Properties include density, principal Young's modulus, and specific Young's modulus. Relationships between weight fraction and volume fraction of SWCN and their arrays are developed for polymeric mixtures.

  10. Conducting carbonized polyaniline nanotubes

    Science.gov (United States)

    Mentus, Slavko; Ćirić-Marjanović, Gordana; Trchová, Miroslava; Stejskal, Jaroslav

    2009-06-01

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 °C min-1 up to a maximum temperature of 800 °C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 µm, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 µm, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm-1, increased to 0.7 S cm-1 upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy.

  11. Conducting carbonized polyaniline nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Mentus, Slavko; Ciric-Marjanovic, Gordana [Faculty of Physical Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade (Serbia); Trchova, Miroslava; Stejskal, Jaroslav [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Square 2, 162 06 Prague 6 (Czech Republic)], E-mail: gordana@ffh.bg.ac.rs

    2009-06-17

    Conducting nitrogen-containing carbon nanotubes were synthesized by the carbonization of self-assembled polyaniline nanotubes protonated with sulfuric acid. Carbonization was carried out in a nitrogen atmosphere at a heating rate of 10 deg. C min{sup -1} up to a maximum temperature of 800 deg. C. The carbonized polyaniline nanotubes which have a typical outer diameter of 100-260 nm, with an inner diameter of 20-170 nm and a length extending from 0.5 to 0.8 {mu}m, accompanied with very thin nanotubes with outer diameters of 8-14 nm, inner diameters 3.0-4.5 nm and length extending from 0.3 to 1.0 {mu}m, were observed by scanning and transmission electron microscopies. Elemental analysis showed 9 wt% of nitrogen in the carbonized product. Conductivity of the nanotubular PANI precursor, amounting to 0.04 S cm{sup -1}, increased to 0.7 S cm{sup -1} upon carbonization. Molecular structure of carbonized polyaniline nanotubes has been analyzed by FTIR and Raman spectroscopies, and their paramagnetic characteristics were compared with the starting PANI nanotubes by EPR spectroscopy.

  12. Electrodeposited gold nanoparticles on carbon nanotube-textile: Anode material for glucose alkaline fuel cells

    KAUST Repository

    Pasta, Mauro

    2012-06-01

    In the present paper we propose a new anode material for glucose-gluconate direct oxidation fuel cells prepared by electrodepositing gold nanoparticles onto a conductive textile made by conformally coating single walled carbon nanotubes (SWNT) on a polyester textile substrate. The electrodeposition conditions were optimized in order to achieve a uniform distribution of gold nanoparticles in the 3D porous structure of the textile. On the basis of previously reported studies, the reaction conditions (pH, electrolyte composition and glucose concentration) were tuned in order to achieve the highest oxidation rate, selectively oxidizing glucose to gluconate. The electrochemical characterization was carried out by means of cyclic voltammetry. © 2012 Elsevier B.V. All rights reserved.

  13. FLUIDIZATION OF CARBON NANOTUBES

    Institute of Scientific and Technical Information of China (English)

    Fei Wei; Cang Huang; Yao Wang

    2005-01-01

    Carbon nanotubes (CNTs) can be fluidized in the form of fluidlike agglomerates made of many three-dimensional sub-agglomerates, having a multi-stage agglomerate (MSA) structure and containing large amounts of twisting CNTs of micrometer magnitude.

  14. Carbon nanotubes: Fibrillar pharmacology

    Science.gov (United States)

    Kostarelos, Kostas

    2010-10-01

    The mechanisms by which chemically functionalized carbon nanotubes flow in blood and are excreted through the kidneys illustrate the unconventional behaviour of these fibrillar nanostructures, and the opportunities they offer as components for the design of advanced delivery vehicles.

  15. Carbon Nanotube Biosensors

    Directory of Open Access Journals (Sweden)

    Carmen-Mihaela eTilmaciu

    2015-10-01

    Full Text Available Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular Carbon Nanotubes (CNTs can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we will describe their structural and physical properties, discuss functionalization and cellular uptake, biocompatibility and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers.

  16. Electrochemical supercapacitors based on novel hybrid materials made of carbon nanotubes and polyoxometalates

    Energy Technology Data Exchange (ETDEWEB)

    Cuentas-Gallegos, Ana Karina; Martinez-Rosales, Rosa; Rincon, Marina E. [Centro de Investigacion en Energia, Universidad Nacional Autonoma de Mexico, Priv. Xochicalco s/n, Col. Centro, C.P. 62580 Temixco, Mor (Mexico); Baibarac, Mihaela; Gomez-Romero, Pedro [Instituto de Ciencia de Materiales de Barcelona, CSIC, Campus de la UAB, 08193 Bellaterra (Spain)

    2007-08-15

    We have characterized symmetric solid-state supercapacitors in swagelok cells using film electrodes made of novel hybrid materials based on multiwalled carbon nanotubes (CNT) and phosphomolybdate polyanion (Cs-PMo12) with PVA as binder. These hybrid materials were carried out by Cs-PMo12 adhesion onto previously functionalized CNT, in order to disperse both components at a molecular level and use Cs-PMo12 as energy density enhancer in supercapacitor cells. Our results show high capacitance values (up to 285 F/g at I = 200 mA/g) due to the contribution of Cs-PMo12, which was revealed on the higher energy density values compared to pure CNT electrodes. Additionally, good stability was observed during 500 charge-discharge cycles for most hybrid electrodes. These preliminary results show a new approach to enhance energy density of double layer supercapacitor cells through the introduction of Cs-PMo12, whereas from a material science point of view these materials are innovative, and open the way to search for diverse applications aside from supercapacitors (sensors, catalysts, photovoltaic cells, etc.). (author)

  17. Purification of carbon nanotube by wet oxidation; Shisshiki sanka ni yoru carbon nanotube no seisei

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, K.; Takarada, T. [Gunma University, Gunma (Japan)

    1997-07-10

    In order to efficiently recover carbon nanotubes, the purification method by wet oxidation with orthoperiodic acid and perchloric acid is investigated. The reactivity of the carbonaceous material toward the acids depends on the type of carbon. Carbon nanotubes are selectively recovered under the mild oxidation conditions. The degree of purification depends on the concentration of orthoperiodic acid. It is suggested that wet oxidation is an effective method for purification of carbon nanotubes. 17 refs., 6 figs.

  18. Quantum transport in carbon nanotubes

    NARCIS (Netherlands)

    Laird, E.A.; Kuemmeth, F.; Steele, G.A.; Grove-Rasmussen, K.; Nygard, J.; Flensberg, K.; Kouwenhoven, L.P.

    2015-01-01

    Carbon nanotubes are a versatile material in which many aspects of condensed matter physics come together. Recent discoveries have uncovered new phenomena that completely change our understanding of transport in these devices, especially the role of the spin and valley degrees of freedom. This revie

  19. On the stability of carbon nanotube and titania nanowire based catalyst materials:from synthesis to applications

    OpenAIRE

    Rautio, A.-R. (Anne-Riikka)

    2016-01-01

    Abstract Degradation of the support and sintering of catalyst nanoparticles inherently leads to a loss of functionality of catalyst materials in converters and sensors. Malfunction in such devices may lead to serious economic and environmental damage. The quest for novel and sustainable catalyst materials with better durability is thus ongoing. In this thesis, one-dimensional nanomaterials such as carbon nanotubes and titanium dioxide nanowires are studied and compared to their convention...

  20. Quantum transport in carbon nanotubes

    DEFF Research Database (Denmark)

    Laird, Edward A.; Kuemmeth, Ferdinand; Steele, Gary A.;

    2015-01-01

    Carbon nanotubes are a versatile material in which many aspects of condensed matter physics come together. Recent discoveries, enabled by sophisticated fabrication, have uncovered new phenomena that completely change our understanding of transport in these devices, especially the role of the spin...... and valley degrees of freedom. This review describes the modern understanding of transport through nanotube devices. Unlike conventional semiconductors, electrons in nanotubes have two angular momentum quantum numbers, arising from spin and from valley freedom. We focus on the interplay between the two....... In single quantum dots defined in short lengths of nanotube, the energy levels associated with each degree of freedom, and the spin-orbit coupling between them, are revealed by Coulomb blockade spectroscopy. In double quantum dots, the combination of quantum numbers modifies the selection rules of Pauli...

  1. Design, fabrication and properties of novel architectures made from carbon nanotubes and nano-porous materials

    Science.gov (United States)

    Kaur, Sumanjeet

    Nanomaterials like carbon nanotubes (CNT) have numerous potential applications due to their unique electrical, thermal and mechanical properties. Building macroscopic architectures using these nanocomponents requires new approaches for organization or assembly of these components. This can be achieved by using various techniques like capillary-induced compaction, template-assisted growth and other synthesis techniques. The vertically aligned multiwalled carbon nanotube arrays were grown using chemical vapor deposition (CVD). Evaporation of liquid from such vertically aligned nanotube arrays induces the assembly of nanotubes into cellular patterns. The role of substrate and orientation of the carbon nanotube array was investigated and analyzed to gain more control over the pattern formation that could help in designing new structures. Electrical measurements on the CNT patterns before and after capillary-induced compaction revealed that compaction results in four-fold increase in electrical conductivity, making them a potential candidate for vertical interconnects. A new method to fabricate a syringe with nanopores by using anodization technique was demonstrated. Experimental parameters were investigated to control the dimension and morphology of the nanopores in the syringe. Capillary force was used to infiltrate and replicate the complete 3D architecture into polymers. The usefulness of syringe as a biological sampler (DNA-RNA separation) was demonstrated. Layered structure of exfoliated mica was used as a substrate for growth of CNTs. This resulted in novel layered hybrid architecture of mica and carbon nanotube arrays. Mechanical properties of such architectures were investigated. Such architectures could be very useful as foams. These simple techniques can be used to assemble nanoscale components into well-defined macroscopic architectures and thus broaden the range of applications where their unique properties can be put into use.

  2. Templated Growth of Carbon Nanotubes

    Science.gov (United States)

    Siochik Emilie J. (Inventor)

    2007-01-01

    A method of growing carbon nanotubes uses a synthesized mesoporous si lica template with approximately cylindrical pores being formed there in. The surfaces of the pores are coated with a carbon nanotube precu rsor, and the template with the surfaces of the pores so-coated is th en heated until the carbon nanotube precursor in each pore is convert ed to a carbon nanotube.

  3. Carbon Nanotube Electron Gun

    Science.gov (United States)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2013-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  4. Carbon nanotube biconvex microcavities

    Science.gov (United States)

    Butt, Haider; Yetisen, Ali K.; Ahmed, Rajib; Yun, Seok Hyun; Dai, Qing

    2015-03-01

    Developing highly efficient microcavities with predictive narrow-band resonance frequencies using the least amount of material will allow the applications in nonlinear photonic devices. We have developed a microcavity array that comprised multi-walled carbon nanotubes (MWCNT) organized in a biconvex pattern. The finite element model allowed designing microcavity arrays with predictive transmission properties and assessing the effects of the microarray geometry. The microcavity array demonstrated negative index and produced high Q factors. 2-3 μm tall MWCNTs were patterned as biconvex microcavities, which were separated by 10 μm in an array. The microcavity was iridescent and had optical control over the diffracted elliptical patterns with a far-field pattern, whose properties were predicted by the model. It is anticipated that the MWCNT biconvex microcavities will have implications for the development of highly efficient lenses, metamaterial antennas, and photonic circuits.

  5. Carbon nanotube optical mirrors

    Science.gov (United States)

    Chen, Peter C.; Rabin, Douglas

    2015-01-01

    We report the fabrication of imaging quality optical mirrors with smooth surfaces using carbon nanotubes (CNT) embedded in an epoxy matrix. CNT/epoxy is a multifunctional composite material that has sensing capabilities and can be made to incorporate self-actuation. Moreover, as the precursor is a low density liquid, large and lightweight mirrors can be fabricated by processes such as replication, spincasting, and three-dimensional printing. Therefore, the technology holds promise for the development of a new generation of lightweight, compact "smart" telescope mirrors with figure sensing and active or adaptive figure control. We report on measurements made of optical and mechanical characteristics, active optics experiments, and numerical modeling. We discuss possible paths for future development.

  6. Carbon nanotube biconvex microcavities

    Energy Technology Data Exchange (ETDEWEB)

    Butt, Haider, E-mail: h.butt@bham.ac.uk; Ahmed, Rajib [Nanotechnology Laboratory, School of Mechanical Engineering, University of Birmingham, Birmingham B15 2TT (United Kingdom); Yetisen, Ali K.; Yun, Seok Hyun [Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom Street, Boston, Massachusetts 02114 (United States); Dai, Qing [National Center for Nanoscience and Technology, Beijing 100190 (China)

    2015-03-23

    Developing highly efficient microcavities with predictive narrow-band resonance frequencies using the least amount of material will allow the applications in nonlinear photonic devices. We have developed a microcavity array that comprised multi-walled carbon nanotubes (MWCNT) organized in a biconvex pattern. The finite element model allowed designing microcavity arrays with predictive transmission properties and assessing the effects of the microarray geometry. The microcavity array demonstrated negative index and produced high Q factors. 2–3 μm tall MWCNTs were patterned as biconvex microcavities, which were separated by 10 μm in an array. The microcavity was iridescent and had optical control over the diffracted elliptical patterns with a far-field pattern, whose properties were predicted by the model. It is anticipated that the MWCNT biconvex microcavities will have implications for the development of highly efficient lenses, metamaterial antennas, and photonic circuits.

  7. OPPORTUNITIES OF BIOMEDICAL USE OF CARBON NANOTUBES

    Directory of Open Access Journals (Sweden)

    I. V. Mitrofanova

    2015-12-01

    Full Text Available Nanomaterials  –  materials,  whouse  structure  elements  has  proportions  doesn’t  exceed  100  nm.  In superdispersed state matter acquire new properties. In the last decade, carbon nanotubes become the most popular nanomaterials, that cause attention of representatives of various scientific field. The сarbon nanotubes offer new opportunities for biological and medical applications: imaging at the molecular, cellular and tissue levels, biosensors and electrodes based on carbon nanotubes, target delivery of various substances, radiation and photothermal therapy. The most promising of carbon nanotubes in the context of biomedical applications is their ability to penetrate the various tissues of the body and carry large doses of agents, providing diagnostic and therapeutic effects. Functionalized nanotubes are biodegradable. Other current direction of using carbon nanotubes in medicine and biology is to visualize objects on the molecular, cellular and tissue level. Associated with carbon nanotubes contrasting substances improve the visualization of cells and tissues, which can detected new patterns of development of the pathological process. Due to the vagueness of the question of biocompatibility and cytotoxicity of carbon nanotubes possibility of their practical application is hampered. Before the introduction of carbon nanotubes into practical health care is necessary to provide all the possible consequences of using nanotubes. High rates of properties and development of new nanostructures based on carbon nanotubes in the near future will lead to new advances related to the application and development of new parameters that will determine their properties and effects. In these review attention is paid to the structure, physico-chemical properties of nanotubes, their functionalization, pharmacokinetics and pharmacodynamics and all aspects of using of carbon nanotubes.

  8. Controlled Deposition and Alignment of Carbon Nanotubes

    Science.gov (United States)

    Smits, Jan M. (Inventor); Wincheski, Russell A. (Inventor); Patry, JoAnne L. (Inventor); Watkins, Anthony Neal (Inventor); Jordan, Jeffrey D. (Inventor)

    2012-01-01

    A carbon nanotube (CNT) attraction material is deposited on a substrate in the gap region between two electrodes on the substrate. An electric potential is applied to the two electrodes. The CNT attraction material is wetted with a solution defined by a carrier liquid having carbon nanotubes (CNTs) suspended therein. A portion of the CNTs align with the electric field and adhere to the CNT attraction material. The carrier liquid and any CNTs not adhered to the CNT attraction material are then removed.

  9. Carbon nanotube junctions and devices

    NARCIS (Netherlands)

    Postma, H.W.Ch.

    2001-01-01

    In this thesis Postma presents transport experiments performed on individual single-wall carbon nanotubes. Carbon nanotubes are molecules entirely made of carbon atoms. The electronic properties are determined by the exact symmetry of the nanotube lattice, resulting in either metallic or semiconduct

  10. Carbon Nanotubes - Polymer Composites with Enhanced Conductivity using Functionalized Nanotubes

    Science.gov (United States)

    Ramasubramaniam, Rajagopal; Chen, Jian; Gupta, Rishi

    2003-03-01

    Individual carbon nanotubes show superior electrical, mechanical and thermal properties [1]. Composite materials using carbon nanotubes as fillers are predicted to show similar superior properties. However, realization of such composites has been plagued by poor dispersion of carbon nanotubes in solvents and in polymer matrices. We have developed a method to homogenously disperse carbon nanotubes in polymer matrices using functionalized nanotubes [2]. Thin films of functionalized single walled nanotubes (SWNT) - polystyrene composites and functionalized SWNT - polycarbonate composites were prepared using solution evaporation and spin coating. Both of the composites show several orders of magnitude increase in conductivity for less than 1 wt thresholds of the composites are less than 0.2 wt nanotubes. We attribute the enhanced conduction to the superior dispersion of the functionalized nanotubes in the polymer matrix and to the reduced nanotube waviness resulting from the rigid backbone of the conjugated polymer. References: [1]. R. H. Baughman, A. A. Zakhidov and W. A. de Heer, Science v297, p787 (2002); [2]. J. Chen, H. Liu, W. A. Weimer, M. D. Halls, D. H. Waldeck and G. C. Walker, J. Am. Chem. Soc. v124, p9034 (2002).

  11. Preparation of Ni(OH){sub 2}-graphene sheet-carbon nanotube composite as electrode material for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y.F. [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); College of Environmental and Chemical Engineering, Heilongjiang University of Science and Technology, Harbin 150022 (China); Yuan, G.H., E-mail: ygh@hit.edu.cn [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Jiang, Z.H., E-mail: jiangzhaohua@hit.edu.cn [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Yao, Z.P. [School of Chemical Engineering and Technology, Harbin Institute of Technology, Harbin 150001 (China); Yue, M. [Shenzhen BTR New Energy Materials INC., Shenzhen 528206 (China)

    2015-01-05

    Highlights: • CNT is introduced into graphene to prevent restacking by solvothermal reaction. • Ethanol as a low cost and green solvent is used in solvothermal reaction. • Ni(OH){sub 2} nanosheets were chemically precipitated into GS-CNT to increase the capacitance. - Abstract: Ni(OH){sub 2}-graphene sheet-carbon nanotube composite was prepared for supercapacitance materials through a simple two-step process involving solvothermal synthesis of graphene sheet-carbon nanotube composite in ethanol and chemical precipitation of Ni(OH){sub 2}. According to N{sub 2} adsorption/desorption analysis, the Brunauer–Emmett–Teller surface area of graphene sheet-carbon nanotube composite (109.07 m{sup 2} g{sup −1}) was larger than that of pure graphene sheets (32.06 m{sup 2} g{sup −1}), indicating that the added carbon nanotubes (15 wt.%) could prevent graphene sheets from restacking in the solvothermal reaction. The results of field emission scanning electron microscopy and transmission electron microscopy showed that Ni(OH){sub 2} nanosheets were uniformly loaded into the three-dimensional interconnected network of graphene sheet-carbon nanotube composite. The microstructure enhanced the rate capability and utilization of Ni(OH){sub 2}. The specific capacitance of Ni(OH){sub 2}-graphene sheet-carbon nanotube composite was 1170.38 F g{sup −1} at a current density of 0.2 A g{sup −1} in the 6 mol L{sup −1} KOH solution, higher than those provided by pure Ni(OH){sub 2} (953.67 Fg{sup −1}) and graphene sheets (178.25 F g{sup −1}). After 20 cycles at each current density (0.2, 0.4, 0.6, 0.8, 1.0 and 1.2 A g{sup −1}), the capacitance of Ni(OH){sub 2}-graphene sheet-carbon nanotube composite decreased 26.96% of initial capacitance compared to 74.52% for pure Ni(OH){sub 2}.

  12. Methods for producing reinforced carbon nanotubes

    Science.gov (United States)

    Ren, Zhifen; Wen, Jian Guo; Lao, Jing Y.; Li, Wenzhi

    2008-10-28

    Methods for producing reinforced carbon nanotubes having a plurality of microparticulate carbide or oxide materials formed substantially on the surface of such reinforced carbon nanotubes composite materials are disclosed. In particular, the present invention provides reinforced carbon nanotubes (CNTs) having a plurality of boron carbide nanolumps formed substantially on a surface of the reinforced CNTs that provide a reinforcing effect on CNTs, enabling their use as effective reinforcing fillers for matrix materials to give high-strength composites. The present invention also provides methods for producing such carbide reinforced CNTs.

  13. Carbon Nanotubes for Human Space Flight

    Science.gov (United States)

    Scott, Carl D.; Files, Brad; Yowell, Leonard

    2003-01-01

    Single-wall carbon nanotubes offer the promise of a new class of revolutionary materials for space applications. The Carbon Nanotube Project at NASA Johnson Space Center has been actively researching this new technology by investigating nanotube production methods (arc, laser, and HiPCO) and gaining a comprehensive understanding of raw and purified material using a wide range of characterization techniques. After production and purification, single wall carbon nanotubes are processed into composites for the enhancement of mechanical, electrical, and thermal properties. This "cradle-to-grave" approach to nanotube composites has given our team unique insights into the impact of post-production processing and dispersion on the resulting material properties. We are applying our experience and lessons-learned to developing new approaches toward nanotube material characterization, structural composite fabrication, and are also making advances in developing thermal management materials and electrically conductive materials in various polymer-nanotube systems. Some initial work has also been conducted with the goal of using carbon nanotubes in the creation of new ceramic materials for high temperature applications in thermal protection systems. Human space flight applications such as advanced life support and fuel cell technologies are also being investigated. This discussion will focus on the variety of applications under investigation.

  14. Horizontal carbon nanotube alignment.

    Science.gov (United States)

    Cole, Matthew T; Cientanni, Vito; Milne, William I

    2016-09-21

    The production of horizontally aligned carbon nanotubes offers a rapid means of realizing a myriad of self-assembled near-atom-scale technologies - from novel photonic crystals to nanoscale transistors. The ability to reproducibly align anisotropic nanostructures has huge technological value. Here we review the present state-of-the-art in horizontal carbon nanotube alignment. For both in and ex situ approaches, we quantitatively assess the reported linear packing densities alongside the degree of alignment possible for each of these core methodologies. PMID:27546174

  15. Electromechanical Behavior of Chemically Reduced Graphene Oxide and Multi-walled Carbon Nanotube Hybrid Material

    Science.gov (United States)

    Benchirouf, Abderrahmane; Müller, Christian; Kanoun, Olfa

    2016-01-01

    In this paper, we propose strain-sensitive thin films based on chemically reduced graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) without adding any further surfactants. In spite of the insulating properties of the thin-film-based GO due to the presence functional groups such as hydroxyl, epoxy, and carbonyl groups in its atomic structure, a significant enhancement of the film conductivity was reached by chemical reduction with hydro-iodic acid. By optimizing the MWCNT content, a significant improvement of electrical and mechanical thin film sensitivity is realized. The optical properties and the morphology of the prepared thin films were studied using ultraviolet-visible spectroscopy (UV-Vis) and scanning electron microscope (SEM). The UV-Vis spectra showed the ability to tune the band gap of the GO by changing the MWCNT content, whereas the SEM indicated that the MWCNTs were well dissolved and coated by the GO. Investigations of the piezoresistive properties of the hybrid nanocomposite material under mechanical load show a linear trend between the electrical resistance and the applied strain. A relatively high gauge factor of 8.5 is reached compared to the commercial metallic strain gauges. The self-assembled hybrid films exhibit outstanding properties in electric conductivity, mechanical strength, and strain sensitivity, which provide a high potential for use in strain-sensing applications.

  16. Damping Property of a Cement-Based Material Containing Carbon Nanotube

    Directory of Open Access Journals (Sweden)

    Wei-Wen Li

    2015-01-01

    Full Text Available This study aimed to explore the damping property of a cement-based material with carbon nanotube (CNT. In the study, the cement composites with different contents of CNT (0 wt%, 0.033 wt%, 0.066 wt%, and 0.1 wt% were investigated. Logarithmic Decrement method and Dynamic Mechanical Analysis (DMA method were utilized to study the damping property of CNT/cement composite. The influences of CNT on pore size distribution and microstructure of composite were analyzed by Mercury Intrusion Porosimetry (MIP and Scanning Electron Microscopy (SEM, respectively. The experimental results showed that CNT/cement composite presented higher flexural strength index than that of a pure cement paste. Additional CNT could improve the vibration-reduction capacity of cement paste. Furthermore, the experiments proved that CNT could bridge adjacent hydration products and support load transfer within cement matrix, which contributed to the energy dissipation during the loading process.

  17. Electromechanical Behavior of Chemically Reduced Graphene Oxide and Multi-walled Carbon Nanotube Hybrid Material.

    Science.gov (United States)

    Benchirouf, Abderrahmane; Müller, Christian; Kanoun, Olfa

    2016-12-01

    In this paper, we propose strain-sensitive thin films based on chemically reduced graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) without adding any further surfactants. In spite of the insulating properties of the thin-film-based GO due to the presence functional groups such as hydroxyl, epoxy, and carbonyl groups in its atomic structure, a significant enhancement of the film conductivity was reached by chemical reduction with hydro-iodic acid. By optimizing the MWCNT content, a significant improvement of electrical and mechanical thin film sensitivity is realized. The optical properties and the morphology of the prepared thin films were studied using ultraviolet-visible spectroscopy (UV-Vis) and scanning electron microscope (SEM). The UV-Vis spectra showed the ability to tune the band gap of the GO by changing the MWCNT content, whereas the SEM indicated that the MWCNTs were well dissolved and coated by the GO. Investigations of the piezoresistive properties of the hybrid nanocomposite material under mechanical load show a linear trend between the electrical resistance and the applied strain. A relatively high gauge factor of 8.5 is reached compared to the commercial metallic strain gauges. The self-assembled hybrid films exhibit outstanding properties in electric conductivity, mechanical strength, and strain sensitivity, which provide a high potential for use in strain-sensing applications. PMID:26732277

  18. Light Emission in Silicon from Carbon Nanotubes

    CERN Document Server

    Gaufrès, Etienne; Noury, Adrien; Roux, Xavier Le; Rasigade, Gilles; Beck, Alexandre; Vivien, Laurent

    2015-01-01

    The use of optics in microelectronic circuits to overcome the limitation of metallic interconnects is more and more considered as a viable solution. Among future silicon compatible materials, carbon nanotubes are promising candidates thanks to their ability to emit, modulate and detect light in the wavelength range of silicon transparency. We report the first integration of carbon nanotubes with silicon waveguides, successfully coupling their emission and absorption properties. A complete study of this coupling between carbon nanotubes and silicon waveguides was carried out, which led to the demonstration of the temperature-independent emission from carbon nanotubes in silicon at a wavelength of 1.3 {\\mu}m. This represents the first milestone in the development of photonics based on carbon nanotubes on silicon.

  19. Development of supercapacitors based on carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Block-type electrodes made of carbon nanotubes were fabricated by different processes. The volumetric specific capacitance based on such electrodes reached 107 F/cm3, which proves carbon nanotubes to be ideal candidate materials for supercapacitors. The composite electrodes consisting of carbon nanotubes and RuO2.xH2O were developed by the deposition of RuO2 on the surface of carbon nanotubes. Supercapacitors based on the composite electrodes show much higher specific capacitance than those based on pure carbon nanotube ones. A specific capacitance of 600 F/g can be achieved when the weight percent of RuO2.xH2O in the composite electrodes reaches 75%. In addition, supercapacitors based on the composite electrodes show both high energy density and high power density characteristics.

  20. Development of supercapacitors based on carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    马仁志; 魏秉庆; 徐才录; 梁吉; 吴德海

    2000-01-01

    Block-type electrodes made of carbon nanotubes were fabricated by different processes. The volumetric specific capacitance based on such electrodes reached 107 F/cm3, which proves carbon nanotubes to be ideal candidate materials for supercapacitors. The composite electrodes consisting of carbon nanotubes and RuO2 ·xH2O were developed by the deposition of RuO2 on the surface of carbon nanotubes. Supercapacitors based on the composite electrodes show much higher specific capacitance than those based on pure carbon nanotube ones. A specific capacitance of 600 F/g can be achieved when the weight percent of RuO2· xH2O in the composite electrodes reaches 75% . In addition , supercapacitors based on the composite electrodes show both high energy density and high power density characteristics.

  1. 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.

  2. Potential threshold of anode materials for foldable lithium-ion batteries featuring carbon nanotube current collectors

    Science.gov (United States)

    Wang, Qing Hui; Zhong, Sheng Wen; Hu, Jing Wei; Liu, Ting; Zhu, Xian Yan; Chen, Jing; Hong, Yin Yan; Wu, Zi Ping

    2016-04-01

    Flexible carbon nanotube macro-films (CMFs) are perfect current collectors for preparing foldable lithium-ion batteries (LIBs). However, selecting appropriate anodes for electrode is difficult because of the different potentials (vs. Li/Li+) of carbon nanotubes and traditional metallic current collector. This study demonstrated an additional reaction at potential below 0.9 V (vs. Li/Li+) caused by CMF, And Li+ will be constrained, which decreased capacity of anode/CMF electrode. Conversely, results changed when the anode potential exceeded 0.9 V (vs. Li/Li+) because Li+ passed the potential threshold, and the CMF retained its electrochemical inactivity. Consequently, the CMF-based foldable LIBs performed well. The potential threshold mechanism of anode is expected to provide new impetus to both academia and industry for exploring flexible or foldable LIBs.

  3. Multiscale Modeling of Novel Carbon Nanotube/Copper-Composite Material Used in Microelectronics

    Science.gov (United States)

    Awad, Ibrahim; Ladani, Leila

    2016-06-01

    Current carrying capacity is one of the elements that hinders further miniaturization of Copper (Cu) interconnects. Therefore, there is a need to propose new materials with higher ampacity (current carrying capacity) that have the potential to replace Cu. Experimental observations have shown that Carbon Nanotube (CNT)/Cu-composite material has a hundredfold ampacity of Cu, which makes it a good candidate to replace Cu. However, sufficient information about the mechanical behavior of the novel CNT/Cu-composite is not available. In the current paper, the CNT/Cu-composite is utilized to construct Through Silicon Via (TSV). The mechanical behavior, specifically the fatigue life, of the CNT/Cu-TSV is evaluated by applying a multiscale modeling approach. Molecular Dynamics (MD) simulations are conducted to evaluate the tensile strength and the coefficient of thermal expansion of CNTs. MD simulation is also used to determine the interface behavior between CNTs and Cu. MD simulation results are integrated into Finite Element analysis at the micro-level to estimate the fatigue life of the CNT/Cu-TSV. A comparison is made with base material; Cu. CNTs addition has redistributed the plastic deformation in Cu to occur at two different locations (Si/Cu interface and Cu/CNT interface) instead of only one location (Si/Cu interface) in the case of Cu-only-TSV. Thus, the maximum equivalent plastic strain has been alleviated in the CNT/Cu-TSV. Accordingly, CNT/Cu-TSV has shown a threefold increase in the fatigue life. This is a solid indication of the improvement in the fatigue life that is attributed to the addition of CNTs.

  4. Electromechanical Behavior of Chemically Reduced Graphene Oxide and Multi-walled Carbon Nanotube Hybrid Material

    OpenAIRE

    Benchirouf, Abderrahmane; Müller, Christian; Kanoun, Olfa

    2016-01-01

    In this paper, we propose strain-sensitive thin films based on chemically reduced graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs) without adding any further surfactants. In spite of the insulating properties of the thin-film-based GO due to the presence functional groups such as hydroxyl, epoxy, and carbonyl groups in its atomic structure, a significant enhancement of the film conductivity was reached by chemical reduction with hydro-iodic acid. By optimizing the MWCNT content,...

  5. Methods for preparation of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Rakov, Eduard G [D.I. Mendeleev Russian University of Chemical Technology, Moscow (Russian Federation)

    2000-01-31

    The most important methods of synthesis and purification of carbon nanotubes, a new form of material, are described. The prospects for increasing the scale of preparation processes and for more extensive application of nanotubes are evaluated. The bibliography includes 282 references.

  6. A Review: Carbon Nanotube-Based Piezoresistive Strain Sensors

    Directory of Open Access Journals (Sweden)

    Waris Obitayo

    2012-01-01

    Full Text Available The use of carbon nanotubes for piezoresistive strain sensors has acquired significant attention due to its unique electromechanical properties. In this comprehensive review paper, we discussed some important aspects of carbon nanotubes for strain sensing at both the nanoscale and macroscale. Carbon nanotubes undergo changes in their band structures when subjected to mechanical deformations. This phenomenon makes them applicable for strain sensing applications. This paper signifies the type of carbon nanotubes best suitable for piezoresistive strain sensors. The electrical resistivities of carbon nanotube thin film increase linearly with strain, making it an ideal material for a piezoresistive strain sensor. Carbon nanotube composite films, which are usually fabricated by mixing small amounts of single-walled or multiwalled carbon nanotubes with selected polymers, have shown promising characteristics of piezoresistive strain sensors. Studies also show that carbon nanotubes display a stable and predictable voltage response as a function of temperature.

  7. Characterization and photocatalytic performance of carbon nanotube material-modified TiO2 synthesized by using the hot CVD process

    OpenAIRE

    Tsubota, Toshiki; Ono, Asami; Murakami, Naoya; Ohno, Teruhisa

    2009-01-01

    Carbon nanotube-modified TiO2 was synthesized by using the hot CVD process. Fe (0.13–1.9 wt%) as the catalyst for synthesis of carbon nanotubes modified on the surface of TiO2, was loaded on commercial TiO2 particles. CH4 gas was used as the carbon source in the CVD process. The color of the Fe-supported TiO2 powder changed to black when CVD treatment was performed. Nano-sized spherical carbon materials were generated on the surface of TiO2 after the CVD process. The spherical materials gradu...

  8. Carbon Nanotube Purification and Functionalization

    Science.gov (United States)

    Lebron, Marisabel; Mintz, Eric; Smalley, Richard E.; Meador, Michael A.

    2003-01-01

    Carbon nanotubes have the potential to significantly enhance the mechanical, thermal, and electrical properties of polymers. However, dispersion of carbon nanotubes in a polymer matrix is hindered by the electrostatic forces that cause them to agglomerate. Chemical modification of the nanotubes is necessary to minimize these electrostatic forces and promote adhesion between the nanotubes and the polymer matrix. In a collaborative research program between Clark Atlanta University, Rice University, and NASA Glenn Research Center several approaches are being explored to chemically modify carbon nanotubes. The results of this research will be presented.

  9. A comparative study of electrochemical properties of two kinds of carbon nanotubes as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shubin; Huo, Junping; Song, Huaihe; Chen, Xiaohong [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China)

    2008-01-01

    Two kinds of carbon nanotubes (CNTs), i.e., short carbon nanotubes (CNTs-1) synthesized by co-pyrolysis method and long carbon nanotubes (CNTs-2) produced using common CVD technique were comparatively investigated as anode materials for lithium ion batteries via transmission electron microscope (TEM), high-resolution TEM and a variety of electrochemical testing techniques. The test results showed that the reversible capacities of CNTs-1 electrode were 266 and 170 mAh g{sup -1} at the current densities of 0.2 and 0.8 mA cm{sup -2}, respectively, which were almost twice those of CNTs-2 electrode. The larger voltage hysteresis in CNTs-2 electrode was not only related to the surface functional groups on CNTs, but also to the surface resistance of CNTs, which results in greater hindrance and higher overvoltage during lithium extraction from electrode. The kinetics properties of these two CNTs electrodes were compared by AC impedance measurements. It was found that, both the surface film and charge-transfer resistances of CNTs-1 were significantly lower than those of CNTs-2; the lithium diffusion coefficient (D{sub Li}) of both CNTs electrodes decreased as the drop of voltage, but the magnitude of the D{sub Li} variation of CNTs-1 electrode was smaller than that of CNTs-2 electrode, indicating CNTs-1 exhibited higher electrochemical activity and more favorable kinetic properties during charge and discharge process. (author)

  10. A comparative study of electrochemical properties of two kinds of carbon nanotubes as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Yang Shubin; Huo Junping [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China); Song Huaihe [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China)], E-mail: songhh@mail.buct.edu.cn; Chen Xiaohong [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China)

    2008-01-01

    Two kinds of carbon nanotubes (CNTs), i.e., short carbon nanotubes (CNTs-1) synthesized by co-pyrolysis method and long carbon nanotubes (CNTs-2) produced using common CVD technique were comparatively investigated as anode materials for lithium ion batteries via transmission electron microscope (TEM), high-resolution TEM and a variety of electrochemical testing techniques. The test results showed that the reversible capacities of CNTs-1 electrode were 266 and 170 mAh g{sup -1} at the current densities of 0.2 and 0.8 mA cm{sup -2}, respectively, which were almost twice those of CNTs-2 electrode. The larger voltage hysteresis in CNTs-2 electrode was not only related to the surface functional groups on CNTs, but also to the surface resistance of CNTs, which results in greater hindrance and higher overvoltage during lithium extraction from electrode. The kinetics properties of these two CNTs electrodes were compared by AC impedance measurements. It was found that, both the surface film and charge-transfer resistances of CNTs-1 were significantly lower than those of CNTs-2; the lithium diffusion coefficient (D{sub Li}) of both CNTs electrodes decreased as the drop of voltage, but the magnitude of the D{sub Li} variation of CNTs-1 electrode was smaller than that of CNTs-2 electrode, indicating CNTs-1 exhibited higher electrochemical activity and more favorable kinetic properties during charge and discharge process.

  11. Carbon nanotube-based hybrid hole-transporting material and selective contact for high efficiency perovskite solar cells

    OpenAIRE

    Aitola, Kerttu; Sveinbjörnsson, Kári; Correa-Baena, Juan-Pablo; Kaskela, Antti; Abate, Antonio; Tian, Ying; Johansson, Erik M. J.; Graetzel, Michael; Kauppinen, Esko I.; Hagfeldt, Anders; Boschloo, Gerrit

    2016-01-01

    We demonstrate a high efficiency perovskite solar cell with a hybrid hole-transporting material-counter electrode based on a thin single-walled carbon nanotube (SWCNT) film and a drop-cast 2,2,7,-7-tetrakis(N, N-di-p-methoxyphenylamine)-9,90-spirobifluorene (Spiro-OMeTAD) hole-transporting material (HTM). The average efficiency of the solar cells was 13.6%, with the record cell yielding 15.5% efficiency. The efficiency of the reference solar cells with spin-coated Spiro-OMeTAD hole-transporti...

  12. Roping and wrapping carbon nanotubes

    Science.gov (United States)

    Ausman, Kevin D.; O'Connell, Michael J.; Boul, Peter; Ericson, Lars M.; Casavant, Michael J.; Walters, Deron A.; Huffman, Chad; Saini, Rajesh; Wang, Yuhuang; Haroz, Erik; Billups, Edward W.; Smalley, Richard E.

    2001-11-01

    Single-walled carbon nanotubes can be dispersed into solvents by ultrasonication to the point that primarily individual tubes, cut to a few hundred nanometers in length, are present. However, when such dispersions are filtered to a thick mat, or paper, only tangles of uniform, seemingly endless ropes are observed. The factors contributing to this "roping" phenomenon, akin to aggregation or crystallization, will be discussed. We have developed methods for generating "super-ropes" more than twenty times the diameter of those formed by filtration, involving the extraction of nanotube material from an oleum dispersion. Nanotubes have been solubilized in water, largely individually, by non-covalently wrapping them with linear polymers. The general thermodynamic drive for this wrapping involves the polymer disrupting both the hydrophobic interface with water and the smooth tube-tube interaction in aggregates. The nanotubes can be recovered from their polymeric wrapping by changing their solvent system. This solubilization process opens the door to solution chemistry on pristine nanotubes, as well as their introduction into biologically relevant systems.

  13. Polymerization initated at sidewalls of carbon nanotubes

    Science.gov (United States)

    Tour, James M. (Inventor); Hudson, Jared L. (Inventor); Krishnamoorti, Ramanan (Inventor); Yurekli, Koray (Inventor); Mitchell, Cynthia A. (Inventor)

    2011-01-01

    The present invention is directed to aryl halide (such as aryl bromide) functionalized carbon nanotubes that can be utilized in anionic polymerization processes to form polymer-carbon nanotube materials with improved dispersion ability in polymer matrices. In this process the aryl halide is reacted with an alkyllithium species or is reacted with a metal to replace the aryl-bromine bond with an aryl-lithium or aryl-metal bond, respectively. It has further been discovered that other functionalized carbon nanotubes, after deprotonation with a deprotonation agent, can similarly be utilized in anionic polymerization processes to form polymer-carbon nanotube materials. Additionally or alternatively, a ring opening polymerization process can be performed. The resultant materials can be used by themselves due to their enhanced strength and reinforcement ability when compared to their unbound polymer analogs. Additionally, these materials can also be blended with pre-formed polymers to establish compatibility and enhanced dispersion of nanotubes in otherwise hard to disperse matrices resulting in significantly improved material properties. The resultant polymer-carbon nanotube materials can also be used in drug delivery processes due to their improved dispersion ability and biodegradability, and can also be used for scaffolding to promote cellular growth of tissue.

  14. Carbon Nanotubes and Related Structures

    Directory of Open Access Journals (Sweden)

    Kingsuk Mukhopadhyay

    2008-07-01

    Full Text Available Carbon nanotubes have attracted the fancy of many scientists world wide. The small dimensions,strength, and the remarkable physical properties of these structures make them a unique material with a whole range of promising applications. In this review, the structural aspects, the advantages and disadvantages of different for their procedures synthesis, the qualitative and quantitative estimation of carbon nanotubes by different analytical techniques, the present status on their applications as well as the current challenges faced in the application field, national, in particular DRDO, DMSRDE status, and interest in this field, have been discussed.Defence Science Journal, 2008, 58(4, pp.437-450, DOI:http://dx.doi.org/10.14429/dsj.58.1666

  15. Ballistic Fracturing of Carbon Nanotubes.

    Science.gov (United States)

    Ozden, Sehmus; Machado, Leonardo D; Tiwary, ChandraSekhar; Autreto, Pedro A S; Vajtai, Robert; Barrera, Enrique V; Galvao, Douglas S; Ajayan, Pulickel M

    2016-09-21

    Advanced materials with multifunctional capabilities and high resistance to hypervelocity impact are of great interest to the designers of aerospace structures. Carbon nanotubes (CNTs) with their lightweight and high strength properties are alternative to metals and/or metallic alloys conventionally used in aerospace applications. Here we report a detailed study on the ballistic fracturing of CNTs for different velocity ranges. Our results show that the highly energetic impacts cause bond breakage and carbon atom rehybridizations, and sometimes extensive structural reconstructions were also observed. Experimental observations show the formation of nanoribbons, nanodiamonds, and covalently interconnected nanostructures, depending on impact conditions. Fully atomistic reactive molecular dynamics simulations were also carried out in order to gain further insights into the mechanism behind the transformation of CNTs. The simulations show that the velocity and relative orientation of the multiple colliding nanotubes are critical to determine the impact outcome.

  16. Coated carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng; Wen, Jian; Chen, Jinghua; Huang, Zhongping; Wang, Dezhi

    2008-10-28

    The present invention provides conductive carbon nanotube (CNT) electrode materials comprising aligned CNT substrates coated with an electrically conducting polymer, and the fabrication of electrodes for use in high performance electrical energy storage devices. In particular, the present invention provides conductive CNTs electrode material whose electrical properties render them especially suitable for use in high efficiency rechargeable batteries. The present invention also provides methods for obtaining surface modified conductive CNT electrode materials comprising an array of individual linear, aligned CNTs having a uniform surface coating of an electrically conductive polymer such as polypyrrole, and their use in electrical energy storage devices.

  17. Surface Modification of Carbon Nanotubes with Conjugated Polyelectrolytes: Fundamental Interactions and Applications in Composite Materials, Nanofibers, Electronics, and Photovoltaics

    KAUST Repository

    Ezzeddine, Alaa

    2015-10-01

    Ever since their discovery, Carbon nanotubes (CNTs) have been renowned to be potential candidates for a variety of applications. Nevertheless, the difficulties accompanied with their dispersion and poor solubility in various solvents have hindered CNTs potential applications. As a result, studies have been developed to address the dispersion problem. The solution is in modifying the surfaces of the nanotubes covalently or non-covalently with a desired dispersant. Various materials have been employed for this purpose out of which polymers are the most common. Non-covalent functionalization of CNTs via polymer wrapping represents an attractive method to obtain a stable and homogenous CNTs dispersion. This method is able to change the surface properties of the nanotubes without destroying their intrinsic structure and preserving their properties. This thesis explores and studies the surface modification and solublization of pristine single and multiwalled carbon nanotubes via a simple solution mixing technique through non-covalent interactions of CNTs with various anionic and cationic conjugated polyelectrolytes (CPEs). The work includes studying the interaction of various poly(phenylene ethynylene) electrolytes with MWCNTs and an imidazolium functionalized poly(3-hexylthiophene) with SWCNTs. Our work here focuses on the noncovalent modifications of carbon nanotubes using novel CPEs in order to use these resulting CPE/CNT complexes in various applications. Upon modifying the CNTs with the CPEs, the resulting CPE/CNT complex has been proven to be easily dispersed in various organic and aqueous solution with excellent homogeneity and stability for several months. This complex was then used as a nanofiller and was dispersed in another polymer matrix (poly(methyl methacrylate), PMMA). The PMMA/CPE/CNT composite materials were cast or electrospun depending on their desired application. The presence of the CPE modified CNTs in the polymer matrix has been proven to enhance

  18. Carbon nanotube network varactor

    Science.gov (United States)

    Generalov, A. A.; Anoshkin, I. V.; Erdmanis, M.; Lioubtchenko, D. V.; Ovchinnikov, V.; Nasibulin, A. G.; Räisänen, A. V.

    2015-01-01

    Microelectromechanical system (MEMS) varactors based on a freestanding layer of single-walled carbon nanotube (SWCNT) films were designed, fabricated and tested. The freestanding SWCNT film was employed as a movable upper patch in the parallel plate capacitor of the MEMS. The measurements of the SWCNT varactors show very high tunability, nearly 100%, of the capacitance with a low actuation voltage of 10 V. The functionality of the varactor is improved by implementing a flexible nanocellulose aerogel filling.

  19. Carbon nanotube IR detectors (SV)

    Energy Technology Data Exchange (ETDEWEB)

    Leonard, F. L.

    2012-03-01

    Sandia National Laboratories (Sandia) and Lockheed Martin Corporation (LMC) collaborated to (1) evaluate the potential of carbon nanotubes as channels in infrared (IR) photodetectors; (2) assemble and characterize carbon nanotube electronic devices and measure the photocurrent generated when exposed to infrared light;(3) compare the performance of the carbon nanotube devices with that of traditional devices; and (4) develop and numerically implement models of electronic transport and opto-electronic behavior of carbon nanotube infrared detectors. This work established a new paradigm for photodetectors.

  20. Heat Transport in Liquid Polyester Resin with Carbon Nanotubes

    Science.gov (United States)

    Vales-Pinzón, C.; Quiñones-Weiss, G.; Alvarado-Gil, J. J.; Medina-Esquivel, R. A.

    2015-11-01

    Carbon nanotubes represent one of the most important materials in nanoscience and nanotechnology, due to their outstanding structural, mechanical, electrical, and thermal properties. It has been shown that when incorporated in a polymeric matrix, carbon nanotubes can improve its physical properties. In this work, thermal-diffusivity measurements of composite materials, prepared by mixing carbon nanotubes in liquid polyester resin, were performed by means of the thermal-wave resonant cavity. The results show an increase of the thermal diffusivity when the volume fraction of carbon nanotubes grows. It is also shown that this increase depends strongly on the diameter of the nanotubes.

  1. From Carbon Nanotube Crystals to Carbon Nanotube Flowers

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhengjun; ZHAO Ye; ZHOU Ya

    2005-01-01

    We have investigated the very initial deposition stages of chemical vapor deposition (CVD) with ferrocene (Fe(C5H5)2) and xylene (C8H10) for growing carbon nanotubes, and made clear that the mechanism for the self-organization behaviors of nanotubes at different growth stages by this approach. For instance, the organization of nanotubes into flower-like structures at prolonged deposition is developed from the crystal-like structures formed at early growth stages, both of which are closely related to and determined by the very initial deposition stages of this CVD approach. Based on this approach, ways have been established to build up different architectures of carbon nanotubes, by controlling the initial deposition stages of the CVD process, with which we have realized the selective growth of self-organized carbon nanotube structures. This study provides a new idea for growing carbon nanotube architectures by CVD.

  2. ALUMINUM FOIL REINFORCED BY CARBON NANOTUBES

    OpenAIRE

    A. V. Alekseev; PREDTECHENSKIY M.R.

    2016-01-01

    In our research, the method of manufacturing an Al-carbon nanotube (CNT) composite by hot pressing and cold rolling was attempted. The addition of one percent of multi-walled carbon nanotubes synthesized by OCSiAl provides a significant increase in the ultimate tensile strength of aluminum. The tensile strength of the obtained composite material is at the tensile strength level of medium-strength aluminum alloys.

  3. Carbon nanotubes as tips for atomic force microscopy

    Institute of Scientific and Technical Information of China (English)

    国立秋; 徐宗伟; 赵铁强; 赵清亮; 张飞虎; 董申

    2004-01-01

    Ordinary AFM probes' characters prevent the AFM' s application in various scopes. Carbon nanotubes represent ideal AFM probe materials for their higher aspect ratio, larger Young' s modulus, unique chemical structure, and well-defined electronic property. Carbon nanotube AFM probes are obtained by using a new method of attaching carbon nanotubes to the end of ordinary AFM probes, and are then used for doing AFM experiments. These experiments indicated that carbon nanotube probes have higher elastic deformation, higher resolution and higher durability. And it was also found that carbon nanotube probes can accurately reflect the morphology of deep narrow gaps, while ordinary probes can not reflect.

  4. Carbon nanotube core graphitic shell hybrid fibers.

    Science.gov (United States)

    Hahm, Myung Gwan; Lee, Jae-Hwang; Hart, Amelia H C; Song, Sung Moo; Nam, Jaewook; Jung, Hyun Young; Hashim, Daniel Paul; Li, Bo; Narayanan, Tharangattu N; Park, Chi-Dong; Zhao, Yao; Vajtai, Robert; Kim, Yoong Ahm; Hayashi, Takuya; Ku, Bon-Cheol; Endo, Morinobu; Barrera, Enrique; Jung, Yung Joon; Thomas, Edwin L; Ajayan, Pulickel M

    2013-12-23

    A carbon nanotube yarn core graphitic shell hybrid fiber was fabricated via facile heat treatment of epoxy-based negative photoresist (SU-8) on carbon nanotube yarn. The effective encapsulation of carbon nanotube yarn in carbon fiber and a glassy carbon outer shell determines their physical properties. The higher electrical conductivity (than carbon fiber) of the carbon nanotube yarn overcomes the drawbacks of carbon fiber/glassy carbon, and the better properties (than carbon nanotubes) of the carbon fiber/glassy carbon make up for the lower thermal and mechanical properties of the carbon nanotube yarn via synergistic hybridization without any chemical doping and additional processes. PMID:24224730

  5. A Tunable Carbon Nanotube Oscillator

    Science.gov (United States)

    Sazonova, Vera

    2005-03-01

    Nanoelectromechanical systems (NEMS) hold promise for a number of scientific and technological applications. Carbon nanotubes (NT) are perhaps the ultimate material for realizing a NEMS device as they are the stiffest material known, have low density, ultrasmall cross sections and can be defect-free. Equally important, a nanotube can act as a transistor and thus is able to sense its own motion. Here, we report the electrical actuation and detection of the guitar-string oscillation modes of doubly-clamped NT oscillators. We observed resonance frequencies in the 5MHz to 150MHz range with quality factors in the 50 to 100 range. We showed that the resonance frequencies can be widely tuned by a gate voltage. We also report on the temperature dependence of the quality factor and present a discussion of possible loss mechanisms.

  6. Thermogravimetric Analysis of Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Arepalli, Sivram; Nikolaev, Pavel; Gorelik, Olga

    2010-01-01

    An improved protocol for thermogravimetric analysis (TGA) of samples of single-wall carbon nanotube (SWCNT) material has been developed to increase the degree of consistency among results so that meaningful comparisons can be made among different samples. This improved TGA protocol is suitable for incorporation into the protocol for characterization of carbon nanotube material. In most cases, TGA of carbon nanotube materials is performed in gas mixtures that contain oxygen at various concentrations. The improved protocol is summarized.

  7. Composite of single walled carbon nanotube and sulfosalicylic acid doped polyaniline: a thermoelectric material

    Science.gov (United States)

    Jana Chatterjee, Mukulika; Banerjee, Dipali; Chatterjee, Krishanu

    2016-08-01

    Nanocomposites containing single walled carbon nanotubes (SWCNTs) and highly ordered polyaniline (PANI) have been synthesized employing an in situ polymerization using different weight percentages of single-walled carbon nanotube (SWCNT) as template and aniline as a reactant. The composites show homogeneously dispersed SWCNTs which are uniformly coated with PANI through a strong interface interaction. Structural characterization shows that the PANI cultivated along the surface of the SWCNTs in an ordered manner during the SWCNT-directed polymerization process. Measurements at room temperature displayed a significant enhancement in both the electrical conductivity and thermoelectric power which could be attributed to the more ordered chain structures of the PANI on SWCNT. As a result, the power factor of the composite is improved which increases with temperature. At the same time, the measured value of thermal conductivity at room temperature being lowest among the reported values, has resulted in best ZT at room temperature. The lowest value of thermal conductivity is attributed to the large phonon scattering due to the introduction of nanointerfaces.

  8. Absorption mechanism of carbon-nanotube paper- titanium dioxide as a multifunctional barrier material for lithium-sulfur batteries

    Institute of Scientific and Technical Information of China (English)

    Guiyin Xu[1; Jiaren Yuan[1; Xinyong Tao[2; Bing Ding[1; Hui Dou[1; Xiaohong Yan[1,3; Yang xiao[1; Xiaogang Zhang[1

    2015-01-01

    Lithium-sulfur batteries attract much interest as energy storage devices for their low cost, high specific capacity, and energy density. However, the insulating properties of sulfur and high solubility of lithium polysulfides decrease the utilization of active materials by the battery resulting in poor cycling performance. Herein, we design a multifunctional carbon-nanotube paper/titanium-dioxide barrier which effectively reduces active material loss and suppresses the diffusion of lithium polysulfides to the anode, thereby improving the cycling stability of lithium-sulfur batteries. Using this barrier, an activated carbon/sulfur cathode with 70% sulfur content delivers stable cycling performance and high Coulombic efficiency (-99%) over 250 cycles at a current rate of 0.5 C. The improved electrochemical performance is attributed to the synergistic effects of the carbon nanotube paper and titanium dioxide, involving the physical barrier, chemical adsorption from the binding formation of Ti-S and S-O, and other interactions unique to the titanium dioxide and sulfur species.

  9. Flow of suspensions of carbon nanotubes carrying phase change materials through microchannels and heat transfer enhancement.

    Science.gov (United States)

    Sinha-Ray, Sumit; Sinha-Ray, Suman; Sriram, Hari; Yarin, Alexander L

    2014-02-01

    This work explores the potential of nano-encapsulated phase change materials (PCMs) in applications related to microelectronics cooling. PCMs (wax or meso-erythritol) were encapsulated in carbon nanotubes (CNTs) by a method of self-sustained diffusion at room temperature and pressure. These nano-encapsulated wax nanoparticles alone allowed heat removal over a relatively wide range of temperatures (different waxes have melting temperatures in the range 40-80 °C). On the other hand, nano-encapsulated meso-erythritol nanoparticles allowed heat removal in the range 118-120 °C. The combination of these two PCMs (wax and meso-erythritol) could extend the temperature range to 40-120 °C, when both types of nanoparticles (wax and meso-erythritol intercalated) would be suspended in the same carrier fluid (an oil). The nanoparticles possess a short response time of the order of 10(-7) s. Such nano-encapsulation can also prevent the PCM from sticking to the wall. In this work, experiments with wax-intercalated CNTs, stable aqueous suspensions of CNTs with concentrations up to 3 wt% with and without nano-encapsulated wax were prepared using a surfactant sodium dodecyl benzene sulfonate (NaDDBS). These suspensions were pumped through two channels of 603 μm or 1803 μm in diameter subjected to a constant heat flux at the wall. It was found that the presence of the surfactant in CNT suspensions results in a pseudo-slip at the channel wall which enhances the flow rate at a fixed pressure drop. When aqueous solutions of the surfactant were employed (with no CNTs added), the enhanced convection alone was responsible for a ~2 °C reduction in temperature in comparison with pure water flows. When CNTs with nano-encapsulated wax were added, an additional ~1.90 °C reduction in temperature due to the PCM fusion was observed when using 3 wt% CNT suspensions. In addition, suspensions of meso-erythritol-intercalated CNTs in alpha-olefin oil were used as coolants in flows through the

  10. CARBON NANOTUBES: PROPERTIES AND APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, John, E.

    2009-07-24

    Carbon nanotubes were discovered in 1991 as a minority byproduct of fullerene synthesis. Remarkable progress has been made in the ensuing years, including the discovery of two basic types of nanotubes (single-wall and multi-wall), great strides in synthesis and purification, elucidation of many fundamental physical properties, and important steps towards practical applications. Both the underlying science and technological potential of SWNT can profitably be studied at the scale of individual tubes and on macroscopic assemblies such as fibers. Experiments on single tubes directly reveal many of the predicted quantum confinement and mechanical properties. Semiconductor nanowires have many features in common with nanotubes, and many of the same fundamental and practical issues are in play – quantum confinement and its effect on properties; possible device structures and circuit architectures; thermal management; optimal synthesis, defect morphology and control, etc. In 2000 we began a small effort in this direction, conducted entirely by undergraduates with minimal consumables support from this grant. With DOE-BES approval, this grew into a project in parallel with the carbon nanotube work, in which we studied of inorganic semiconductor nanowire growth, characterization and novel strategies for electronic and electromechanical device fabrication. From the beginnings of research on carbon nanotubes, one of the major applications envisioned was hydrogen storage for fuel-cell powered cars and trucks. Subsequent theoretical models gave mixed results, the most pessimistic indicating that the fundamental H2-SWNT interaction was similar to flat graphite (physisorption) with only modest binding energies implying cryogenic operation at best. New material families with encouraging measured properties have emerged, and materials modeling has gained enormously in predictive power, sophistication, and the ability to treat a realistically representative number of atoms. One of

  11. Mechanics of filled carbon nanotubes

    KAUST Repository

    Monteiro, A.O.

    2014-04-01

    The benefits of filling carbon nanotubes (CNTs) with assorted molecular and crystalline substances have been investigated for the past two decades. Amongst the study of new structural phases, defects, chemical reactions and varied types of host-guest interactions, there is one fundamental characterisation aspect of these systems that continues to be overlooked: the mechanical behaviour of filled CNTs. In contrast to their empty counterparts, the mechanics of filled CNTs is a subject where reports appear far and apart, this despite being key to the application of these materials in technological devices. In the following paragraphs, we review the work that has been carried out up to the present on the mechanics of filled CNTs. The studies discussed range from experimental resonant frequency essays performed within electron microscopes to modelling, via molecular dynamics, of three-point bending of nanotubes filled with gases. (C) 2014 Elsevier B.V. All rights reserved.

  12. Varied morphology carbon nanotubes and method for their manufacture

    Science.gov (United States)

    Li, Wenzhi; Wen, Jian Guo; Ren, Zhi Feng

    2007-01-02

    The present invention describes the preparation of carbon nanotubes of varied morphology, catalyst materials for their synthesis. The present invention also describes reactor apparatus and methods of optimizing and controlling process parameters for the manufacture carbon nanotubes with pre-determined morphologies in relatively high purity and in high yields. In particular, the present invention provides methods for the preparation of non-aligned carbon nanotubes with controllable morphologies, catalyst materials and methods for their manufacture.

  13. Substituted copper phthalocyanine/multiwalled carbon nanotubes hybrid material for Cl{sub 2} sensing application

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Anshul Kumar, E-mail: dramanmahajan@yahoo.co.in; Saini, Rajan, E-mail: dramanmahajan@yahoo.co.in; Singh, Rajinder, E-mail: dramanmahajan@yahoo.co.in; Mahajan, Aman, E-mail: dramanmahajan@yahoo.co.in; Bedi, R. K., E-mail: dramanmahajan@yahoo.co.in [Material Science Laboratory, Department of Physics, Guru Nanak Dev University, Amritsar-143005 (India); Aswal, D. K. [Technical Physics Division, Bhabha Atomic Research Center, Mumbai-400085 (India)

    2014-04-24

    In this work, hybrid of soluble copper phthalocyanine (CuPcOC{sub 8}) and functionalized multi-walled carbon nanotubes (MWCNTs) has been synthesized. The formation of CuPcOC{sub 8}-MWCNTs hybrid is confirmed by atomic force microscopy, UV-Visible and FTIR spectroscopy. Subsequently, a chemi-resistive sensor is fabricated by drop casting CuPcOC{sub 8}-MWCNTs hybrid onto glass substrate. It has been demonstrated that CuPcOC{sub 8}-MWCNTs hybrid is highly selective towards Cl{sub 2} gas with minimum detection limit of 100 ppb. The response of sensor increases linearly with increase in the concentration of Cl{sub 2} gas. For 2000 ppb of Cl{sub 2}, CuPcOC{sub 8}-MWCNTs hybrid gives a response as large as 53% in 40 seconds.

  14. Teslaphoresis of Carbon Nanotubes.

    Science.gov (United States)

    Bornhoeft, Lindsey R; Castillo, Aida C; Smalley, Preston R; Kittrell, Carter; James, Dustin K; Brinson, Bruce E; Rybolt, Thomas R; Johnson, Bruce R; Cherukuri, Tonya K; Cherukuri, Paul

    2016-04-26

    This paper introduces Teslaphoresis, the directed motion and self-assembly of matter by a Tesla coil, and studies this electrokinetic phenomenon using single-walled carbon nanotubes (CNTs). Conventional directed self-assembly of matter using electric fields has been restricted to small scale structures, but with Teslaphoresis, we exceed this limitation by using the Tesla coil's antenna to create a gradient high-voltage force field that projects into free space. CNTs placed within the Teslaphoretic (TEP) field polarize and self-assemble into wires that span from the nanoscale to the macroscale, the longest thus far being 15 cm. We show that the TEP field not only directs the self-assembly of long nanotube wires at remote distances (>30 cm) but can also wirelessly power nanotube-based LED circuits. Furthermore, individualized CNTs self-organize to form long parallel arrays with high fidelity alignment to the TEP field. Thus, Teslaphoresis is effective for directed self-assembly from the bottom-up to the macroscale. PMID:27074626

  15. Carbon nanotube-based glucose oxidase nanocomposite anode materials for bio-fuel cells

    Science.gov (United States)

    Dudzik, Jonathan

    The field of nanotechnology has benefited medicine, science, and engineering. The advent of Carbon Nanotubes (CNTs) and protein-inorganic interfacing have received much attention due to their unique nanostructures which can be modified to act as a scaffold to house proteins or create nanowires. The current trend incorporates the robustness and specificity characteristics of proteins to the mechanical strength, enlarged surface area, and conductive capabilities emblematic of their inorganic counterparts. Bio-Fuel Cells (BFCs) and Biosensors remain at the forefront and devices such as implantable glucose monitors are closer to realization than ever before. This research strives to exploit potential energy from the eukaryotic enzyme Glucose Oxidase (GOx) during oxidation of its substrate, glucose. During this process, a two-electron transfer occurs at its two FAD redox centres which can be harnessed via an electrochemical setup involving a Multi-Walled Carbon Nanotube (MWCNTs) modified electrode. The objective is to develop a MWCNT-GOx bionanocomposite capable of producing and sustaining a competitive power output. To help with this aim, investigation into a crosslinked enzyme cluster (CEC) immobilization technique is envisioned to amplify power output due to its highly concentrated, reusable, and thermally stable characteristics. Numerous CEC-GOx-MWCNT composites were fabricated with the highest initial output reaching 170 muW/cm 2. It was hypothesized that the carbohydrate moiety increased tunnelling distance and therefore hindered electron transfer. Efforts to produce a recombinant GOx without the encumbrance were unsuccessful. Two sub-clone constructs were explored and although a recombinant protein was identified, it was not confirmed to be GOx. BFC testing on bionanocomposites integrating non-glycosylated GOx could not be performed although there remains a strong contention that the recombinant would demonstrate superior power densities in comparison to its

  16. Luminescence of carbon nanotube bulbs

    Institute of Scientific and Technical Information of China (English)

    LI ChuanGang; WU DeHai; WANG KunLin; WEI JinQuan; WEI BingQing; ZHU HongWei; WANG ZhiCheng; LUO JianBin; LIU WenJin; ZHENG MingXin

    2007-01-01

    Carbon nanotube (CNT) bulbs made of decimeter-scale double-walled carbon nanotube (DWCNT) strands and films were fabricated and their luminescence properties, including the lighting efficiency, voltage-current relation and thermal stability were investigated. The results show that the DWCNT bulb has a comparable spectrum of visible light with tungsten bulb and its average efficiency is 40% higher than that of a tungsten filament at the same temperature (1400-2300 K). The nanotube filaments show both resistance and thermal stability over a large temperature region. No obvious damage was found for a nanotube bulb illuminating at 2300 K for more than 24 hours in vacuum.

  17. Titanium coated with functionalized carbon nanotubes — A promising novel material for biomedical application as an implantable orthopaedic electronic device

    Energy Technology Data Exchange (ETDEWEB)

    Przekora, Agata, E-mail: agata.przekora@umlub.pl [Department of Biochemistry and Biotechnology, Medical University of Lublin, Faculty of Pharmacy with Medical Analytics Division, Chodzki 1, 20-093 Lublin (Poland); Benko, Aleksandra; Nocun, Marek; Wyrwa, Jan; Blazewicz, Marta [Faculty of Materials Science and Ceramics, AGH-Univ. of Science and Technology, A. Mickiewicz 30 Ave., 30-059 Cracow (Poland); Ginalska, Grazyna [Department of Biochemistry and Biotechnology, Medical University of Lublin, Faculty of Pharmacy with Medical Analytics Division, Chodzki 1, 20-093 Lublin (Poland)

    2014-12-01

    The aim of the study was to fabricate titanium (Ti) material coated with functionalized carbon nanotubes (f-CNTs) that would have potential medical application in orthopaedics as an implantable electronic device. The novel biomedical material (Ti-CNTs-H{sub 2}O) would possess specific set of properties, such as: electrical conductivity, non-toxicity, and ability to inhibit connective tissue cell growth and proliferation protecting the Ti-CNTs-H{sub 2}O surface against covering by cells. The novel material was obtained via an electrophoretic deposition of CNTs-H{sub 2}O on the Ti surface. Then, physicochemical, electrical, and biological properties were evaluated. Electrical property evaluation revealed that a Ti-CNTs-H{sub 2}O material is highly conductive and X-ray photoelectron spectroscopy analysis demonstrated that there are mainly COOH groups on the Ti-CNTs-H{sub 2}O surface that are found to inhibit cell growth. Biological properties were assessed using normal human foetal osteoblast cell line (hFOB 1.19). Conducted cytotoxicity tests and live/dead fluorescent staining demonstrated that Ti-CNTs-H{sub 2}O does not exert toxic effect on hFOB cells. Moreover, fluorescence laser scanning microscope observation demonstrated that Ti-CNTs-H{sub 2}O surface retards to a great extent cell proliferation. The study resulted in successful fabrication of highly conductive, non-toxic Ti-CNTs-H{sub 2}O material that possesses ability to inhibit osteoblast proliferation and thus has a great potential as an orthopaedic implantable electronic device. - Highlights: • Functionalized carbon nanotubes were electrophoretically deposited on Ti surface. • Physicochemical, electrical, and biological properties were evaluated. • Ti-CNTs-H{sub 2}O is highly conductive and there are mainly COOH groups on its surface. • Novel material is non-toxic and retards to a great extent osteoblast proliferation. • Ti-CNTs-H{sub 2}O has a promising potential as implantable orthopaedic

  18. Manipulation and cutting of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Nanomanipulation plays an important role in nanofabrication, it is also a technology necessary in exploring the secrets of nanoworld, and it thus beco mesa start point to research future nanomachine. In this study, manipulation and cutting of carbon nanotubes have been conducted in order to examine whether we can move a nanocomponent from one site to another by using the tip of atomic fo rce microscope (AFM). The technique may also be valuable for providing the const ructive materials of nanofabrication. While exploring the method for manipulatin g and cutting of nanotubes, some new phenomena have been observed during the process. Results show that carbon nanotubes present a feature of deformation combin ing bending and distortion when subjected to large mechanical forces exerted by the tip of AFM. In special cases, long carbon nanotubes can be cut into two part s, by which we can remove the part where crystal lattice is flawed, and therefor e a perfect nanocomponent can be obtained.

  19. Nickel Sulfide/Graphene/Carbon Nanotube Composites as Electrode Material for the Supercapacitor Application in the Sea Flashing Signal System

    Institute of Scientific and Technical Information of China (English)

    Hailong Chen; Ji Li; Conglai Long; Tong Wei; Guoqing Ning; Jun Yan; Zhuangjun Fan

    2014-01-01

    This work presents NiS/graphene/carbon nanotube (NiS/GNS/CNT) composites as electrode material for the supercapacitor application in sea flashing signal systems. NiS nanosheets were closely anchored on the conductive GNS-CNT networks. As a result, the NiS/GNS/CNT electrode showed a high specific capacitance of 2 377 F·g-1 at 2 mV·s-1 and good cycling stability compared with the pure NiS (1 599 F·g-1 ). The enhanced electrochemical performances are attributed to the synergetic effect between the conductive carbon and the pseudo-capacitive NiS. The high performance supercapacitor may provide application in the sea flashing signal system.

  20. Cyclophosphazene based conductive polymer-carbon nanotube composite as novel supporting material for methanol fuel cell applications.

    Science.gov (United States)

    Prasanna, Dakshinamoorthy; Selvaraj, Vaithilingam

    2016-06-15

    This present study reports the development of novel catalyst support of amine terminated cyclophosphazene/cyclophosphazene/hexafluoroisopropylidenedianiline-carbon nanotube (ATCP/CP/HFPA-CNT) composite. The ATCP/CP/HFPA-CNT composite has been used as a catalyst support for platinum (Pt) and platinum-gold (Pt-Au) nanoparticles towards electrooxidation of methanol in alkaline medium. The obtained anode materials were characterized by X-ray diffraction, transmission electron microscope and energy dispersive X-ray analysis. Electrocatalytic performances of Pt/ATCP/CP/HFPA-CNT and Pt-Au/ATCP/CP/HFPA-CNT catalysts were investigated by cyclic voltammetry, CO stripping and chronoamperometric techniques. The electrooxidation of methanol and CO stripping results conclude that the metal nanocatalyst embedded with ATCP/CP/HFPA-CNT composite shows significantly higher anodic oxidation current, more CO tolerance and lower onset potential when compared to that of the Pt/CNT and Pt/C (Vulcan carbon) catalysts. PMID:27016917

  1. Gold nanoparticle/carbon nanotube hybrids as an enhanced material for sensitive amperometric determination of tryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Guo Yujing [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, Jilin (China); Research Center for Environmental Science and Engineering, Shanxi University, Taiyuan 030006 (China); Guo Shaojun; Fang Youxing [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, Jilin (China); Dong Shaojun, E-mail: dongsj@ciac.jl.c [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun 130022, Jilin (China)

    2010-04-30

    In this work, a highly sensitive electrochemical sensor for the determination of tryptophan (Trp) was fabricate by electrodeposition of gold nanoparticles (AuNPs) onto carbon nanotube (CNT) films pre-cast on a glassy carbon electrode (GCE), forming an AuNP-CNT composite-modified GCE (AuNP-CNT/GCE). Scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used for the surface analysis of the electrode. The results indicate that the hybrid nanomaterials induced a substantial decrease in the overpotential of the Trp oxidation reaction and exhibited a remarkable synergistic effect on the electrocatalytic activity toward the oxidation of Trp. In phosphate buffer solution (pH 7.4), the modified electrode showed excellent analytical performance for the amperometric determination of Trp. The peak currents possess a linear relationship with the concentration of Trp in the range of 30 nM to 2.5 muM, and the detection limit is 10 nM (S/N = 3). In addition, the modified electrode was used to determine Trp concentration in pharmaceutical samples with satisfactory results.

  2. Immobilization of redox mediators on functionalized carbon nanotube: A material for chemical sensor fabrication and amperometric determination of hydrogen peroxide

    Indian Academy of Sciences (India)

    D R Shobha Jeykumari; S Senthil Kumar; S Sriman Narayanan

    2005-10-01

    Chemical functionalization of single-walled carbon nanotubes with redox mediators, namely, toluidine blue and thionin have been carried out and the performance of graphite electrode modified with functionalized carbon nanotubes is described. Mechanical immobilization of functionalized single-walled nanotube (SWNT) on graphite electrode was achieved by gently rubbing the electrode surface on carbon nanotubes supported on a glass slide. The electrochemical behaviour of the modified electrodes was investigated by cyclic voltammetry. The SWNT-modified electrodes showed excellent electrocatalytic effect for the reduction of hydrogen peroxide. A decrease in overvoltage was observed as well as an enhanced peak current compared to a bare graphite electrode for the reduction of hydrogen peroxide. The catalytic current was found to be directly proportional to the amount of hydrogen peroxide taken.

  3. Immobilization of carbon nanotubes on functionalized graphene film grown by chemical vapor deposition and characterization of the hybrid material

    International Nuclear Information System (INIS)

    We report the surface functionalization of graphene films grown by chemical vapor deposition and fabrication of a hybrid material combining multi-walled carbon nanotubes and graphene (CNT–G). Amine-terminated self-assembled monolayers were prepared on graphene by the UV-modification of oxidized groups introduced onto the film surface. Amine-termination led to effective interaction with functionalized CNTs to assemble a CNT–G hybrid through covalent bonding. Characterization clearly showed no defects of the graphene film after the immobilization reaction with CNT. In addition, the hybrid graphene material revealed a distinctive CNT–G structure and p–n type electrical properties. The introduction of functional groups on the graphene film surface and fabrication of CNT–G hybrids with the present technique could provide an efficient, novel route to device fabrication. (paper)

  4. Illuminating the future of silicon photonics: optical coupling of carbon nanotubes to microrings

    International Nuclear Information System (INIS)

    Advances in carbon nanotube material quality and processing techniques have led to an increased interest in nanotube photonics. In particular, emission in the telecommunication wavelengths makes nanotubes compatible with silicon photonics. Noury et al (2014 Nanotechnology 25 215201) have reported on carbon nanotube photoluminescence coupled to silicon microring resonators, underscoring the advantage of combining carbon nanotube emitters with silicon photonics. Their results open up the possibility of using nanotubes in other waveguide-based devices, taking advantage of well-established technologies. (viewpoint)

  5. Method for synthesizing carbon nanotubes

    Science.gov (United States)

    Fan, Hongyou

    2012-09-04

    A method for preparing a precursor solution for synthesis of carbon nanomaterials, where a polar solvent is added to at least one block copolymer and at least one carbohydrate compound, and the precursor solution is processed using a self-assembly process and subsequent heating to form nanoporous carbon films, porous carbon nanotubes, and porous carbon nanoparticles.

  6. Simultaneous Electrochemical Determination of Hydroquinone, Catechol and Resorcinol at Nitrogen Doped Porous Carbon Nanopolyhedrons-multiwall Carbon Nanotubes Hybrid Materials Modified Glassy Carbon Electrode

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei; Wu, Liang; Zhang, Xiaohua; Chen, Jinhua [Hunan Univ., Changsha (China)

    2014-01-15

    The nitrogen doped porous carbon nanopolyhedrons (N-PCNPs)-multi-walled carbon nanotubes (MWCNTs) hybrid materials were prepared for the first time. Combining the excellent catalytic activities, good electrical conductivities and high surface areas of N-PCNPs and MWCNTs, the simultaneous determination of hydroquinone (HQ), catechol (CC) and resorcinol (RE) with good analytical performance was achieved at the N-PCNPs-MWCNTs modified electrode. The linear response ranges for HQ, CC and RE are 0.2-455 μM, 0.7-440 μM and 3.0-365 μM, respectively, and the detection limits (S/N = 3) are 0.03 μM, 0.11 μM and 0.38 μM, respectively. These results are much better than that obtained on some graphene or CNTs-based materials modified electrodes. Furthermore, the developed sensor was successfully applied to simultaneously detect HQ, CC and RE in the local river water samples.

  7. Hydrothermal synthesis of manganese oxides/carbon nanotubes composites as anode materials for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shou-Dong [School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China); Lithium-ion Batteries Laboratory, School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China); Zhu, Ya-Bo, E-mail: zhuyabo@163.com [School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China); Zhuang, Quan-Chao [Lithium-ion Batteries Laboratory, School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China); Wu, Chao [School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China); Lithium-ion Batteries Laboratory, School of Materials Science and Engineering, China University of Mining and Technology, Xuzhou, Jiangsu 221116 (China)

    2013-09-01

    Graphical abstract: Carbon nanotubes in the composites not only accommodate the volume change during charge/discharge processes, but also provide a good electron conducting network at high power rates, resulting in high reversible capacity of the electrodes. - Highlights: • MnO/CNTs composites are obtained by heating Mn{sub 3}O{sub 4}/CNTs at 500 °C for 3 h in flowing Ar/H{sub 2}. • MnO/CNTs electrode exhibits higher specific capacity at the current density of 100 mAh g{sup −1} and a better cycle performance. • Enhancement of cyclability of MnO/CNTs electrode can be attributed to the presence of CNTs in the composites. - Abstract: Mn{sub 3}O{sub 4} nanoparticles and Mn{sub 3}O{sub 4}/carbon nanotubes (CNTs) composites are prepared via a hydrothermal synthesis method. MnO and MnO/CNTs composites are obtained by heating Mn{sub 3}O{sub 4} and Mn{sub 3}O{sub 4}/CNTs at 500 for 3 h in flowing Ar/H{sub 2}. The phase structure, composition and morphology of the composites are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM). The electrochemical properties of the composite electrodes are studied by performing cyclic voltammetry (CV), galvanostatic charge and discharge tests. The results reveal that the Mn{sub 3}O{sub 4}/CNTs and MnO/CNTs electrodes exhibit higher specific capacity at the current density of 100 mAh g{sup −1} and a better cycle performance than pure Mn{sub 3}O{sub 4} and MnO electrodes. The excellent electrochemical properties of Mn{sub 3}O{sub 4}/CNTs and MnO/CNTs electrodes can be attributed to the presence of CNTs in the composites offering an electron conducting network and suppressing the volume expansion of Mn{sub 3}O{sub 4} and MnO particles efficiently during the charge and discharge processes.

  8. Carbon Nanotube Composites for Electronic Packaging Applications: A Review

    OpenAIRE

    Lavanya Aryasomayajula; Klaus-Juergen Wolter

    2013-01-01

    Composite engineering comprises of metal matrix composites. They have high strength-weight ratio, better stiffness, economical production, and ease of availability of raw materials. The discovery of carbon nanotubes has opened new possibilities to face challenges better. Carbon Nanotubes are known for their high mechanical strength, excellent thermal and electrical properties. Recent research has made progress in fabricating carbon nanotube metal matrix and polymer-based composites. The metho...

  9. A statistical mechanics model of carbon nanotube macro-films

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Carbon nanotube macro-films are two-dimensional films with micrometer thickness and centimeter by centimeter in-plane dimension.These carbon nanotube macroscopic assemblies have attracted significant attention from the material and mechanics communities recently because they can be easily handled and tailored to meet specific engineering needs.This paper reports the experimental methods on the preparation and characterization of single-walled carbon nanotube macro-films,and a statistical mechanics model on ...

  10. Lithium storage properties of multiwall carbon nanotubes prepared by CVD

    International Nuclear Information System (INIS)

    Full text: Multiwall carbon nanotubes (MWCNTs) were synthesised by chemical vapour deposition (CVD) method using acetylene gas. The XRD pattern of as prepared carbon nanotubes showed that the d002 value is 3.44 Angstroms. The morphology and microstructure of carbon nanotubes were characterized by HRTEM. Most of carbon nanotubes are entangled together to form bundles or ropes. The diameter of the carbon nanotubes is in the range of 10 ∼ 20 nm. There is a small amount of amorphous carbon particles presented in the sample. However, the yield of carbon nanotubes is more than 95%. Electrochemical properties of carbon nanotubes were characterised via a variety of electrochemical testing techniques. The result of CV test showed that the Li insertion potential is quite low, which is very close to O V versus Li+/Li reference electrode, whereas the potential for Li de-intercalation is in the range of 0.2-0.4 V. There exists a slight voltage hysteresis between Li intercalation and Li de-intercalation, which is similar to the other carbonaceous materials. The intensity of redox peaks of carbon nanotubes decrease with scanning cycle, indicating that the reversible Li insertion capacity gradually decreases. The carbon nanotubes electrode demonstrated a reversible lithium storage capacity of 340 mAh/g with good cyclability at moderate current density. Further improvement of Li storage capacity is possible by opening the end of carbon nanotubes to allow lithium insertion into inner graphene sheet of carbon nanotubes. The kinetic properties of lithium insertion in carbon nanotube electrodes were characterised by a.c. impedance measurements. It was found that the lithium diffusion coefficient dLi decreases with an increase of Li ion concentration in carbon nanotube host

  11. Carbon Nanotube Tower-Based Supercapacitor

    Science.gov (United States)

    Meyyappan, Meyya (Inventor)

    2012-01-01

    A supercapacitor system, including (i) first and second, spaced apart planar collectors, (ii) first and second arrays of multi-wall carbon nanotube (MWCNT) towers or single wall carbon nanotube (SWCNT) towers, serving as electrodes, that extend between the first and second collectors where the nanotube towers are grown directly on the collector surfaces without deposition of a catalyst and without deposition of a binder material on the collector surfaces, and (iii) a porous separator module having a transverse area that is substantially the same as the transverse area of at least one electrode, where (iv) at least one nanotube tower is functionalized to permit or encourage the tower to behave as a hydrophilic structure, with increased surface wettability.

  12. Boron-Filled Hybrid Carbon Nanotubes.

    Science.gov (United States)

    Patel, Rajen B; Chou, Tsengming; Kanwal, Alokik; Apigo, David J; Lefebvre, Joseph; Owens, Frank; Iqbal, Zafar

    2016-01-01

    A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs. PMID:27460526

  13. Boron-Filled Hybrid Carbon Nanotubes

    Science.gov (United States)

    Patel, Rajen B.; Chou, Tsengming; Kanwal, Alokik; Apigo, David J.; Lefebvre, Joseph; Owens, Frank; Iqbal, Zafar

    2016-07-01

    A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs.

  14. Boron-Filled Hybrid Carbon Nanotubes

    Science.gov (United States)

    Patel, Rajen B.; Chou, Tsengming; Kanwal, Alokik; Apigo, David J.; Lefebvre, Joseph; Owens, Frank; Iqbal, Zafar

    2016-01-01

    A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs. PMID:27460526

  15. Carbon nanotubes – becoming clean

    Directory of Open Access Journals (Sweden)

    Nicole Grobert

    2007-01-01

    Full Text Available Carbon nanotubes (CNTs are now well into their teenage years. Early on, theoretical predictions and experimental data showed that CNTs possess chemical and mechanical properties that exceed those of many other materials. This has triggered intense research into CNTs. A variety of production methods for CNTs have been developed; chemical modification, functionalization, filling, and doping have been achieved; and manipulation, separation, and characterization of individual CNTs is now possible. Today, products containing CNTs range from tennis rackets and golf clubs to vehicle fenders, X-ray tubes, and Li ion batteries. Breakthroughs for CNT-based technologies are anticipated in the areas of nanoelectronics, biotechnology, and materials science. In this article, I review the current situation in CNT production and highlight the importance of clean CNT material for the success of future applications.

  16. Potentiometric urea biosensor based on multi-walled carbon nanotubes (MWCNTs)/silica composite material

    International Nuclear Information System (INIS)

    A novel potentiometric urea biosensor has been fabricated with urease (Urs) immobilized multi-walled carbon nanotubes (MWCNTs) embedded in silica matrix deposited on the surface of indium tin oxide (ITO) coated glass plate. The enzyme Urs was covalently linked with the exposed free -COOH groups of functionalized MWCNTs (F-MWCNTs), which are subsequently incorporated within the silica matrix by sol-gel method. The Urs/MWCNTs/SiO2/ITO composite modified electrode was characterized by Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA) and UV-visible spectroscopy. The morphologies and electrochemical performance of the modified Urs/MWCNTs/SiO2/ITO electrode have been investigated by scanning electron microscopy (SEM) and potentiometric method, respectively. The synergistic effect of silica matrix, F-MWCNTs and biocompatibility of Urs/MWCNTs/SiO2 made the biosensor to have the excellent electro catalytic activity and high stability. The resulting biosensor exhibits a good response performance to urea detection with a wide linear range from 2.18 x 10-5 to 1.07 x 10-3 M urea. The biosensor shows a short response time of 10-25 s and a high sensitivity of 23 mV/decade/cm2.

  17. Potentiometric urea biosensor based on multi-walled carbon nanotubes (MWCNTs)/silica composite material

    Energy Technology Data Exchange (ETDEWEB)

    Ahuja, Tarushee [National Physical Laboratory (Council of Scientific and Industrial Research), Dr. K.S. Krishnan Road, New Delhi-110012 (India); Department of Applied Chemistry, Delhi College of Engineering, University of Delhi, Bawana Road, Delhi-110042 (India); Kumar, D. [Department of Applied Chemistry, Delhi College of Engineering, University of Delhi, Bawana Road, Delhi-110042 (India); Singh, Nahar; Biradar, A.M. [National Physical Laboratory (Council of Scientific and Industrial Research), Dr. K.S. Krishnan Road, New Delhi-110012 (India); Rajesh, E-mail: rajesh_csir@yahoo.com [National Physical Laboratory (Council of Scientific and Industrial Research), Dr. K.S. Krishnan Road, New Delhi-110012 (India)

    2011-03-12

    A novel potentiometric urea biosensor has been fabricated with urease (Urs) immobilized multi-walled carbon nanotubes (MWCNTs) embedded in silica matrix deposited on the surface of indium tin oxide (ITO) coated glass plate. The enzyme Urs was covalently linked with the exposed free -COOH groups of functionalized MWCNTs (F-MWCNTs), which are subsequently incorporated within the silica matrix by sol-gel method. The Urs/MWCNTs/SiO{sub 2}/ITO composite modified electrode was characterized by Fourier transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA) and UV-visible spectroscopy. The morphologies and electrochemical performance of the modified Urs/MWCNTs/SiO{sub 2}/ITO electrode have been investigated by scanning electron microscopy (SEM) and potentiometric method, respectively. The synergistic effect of silica matrix, F-MWCNTs and biocompatibility of Urs/MWCNTs/SiO{sub 2} made the biosensor to have the excellent electro catalytic activity and high stability. The resulting biosensor exhibits a good response performance to urea detection with a wide linear range from 2.18 x 10{sup -5} to 1.07 x 10{sup -3} M urea. The biosensor shows a short response time of 10-25 s and a high sensitivity of 23 mV/decade/cm{sup 2}.

  18. Functionalization of Carbon Nanotubes

    Science.gov (United States)

    Khare, Bishun N. (Inventor); Meyyappan, Meyya (Inventor)

    2009-01-01

    Method and system for functionalizing a collection of carbon nanotubes (CNTs). A selected precursor gas (e.g., H2 or F2 or CnHm) is irradiated to provide a cold plasma of selected target species particles, such as atomic H or F, in a first chamber. The target species particles are d irected toward an array of CNTs located in a second chamber while suppressing transport of ultraviolet radiation to the second chamber. A CNT array is functionalized with the target species particles, at or below room temperature, to a point of saturation, in an exposure time interval no longer than about 30 sec. *Discrimination against non-target species is provided by (i) use of a target species having a lifetime that is much greater than a lifetime of a non-target species and/or (2) use of an applied magnetic field to discriminate between charged particle trajectories for target species and for non-target species.

  19. Carbon Nanotube and Graphene Nanoelectromechanical Systems

    Science.gov (United States)

    Aleman, Benjamin Jose

    One-dimensional and two-dimensional forms of carbon are composed of sp 2-hybridized carbon atoms arranged in a regular hexagonal, honeycomb lattice. The two-dimensional form, called graphene, is a single atomic layer of hexagonally-bonded carbon atoms. The one-dimensional form, known as a carbon nanotube, can be conceptualized as a rectangular piece of graphene wrapped into a seamless, high-aspect-ratio cylinder or tube. This dissertation addresses the physics and applied physics of these one and two-dimensional carbon allotropes in nanoelectromechanical systems (NEMS). First, we give a theoretical background on the electrodynamics and mechanics of carbon nanotube NEMS. We then describe basic experimental techniques, such as electron and scanning probe microscopy, that we then use to probe static and dynamic mechanical and electronic behavior of the carbon nanotube NEMS. For example, we observe and control non-linear beam bending and single-electron quantum tunneling effects in carbon nanotube resonators. We then describe parametric amplification, self-oscillation behavior, and dynamic, non-linear effects in carbon nanotube mechanical resonators. We also report a novel approach to fabricate carbon nanotube atomic force microscopy (AFM) probes, and show that they can lead to exceptional lateral resolution enhancement in AFM when imaging both hard and soft (biological) materials. Finally, we describe novel fabrication techniques for large-area, suspended graphene membranes, and utilize these membranes as TEM-transparent, AFM-compatible, NEMS resonators. Laser-driven mechanical vibrations of the graphene resonators are detected by optical interferometry and several vibration harmonics are observed. A degeneracy splitting is observed in the vibrational modes of square-geometry resonators. We then attribute the observed degeneracy splitting to local mass inhomogeneities and membrane defects, and find good overall agreement with the developed theoretical model.

  20. Molybdenum Disulfide Sheathed Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    Xu Chun SONG; Zhu De XU; Yi Fan ZHENG; Gui HAN; Bo LIU; Wei Xiang CHEN

    2004-01-01

    Single and double layered MoS2-coated multiwalled carbon nanotubes (MWCNs) were successfully prepared by pyrolyzing (NH4)2MoS4-coated multiwalled carbon nanotubes in an H2 atmosphere at 900℃. MoS2-coated MWCNs would be expected to have different tribological and mechanical properties compared to MoS2, so it may have potential applications in many fields.

  1. Carbon nanotubes for coherent spintronics

    Directory of Open Access Journals (Sweden)

    F. Kuemmeth

    2010-03-01

    Full Text Available Carbon nanotubes bridge the molecular and crystalline quantum worlds, and their extraordinary electronic, mechanical and optical properties have attracted enormous attention from a broad scientific community. We review the basic principles of fabricating spin-electronic devices based on individual, electrically-gated carbon nanotubes, and present experimental efforts to understand their electronic and nuclear spin degrees of freedom, which in the future may enable quantum applications.

  2. Selective functionalization of carbon nanotubes

    Science.gov (United States)

    Strano, Michael S. (Inventor); Usrey, Monica (Inventor); Barone, Paul (Inventor); Dyke, Christopher A. (Inventor); Tour, James M. (Inventor); Kittrell, W. Carter (Inventor); Hauge, Robert H. (Inventor); Smalley, Richard E. (Inventor)

    2009-01-01

    The present invention is directed toward methods of selectively functionalizing carbon nanotubes of a specific type or range of types, based on their electronic properties, using diazonium chemistry. The present invention is also directed toward methods of separating carbon nanotubes into populations of specific types or range(s) of types via selective functionalization and electrophoresis, and also to the novel compositions generated by such separations.

  3. Carbon nanotubes for coherent spintronics

    DEFF Research Database (Denmark)

    Kuemmeth, Ferdinand; Churchill, H O H; Herring, P K;

    2010-01-01

    Carbon nanotubes bridge the molecular and crystalline quantum worlds, and their extraordinary electronic, mechanical and optical properties have attracted enormous attention from a broad scientific community. We review the basic principles of fabricating spin-electronic devices based on individual......, electrically-gated carbon nanotubes, and present experimental efforts to understand their electronic and nuclear spin degrees of freedom, which in the future may enable quantum applications....

  4. Carbon Nanotube-based Nanohybrid Materials as Counter Electrode for Highly Efficient Dye-sensitized Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji-Soo; Sim, Eun-Ju; Dao, Van-Duong; Choi, Ho-Suk [Chungnam National University, Daejeon (Korea, Republic of)

    2016-04-15

    In this study, we present an excellent approach for easily and uniformly immobilizing Pt, Au and bimetallic PtAu nanoparticles (NPs) on a multi-walled carbon nanotube (MWNT)-coated layer through dry plasma reduction. The NPs are stably and uniformly immobilized on the surface of MWNTs and the nanohybrid materials are applied to counter electrode (CE) of dye-sensitized solar cells (DSCs). The electrochemical properties of CEs are examined through cyclic voltammogram, electrochemical impedance spectroscopy, and Tafel measurements. As a result, both electrochemical catalytic activity and electrical conductivity are highest for PtAu/MWNT electrode. The DSC employing PtAu/MWNT CE exhibits power conversion efficiency of 7.9%. The efficiency is better than those of devices with MWNT (2.6%), AuNP/MWNT (2.7%) and PtNP/MWNT (7.5%) CEs.

  5. Bio-based hyperbranched thermosetting polyurethane/triethanolamine functionalized multi-walled carbon nanotube nanocomposites as shape memory materials.

    Science.gov (United States)

    Kalita, Hemjyoti; Karak, Niranjan

    2014-07-01

    Here, bio-based shape memory polymers have generated immense interest in recent times. Here, Bio-based hyperbranched polyurethane/triethanolamine functionalized multi-walled carbon nanotube (TEA-f-MWCNT) nanocomposites were prepared by in-situ pre-polymerization technique. The Fourier transform infrared spectroscopy and the transmission electron microscopic studies showed the strong interfacial adhesion and the homogeneous distribution of TEA-f-MWCNT in the polyurethane matrix. The prepared epoxy cured thermosetting nanocomposites exhibited enhanced tensile strength (6.5-34.5 MPa), scratch hardness (3.0-7.5 kg) and thermal stability (241-288 degrees C). The nanocomposites showed excellent shape fixity and shape recovery. The shape recovery time decreases (24-10 s) with the increase of TEA-f-MWCNT content in the nanocomposites. Thus the studied nanocomposites have potential to be used as advanced shape memory materials. PMID:24758045

  6. Carbon Nanotubes Hybrid Hydrogels in Drug Delivery: A Perspective Review

    Directory of Open Access Journals (Sweden)

    Giuseppe Cirillo

    2014-01-01

    Full Text Available The use of biologics, polymers, silicon materials, carbon materials, and metals has been proposed for the preparation of innovative drug delivery devices. One of the most promising materials in this field are the carbon-nanotubes composites and hybrid materials coupling the advantages of polymers (biocompatibility and biodegradability with those of carbon nanotubes (cellular uptake, stability, electromagnatic, and magnetic behavior. The applicability of polymer-carbon nanotubes composites in drug delivery, with particular attention to the controlled release by composites hydrogel, is being extensively investigated in the present review.

  7. A tunable carbon nanotube electromechanical oscillator

    Science.gov (United States)

    Sazonova, Vera; Yaish, Yuval; Üstünel, Hande; Roundy, David; Arias, Tomás A.; McEuen, Paul L.

    2004-09-01

    Nanoelectromechanical systems (NEMS) hold promise for a number of scientific and technological applications. In particular, NEMS oscillators have been proposed for use in ultrasensitive mass detection, radio-frequency signal processing, and as a model system for exploring quantum phenomena in macroscopic systems. Perhaps the ultimate material for these applications is a carbon nanotube. They are the stiffest material known, have low density, ultrasmall cross-sections and can be defect-free. Equally important, a nanotube can act as a transistor and thus may be able to sense its own motion. In spite of this great promise, a room-temperature, self-detecting nanotube oscillator has not been realized, although some progress has been made. Here we report the electrical actuation and detection of the guitar-string-like oscillation modes of doubly clamped nanotube oscillators. We show that the resonance frequency can be widely tuned and that the devices can be used to transduce very small forces.

  8. Functionalized carbon nanotubes: biomedical applications

    Directory of Open Access Journals (Sweden)

    Vardharajula S

    2012-10-01

    Full Text Available Sandhya Vardharajula,1 Sk Z Ali,2 Pooja M Tiwari,1 Erdal Eroğlu,1 Komal Vig,1 Vida A Dennis,1 Shree R Singh11Center for NanoBiotechnology and Life Sciences Research, Alabama State University, Montgomery, AL, USA; 2Department of Microbiology, Osmania University, Hyderabad, IndiaAbstract: Carbon nanotubes (CNTs are emerging as novel nanomaterials for various biomedical applications. CNTs can be used to deliver a variety of therapeutic agents, including biomolecules, to the target disease sites. In addition, their unparalleled optical and electrical properties make them excellent candidates for bioimaging and other biomedical applications. However, the high cytotoxicity of CNTs limits their use in humans and many biological systems. The biocompatibility and low cytotoxicity of CNTs are attributed to size, dose, duration, testing systems, and surface functionalization. The functionalization of CNTs improves their solubility and biocompatibility and alters their cellular interaction pathways, resulting in much-reduced cytotoxic effects. Functionalized CNTs are promising novel materials for a variety of biomedical applications. These potential applications are particularly enhanced by their ability to penetrate biological membranes with relatively low cytotoxicity. This review is directed towards the overview of CNTs and their functionalization for biomedical applications with minimal cytotoxicity.Keywords: carbon nanotubes, cytotoxicity, functionalization, biomedical applications

  9. Different Technical Applications of Carbon Nanotubes.

    Science.gov (United States)

    Abdalla, S; Al-Marzouki, F; Al-Ghamdi, Ahmed A; Abdel-Daiem, A

    2015-12-01

    Carbon nanotubes have been of great interest because of their simplicity and ease of synthesis. The novel properties of nanostructured carbon nanotubes such as high surface area, good stiffness, and resilience have been explored in many engineering applications. Research on carbon nanotubes have shown the application in the field of energy storage, hydrogen storage, electrochemical supercapacitor, field-emitting devices, transistors, nanoprobes and sensors, composite material, templates, etc. For commercial applications, large quantities and high purity of carbon nanotubes are needed. Different types of carbon nanotubes can be synthesized in various ways. The most common techniques currently practiced are arc discharge, laser ablation, and chemical vapor deposition and flame synthesis. The purification of CNTs is carried out using various techniques mainly oxidation, acid treatment, annealing, sonication, filtering chemical functionalization, etc. However, high-purity purification techniques still have to be developed. Real applications are still under development. This paper addresses the current research on the challenges that are associated with synthesis methods, purification methods, and dispersion and toxicity of CNTs within the scope of different engineering applications, energy, and environmental impact.

  10. Surface Anchoring of Nematic Phase on Carbon Nanotubes: Nanostructure of Ultra-High Temperature Materials

    Energy Technology Data Exchange (ETDEWEB)

    Ogale, Amod A

    2012-04-27

    Nuclear energy is a dependable and economical source of electricity. Because fuel supply sources are available domestically, nuclear energy can be a strong domestic industry that can reduce dependence on foreign energy sources. Commercial nuclear power plants have extensive security measures to protect the facility from intruders [1]. However, additional research efforts are needed to increase the inherent process safety of nuclear energy plants to protect the public in the event of a reactor malfunction. The next generation nuclear plant (NGNP) is envisioned to utilize a very high temperature reactor (VHTR) design with an operating temperature of 650-1000°C [2]. One of the most important safety design requirements for this reactor is that it must be inherently safe, i.e., the reactor must shut down safely in the event that the coolant flow is interrupted [2]. This next-generation Gen IV reactor must operate in an inherently safe mode where the off-normal temperatures may reach 1500°C due to coolant-flow interruption. Metallic alloys used currently in reactor internals will melt at such temperatures. Structural materials that will not melt at such ultra-high temperatures are carbon/graphtic fibers and carbon-matrix composites. Graphite does not have a measurable melting point; it is known to sublime starting about 3300°C. However, neutron radiation-damage effects on carbon fibers are poorly understood. Therefore, the goal of this project is to obtain a fundamental understanding of the role of nanotexture on the properties of resulting carbon fibers and their neutron-damage characteristics. Although polygranular graphite has been used in nuclear environment for almost fifty years, it is not suitable for structural applications because it do not possess adequate strength, stiffness, or toughness that is required of structural components such as reaction control-rods, upper plenum shroud, and lower core-support plate [2,3]. For structural purposes, composites

  11. CARBON NANOTUBES: AN APPROACH TO NOVEL DRUG DELIVERY SYSTEM

    Directory of Open Access Journals (Sweden)

    M. H. Alai et al.

    2012-01-01

    Full Text Available Carbon nanotubes are cylindrical carbon molecules have novel properties, making them potentially useful in many applications in nanotechnology, electronics, optics, and other fields of material science as well as potential uses in architectural fields. They have unique electronic, mechanical, optical and chemical properties that make them good candidates for a wide variety of applications, including drug transporters, new therapeutics, delivery systems and diagnostics. Their unique surface area, stiffness, strength and resilience have led to much excitement in the field of pharmacy. Nanotubes are categorized as single-walled nanotubes, multiple walled nanotubes. Various techniques have been developed to produce nanotubes in sizeable quantities, including arc discharge, laser ablation, chemical vapor deposition. They can pass through membranes, carrying therapeutic drugs, vaccines and nucleic acids deep into the cell to targets previously unreachable. Purification of the tubes can be divided into a couple of main techniques: oxidation, acid treatment, annealing, sonication, filtering and functionalization techniques. The main problem of insolubility in aqueous media has been solved by developing a synthetic protocol that allows highly water-soluble carbon NTs to be obtained. The modifications are done to improve efficiency of carbon nanotubes by formulating luminescent carbon nanotubes, ultrathin carbon nanoneedles, magnetically guided nanotubes. The application of carbon nanotube in tissue engineering, drug carrier release system, wound healing, in cancer treatment and as biosensor. Researchers have recently developed a new approach to Boron Neutron Capture Therapy in the treatment of cancer using substituted Carborane-Appended Water-Soluble single-wall carbon nanotubes.

  12. Carbon nanotube computer.

    Science.gov (United States)

    Shulaker, Max M; Hills, Gage; Patil, Nishant; Wei, Hai; Chen, Hong-Yu; Wong, H-S Philip; Mitra, Subhasish

    2013-09-26

    The miniaturization of electronic devices has been the principal driving force behind the semiconductor industry, and has brought about major improvements in computational power and energy efficiency. Although advances with silicon-based electronics continue to be made, alternative technologies are being explored. Digital circuits based on transistors fabricated from carbon nanotubes (CNTs) have the potential to outperform silicon by improving the energy-delay product, a metric of energy efficiency, by more than an order of magnitude. Hence, CNTs are an exciting complement to existing semiconductor technologies. Owing to substantial fundamental imperfections inherent in CNTs, however, only very basic circuit blocks have been demonstrated. Here we show how these imperfections can be overcome, and demonstrate the first computer built entirely using CNT-based transistors. The CNT computer runs an operating system that is capable of multitasking: as a demonstration, we perform counting and integer-sorting simultaneously. In addition, we implement 20 different instructions from the commercial MIPS instruction set to demonstrate the generality of our CNT computer. This experimental demonstration is the most complex carbon-based electronic system yet realized. It is a considerable advance because CNTs are prominent among a variety of emerging technologies that are being considered for the next generation of highly energy-efficient electronic systems.

  13. Carbon Nanotube Purification

    Science.gov (United States)

    Delzeit, Lance D. (Inventor); Delzeit, Clement J. (Inventor)

    2005-01-01

    A method for cleaning or otherwise removing amorphous carbon and other residues that arise in growth of a carbon nanotube (CNT) array. The CNT array is exposed to a plurality of hydroxyls or hydrogen, produced from a selected vapor or liquid source such as H2O or H2O2. and the hydroxyls or hydrogen (neutral or electrically charged) react with the residues to produce partly or fully dissolved or hydrogenated or hydroxylizated products that can be removed or separated from the CNT array. The hydroxyls or hydrogen can be produced by heating the CNT array, residue and selected vapor or liquid source or by application of an electromagnetic excitation signal with a selected frequency or range of frequencies to dissociate the selected vapor or liquid. The excitation frequency can be chirped to cover a selected range of frequencies corresponding to dissociation of the selected vapor or liquid. Sonication may be uscd to supplement dissociation of the H2O and/or H2O2.

  14. New Effective Material Couple--Oxide Ceramic and Carbon Nanotube-- Developed for Aerospace Microsystem and Micromachine Technologies

    Science.gov (United States)

    Miyoshi, Kazuhisa; VanderWal, Randall L.; Tomasek, Aaron J.; Sayir, Ali; Farmer, Serene C.

    2004-01-01

    The prime driving force for using microsystem and micromachine technologies in transport vehicles, such as spacecraft, aircraft, and automobiles, is to reduce the weight, power consumption, and volume of components and systems to lower costs and increase affordability and reliability. However, a number of specific issues need to be addressed with respect to using microsystems and micromachines in aerospace applications--such as the lack of understanding of material characteristics; methods for producing and testing the materials in small batches; the limited proven durability and lifetime of current microcomponents, packaging, and interconnections; a cultural change with respect to system designs; and the use of embedded software, which will require new product assurance guidelines. In regards to material characteristics, there are significant adhesion, friction, and wear issues in using microdevices. Because these issues are directly related to surface phenomena, they cannot be scaled down linearly and they become increasingly important as the devices become smaller. When microsystems have contacting surfaces in relative motion, the adhesion and friction affect performance, energy consumption, wear damage, maintenance, lifetime and catastrophic failure, and reliability. Ceramics, for the most part, do not have inherently good friction and wear properties. For example, coefficients of friction in excess of 0.7 have been reported for ceramics and ceramic composite materials. Under Alternate Fuels Foundation Technologies funding, two-phase oxide ceramics developed for superior high-temperature wear resistance in NASA's High Operating Temperature Propulsion Components (HOTPC) project and new two-layered carbon nanotube (CNT) coatings (CNT topcoat/iron bondcoat/quartz substrate) developed in NASA's Revolutionary Aeropropulsion Concepts (RAC) project have been chosen as a materials couple for aerospace applications, including micromachines, in the nanotechnology

  15. Effect of substrate material on the growth and field emission characteristics of large-area carbon nanotube forests

    Energy Technology Data Exchange (ETDEWEB)

    Ummethala, Raghunandan; Täschner, Christine; Leonhardt, Albrecht; Büchner, Bernd [IFW Dresden, P.O. Box 270116, D-01171 Dresden (Germany); Wenger, Daniela; Tedde, Sandro F. [Siemens Healthcare GmbH, Technology Centre, Guenther-Scharowsky-Strasse 1, 91058 Erlangen (Germany); Eckert, Jürgen [Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstrasse 12, A-8700 Leoben (Austria); Department Materials Physics, Montanuniversität Leoben, Jahnstraße 12, A-8700 Leoben (Austria)

    2016-01-28

    Carbon nanotubes (CNTs) are a promising replacement for tungsten filaments as electron emitters in conventional x-ray sources, owing to their higher aspect ratio, superior mechanical stability, chemical inertness, and high electrical and thermal conductivities. Conditions for realizing the best emission behavior from CNTs have been formulated over the last few years. In this paper, we report the relatively less-investigated factor, namely, the influence of the nature of substrate material on the growth as well as field emission characteristics of large-area multiwalled CNTs for their practical application in medical x-ray sources. We compare the morphology of CNTs on a variety of substrates such as stainless steel, copper, molybdenum, graphite, few-layer graphene, and carbon nanowalls grown by thermal chemical vapor deposition following a simple drop-coating of catalyst. We find that CNTs grown on stainless steel and graphite show the best combination of emission characteristics under pulsed operation mode. These studies are helpful in selecting the optimum substrate material for field emission applications. Ex situ studies on field emission degradation of CNTs are presented towards the end.

  16. Effect of substrate material on the growth and field emission characteristics of large-area carbon nanotube forests

    International Nuclear Information System (INIS)

    Carbon nanotubes (CNTs) are a promising replacement for tungsten filaments as electron emitters in conventional x-ray sources, owing to their higher aspect ratio, superior mechanical stability, chemical inertness, and high electrical and thermal conductivities. Conditions for realizing the best emission behavior from CNTs have been formulated over the last few years. In this paper, we report the relatively less-investigated factor, namely, the influence of the nature of substrate material on the growth as well as field emission characteristics of large-area multiwalled CNTs for their practical application in medical x-ray sources. We compare the morphology of CNTs on a variety of substrates such as stainless steel, copper, molybdenum, graphite, few-layer graphene, and carbon nanowalls grown by thermal chemical vapor deposition following a simple drop-coating of catalyst. We find that CNTs grown on stainless steel and graphite show the best combination of emission characteristics under pulsed operation mode. These studies are helpful in selecting the optimum substrate material for field emission applications. Ex situ studies on field emission degradation of CNTs are presented towards the end

  17. Atomic layer deposition of amorphous iron phosphates on carbon nanotubes as cathode materials for lithium-ion batteries

    International Nuclear Information System (INIS)

    A non-aqueous approach was developed to synthesize iron phosphate cathode materials by the atomic layer deposition (ALD) technique. Deposition of iron phosphate thin films was achieved on nitrogen-doped carbon nanotubes (NCNTs) by combining ALD subcycles of Fe2O3 (ferrocene-ozone) and POx (trimethyl phosphate-water) at 200 – 350 °C. The thickness of iron phosphate thin films depends linearly on the ALD cycle, indicating their self-limiting growth behavior. The growth per cycle of iron phosphate thin films was determined to be ∼ 0.2, 0.4, 0.6, and 0.5 Å, at 200, 250, 300, and 350 °C, respectively. Characterization by SEM, TEM, and HRTEM techniques revealed uniform and conformal coating of amorphous iron phosphates on the surface of NCNTs. XANES analysis confirmed Fe−O−P bonding in the iron phosphates prepared by ALD. Furthermore, electrochemical measurement verified the high electrochemical activity of the amorphous iron phosphate as a cathode material in lithium-ion batteries. It is expected that the amorphous iron phosphate prepared by this facile and cost-effective ALD approach will find applications in the next generation of lithium-ion batteries and thin film batteries as either cathode materials or surface coating materials

  18. Carbon Nanotubes Synthesis Through Gamma Radiation

    Science.gov (United States)

    Tirado, Pablo; Garcia, Rafael; Montes, Jorge; Melendrez, Rodrigo; Barboza, Marcelino; Contreras, Oscar

    2015-03-01

    Carbon nanotubes show a great potential of applications since there discovery by Iijima in 1991[1] due to their numerous physical-chemical properties such as their high weight to strength relationship, which make them ideal to use in high resistance compound materials, and in many other applications[2] In this work, a novel method for the synthesis of carbon nanotubes is presented, starting from an ultra-thin sheet of graphite synthesized by the chemical vapor decomposition technique (CVD), using ultra high purity methane and hydrogen at 1200°C in a horizontal quartz reactor. For the synthesis of carbon nanotubes, the graphite sheets were exposed to different doses of radiation, with the objective of breaking the graphite bonds and form carbon nanotubes; a Gammacell equipment model 220 Excel was used for the purpose, which counts with a radiation source of cobalt 60, and a current radiation rate of 0.9 Gy/seconds. The time of exposure to radiation was varied in each sample, according to the desired dose of radiation in each case, afterwards the samples were characterized using the Raman spectroscopy and TEM microscopy techniques with the objective of observing the kind of nanotubes formed, their morphology and their number of defects. Results will be shown during the poster session.

  19. Probing Photosensitization by Functionalized Carbon Nanotubes

    Science.gov (United States)

    Carbon nanotubes (CNTs) photosensitize the production of reactive oxygen species that can damage organisms by biomembrane oxidation or mediate CNTs' environmental transformations. The photosensitized nature of derivatized carbon nanotubes from various synthetic methods, and thus ...

  20. Functional Materials Based on Surface Modification of Carbon Nanotubes for Biomedical and Environmental Applications

    KAUST Repository

    Mashat, Afnan

    2015-05-01

    Since the discovery of carbon nanotubes (CNTs), they have gained much interest in many science and engineering fields. The modification of CNTs by introducing different functional groups to their surface is important for CNTs to be tailored to fit the need of specific applications. This dissertation presents several CNT-based systems that can provide biomedical and environmental advantages. In this research, polyethylenimine (PEI) and polyvinyl alcohol (PVA) were used to coat CNTs through hydrogen bonding. The release of doxorubicin (DOX, an anticancer drug) from this system was controlled by temperature. This system represents a promising method for incorporating stimuli triggered polymer-gated CNTs in controlled release applications. To create an acid responsive system CNTs were coated with 1,2-Distearoyl-snglycero- 3-Phosphoethanolamine-N-[Amino(Polyethylene glycol)2000]-(PE-PEG) and Poly(acrylic acid) modified dioleoy lphosphatidyl-ethanolamine (PE-PAA). An acidlabile linker was used to cross-link PAA, forming ALP@CNTs, thus making the system acid sensitive. The release of DOX from ALP@CNTs was found to be higher in an acidic environment. Moreover, near infrared (NIR) light was used to enhance the release of DOX from ALP@CNTs. A CNT-based membrane with controlled diffusion was prepared in the next study. CNTs were used as a component of a cellulose/gel membrane due to their optical property, which allows them to convert NIR light into heat. Poly(Nisopropylacrylamide) (PNIPAm) was used due to its thermo-sensitivity. The properties of both the CNTs and PNIPAm’s were used to control the diffusion of the cargo from the system, under the influence of NIR. CNTs were also used to fabricate an antibacterial agent, for which they were coated with polydopamine (PDA) and decorated with silver particles (Ag). Galactose (Gal) terminated with thiol groups conjugated with the above system was used to strengthen the bacterial targeting ability. The antibacterial activity of

  1. Computational Nanomechanics of Carbon Nanotubes and Composites

    Science.gov (United States)

    Srivastava, Deepak; Wei, Chenyu; Cho, Kyeongjae; Biegel, Bryan (Technical Monitor)

    2002-01-01

    Nanomechanics of individual carbon and boron-nitride nanotubes and their application as reinforcing fibers in polymer composites has been reviewed with interplay of theoretical modeling, computer simulations and experimental observations. The emphasis in this work is on elucidating the multi-length scales of the problems involved, and of different simulation techniques that are needed to address specific characteristics of individual nanotubes and nanotube polymer-matrix interfaces. Classical molecular dynamics simulations are shown to be sufficient to describe the generic behavior such as strength and stiffness modulus but are inadequate to describe elastic limit and nature of plastic buckling at large strength. Quantum molecular dynamics simulations are shown to bring out explicit atomic nature dependent behavior of these nanoscale materials objects that are not accessible either via continuum mechanics based descriptions or through classical molecular dynamics based simulations. As examples, we discus local plastic collapse of carbon nanotubes under axial compression and anisotropic plastic buckling of boron-nitride nanotubes. Dependence of the yield strain on the strain rate is addressed through temperature dependent simulations, a transition-state-theory based model of the strain as a function of strain rate and simulation temperature is presented, and in all cases extensive comparisons are made with experimental observations. Mechanical properties of nanotube-polymer composite materials are simulated with diverse nanotube-polymer interface structures (with van der Waals interaction). The atomistic mechanisms of the interface toughening for optimal load transfer through recycling, high-thermal expansion and diffusion coefficient composite formation above glass transition temperature, and enhancement of Young's modulus on addition of nanotubes to polymer are discussed and compared with experimental observations.

  2. Kondo physics in carbon nanotubes

    OpenAIRE

    Nygard, Jesper; Cobden, David Henry; Lindelof, Poul Erik

    2000-01-01

    The connection of electrical leads to wire-like molecules is a logical step in the development of molecular electronics, but also allows studies of fundamental physics. For example, metallic carbon nanotubes are quantum wires that have been found to act as one-dimensional quantum dots, Luttinger-liquids, proximity-induced superconductors and ballistic and diffusive one-dimensional metals. Here we report that electrically-contacted single-wall nanotubes can serve as powerful probes of Kondo ph...

  3. Carbon nanotubes for stem cell control

    Directory of Open Access Journals (Sweden)

    David A. Stout

    2012-07-01

    Full Text Available In the past decade, two major advancements have transformed the world of tissue engineering and regenerative medicine—stem cells and carbon nano-dimensional materials. In the past, stem cell therapy seemed like it may present a cure for all medical ailments, but problems arose (i.e., immune system clearance, control of differentiation in the body, etc. that have hindered progress. But, with the synergy of carbon nano-dimensional materials, researchers have been able to overcome these tissue engineering and regenerative medicine obstacles and have begun developing treatments for strokes, bone failure, cardiovascular disease, and many other conditions. Here, we briefly review research involving carbon nanotubes which are relevant to the tissue engineering and regenerative medicine field with a special emphasis on carbon nanotube applications for stem cell delivery, drug delivery applications, and their use as improved medical devices.

  4. Cytotoxicity of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    With large-scale production and application at large scale, carbon nanotubes (CNTs) may cause ad-verse response to the environment and human health. Thus, study on bio-effects and safety of CNTs has attracted great attention from scientists and governments worldwide. This report briefly summa-rizes the main results from the in vitro toxicity study of CNTs. The emphasis is placed on the descrip-tion of a variety of factors affecting CNTs cytotoxicity, including species of CNTs, impurities contained, lengths of CNTs, aspect ratios, chemical modification, and assaying methods of cytotoxicity. However, experimental information obtained thus far on CNTs’ cytotoxicity is lacking in comparability, and some-times there is controversy about it. In order to assess more accurately the potential risks of CNTs to human health, we suggest that care should be taken for issues such as chemical modification and quantitative characterization of CNTs in cytotoxicity assessment. More importantly, studies on physical and chemical mechanisms of CNTs’ cytotoxicity should be strengthened; assaying methods and evaluating criteria characterized by nanotoxicology should be gradually established.

  5. Cytotoxicity of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    ZHU Ying; LI WenXin

    2008-01-01

    With large-scale production and application at large scale, carbon nanotubes (CNTs) may cause ad-verse response to the environment and human health. Thus, study on bio-effects and safety of CNTs has attracted great attention from scientists and governments worldwide. This report briefly summa-rizes the main results from the in vitro toxicity study of CNTs. The emphasis is placed on the descrip-tion of a variety of factors affecting CNTs cytotoxicity, including species of CNTs, impurities contained,lengths of CNTs, aspect ratios, chemical modification, and assaying methods of cytotoxicity. However,experimental information obtained thus far on CNTs' cytotoxicity is lacking in comparability, and some-times there is controversy about it. In order to assess more accurately the potential risks of CNTs to human health, we suggest that care should be taken for issues such as chemical modification and quantitative characterization of CNTa in cytotoxicity assessment. More importantly, studies on physical and chemical mechanisms of CNTs' cytotoxicity should be strengthened; assaying methods and evaluating criteria characterized by nanotoxicology should be gradually established.

  6. Developing Single-Wall Carbon Nanotubes into an Industrial Material through the Super-Growth CVD Method

    Science.gov (United States)

    Futaba, Don

    2013-03-01

    Since the discovery of the carbon nanotube (CNT) 20 years ago, extensive effort has been made to utilize their exceptional intrinsic properties toward industrial applications. However, availability has significantly thwarted these endeavors. In one section of my presentation, I will describe our efforts toward the economical mass-production of single-walled carbon nanotubes (SWCNT) based on the water-assisted chemical vapor deposition technique, from which highly efficient synthesis of vertically aligned SWCNTs grow from substrates (SWCNT forests). Further, I will discuss our work to promote the industrial use of SWCNTs as a member of the Technology Research Association for Single-Walled Carbon Nanotubes (TASC) (A consortium of five companies and AIST founded for the specific purpose of developing SWCNT industrial technology.) Specifically, I will present our progress on developing the technology for the synthetic control of SWCNTs and the development of standardized evaluation techniques for the purpose of understanding the relationship between the SWCNT forest structure, e.g. length, density, crystallinity, etc and the targeted property, e.g. conductivity, mechanical reinforcement, etc. Finally, I will present several examples of applications from composites to CNT-based devices. Technology Research Association for Single Wall Carbon Nanotubes (TASC), Japan

  7. Exploring the Immunotoxicity of Carbon Nanotubes

    Science.gov (United States)

    Yu, Yanmei; Zhang, Qiu; Mu, Qingxin; Zhang, Bin; Yan, Bing

    2008-08-01

    Mass production of carbon nanotubes (CNTs) and their applications in nanomedicine lead to the increased exposure risk of nanomaterials to human beings. Although reports on toxicity of nanomaterials are rapidly growing, there is still a lack of knowledge on the potential toxicity of such materials to immune systems. This article reviews some existing studies assessing carbon nanotubes’ toxicity to immune system and provides the potential mechanistic explanation.

  8. Synthesis and Application of Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    Qun Zeng; Zhenhua Li; Yuhong Zhou

    2006-01-01

    Owing to the unique structure, the superior physical and chemical properties, the super strong mechanical performances, and so on, carbon nanotubes have attracted the attention of researchers all over the world. In this article, the basic properties and the main production processes of carbon nanotubes are introduced in brief, and the progress of applied research for carbon nanotubes is reviewed.

  9. Dispersions of Carbon nanotubes in Polymer Matrices

    Science.gov (United States)

    Wise, Kristopher Eric (Inventor); Park, Cheol (Inventor); Siochi, Emilie J. (Inventor); Harrison, Joycelyn S. (Inventor); Lillehei, Peter T. (Inventor); Lowther, Sharon E. (Inventor)

    2010-01-01

    Dispersions of carbon nanotubes exhibiting long term stability are based on a polymer matrix having moieties therein which are capable of a donor-acceptor complexation with carbon nanotubes. The carbon nanotubes are introduced into the polymer matrix and separated therein by standard means. Nanocomposites produced from these dispersions are useful in the fabrication of structures, e.g., lightweight aerospace structures.

  10. Developing Carbon Nanotube Standards at NASA

    Science.gov (United States)

    Nikolaev, Pasha; Arepalli, Sivaram; Sosa, Edward; Gorelik, Olga; Yowell, Leonard

    2007-01-01

    Single wall carbon nanotubes (SWCNTs) are currently being produced and processed by several methods. Many researchers are continuously modifying existing methods and developing new methods to incorporate carbon nanotubes into other materials and utilize the phenomenal properties of SWCNTs. These applications require availability of SWCNTs with known properties and there is a need to characterize these materials in a consistent manner. In order to monitor such progress, it is critical to establish a means by which to define the quality of SWCNT material and develop characterization standards to evaluate of nanotube quality across the board. Such characterization standards should be applicable to as-produced materials as well as processed SWCNT materials. In order to address this issue, NASA Johnson Space Center has developed a protocol for purity and dispersion characterization of SWCNTs. The NASA JSC group is currently working with NIST, ANSI and ISO to establish purity and dispersion standards for SWCNT material. A practice guide for nanotube characterization is being developed in cooperation with NIST. Furthermore, work is in progress to incorporate additional characterization methods for electrical, mechanical, thermal, optical and other properties of SWCNTs.

  11. Adsorption on the carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    DING Yi; YANG Xiao-bao; NI Jun

    2006-01-01

    Adsorption on single walled carbon nanotubes (SWCNTs) is a subject of growing experimental and theoretical interest.The possible adsorbed patterns of atoms and molecules on the single-walled carbon nanotubes vary with the diameters and chirality of the tubes due to the confinement.The curvature of the carbon nanotube surface enlarges the distance of the adsorbate atoms and thus enhances the stability of high coverage structures of adsorbate.There exist two novel high-coverage stable structures of potassium adsorbed on SWCNTs,which are not stable on graphite.The electronic properties of SWCNTs can be modified by adsorbate atoms and metal-semiconductor and semiconductor-semi-conductor transitions can be achieved by the doping of alkali atoms.

  12. Nanostructured Black Phosphorus/Ketjenblack-Multiwalled Carbon Nanotubes Composite as High Performance Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Xu, Gui-Liang; Chen, Zonghai; Zhong, Gui-Ming; Liu, Yuzi; Yang, Yong; Ma, Tianyuan; Ren, Yang; Zuo, Xiaobing; Wu, Xue-Hang; Zhang, Xiaoyi; Amine, Khalil

    2016-06-01

    Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack-multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (∼1700 mAh g(-1) after 100 cycles at 1.3 A g(-1) based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries.

  13. Nanostructured Black Phosphorus/Ketjenblack-Multiwalled Carbon Nanotubes Composite as High Performance Anode Material for Sodium-Ion Batteries.

    Science.gov (United States)

    Xu, Gui-Liang; Chen, Zonghai; Zhong, Gui-Ming; Liu, Yuzi; Yang, Yong; Ma, Tianyuan; Ren, Yang; Zuo, Xiaobing; Wu, Xue-Hang; Zhang, Xiaoyi; Amine, Khalil

    2016-06-01

    Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack-multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (∼1700 mAh g(-1) after 100 cycles at 1.3 A g(-1) based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries. PMID:27222911

  14. 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.

  15. Density controlled carbon nanotube array electrodes

    Science.gov (United States)

    Ren, Zhifeng F.; Tu, Yi

    2008-12-16

    CNT materials comprising aligned carbon nanotubes (CNTs) with pre-determined site densities, catalyst substrate materials for obtaining them and methods for forming aligned CNTs with controllable densities on such catalyst substrate materials are described. The fabrication of films comprising site-density controlled vertically aligned CNT arrays of the invention with variable field emission characteristics, whereby the field emission properties of the films are controlled by independently varying the length of CNTs in the aligned array within the film or by independently varying inter-tubule spacing of the CNTs within the array (site density) are disclosed. The fabrication of microelectrode arrays (MEAs) formed utilizing the carbon nanotube material of the invention is also described.

  16. Gears Based on Carbon Nanotubes

    Science.gov (United States)

    Jaffe, Richard; Han, Jie; Globus, Al; Deardorff, Glenn

    2005-01-01

    Gears based on carbon nanotubes (see figure) have been proposed as components of an emerging generation of molecular- scale machines and sensors. In comparison with previously proposed nanogears based on diamondoid and fullerene molecules, the nanotube-based gears would have simpler structures and are more likely to be realizable by practical fabrication processes. The impetus for the practical development of carbon-nanotube- based gears arises, in part, from rapid recent progress in the fabrication of carbon nanotubes with prescribed diameters, lengths, chiralities, and numbers of concentric shells. The shafts of the proposed gears would be made from multiwalled carbon nanotubes. The gear teeth would be rigid molecules (typically, benzyne molecules), bonded to the nanotube shafts at atomically precise positions. For fabrication, it may be possible to position the molecular teeth by use of scanning tunneling microscopy (STM) or other related techniques. The capability to position individual organic molecules at room temperature by use of an STM tip has already been demonstrated. Routes to the chemical synthesis of carbon-nanotube-based gears are also under investigation. Chemical and physical aspects of the synthesis of molecular scale gears based on carbon nanotubes and related molecules, and dynamical properties of nanotube- based gears, have been investigated by computational simulations using established methods of quantum chemistry and molecular dynamics. Several particularly interesting and useful conclusions have been drawn from the dynamical simulations performed thus far: The forces acting on the gears would be more sensitive to local molecular motions than to gross mechanical motions of the overall gears. Although no breakage of teeth or of chemical bonds is expected at temperatures up to at least 3,000 K, the gears would not work well at temperatures above a critical range from about 600 to about 1,000 K. Gear temperature could probably be controlled by

  17. CMOS Integrated Carbon Nanotube Sensor

    International Nuclear Information System (INIS)

    Recently carbon nanotubes (CNTs) have been gaining their importance as sensors for gases, temperature and chemicals. Advances in fabrication processes simplify the formation of CNT sensor on silicon substrate. We have integrated single wall carbon nanotubes (SWCNTs) with complementary metal oxide semiconductor process (CMOS) to produce a chip sensor system. The sensor prototype was designed and fabricated using a 0.30 um CMOS process. The main advantage is that the device has a voltage amplifier so the electrical measure can be taken and amplified inside the sensor. When the conductance of the SWCNTs varies in response to media changes, this is observed as a variation in the output tension accordingly.

  18. Fermentation based carbon nanotube multifunctional bionic composites

    OpenAIRE

    Luca Valentini; Silvia Bittolo Bon; Stefano Signetti; Manoj Tripathi; Erica Iacob; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extr...

  19. Aqueous solution dispersement of carbon nanotubes

    Science.gov (United States)

    Kim, Jae-Woo (Inventor); Park, Cheol (Inventor); Choi, Sang H. (Inventor); Lillehei, Peter T. (Inventor); Harrison, Joycelyn S. (Inventor)

    2011-01-01

    Carbon nanotubes (CNTs) are dispersed in an aqueous buffer solution consisting of at least 50 weight percent water and a remainder weight percent that includes a buffer material. The buffer material has a molecular structure defined by a first end, a second end, and a middle disposed between the first and second ends. The first end is a cyclic ring with nitrogen and oxygen heteroatomes, the middle is a hydrophobic alkyl chain, and the second end is a charged group.

  20. SnO2 nanocrystals deposited on multiwalled carbon nanotubes with superior stability as anode material for Li-ion batteries

    Science.gov (United States)

    Ren, Jianguo; Yang, Junbing; Abouimrane, Ali; Wang, Dapeng; Amine, Khalil

    2011-10-01

    We report a novel ethylene glycol-mediated solvothermal-polyol route for synthesis of SnO2-CNT nanocomposites, which consist of highly dispersed 3-5 nm SnO2 nanocrystals on the surface of multiwalled carbon nanotubes (CNTs). As anode materials for Li-ion batteries, the nanocomposites showed high rate capability and superior cycling stability with specific capacity of 500 mAh g-1 for up to 300 cycles. The CNTs served as electron conductors and volume buffers in the nanocomposites. This strategy could be extended to synthesize other metal oxides composites with other carbon materials.

  1. Carbon nanotubes on a spider silk scaffold

    Science.gov (United States)

    Steven, Eden; Saleh, Wasan R.; Lebedev, Victor; Acquah, Steve F. A.; Laukhin, Vladimir; Alamo, Rufina G.; Brooks, James S.

    2013-09-01

    Understanding the compatibility between spider silk and conducting materials is essential to advance the use of spider silk in electronic applications. Spider silk is tough, but becomes soft when exposed to water. Here we report a strong affinity of amine-functionalised multi-walled carbon nanotubes for spider silk, with coating assisted by a water and mechanical shear method. The nanotubes adhere uniformly and bond to the silk fibre surface to produce tough, custom-shaped, flexible and electrically conducting fibres after drying and contraction. The conductivity of coated silk fibres is reversibly sensitive to strain and humidity, leading to proof-of-concept sensor and actuator demonstrations.

  2. Modified carbon nanotubes and methods of forming carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Heintz, Amy M.; Risser, Steven; Elhard, Joel D.; Moore, Bryon P.; Liu, Tao; Vijayendran, Bhima R.

    2016-06-14

    In this invention, processes which can be used to achieve stable doped carbon nanotubes are disclosed. Preferred CNT structures and morphologies for achieving maximum doping effects are also described. Dopant formulations and methods for achieving doping of a broad distribution of tube types are also described.

  3. Investigation on the Mechanical Properties of a Cement-Based Material Containing Carbon Nanotube under Drying and Freeze-Thaw Conditions

    OpenAIRE

    Wei-Wen Li; Wei-Ming Ji; Yao-Cheng Wang; Yi Liu; Ruo-Xu Shen; Feng Xing

    2015-01-01

    This paper aimed to explore the mechanical properties of a cement-based material with carbon nanotube (CNT) under drying and freeze-thaw environments. Mercury Intrusion Porosimetry and Scanning Electron Microscopy were used to analyze the pore structure and microstructure of CNT/cement composite, respectively. The experimental results showed that multi-walled CNT (MWCNT) could improve to different degrees the mechanical properties (compressive and flexural strengths) and physical performances...

  4. Catalytic growth of carbon nanotubes with large inner diameters

    Directory of Open Access Journals (Sweden)

    WEI REN ZHONG

    2005-02-01

    Full Text Available Carbon nanotubes (2.4 g/g catalyst, with large inner diameters were successfully synthesized through pyrolysis of methane on a Ni–Cu–Al catalyst by adding sodium carbonate into the carbon nanotubes growth system. The inner diameter of the carbon nanotubes prepared by this method is about 20–60 nm, while their outer diameter is about 40–80 nm. Transmission electron microscopy and X-ray diffraction were employed to investigate the morphology and microstructures of the carbon nanotubes. The analyses showed that these carbon nanotubes have large inner diameters and good graphitization. The addition of sodium carbonate into the reaction system brings about a slight decrease in the methane conversion and the yield of carbon. The experimental results showed that sodium carbonate is a mildly toxic material which influenced the catalytic activity of the Ni–Cu–Al catalyst and resulted in the formation of carbon nanotubes with large inner diameters. The growth mechanism of the carbon nanotubes with large inner diameters is discussed in this paper.

  5. ELECTROCHEMICAL INVESTIGATION ON CARBON NANOTUBE FILM WITH DIFFERENT PRETREATMENTS

    Institute of Scientific and Technical Information of China (English)

    C.G. Hu; W.L. Wang; Y. Ma; W. Zhu

    2003-01-01

    Wide potential windows were found at carbon nanotube film electrodes in neutral solutions after being treated with nitric acid and mixed acid. Electrochemical reversibility was investigated at carbon nanotube films with different pretreatments for ferri/ferrocyanide and quinone /hydroquinone. Carbon nanotube film electrodes presented quasi-reversible electrochemical behavior for both electrolytes. In the range of scan rate, carbon nanotube film electrodes treated with acids showed heterogeneous electron-transfer properties, which was mainly controlled by its electron state density on the surface of the film. On the whole, the carbon nanotube electrode with nitric acid treatment presented the best electrochemical behaviors, so we chose it as an analytical electrode to determine the trace compound in dilute solution. The results demonstrated that this new electrode material exhibits superior performance characteristics for the detection of azide anion.

  6. Growing carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Yoshinori Ando

    2004-10-01

    Full Text Available The discovery of ‘fullerenes’ added a new dimension to the knowledge of carbon science1; and the subsequent discovery of ‘carbon nanotubes’ (CNTs, the elongated fullerene added a new dimension to the knowledge of technology2;. Today, ‘nanotechnology’ is a hot topic attracting scientists, industrialists, journalists, governments, and even the general public. Nanotechnology is the creation of functional materials, devices, and systems through control of matter on the nanometer scale and the exploitation of novel phenomena and properties of matter (physical, chemical, biological, electrical, etc. at that length scale. CNTs are supposed to be a key component of nanotechnology. Almost every week a new potential application of CNTs is identified, stimulating scientists to peep into this tiny tube with ever increasing curiosity.

  7. Development of Carbon Nanotube Modified Cement Paste with Microencapsulated Phase-Change Material for Structural–Functional Integrated Application

    Science.gov (United States)

    Cui, Hongzhi; Yang, Shuqing; Memon, Shazim Ali

    2015-01-01

    Microencapsulated phase-change materials (MPCM) can be used to develop a structural–functional integrated cement paste having high heat storage efficiency and suitable mechanical strength. However, the incorporation of MPCM has been found to degrade the mechanical properties of cement based composites. Therefore, in this research, the effect of carbon nanotubes (CNTs) on the properties of MPCM cement paste was evaluated. Test results showed that the incorporation of CNTs in MPCM cement paste accelerated the cement hydration reaction. SEM micrograph showed that CNTs were tightly attached to the cement hydration products. At the age of 28 days, the percentage increase in flexural and compressive strength with different dosage of CNTs was found to be up to 41% and 5% respectively. The optimum dosage of CNTs incorporated in MPCM cement paste was found to be 0.5 wt %. From the thermal performance test, it was found that the cement paste panels incorporated with different percentages of MPCM reduced the temperature measured at the center of the room by up to 4.6 °C. Inverse relationship was found between maximum temperature measured at the center of the room and the dosage of MPCM. PMID:25867476

  8. Progress in the Raman spectra analysis of covalently functionalized multiwalled carbon nanotubes: unraveling disorder in graphitic materials.

    Science.gov (United States)

    Rebelo, Susana L H; Guedes, Alexandra; Szefczyk, Monika E; Pereira, André M; Araújo, João P; Freire, Cristina

    2016-05-14

    Raman spectroscopy is highly sensitive to the morphology and electronic structures of graphitic materials, but a convenient interpretation model has been lacking for multiwalled carbon nanotubes (MWCNTs), in particular for the discrimination of spectral changes induced by covalent functionalization. The present work describes a systematic investigation of the Raman analysis of covalently functionalized MWCNTs by diazonium chemistry and oxidation methodologies, with typically different mechanisms and reaction sites. A multi-peak deconvolution system and spectral band assignment were proposed based on the chemical and structural modifications identified by X-ray photoelectron spectroscopy, thermogravimetry, X-ray diffraction, specific surface areas and the comparative analysis of the first and second order regions of the Raman spectra. Diazonium functionalization takes place mainly in the π-system of the external sidewall, while oxidation occurs on defects and leads to structure burning. This allowed us to distinguish between spectral features related to aromaticity disruptions within the sidewalls and spectral features related to changes within the inner tubes. The model was validated extending the studies to the functionalization of MWCNTs by the Bingel reaction.

  9. Controlled growth of carbon nanotube-graphene hybrid materials for flexible and transparent conductors and electron field emitters

    Science.gov (United States)

    Nguyen, Duc Dung; Tai, Nyan-Hwa; Chen, Szu-Ying; Chueh, Yu-Lun

    2012-01-01

    We report a versatile synthetic process based on rapid heating and cooling chemical vapor deposition for the growth of carbon nanotube (CNT)-graphene hybrid materials where the thickness of graphene and density of CNTs are properly controlled. Graphene films are demonstrated as an efficient barrier layer for preventing poisoning of iron nanoparticles, which catalyze the growth of CNTs on copper substrates. Based on this method, the opto-electronic and field emission properties of graphene integrated with CNTs can be remarkably tailored. A graphene film exhibits a sheet resistance of 2.15 kΩ sq-1 with a transmittance of 85.6% (at 550 nm), while a CNT-graphene hybrid film shows an improved sheet resistance of 420 Ω sq-1 with an optical transmittance of 72.9%. Moreover, CNT-graphene films are demonstrated as effective electron field emitters with low turn-on and threshold electric fields of 2.9 and 3.3 V μm-1, respectively. The development of CNT-graphene films with a wide range of tunable properties presented in this study shows promising applications in flexible opto-electronic, energy, and sensor devices.

  10. Carbon nanotube suspensions, dispersions, & composites

    Science.gov (United States)

    Simmons, Trevor John

    Carbon Nanotubes (CNTs) are amazing structures that hold the potential to revolutionize many areas of scientific research. CNTs can be behave both as semiconductors and metals, can be grown in highly ordered arrays and patterns or in random orientation, and can be comprised of one graphene cylinder (single wall nanotube, SWNT) or several concentric graphene cylinders (multi-wall nanotube, MWNT). Although these structures are usually only a few nanometers wide, they can be grown up to centimeter lengths, and in massive quantities. CNTs can be produced in a variety of processes ranging from repeated combustion of organic material such as dried grass, arc-discharge with graphite electrodes, laser ablation of a graphitic target, to sophisticated chemical vapor deposition (CVD) techniques. CNTs are stronger than steel but lighter than aluminum, and can be more conductive than copper or semiconducting like silicon. This variety of properties has been matched by the wide variety of applications that have been developed for CNTs. Many of these applications have been limited by the inability of researchers to tame these structures, and incorporating CNTs into existing technologies can be exceedingly difficult and prohibitively expensive. It is therefore the aim of the current study to develop strategies for the solution processing and deposition of CNTs and CNT-composites, which will enable the use of CNTs in existing and emerging technologies. CNTs are not easily suspended in polar solvents and are extremely hydrophobic materials, which has limited much of the solution processing to organic solvents, which also cannot afford high quality dispersions of CNTs. The current study has developed a variety of aqueous CNT solutions that employ surfactants, water-soluble polymers, or both to create suspensions of CNTs. These CNT 'ink' solutions were deposited with a variety of techniques that have afforded many interesting structures, both randomly oriented as well as highly

  11. CARBON NANOTUBES AND PHARMACEUTICAL APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Ram Pavani

    2011-07-01

    Full Text Available Carbon nanotubes (CNTs are often described as a graphene sheet rolled up into the shape of a cylinder. These have fascinated scientists with their extraordinary properties. These compounds have become increasingly popular in various fields simply because of their small size and amazing optical, electric and magnetic properties when used alone or with additions of metals. Carbon nanotubes have potential therapeutic applications in the field of drug delivery, diagnostics, and biosensing. Functionalized carbon nanotubes can also act as vaccine delivery systems.Carbon nanotubes (CNTs are considered to be one of the innovative resources in nanotechnology with possible use in wide range of biomedical applications viz. cancer treatment, bioengineering, cardiac autonomic regulation, platelet activation and tissue regeneration. The effect of CNTs on cells and tissues are extremely important for their use in various complex biological systems. With the increasing interest shown by the nanotechnology research community in this field, it is expected that plenty of applications of CNTs will be explored in future.

  12. Behavior of multi-walled carbon nanotubes on the porosity and microstructure of cement-based materials

    Science.gov (United States)

    Nochaiya, Thanongsak; Chaipanich, Arnon

    2011-01-01

    The porosity and microstructure of a Portland cement-multi-walled carbon nanotube composite were investigated. Multi-walled carbon nanotubes (CNTs), up to 1 wt.% of cement, synthesized by infusion chemical vapor deposition, and Portland cement type I (PC) were used to produce pastes with a water to cement ratio of 0.5. Mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) were used to characterize Portland cement-CNTs systems. MIP analysis of the results indicates that total porosity of the mixes with CNTs was found to decrease with increasing CNTs content. Moreover, an important effect of additional CNTs was a reduction in the number of mesopores, while SEM technique showed dispersion of CNTs between the hydration phases of Portland cement pastes.

  13. Epoxy elastomers reinforced with functionalized multi-walled carbon nanotubes as stimuli-responsive shape memory materials

    Energy Technology Data Exchange (ETDEWEB)

    Lama, G. C.; Nasti, G.; Cerruti, P.; Gentile, G.; Carfagna, C. [Institute of Polymer Chemistry and Technology (ICTP-CNR), via Campi Flegrei 34, 80078 Pozzuoli (Italy); Ambrogi, V. [Department of Chemical, Materials and Production Engineering - University of Naples Federico II, Piazzale Tecchio 80, 80125 Napoli (Italy)

    2014-05-15

    In this work, the incorporation of multiwalled carbon nanotubes (MWCNT) into epoxy-based elastomers was carried out in order to obtain nanocomposite systems with shape memory effect. For the preparation of elastomeric matrices, p-bis(2,3-epoxypropoxy)-α-methylstilbene (DOMS) was cured with sebacic acid. DOMS was synthesized in our laboratory and it is characterized by a rigid-rod, potentially liquid crystalline structure. A lightly cross-linked liquid crystalline elastomer was obtained. As for nanocomposites, variable amounts (0.75, 1.50, 3.0, 6.0, 12.0 wt.%) of COOH-MWCNTs were employed. In order to improve the nanotubes dispersibility and the interfacial adhesion with the epoxy matrix, an optimized two-step procedure was developed, which consisted in grafting the epoxy monomer onto the nanotube surface and then curing it in presence of crosslinking agent. DOMS-functionalized MWCNT were characterized through solvent dispersion experiments, FTIR spectroscopy and TGA analysis, which demonstrated the occurred covalent functionalization of the nanotubes with the epoxy monomers. The morphological analysis through electron microscopy demonstrated that this was an efficient strategy to improve the dispersion of nanotubes within the matrix. The second part of the work was devoted to the structural, thermal, mechanical and electric characterization of elastomeric nanocomposites. The results indicated a general improvement of properties of nanocomposites. Also, independently of the nanotube content, a smectic phase formed. Shape memory features of LC systems were also evaluated. It was demonstrated the shape could be recovered through heating, solvent immersion, as well as upon the application of an electrical field.

  14. Polymerization Initiated at the Sidewalls of Carbon Nanotubes

    Science.gov (United States)

    Tour, James M.; Hudson, Jared L.

    2011-01-01

    A process has been developed for growing polymer chains via anionic, cationic, or radical polymerization from the side walls of functionalized carbon nanotubes, which will facilitate greater dispersion in polymer matrices, and will greatly enhance reinforcement ability in polymeric material.

  15. High-Conductance Thermal Interfaces Based on Carbon Nanotubes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a novel thermal interface material (TIM) that is based on an array of vertical carbon nanotubes (CNTs) for high heat flux applications. For...

  16. Hybrid Multi-Walled Carbon Nanotube TiO2 Electrode Material for Next Generation Energy Storage Devices

    OpenAIRE

    Marler, Sydney

    2016-01-01

    Current supercapacitors present several distinct limitations that severely inhibit the efficiency, power, and electrical capacitance of energy storage devices. Supercapacitors present an exciting prospect that has countless applications in renewable energy storage and modern day electronic devices. In recent years the exciting development of carbon nanotubes (CNTs) has presented an advantage in electrode development. CNTs, however beneficial for their increased electrode surface area, have se...

  17. Nanosystems of Polymerized Fullerenes and Carbon Nanotubes

    Science.gov (United States)

    Scharff, Peter; Cui, Shen

    Nanosystems based on polymerized fullerenes and carbon-nanotubes begin to play an important role in the field of nanotechnology. Nanotubes can be used as molecular wires, and can even figure as building elements for molecular electronics. Furthermore nanotubes can be used as amplifiers in composite materials, as a result of their unique mechanical properties. Many other applications, as for example as electron emitters for flat screens, are currently under development. Fullerens are known to be strong electron acceptors, which enables them to support the electron-hole pair separation in polymer based photovoltaic cells. The use of fulleren chains instead of fullerenes could improve the anisotropic electronic conductivity in the contained polymer layer, and therefore enhance their performance.

  18. Functionalized Carbon Nanotube-Polymer Composites and Interactions with Radiation

    Science.gov (United States)

    Barrera, Enrique V. (Inventor); Wilkins, Richard (Inventor); Shofner, Meisha (Inventor); Pulikkathara, Merlyn X. (Inventor); Vaidyanathan, Ranjii (Inventor)

    2014-01-01

    The present invention involves the interaction of radiation with functionalized carbon nanotubes that have been incorporated into various host materials, particularly polymeric ones. The present invention is directed to chemistries, methods, and apparatuses which exploit this type of radiation interaction, and to the materials which result from such interactions. The present invention is also directed toward the time dependent behavior of functionalized carbon nanotubes in such composite systems.

  19. Attachment of Gold Nanoparticles to Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    Xi Cheng MA; Ning LUN; Shu Lin WEN

    2005-01-01

    Carbon nanotubes were initially chemically modified with an H2SO4-HNO3 treatment,and subsequently activated with Pd-Sn catalytic nuclei via a one-step activation approach. These activated nanotubes were used as precursors for obtaining gold nanoparticles-attached nanotubes via simple electroless plating. This approach provides an efficient method for attachment of metal nanostructures to carbon nanotubes. Such novel hybrid nanostructures are attractive for many applications.

  20. Carbon Nanotube Flexible and Stretchable Electronics.

    Science.gov (United States)

    Cai, Le; Wang, Chuan

    2015-12-01

    The low-cost and large-area manufacturing of flexible and stretchable electronics using printing processes could radically change people's perspectives on electronics and substantially expand the spectrum of potential applications. Examples range from personalized wearable electronics to large-area smart wallpapers and from interactive bio-inspired robots to implantable health/medical apparatus. Owing to its one-dimensional structure and superior electrical property, carbon nanotube is one of the most promising material platforms for flexible and stretchable electronics. Here in this paper, we review the recent progress in this field. Applications of single-wall carbon nanotube networks as channel semiconductor in flexible thin-film transistors and integrated circuits, as stretchable conductors in various sensors, and as channel material in stretchable transistors will be discussed. Lastly, state-of-the-art advancement on printing process, which is ideal for large-scale fabrication of flexible and stretchable electronics, will also be reviewed in detail.

  1. Carbon Nanotube Flexible and Stretchable Electronics

    Science.gov (United States)

    Cai, Le; Wang, Chuan

    2015-08-01

    The low-cost and large-area manufacturing of flexible and stretchable electronics using printing processes could radically change people's perspectives on electronics and substantially expand the spectrum of potential applications. Examples range from personalized wearable electronics to large-area smart wallpapers and from interactive bio-inspired robots to implantable health/medical apparatus. Owing to its one-dimensional structure and superior electrical property, carbon nanotube is one of the most promising material platforms for flexible and stretchable electronics. Here in this paper, we review the recent progress in this field. Applications of single-wall carbon nanotube networks as channel semiconductor in flexible thin-film transistors and integrated circuits, as stretchable conductors in various sensors, and as channel material in stretchable transistors will be discussed. Lastly, state-of-the-art advancement on printing process, which is ideal for large-scale fabrication of flexible and stretchable electronics, will also be reviewed in detail.

  2. From carbon nanotubes to carbon atomic chains

    Science.gov (United States)

    Casillas García, Gilberto; Zhang, Weijia; José-Yacamán, Miguel

    2010-10-01

    Carbyne is a linear allotrope of carbon. It is formed by a linear arrangement of carbon atoms with sp-hybridization. We present a reliable and reproducible experiment to obtain these carbon atomic chains using few-layer-graphene (FLG) sheets and a HRTEM. First the FLG sheets were synthesized from worm-like exfoliated graphite and then drop-casted on a lacey-carbon copper grid. Once in the TEM, two holes are opened near each other in a FLG sheet by focusing the electron beam into a small spot. Due to the radiation, the carbon atoms rearrange themselves between the two holes and form carbon fibers. The beam is concentrated on the carbon fibers in order excite the atoms and induce a tension until multi wall carbon nanotube (MWCNT) is formed. As the radiation continues the MWCNT breaks down until there is only a single wall carbon nanotube (SWCNT). Then, when the SWCNT breaks, an atomic carbon chain is formed, lasts for several seconds under the radiation and finally breaks. This demonstrates the stability of this carbon structure.

  3. Fermentation based carbon nanotube bionic functional composites

    OpenAIRE

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique mechanical and physical properties that are not produced by abiotic processes. Based on grape must and bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at r...

  4. Bloch oscillations in carbon nanotubes.

    Science.gov (United States)

    Jódar, Esther; Pérez-Garrido, Antonio; Rojas, Fernando

    2009-05-27

    Bloch oscillations arise when electrons are in a one-dimensional linear chain of atoms under a constant electric field. In this paper we show numerically that electrons in different types of carbon nanotubes show oscillations with a Bloch frequency proportional to the constant electric field applied along the nanotube axis. We show these oscillations, calculating the quadratic displacement as a function of the electric field. Because of the double periodicity of the nanotubes' geometry (the lattice constant and the lines of atoms) two frequencies appear, one twice the value of the other. These frequencies coincide perfectly with those predicted for a linear chain of atoms, taking into account the periodicity considered in each case.

  5. Modeling of carbon nanotubes and carbon nanotube-polymer composites

    Science.gov (United States)

    Pal, G.; Kumar, S.

    2016-01-01

    In order to meet stringent environmental, safety and performance requirements from respective regulatory bodies, various technology-based industries are promoting the use of advanced carbon nanotube (CNT) reinforced lightweight and high strength polymer nanocomposites (PNCs) as a substitute to conventional materials both in structural and non-structural applications. The superior mechanical properties of PNCs made up of CNTs or bundles of CNTs can be attributed to the interfacial interaction between the CNTs and matrix, CNT's morphologies and to their uniform dispersion in the matrix. In PNCs, CNTs physically bond with polymeric matrix at a level where the assumption of continuum level interactions is not applicable. Modeling and prediction of mechanical response and failure behavior of CNTs and their composites becomes a complex task and is dealt with the help of up-scale modeling strategies involving multiple spatial and temporal scales in hierarchical or concurrent manner. Firstly, the article offers an insight into various modeling techniques in studying the mechanical response of CNTs; namely, equivalent continuum approach, quasi-continuum approach and molecular dynamics (MD) simulation. In the subsequent steps, these approaches are combined with analytical and numerical micromechanics models in a multiscale framework to predict the average macroscopic response of PNCs. The review also discusses the implementation aspects of these computational approaches, their current status and associated challenges with a future outlook.

  6. Multifunctional Carbon Electromagnetic Materials, Motors, and Actuators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of the proposal is to apply multifunctional carbon electromagnetic materials, including carbon nanotube electrical thread (replaces copper wire) and...

  7. Synthesis of anisotropic gold shell on carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Minati, L., E-mail: luminati@fbk.eu [CNR-IFN, CSMFO Lab. (Italy); Torrengo, S. [FBK (Italy); Ischia, G. [University of Trento, Department of Industrial Engineering (Italy); Speranza, G. [FBK (Italy)

    2013-11-15

    This paper reports a simple procedure to synthesize gold-coated carbon nanotubes. The method involves the reduction of gold precursor on oxidized carbon nanotubes. UV–Visible absorption spectroscopy and electron microscopy were used to study the gold precursor reduction on the carbon nanotubes. Scanning and transmission electron microscopy analysis showed the formation of an irregular gold layer around the CNT surface. The resulting nanoparticles show an anisotropic shape with dimensions between 100 and 200 nm. This hybrid material displays an intense absorption in the near infrared range with an absorption maximum at 840 nm.

  8. 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

  9. Structural and surface features of multiwall carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Hembram, K.P.S.S., E-mail: hembram@isu.iisc.ernet.in [Department of Instrumentation, Indian Institute of Science, Bangalore, 560012 (India); Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, 560064 (India); Rao, G. Mohan [Department of Instrumentation, Indian Institute of Science, Bangalore, 560012 (India)

    2011-04-15

    We present the direct evidence of defective and disorder places on the surface of multiwall carbon nanotube (MWCNT), visualizing the presence of amorphous carbon at those sites. These defective surfaces being higher in energy are the key features of functionalization with different materials. The interaction of the {pi} orbital electrons of different carbon atoms of adjacent layers is more at the bent portion, than that of regular portion of the CNT. Hence the tubular structure of the bent portion of nanotubes is spaced more than that of regular portion of the nanotubes, minimizing the stress.

  10. Structural and surface features of multiwall carbon nanotube

    Science.gov (United States)

    Hembram, K. P. S. S.; Rao, G. Mohan

    2011-04-01

    We present the direct evidence of defective and disorder places on the surface of multiwall carbon nanotube (MWCNT), visualizing the presence of amorphous carbon at those sites. These defective surfaces being higher in energy are the key features of functionalization with different materials. The interaction of the π orbital electrons of different carbon atoms of adjacent layers is more at the bent portion, than that of regular portion of the CNT. Hence the tubular structure of the bent portion of nanotubes is spaced more than that of regular portion of the nanotubes, minimizing the stress.

  11. Thermal Spreading in Carbon Nanotube Coating.

    Science.gov (United States)

    Kim, Duckjong; Shin, Dong-Sig; Yu, Jeonghwan; Kim, Haesik; Kim, Jae-Hyun; Woo, Chang-Su

    2015-11-01

    Carbon nanomaterials, such as carbon nanotubes (CNTs) and graphene, have attracted significant attention as good candidates for next-generation heat-spreading materials because of their high thermal conductivity, mechanical flexibility, etc. Regarding the thermal spreading performance of carbon-based nanofilms, remarkable test results have been reported mainly from the industrial side, but their validity and the physical mechanism underlying the heat transfer enhancement are still under debate. In this study, we assess the thermal spreading performance of a multi-walled CNT film on a copper foil using a non-contact characterization method in a simple and methodical manner, and discuss the possibility of carbon nanofilms as heat spreaders based on the experimental and numerical results. This study provides useful information on heat transfer enhancement by carbon nanofilms and could contribute to the development of high-performance carbon-based heat-spreading coatings. PMID:26726629

  12. Electromagnetic interference shielding materials derived from gelation of multiwall carbon nanotubes in polystyrene/poly(methyl methacrylate) blends.

    Science.gov (United States)

    Rohini, Rani; Bose, Suryasarathi

    2014-07-23

    Blends of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with different surface-functionalized multiwall carbon nanotubes (MWNTs) were prepared by solution blending to design materials with tunable EMI (electromagnetic interference) shielding. Different MWNTs like pristine, amine (∼NH2), and carboxyl acid (∼COOH) functionalized were incorporated in the polymer by solution blending. The specific interaction driven localization of MWNTs in the blend during annealing was monitored using contact mode AFM (atomic force microscopy) on thin films. Surface composition of the phase separated blends was further evaluated using X-ray photoelectron spectroscopy (XPS). The localization of MWNTs in a given phase in the bulk was further supported by selective dissolution experiments. Solution-casted PS/PMMA (50/50, wt/wt) blend exhibited a cocontinuous morphology on annealing for 30 min, whereas on longer annealing times it coarsened into matrix-droplet type of morphology. Interestingly, both pristine MWNTs and NH2-MWNTs resulted in interconnected structures of PMMA in PS matrix upon annealing, whereas COOH-MWNTs were localized in the PMMA droplets. Room-temperature electrical conductivity and electromagnetic shielding effectiveness (SE) were measured in a broad range of frequency. It was observed that both electrical conductivity and SE were strongly contingent on the type of surface functional groups on the MWNTs. The thermal conductivity of the blends was measured with laser flash technique at different temperatures. Interestingly, the SE for blends with pristine and NH2-MWNTs was >-24 dB at room temperature, which is commercially important, and with very marginal variation in thermal conductivity in the temperature range of 303-343 K. The gelation of MWNTs in the blends resulted in a higher SE than those obtained using the composites. PMID:24980551

  13. Fluoride and lead adsorption on carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    WANG Shuguang; LI Yanhui

    2004-01-01

    The properties and applications of CNT have been studied extensively since Iijima discovered them in 1991[1,2]. They have exceptional mechanical properties and unique electrical property, highly chemical stability and large specific surface area. Thus far, they have widely potential applications in many fields. They can be used as reinforcing materials in composites[3], field emissions[4], hydrogen storage[5], nanoelectronic components[6], catalyst supports[7], adsorption material and so on. However, the study on the potential application of CNT, environmental protection field in particular, was hardly begun.Long[8] et al. reported that CNT had a significantly higher dioxin removal efficiency than that of activated carbon. The Langmuir adsorption constant is 2.7 × 1052, 1.3 × 1018 respectively. The results indicated that CNT is potential candidate for the removal of micro-organic pollutants. However, the reports on the CNT used as fluoride and heavy metal adsorbent are seldom.In this paper, A novel material, alumina supported on carbon nanotubes (Al2O3/CNT), was prepared from carbon nanotubes and Al(NO3)3. X-ray diffraction (XRD) spectra demonstrate that alumina is amorphous, and scanning electron microscope (SEM) images show that CNT and alumina are homogeneously mixed. Furthermore, the fluoride adsorption behavior on the surface of Al2O3/CNT has been investigated and compared with other adsorbents. The results indicate that Al2O3/CNT has a high adsorption capacity, with a saturation adsorption capacity of 39.4 mg/g. It is also found that the adsorption capacity of Al2O3/CNT is 3.0~4.5 times that of γ-Al2O3while almost equal to that of IRA-410 polymeric resin at 25 ℃. The adsorption isotherms of fluoride on Al2O3/CNT is fit the Freundlich equation well, optimal pH ranging from 5.0 to 9.0.Also in this paper, a novel material, modified carbon nanotubes (CNT), was prepared from carbon nanotubes and HNO3 under boiling condition. Infrared spectroscopy (IR

  14. Carbon Nanotubes for Space Photovoltaic Applications

    Science.gov (United States)

    Efstathiadis, Harry; Haldar, Pradeep; Landi, Brian J.; Denno, Patrick L.; DiLeo, Roberta A.; VanDerveer, William; Raffaelle, Ryne P.

    2007-01-01

    Carbon nanotubes (CNTs) can be envisioned as an individual graphene sheet rolled into a seamless cylinder (single-walled, SWNT), or concentric sheets as in the case of a multi-walled carbon nanotube (MWNT) (1). The role-up vector will determine the hexagonal arrangement and "chirality" of the graphene sheet, which will establish the nanotube to be metallic or semiconducting. The optoelectronic properties will depend directly on this chiral angle and the diameter of the SWNT, with semiconductor types exhibiting a band gap energy (2). Characteristic of MWNTs are the concentric graphene layers spaced 0.34 nm apart, with diameters from 10-200 nm and lengths up to hundreds of microns (2). In the case of SWNTs, the diameters range from 0.4 - 2 nm and lengths have been reported up to 1.5 cm (3). SWNTs have the distinguishable property of "bundling" together due to van der Waal's attractions to form "ropes." A comparison of these different structural types is shown in Figure 1. The use of SWNTS in space photovoltaic (PV) applications is attractive for a variety of reasons. Carbon nanotubes as a class of materials exhibit unprecedented optical, electrical, mechanical properties, with the added benefit of being nanoscale in size which fosters ideal interaction in nanomaterial-based devices like polymeric solar cells. The optical bandgap of semiconducting SWNTs can be varied from approx. 0.4 - 1.5 eV, with this property being inversely proportional to the nanotube diameter. Recent work at GE Global Research has shown where a single nanotube device can behave as an "ideal" pn diode (5). The SWNT was bridged over a SiO2 channel between Mo contacts and exhibited an ideality factor of 1, based on a fit of the current-voltage data using the diode equation. The measured PV efficiency under a 0.8 eV monochromatic illumination showed a power conversion efficiency of 0.2 %. However, the projected efficiency of these junctions is estimated to be > 5 %, especially when one considers the

  15. Remote Joule heating by a carbon nanotube

    Science.gov (United States)

    Baloch, Kamal H.; Voskanian, Norvik; Bronsgeest, Merijntje; Cumings, John

    2012-05-01

    Minimizing Joule heating remains an important goal in the design of electronic devices. The prevailing model of Joule heating relies on a simple semiclassical picture in which electrons collide with the atoms of a conductor, generating heat locally and only in regions of non-zero current density, and this model has been supported by most experiments. Recently, however, it has been predicted that electric currents in graphene and carbon nanotubes can couple to the vibrational modes of a neighbouring material, heating it remotely. Here, we use in situ electron thermal microscopy to detect the remote Joule heating of a silicon nitride substrate by a single multiwalled carbon nanotube. At least 84% of the electrical power supplied to the nanotube is dissipated directly into the substrate, rather than in the nanotube itself. Although it has different physical origins, this phenomenon is reminiscent of induction heating or microwave dielectric heating. Such an ability to dissipate waste energy remotely could lead to improved thermal management in electronic devices.

  16. Nanoscale fluid transportation through individual carbon nanotubes

    Science.gov (United States)

    He, Jin; Cao, Di; Pang, Pei; Luo, Tao; Lindsay, Stuart; Kristic, Predrag; Nuckolls, Colin

    2011-03-01

    There are great interest in both simulation and experiment of fluid flow on the nanoscale. Carbon nanotubes, with their extremely small inner diameter (usually below 2 nm) and atomic smooth inner surface, are ideal materials for studying nanoconfinement and ion and molecule nanoscale translocation. The excellent electrical properties of CNTs can also be integrated to achieve nanoelectrofluidic device. This presentation describes our recent progress in studying fluid transport through individual carbon nanotubes, including simultaneously ionic and electronic measurements during water, ion and molecule translocation. This work was supported by the DNA Sequencing Technology Program of the National Human Genome Research Institute (1RC2HG005625-01, 1R21HG004770-01).

  17. Advanced technology for functionalization of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Lingjie Meng; Chuanlong Fu; Qinghua Lu

    2009-01-01

    Functionalization of carbon nanotubes (CNTs) has attracted considerable interest in the fields of physics, chemistry, material science and biology. The functionalized CNTs exhibit improved properties enabling facile fabrication of novel nanomaterials and nanodevices. Most of the functionalization approaches developed at present could be categorized into the covalent attachment of functional groups and the non-covalent adsorption of various functional molecules onto the surface of CNTs. This review highlights recent development and our work in functionalization of carbon nanotubes, leading to bio-compatible CNTs, fluorescent CNTs and transition metal func-tionalizcd CNTs. These novel methods possess advantages such as simplified technical procedures and reduced cost of novel nanoma-terials and nanodcvices fabrication.

  18. Printed Carbon Nanotube Electronics and Sensor Systems.

    Science.gov (United States)

    Chen, Kevin; Gao, Wei; Emaminejad, Sam; Kiriya, Daisuke; Ota, Hiroki; Nyein, Hnin Yin Yin; Takei, Kuniharu; Javey, Ali

    2016-06-01

    Printing technologies offer large-area, high-throughput production capabilities for electronics and sensors on mechanically flexible substrates that can conformally cover different surfaces. These capabilities enable a wide range of new applications such as low-cost disposable electronics for health monitoring and wearables, extremely large format electronic displays, interactive wallpapers, and sensing arrays. Solution-processed carbon nanotubes have been shown to be a promising candidate for such printing processes, offering stable devices with high performance. Here, recent progress made in printed carbon nanotube electronics is discussed in terms of materials, processing, devices, and applications. Research challenges and opportunities moving forward from processing and system-level integration points of view are also discussed for enabling practical applications.

  19. Small Diameter Few- Walled Carbon Nanotubes: An Alternative for Single Walled nanotubes in Bulk Applications

    Institute of Scientific and Technical Information of China (English)

    Jie Liu

    2005-01-01

    @@ 1Introduction Although Single walled carbon nanotubes have shown tremendous potential in many applications due to their unique electrical and mechanical properties, the lack of a large scale synthesis method at low cost is still the main limiting factor for the realization of the full potential of this unique materials. On the other hand, multiwalled carbon nanotubes are being made in tons per year quantity and found their application in conducting plastic and other bulk applications.

  20. Carbon nanotubes enhanced the lead toxicity on the freshwater fish

    Science.gov (United States)

    Martinez, D. S. T.; Alves, O. L.; Barbieri, E.

    2013-04-01

    Carbon nanotubes are promising nanostructures for many applications in materials industry and biotechnology. However, it is mandatory to evaluate their toxicity and environmental implications. We evaluated nitric acid treated multiwalled carbon nanotubes (HNO3-MWCNT) toxicity in Nile tilapia (Oreochromis niloticus) and also the lead (Pb) toxicity modulation after the nanotube interaction. Industrial grade multiwalled carbon nanotubes [Ctube 100, CNT Co. Ltd] were treated with 9M HNO3 for 12h at 150°C to generate oxygenated groups on the nanotube surface, to improve water dispersion and heavy metal interaction. The HNO3-treated multiwalled carbon nanotubes were physico-chemically characterized by several techniques [e.g. TEM, FE-SEM, TGA, ζ-potential and Raman spectroscopy]. HNO3-MWCNT did not show toxicity on Nile tilapia when the concentration ranged from 0.1 to 3.0 mg/L, and the maximum exposure time was 96h. After 24, 48, 72 and 96h the LC50 values of Pb were 1.65, 1.32, 1.10 and 0.99 mg/L, respectively. To evaluate the Pb-nanotube interaction influence on the ecotoxicity, we submitted the Nile tilapia to different concentrations of Pb mixed with a non-toxic concentration of HNO3-MWCNT (1.0 mg/L). After 24, 48, 72, 96 h the LC50 values of Pb plus nanotubes were: 0.32, 0.25, 0.20, 0.18 mg/L, respectively. These values showed a synergistic effect after Pb-nanotube interaction since Pb toxicity increased over five times. X-ray energy dispersive spectroscopy (EDS) was used to confirm lead adsorption on the carbon nanotube oxidized surface. The exposure of Nile tilapia to Pb plus HNO3-MWCNT caused both oxygen consumption and ammonium excretion decrease, when compared to the control. Finally, our results show that carbon nanotubes interact with classical pollutants drawing attention to the environmental implications.

  1. Photoluminescence Study of Carbon Nanotubes

    OpenAIRE

    Han, H. X.; Li, G. H.; Ge, W. K.; Wang, Z. P.; Xu, Z. Y.; Xie, S. S.; Chang, B H; Sun, L. F.; Wang, B S; G. Xu; Su, Z.B.

    2000-01-01

    ultiwalled carbon nanotubes, prepared by both electric arc discharge and chemical vapor deposition methods, show a strong visible light emission in photoluminescence experiments. All the samples employed in the experiments exhibit nearly same super-linear intensity dependence of the emission bands on the excitation intensity, and negligible temperature dependence of the central position and the line shapes of the emission bands. Based upon theoretical analysis of the electronic band structure...

  2. Photonics based on carbon nanotubes

    OpenAIRE

    Gu, Qingyuan; Gicquel-Guézo, Maud; Loualiche, Slimane; Pouliquen, Julie Le; Batte, Thomas; Folliot, Hervé; Dehaese, Olivier; Grillot, Frederic; Battie, Yann; Loiseau, Annick; Liang, Baolai; Huffaker, Diana

    2013-01-01

    Among direct-bandgap semiconducting nanomaterials, single-walled carbon nanotubes (SWCNT) exhibit strong quasi-one-dimensional excitonic optical properties, which confer them a great potential for their integration in future photonics devices as an alternative solution to conventional inorganic semiconductors. In this paper, we will highlight SWCNT optical properties for passive as well as active applications in future optical networking. For passive applications, we directly compare the effi...

  3. Measurement of nanotube content in pyrolytically generated carbon soot

    OpenAIRE

    Coleman, Jonathan; Blau, Werner; DRURY, ANNA

    2000-01-01

    PUBLISHED Carbon nanotubes can be efficiently separated from impurity material in carbon soot using a conjugated polymer filtration system as monitored by EPR, allowing the calculation of purity of the crude carbon soot. The authors wish to thank the Irish Higher Educational Authority for partly funding this work.

  4. Nondestructive Evaluation Techniques for Development and Characterization of Carbon Nanotube Based Superstructures

    Science.gov (United States)

    Wincheski, Buzz; Kim, Jae-Woo; Sauti, Godfrey; Wainwright, Elliot; Williams, Phillip; Siochi, Emile J.

    2014-01-01

    Recently, multiple commercial vendors have developed capability for the production of large-scale quantities of high-quality carbon nanotube sheets and yarns. While the materials have found use in electrical shielding applications, development of structural systems composed of a high volume fraction of carbon nanotubes is still lacking. A recent NASA program seeks to address this by prototyping a structural nanotube composite with strength-toweight ratio exceeding current state-of-the-art carbon fiber composites. Commercially available carbon nanotube sheets, tapes, and yarns are being processed into high volume fraction carbon nanotube-polymer nanocomposites. Nondestructive evaluation techniques have been applied throughout this development effort for material characterization and process control. This paper will report on the progress of these efforts, including magnetic characterization of residual catalyst content, Raman scattering characterization of nanotube diameter, defect ratio, and nanotube strain, and polarized Raman scattering for characterization of nanotube alignment.

  5. Cytocompatibility studies of vertically-aligned multi-walled carbon nanotubes: Raw material and functionalized by oxygen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, A.O., E-mail: loboao@yahoo.com [Laboratorio Associado de Sensores e Materiais, INPE, Sao Jose dos Campos/SP (Brazil); Instituto Tecnologico de Aeronautica, ITA, Sao Jose dos Campos/SP (Brazil); Laboratorio de Nanotecnologia Biomedica, Universidade do Vale do Paraiba, Sao Jose dos Campos/SP (Brazil); Corat, M.A.F. [Centro Multidisciplinar para Investigacao Biologica na Area da Ciencia em Animais de Laboratorio, CEMIB, UNICAMP, Campinas/SP (Brazil); Antunes, E.F. [Laboratorio Associado de Sensores e Materiais, INPE, Sao Jose dos Campos/SP (Brazil); Instituto Tecnologico de Aeronautica, ITA, Sao Jose dos Campos/SP (Brazil); Ramos, S.C. [Instituto Tecnologico de Aeronautica, ITA, Sao Jose dos Campos/SP (Brazil); Pacheco-Soares, C. [Laboratorio de Dinamica de Compartimentos Celulares, UNIVAP, Sao Jose dos Campos/SP (Brazil); and others

    2012-05-01

    It was presented a strong difference on cell adhesion and proliferation of functionalized vertically-aligned multi-walled carbon nanotube (VACNT) scaffolds compared to raw-VACNT. Biocompatibility in vitro tests were performed on raw-VACNT after superficial modification by oxygen plasma, which changes its superhydrophobic character to superhydrophilic. Two cytocompatibility tests were applied: 1) total lactate dehydrogenase colorimetric assay for the study of proliferating cells; and 2) cellular adhesion by scanning electron microscopy. Results showed that superhydrophilic VACNT scaffolds stimulate cell growth with proliferation up to 70% higher than normal growth of cell culture.

  6. Membranes with functionalized carbon nanotube pores for selective transport

    Energy Technology Data Exchange (ETDEWEB)

    Bakajin, Olgica; Noy, Aleksandr; Fornasiero, Francesco; Park, Hyung Gyu; Holt, Jason K; Kim, Sangil

    2015-01-27

    Provided herein composition and methods for nanoporous membranes comprising single walled, double walled, or multi-walled carbon nanotubes embedded in a matrix material. Average pore size of the carbon nanotube can be 6 nm or less. These membranes are a robust platform for the study of confined molecular transport, with applications in liquid and gas separations and chemical sensing including desalination, dialysis, and fabric formation.

  7. Carbon Nanotube Electrodes for Effective Interfacing with Retinal Tissue

    OpenAIRE

    Shoval, Asaf; Adams, Christopher; David-Pur, Moshe; Shein, Mark; Hanein, Yael; Sernagor, Evelyne

    2009-01-01

    We have investigated the use of carbon nanotube coated microelectrodes as an interface material for retinal recording and stimulation applications. Test devices were micro-fabricated and consisted of 60, 30 μm diameter electrodes at spacing of 200 μm. These electrodes were coated via chemical vapor deposition of carbon nanotubes, resulting in conducting, three dimensional surfaces with a high interfacial area. These attributes are important both for the quality of the cell-surface coupling as...

  8. Carbon nanotube electrodes for effective interfacing with retinal tissue

    OpenAIRE

    Asaf Shoval; Christopher Adams; Moshe David-Pur; MArk Shein; Yael Hanein; Evelyne Sernagor

    2009-01-01

    We have investigated the use of carbon nanotube microelectrodes as an interface material for retinal recording and stimulation applications. Test devices were micro-fabricated and consisted of 60 pristine 30 um electrodes coated with chemical vapor deposited carbon nanotubes, resulting in conducting, three dimensional surfaces with a high effective interfacial area. These attributes are important both for the quality of the cell-surface coupling as well as for electro-chemical interfacing eff...

  9. LDRD final report on carbon nanotube composites

    Energy Technology Data Exchange (ETDEWEB)

    Cahill, P.A.; Rand, P.B.

    1997-04-01

    Carbon nanotubes and their composites were examined using computational and experimental techniques in order to modify the mechanical and electrical properties of resins. Single walled nanotubes were the focus of the first year effort; however, sufficient quantities of high purity single walled nanotubes could not be obtained for mechanical property investigations. The unusually high electrical conductivity of composites loaded with <1% of multiwalled nanotubes is useful, and is the focus of continuing, externally funded, research.

  10. Engineering carbon nanotubes and nanotube circuits using electrical breakdown.

    Science.gov (United States)

    Collins, P G; Arnold, M S; Avouris, P

    2001-04-27

    Carbon nanotubes display either metallic or semiconducting properties. Both large, multiwalled nanotubes (MWNTs), with many concentric carbon shells, and bundles or "ropes" of aligned single-walled nanotubes (SWNTs), are complex composite conductors that incorporate many weakly coupled nanotubes that each have a different electronic structure. Here we demonstrate a simple and reliable method for selectively removing single carbon shells from MWNTs and SWNT ropes to tailor the properties of these composite nanotubes. We can remove shells of MWNTs stepwise and individually characterize the different shells. By choosing among the shells, we can convert a MWNT into either a metallic or a semiconducting conductor, as well as directly address the issue of multiple-shell transport. With SWNT ropes, similar selectivity allows us to generate entire arrays of nanoscale field-effect transistors based solely on the fraction of semiconducting SWNTs.

  11. Production and Characterization of Carbon Nanotubes and Nanotube-Based Composites

    Science.gov (United States)

    Nikolaev, Pavel; Arepalli, Sivaram; Holmes, William; Gorelik, Olga; Files, Brad; Scott, Carl; Santos, Beatrice; Mayeaux, Brian; Victor, Joe

    1999-01-01

    The Nobel Prize winning discovery of the Buckuball (C60) in 1985 at Rice University by a group including Dr. Richard Smalley led to the whole new class of carbon allotropes including fullerenes and nanotubes. Especially interesting from many viewpoints are single-walled carbon nanotubes, which structurally are like a single graphitic sheet wrapped around a cylinder and capped at the ends. This cylinders have diameter as small as 0.5 - 2 nm (1/100,000th the diameter of a human hair) and are as long as 0.1 - 1 mm. Nanotubes are really individual molecules and believed to be defect-free, leading to high tensile strength despite their low density. Additionally, these fibers exhibit electrical conductivity as high as copper, thermal conductivity as high as diamond, strength 100 times higher than steel at one-sixth the weight, and high strain to failure. Thus it is believed that developments in the field of nanotechnology will lead to stronger and lighter composite materials for next generation spacecraft. Lack of a bulk method of production is the primary reason nanotubes are not used widely today. Toward this goal JSC nanotube team is exploring three distinct production techniques: laser ablation, arc discharge and chemical vapor deposition (CVD, in collaboration with Rice University). In laser ablation technique high-power laser impinges on the piece of carbon containing small amount of catalyst, and nanotubes self-assemble from the resulting carbon vapor. In arc generator similar vapor is created in arc discharge between carbon electrodes with catalyst. In CVD method nanotubes grow at much lower temperature on small catalyst particles from carbon-containing feedstock gas (methane or carbon monoxide). As of now, laser ablation produces cleanest material, but mass yield is rather small. Arc discharge produces grams of material, but purity is low. CVD technique is still in baby steps, but preliminary results look promising, as well as perspective of scaling the process

  12. Frontiers of graphene and carbon nanotubes devices and applications

    CERN Document Server

    2015-01-01

    This book focuses on carbon nanotubes and graphene as representatives of nano-carbon materials, and describes the growth of new technology and applications of new devices. As new devices and as new materials, nano-carbon materials are expected to be world pioneers that could not have been realized with conventional semiconductor materials, and as those that extend the limits of conventional semiconductor performance. This book introduces the latest achievements of nano-carbon devices, processes, and technology growth. It is anticipated that these studies will also be pioneers in the development of future research of nano-carbon devices and materials. This book consists of 18 chapters. Chapters 1 to 8 describe new device applications and new growth methods of graphene, and Chapters 9 to 18, those of carbon nanotubes. It is expected that by increasing the advantages and overcoming the weak points of nanocarbon materials, a new world that cannot be achieved with conventional materials will be greatly expanded. W...

  13. Micromechanics of carbon nanotube turfs

    Science.gov (United States)

    Torabi, Hamid

    Complex structures consisting of intertwined, nominally vertical carbon nanotubes (CNTs) are called turfs. Unique electrical, thermal, optical, and permeability properties of these turfs have attracted growing attention during the past decade, and have rendered them as appropriate candidates for applications such as contact thermal switches. These properties are controlled by the details of the turf microstructures. Due to the application of the turfs in different fields, they are subjected to different loading conditions. Deformation changes the microstructure of a CNT turf, which results in change of effective properties. Many researchers have recently studied the collective mechanical behavior of CNT turfs to compression loading, as this behavior determines their performance. However, their complex and intertwined structure must be investigated in more details to find the relation between their deformation and their underlying morphology. Under uniform compression experiments, CNT turfs exhibit irreversible collective buckling of a layer preceded by reorientation of CNT segments. Experimentally observed independence of the buckling stress and the buckling wavelength on the turf width suggests the existence of an intrinsic material length. To investigate the relationship the macroscopic material properties and the statistical parameters describing the nano-scale geometry of the turf (tortuosity, density and connectivity) we develop a nano-scale computational model, based on the representation of CNT segments as elastica finite elements with van der Waals interactions. The virtual turfs are generated by means of a constrained random walk algorithm and subsequent relaxation. The resulting computational model is robust and is capable of modeling the collective behavior of CNTs. We first establish the dependence of statistical parameters on the computational parameters used for turf generation, then establish relationships between post-buckling stress, initial

  14. Multi-walled carbon nanotube-reinforced porous iron oxide as a superior anode material for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Xin-Jing; Zhang, Juan; Qi, Gong-Wei; Dai, Xiao-Hui; Zhou, Jun-Ping [School of Chemistry and Chemical Engineering, Shandong University, No. 27, Shanda Nan Rd., Jinan 250100 (China); Zhang, Shu-Yong, E-mail: syzhang@sdu.edu.cn [School of Chemistry and Chemical Engineering, Shandong University, No. 27, Shanda Nan Rd., Jinan 250100 (China); National Key Lab of Crystal, Shandong University, No. 27, Shanda Nan Rd., Jinan 250100 (China)

    2015-08-15

    Highlights: • Electrochemical performance of Fe{sub 3}O{sub 4} is improved by combining different approaches. • Porous Cu substrate is used to enlarge surface area and improve conductivity. • MWCNT is used to reinforce the electrode structure and change morphology of Fe{sub 3}O{sub 4}. • Reversible capacity, capacity retention and high-rate performance are improved. - Abstract: Multi-walled carbon nanotube-reinforced porous iron oxide (Fe{sub 3}O{sub 4}/MWCNT) is synthesized by a two-step approach with porous Cu substrate serving as current collector. Porous Cu substrate is prepared through electroless deposition with hydrogen bubble serving as template. Fe{sub 3}O{sub 4}/MWCNT composites are prepared by the electrodeposition of Fe{sub 3}O{sub 4} in the presence of dispersed MWCNTs from a Fe{sub 2}(SO{sub 4}){sub 3} solution with MWCNT suspension. Results showed that Fe{sub 3}O{sub 4} forms granular nanoparticles on the porous Cu substrate with several MWCNTs embedded in it. Adding MWCNTs changes the morphology of Fe{sub 3}O{sub 4}. Smooth Fe{sub 3}O{sub 4}, smooth Fe{sub 3}O{sub 4}/MWCNT, and porous Fe{sub 3}O{sub 4} composites are also prepared for comparison. When used as anode materials, porous Fe{sub 3}O{sub 4}/MWCNT composites have a reversible capacity of approximately 601 mA h g{sup −1} at the 60th cycle at a cycling rate of 100 mA g{sup −1}. This value is higher than that of the other materials. The reversible capacity at a cycling rate of 10,000 mA g{sup −1} is approximately 50% of that at 100 mA g{sup −1}. Therefore, the MWCNT-reinforced porous Fe{sub 3}O{sub 4} composite exhibits much better reversible capacity, capacity retention, and high-rate performance than the other samples. This finding can be ascribed to the porous structure of Fe{sub 3}O{sub 4}, better conductivity of porous Cu substrate and MWCNTs, and the morphology change of Fe{sub 3}O{sub 4} nanoparticles upon the addition of MWCNTs.

  15. Carbon nanotube scaffolds with controlled porosity as electromagnetic absorbing materials in the gigahertz range.

    Science.gov (United States)

    González, M; Crespo, M; Baselga, J; Pozuelo, J

    2016-05-19

    Control of the microscopic structure of CNT nanocomposites allows modulation of the electromagnetic shielding in the gigahertz range. The porosity of CNT scaffolds has been controlled by two freezing protocols and a subsequent lyophilization step: fast freezing in liquid nitrogen and slow freezing at -20 °C. Mercury porosimetry shows that slowly frozen specimens present a more open pore size (100-150 μm) with a narrow distribution whereas specimens frozen rapidly show a smaller pore size and a heterogeneous distribution. 3D-scaffolds containing 3, 4, 6 and 7% CNT were infiltrated with epoxy and specimens with 2, 5 and 8 mm thicknesses were characterized in the GHz range. Samples with the highest pore size and porosity presented the lowest reflected power (about 30%) and the highest absorbed power (about 70%), which allows considering them as electromagnetic radiation absorbing materials. PMID:27152472

  16. Dielectrophoretic assembly of carbon nanotube devices

    DEFF Research Database (Denmark)

    Dimaki, Maria

    The purpose of this project has been to assemble single-walled carbon nanotubes on electrodes at the tip of a biocompatible cantilever and use these for chemical species sensing in air and liquid, for example in order to measure the local activity from ion channels in the cell membrane....... The electrical resistance of carbon nanotubes has been shown to be extremely sensitive to gas molecules. Dielectrophoresis is a method capable of quickly attracting nanotubes on microelectrodes by using an electric field, thus enabling nanotube integration in microsystems. Dielectrophoresis offers also...... the potential of distinguishing between nanotubes of different electrical properties, which is very important for the optimisation of the properties of the carbon nanotube sensors. Various cantilever and planar structures were designed, fabricated and tested both with multi-walled and single-walled carbon...

  17. Study of Carbon Nanotube-Substrate Interaction

    Directory of Open Access Journals (Sweden)

    Jaqueline S. Soares

    2012-01-01

    Full Text Available Environmental effects are very important in nanoscience and nanotechnology. This work reviews the importance of the substrate in single-wall carbon nanotube properties. Contact with a substrate can modify the nanotube properties, and such interactions have been broadly studied as either a negative aspect or a solution for developing carbon nanotube-based nanotechnologies. This paper discusses both theoretical and experimental studies where the interaction between the carbon nanotubes and the substrate affects the structural, electronic, and vibrational properties of the tubes.

  18. Carbon nanotube scaffolds with controlled porosity as electromagnetic absorbing materials in the gigahertz range

    Science.gov (United States)

    González, M.; Crespo, M.; Baselga, J.; Pozuelo, J.

    2016-05-01

    Control of the microscopic structure of CNT nanocomposites allows modulation of the electromagnetic shielding in the gigahertz range. The porosity of CNT scaffolds has been controlled by two freezing protocols and a subsequent lyophilization step: fast freezing in liquid nitrogen and slow freezing at -20 °C. Mercury porosimetry shows that slowly frozen specimens present a more open pore size (100-150 μm) with a narrow distribution whereas specimens frozen rapidly show a smaller pore size and a heterogeneous distribution. 3D-scaffolds containing 3, 4, 6 and 7% CNT were infiltrated with epoxy and specimens with 2, 5 and 8 mm thicknesses were characterized in the GHz range. Samples with the highest pore size and porosity presented the lowest reflected power (about 30%) and the highest absorbed power (about 70%), which allows considering them as electromagnetic radiation absorbing materials.Control of the microscopic structure of CNT nanocomposites allows modulation of the electromagnetic shielding in the gigahertz range. The porosity of CNT scaffolds has been controlled by two freezing protocols and a subsequent lyophilization step: fast freezing in liquid nitrogen and slow freezing at -20 °C. Mercury porosimetry shows that slowly frozen specimens present a more open pore size (100-150 μm) with a narrow distribution whereas specimens frozen rapidly show a smaller pore size and a heterogeneous distribution. 3D-scaffolds containing 3, 4, 6 and 7% CNT were infiltrated with epoxy and specimens with 2, 5 and 8 mm thicknesses were characterized in the GHz range. Samples with the highest pore size and porosity presented the lowest reflected power (about 30%) and the highest absorbed power (about 70%), which allows considering them as electromagnetic radiation absorbing materials. Electronic supplementary information (ESI) available: Scheme of hydrogenated derivative of diglycidyl ether of bisphenol-A (HDGEBA) and m-xylylenediamine; X-ray diffractograms of pristine CNT

  19. Carbon nanotube based pressure sensor for flexible electronics

    Energy Technology Data Exchange (ETDEWEB)

    So, Hye-Mi [Department of Nano Mechanics, Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials, Daejeon 305-343 (Korea, Republic of); Sim, Jin Woo [Advanced Nano Technology Ltd., Seoul 132-710 (Korea, Republic of); Kwon, Jinhyeong [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); Yun, Jongju; Baik, Seunghyun [SKKU Advanced Institute of Nanotechnology (SAINT), Department of Energy Science and School of Mechanical Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Chang, Won Seok, E-mail: paul@kimm.re.kr [Department of Nano Mechanics, Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials, Daejeon 305-343 (Korea, Republic of)

    2013-12-15

    Highlights: • The electromechanical change of vertically aligned carbon nanotubes. • Fabrication of CNT field-effect transistor on flexible substrate. • CNT based FET integrated active pressure sensor. • The integrated device yields an increase in the source-drain current under pressure. - Abstract: A pressure sensor was developed based on an arrangement of vertically aligned carbon nanotubes (VACNTs) supported by a polydimethylsiloxane (PDMS) matrix. The VACNTs embedded in the PDMS matrix were structurally flexible and provided repeated sensing operation due to the high elasticities of both the polymer and the carbon nanotubes (CNTs). The conductance increased in the presence of a loading pressure, which compressed the material and induced contact between neighboring CNTs, thereby producing a dense current path and better CNT/metal contacts. To achieve flexible functional electronics, VACNTs based pressure sensor was integrated with field-effect transistor, which is fabricated using sprayed semiconducting carbon nanotubes on plastic substrate.

  20. Synthesis of carbon nanotubes with Ni/CNTs catalyst

    Institute of Scientific and Technical Information of China (English)

    LI; Chunhua; (李春华); YAO; Kefu; (姚可夫); RUAN; Dianbo; (阮殿波); LIANG; Ji; (梁; 吉); XU; Cailu; (徐才录); WU; Dehai; (吴德海)

    2003-01-01

    Carbon nanotubes (CNTs), owing to their large specific area, good chemical stability and modifiable surface properties after acidic or basic treatment, can be used as catalytic support materials. In this paper, the activities and selectivities of two catalysts, i. e. Ni catalyst supported by carbon nanotubes (Ni/CNTs) and that supported by diatomite (Ni/SiO2), are compared. It is found that the quality of the carbon nanotubes synthesized by the two catalysts is similar, but the yield of the former is 1.5 times higher than that of the latter. The excellent performance of the Ni/CNTs catalyst should be ascribed to the larger specific surface area and proper pore distribution and the structure of the carbon nanotube support.

  1. Amorphous Carbon-Boron Nitride Nanotube Hybrids

    Science.gov (United States)

    Kim, Jae Woo (Inventor); Siochi, Emilie J. (Inventor); Wise, Kristopher E. (Inventor); Lin, Yi (Inventor); Connell, John (Inventor)

    2016-01-01

    A method for joining or repairing boron nitride nanotubes (BNNTs). In joining BNNTs, the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures. In repairing BNNTs, the damaged site of the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures at the damage site.

  2. Multi-walled carbon nanotubes act as charge transport channel to boost the efficiency of hole transport material free perovskite solar cells

    Science.gov (United States)

    Cheng, Nian; Liu, Pei; Qi, Fei; Xiao, Yuqin; Yu, Wenjing; Yu, Zhenhua; Liu, Wei; Guo, Shi-Shang; Zhao, Xing-Zhong

    2016-11-01

    The two-step spin coating process produces rough perovskite surfaces in ambient condition with high humidity, which are unfavorable for the contact between the perovskite film and the low temperature carbon electrode. To tackle this problem, multi-walled carbon nanotubes (MWCNTs) are embedded into the perovskite layer. The MWCNTs can act as charge transport high way between individual perovskite nanoparticles and facilitate the collection of the photo-generated holes by the carbon electrode. Longer carrier lifetime is confirmed in the perovskite solar cells with addition of MWCNTs using open circuit voltage decay measurement. Under optimized concentration of MWCNT, average power conversion efficiency of 11.6% is obtained in hole transport material free perovskite solar cells, which is boosted by ∼15% compared to solar cells without MWCNT.

  3. Glucose oxidase immobilization onto carbon nanotube networking

    CERN Document Server

    Karachevtsev, V A; Zarudnev, E S; Karachevtsev, M V; Leontiev, V S; Linnik, A S; Lytvyn, O S; Plokhotnichenko, A M; Stepanian, S G

    2012-01-01

    When elaborating the biosensor based on single-walled carbon nanotubes (SWNTs), it is necessary to solve such an important problem as the immobilization of a target biomolecule on the nanotube surface. In this work, the enzyme (glucose oxidase (GOX)) was immobilized on the surface of a nanotube network, which was created by the deposition of nanotubes from their solution in 1,2-dichlorobenzene by the spray method. 1-Pyrenebutanoic acid succinimide ester (PSE) was used to form the molecular interface, the bifunctional molecule of which provides the covalent binding with the enzyme shell, and its other part (pyrene) is adsorbed onto the nanotube surface. First, the usage of such a molecular interface leaves out the direct adsorption of the enzyme (in this case, its activity decreases) onto the nanotube surface, and, second, it ensures the enzyme localization near the nanotube. The comparison of the resonance Raman (RR) spectrum of pristine nanotubes with their spectrum in the PSE environment evidences the creat...

  4. In silico assembly and nanomechanical characterization of carbon nanotube buckypaper.

    Science.gov (United States)

    Cranford, Steven W; Buehler, Markus J

    2010-07-01

    Carbon nanotube sheets or films, also known as 'buckypaper', have been proposed for use in actuating, structural and filtration systems, based in part on their unique and robust mechanical properties. Computational modeling of such a fibrous nanostructure is hindered by both the random arrangement of the constituent elements as well as the time- and length-scales accessible to atomistic level molecular dynamics modeling. Here we present a novel in silico assembly procedure based on a coarse-grain model of carbon nanotubes, used to attain a representative mesoscopic buckypaper model that circumvents the need for probabilistic approaches. By variation in assembly parameters, including the initial nanotube density and ratio of nanotube type (single- and double-walled), the porosity of the resulting buckypaper can be varied threefold, from approximately 0.3 to 0.9. Further, through simulation of nanoindentation, the Young's modulus is shown to be tunable through manipulation of nanotube type and density over a range of approximately 0.2-3.1 GPa, in good agreement with experimental findings of the modulus of assembled carbon nanotube films. In addition to carbon nanotubes, the coarse-grain model and assembly process can be adapted for other fibrous nanostructures such as electrospun polymeric composites, high performance nonwoven ballistic materials, or fibrous protein aggregates, facilitating the development and characterization of novel nanomaterials and composites as well as the analysis of biological materials such as protein fiber films and bulk structures.

  5. Suspended carbon nanotubes coupled to superconducting circuits

    NARCIS (Netherlands)

    Schneider, B.H.

    2014-01-01

    Carbon nanotubes are unique candidates to study quantum mechanical properties of a nanomechanical resonator. However to access this quantum regime, present detectors are not yet sensitive enough. In this thesis we couple a carbon nanotube CNT mechanical resonator to a superconducting circuit which i

  6. Fast Electromechanical Switches Based on Carbon Nanotubes

    Science.gov (United States)

    Kaul, Anupama; Wong, Eric; Epp, Larry

    2008-01-01

    Electrostatically actuated nanoelectromechanical switches based on carbon nanotubes have been fabricated and tested in a continuing effort to develop high-speed switches for a variety of stationary and portable electronic equipment. As explained below, these devices offer advantages over electrostatically actuated microelectromechanical switches, which, heretofore, have represented the state of the art of rapid, highly miniaturized electromechanical switches. Potential applications for these devices include computer memories, cellular telephones, communication networks, scientific instrumentation, and general radiation-hard electronic equipment. A representative device of the present type includes a single-wall carbon nanotube suspended over a trench about 130 nm wide and 20 nm deep in an electrically insulating material. The ends of the carbon nanotube are connected to metal electrodes, denoted the source and drain electrodes. At bottom of the trench is another metal electrode, denoted the pull electrode (see figure). In the off or open switch state, no voltage is applied, and the nanotube remains out of contact with the pull electrode. When a sufficiently large electric potential (switching potential) is applied between the pull electrode and either or both of the source and drain electrodes, the resulting electrostatic attraction bends and stretches the nanotube into contact with the pull electrode, thereby putting the switch into the "on" or "closed" state, in which substantial current (typically as much as hundreds of nanoamperes) is conducted. Devices of this type for use in initial experiments were fabricated on a thermally oxidized Si wafer, onto which Nb was sputter-deposited for use as the pull-electrode layer. Nb was chosen because its refractory nature would enable it to withstand the chemical and thermal conditions to be subsequently imposed for growing carbon nanotubes. A 200- nm-thick layer of SiO2 was formed on top of the Nb layer by plasma

  7. Investigation on the Mechanical Properties of a Cement-Based Material Containing Carbon Nanotube under Drying and Freeze-Thaw Conditions

    Directory of Open Access Journals (Sweden)

    Wei-Wen Li

    2015-12-01

    Full Text Available This paper aimed to explore the mechanical properties of a cement-based material with carbon nanotube (CNT under drying and freeze-thaw environments. Mercury Intrusion Porosimetry and Scanning Electron Microscopy were used to analyze the pore structure and microstructure of CNT/cement composite, respectively. The experimental results showed that multi-walled CNT (MWCNT could improve to different degrees the mechanical properties (compressive and flexural strengths and physical performances (shrinkage and water loss of cement-based materials under drying and freeze-thaw conditions. This paper also demonstrated that MWCNT could interconnect hydration products to enhance the performance of anti-microcracks for cement-based materials, as well as the density of materials due to CNT’s filling action.

  8. Computational Aspects of Carbon and Boron Nanotubes

    Directory of Open Access Journals (Sweden)

    Paul Manuel

    2010-11-01

    Full Text Available Carbon hexagonal nanotubes, boron triangular nanotubes and boron a-nanotubes are a few popular nano structures. Computational researchers look at these structures as graphs where each atom is a node and an atomic bond is an edge. While researchers are discussing the differences among the three nanotubes, we identify the topological and structural similarities among them. We show that the three nanotubes have the same maximum independent set and their matching ratios are independent of the number of columns. In addition, we illustrate that they also have similar underlying broadcasting spanning tree and identical communication behavior.

  9. Liquid surface model for carbon nanotube energetics

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Mathew, Maneesh; Solov'yov, Andrey V.;

    2008-01-01

    In the present paper we developed a model for calculating the energy of single-wall carbon nanotubes of arbitrary chirality. This model, which we call as the liquid surface model, predicts the energy of a nanotube with relative error less than 1% once its chirality and the total number of atoms...... an important insight in the energetics and stability of nanotubes of different chirality and might be important for the understanding of nanotube growth process. For the computations we use empirical Brenner and Tersoff potentials and discuss their applicability to the study of carbon nanotubes. From...... the calculated energies we determine the elastic properties of the single-wall carbon nanotubes (Young modulus, curvature constant) and perform a comparison with available experimental measurements and earlier theoretical predictions....

  10. Studies of DNA-carbon nanotube interactions

    Science.gov (United States)

    Hughes, Mary Elizabeth

    2008-10-01

    Recently a new biomaterial consisting of a DNA-wrapped single-walled carbon nanotube, and known as a DNA/SWNT, has been discovered. The possible applications of this hybrid are varied and range from genomic sequencing to nanoscale electronics to molecular delivery. The realization of these potential applications requires more knowledge about the microscopic properties of this material. In this thesis, I present studies of: the orientation of nucleobases on the nanotube sidewall; the sequence and length dependence of the DNA-nanotube interaction; and solution conditions to manipulate the DNA/SWNT hybrid. The measurement of the UV optical absorbance of DNA/SWNT and the nucleotide absorbance from DNA/SWNT provide the first experimental confirmation that DNA binds to nanotubes through pi-stacking. Because the hypochromic absorbance typical of pi-stacked structures are expected to occur primarily for DNA dipole transitions that lie along the axis of the optically anisotropic SWNTs, the absorbance changes following binding of DNA to the nanotubes reveals the preferred orientation assumed by each of the four bound nucleotides with respect to the nanotube's long axis. The first observations of pronounced sequence- and length-dependent variations in the binding between ssDNA and SWNTs in aqueous solution are presented. These observations rely on the discovery that there exists a range of DNA lengths able to hybridize with SWNTs that can nevertheless be dissociated at temperatures below the boiling point of water. Quantitative results comparing the isochronal dissociation temperatures and binding energies of DNA/SWNT composed of differing DNA sequences and lengths are given. These results indicate variability and complexity in the binding mechanism responsible for the stability of the hybrid system that transcends simple models based on the sum of independent base-nanotube interactions. Binding energies between a DNA base and nanotube (0.05 to 0.09 eV per base) are similar

  11. Improved synthesis of carbon nanotubes with junctions and of single-walled carbon nanotubes

    Indian Academy of Sciences (India)

    F L Deepak; A Govindaraj; C N R Rao

    2006-01-01

    Pyrolysis of thiophene over nickel nanoparticles dispersed on silica is shown to yield Yjunction carbon nanotubes with smaller diameters than those obtained by the pyrolysis of organometallicthiophene mixtures. In the presence of water vapour, the pyrolysis of organometallic-hydrocarbon mixtures yields single-walled nanotubes, as well as relatively narrow-diameter carbon nanotubes with Y-junctions. Pyrolysis of organometallic-hydrocarbon mixtures, in the absence of water vapour, only gives nanotubes with T- and Y-junctions.

  12. Field emission from hybrid diamond-like carbon and carbon nanotube composite structures.

    Science.gov (United States)

    Zanin, H; May, P W; Hamanaka, M H M O; Corat, E J

    2013-12-11

    A thin diamond-like carbon (DLC) film was deposited onto a densely packed "forest" of vertically aligned multiwalled carbon nanotubes (VACNT). DLC deposition caused the tips of the CNTs to clump together to form a microstructured surface. Field-emission tests of this new composite material show the typical low threshold voltages for carbon nanotube structures (2 V μm(-1)) but with greatly increased emission current, better stability, and longer lifetime. PMID:24224845

  13. Carbon nanotube growth density control

    Science.gov (United States)

    Delzeit, Lance D. (Inventor); Schipper, John F. (Inventor)

    2010-01-01

    Method and system for combined coarse scale control and fine scale control of growth density of a carbon nanotube (CNT) array on a substrate, using a selected electrical field adjacent to a substrate surface for coarse scale density control (by one or more orders of magnitude) and a selected CNT growth temperature range for fine scale density control (by multiplicative factors of less than an order of magnitude) of CNT growth density. Two spaced apart regions on a substrate may have different CNT growth densities and/or may use different feed gases for CNT growth.

  14. Multiwalled Carbon nanotube - Strength to polymer composite

    Science.gov (United States)

    Pravin, Jagdale; Khan, Aamer. A.; Massimo, Rovere; Carlo, Rosso; Alberto, Tagliaferro

    2016-02-01

    Carbon nanotubes (CNTs), a rather fascinating material, are among the pillars of nanotechnology. CNTs exhibit unique electrical, mechanical, adsorption, and thermal properties with high aspect ratio, exceptional stiffness, excellent strength, and low density, which can be exploited in the manufacturing of revolutionary smart nano composite materials. The demand for lighter and stronger polymer composite material in various applications is increasing every day. Among all the possibilities to research and exploit the exceptional properties of CNTs in polymer composites we focused on the reinforcement of epoxy resin with different types of multiwalled carbon nano tubes (MWCNTs). We studied mechanical properties such as stress, strain, ultimate tensile strength, yield point, modulus and fracture toughness, and Young's modulus by plotting and calculating by means of the off-set method. The mechanical strength of epoxy composite is increased intensely with 1 and 3 wt.% of filler.

  15. Nitrogen-Doped Carbon Nanotube/Graphite Felts as Advanced Electrode Materials for Vanadium Redox Flow Batteries.

    Science.gov (United States)

    Wang, Shuangyin; Zhao, Xinsheng; Cochell, Thomas; Manthiram, Arumugam

    2012-08-16

    Nitrogen-doped carbon nanotubes have been grown, for the first time, on graphite felt (N-CNT/GF) by a chemical vapor deposition approach and examined as an advanced electrode for vanadium redox flow batteries (VRFBs). The unique porous structure and nitrogen doping of N-CNT/GF with increased surface area enhances the battery performance significantly. The enriched porous structure of N-CNTs on graphite felt could potentially facilitate the diffusion of electrolyte, while the N-doping could significantly contribute to the enhanced electrode performance. Specifically, the N-doping (i) modifies the electronic properties of CNT and thereby alters the chemisorption characteristics of the vanadium ions, (ii) generates defect sites that are electrochemically more active, (iii) increases the oxygen species on CNT surface, which is a key factor influencing the VRFB performance, and (iv) makes the N-CNT electrochemically more accessible than the CNT. PMID:26295765

  16. Nitrogen-Doped Carbon Nanotube/Graphite Felts as Advanced Electrode Materials for Vanadium Redox Flow Batteries.

    Science.gov (United States)

    Wang, Shuangyin; Zhao, Xinsheng; Cochell, Thomas; Manthiram, Arumugam

    2012-08-16

    Nitrogen-doped carbon nanotubes have been grown, for the first time, on graphite felt (N-CNT/GF) by a chemical vapor deposition approach and examined as an advanced electrode for vanadium redox flow batteries (VRFBs). The unique porous structure and nitrogen doping of N-CNT/GF with increased surface area enhances the battery performance significantly. The enriched porous structure of N-CNTs on graphite felt could potentially facilitate the diffusion of electrolyte, while the N-doping could significantly contribute to the enhanced electrode performance. Specifically, the N-doping (i) modifies the electronic properties of CNT and thereby alters the chemisorption characteristics of the vanadium ions, (ii) generates defect sites that are electrochemically more active, (iii) increases the oxygen species on CNT surface, which is a key factor influencing the VRFB performance, and (iv) makes the N-CNT electrochemically more accessible than the CNT.

  17. Multiwalled carbon nanotubes as a sorbent material for the solid phase extraction of lead from urine and subsequent determination by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Peña Crecente, Rosa M.; Lovera, Carlha Gutiérrez; García, Julia Barciela; Méndez, Jennifer Álvarez; Martín, Sagrario García; Latorre, Carlos Herrero, E-mail: carlos.herrero@usc.es

    2014-11-01

    The determination of lead in urine is a way of monitoring the chemical exposure to this metal. In the present paper, a new method for the Pb determination by electrothermal atomic absorption spectrometry (ETAAS) in urine at low levels has been developed. Lead was separated from the undesirable urine matrix by means of a solid phase extraction (SPE) procedure. Oxidized multiwalled carbon nanotubes have been used as a sorbent material. Lead from urine was retained at pH 4.0 and was quantitatively eluted using a 0.7 M nitric acid solution and was subsequently measured by ETAAS. The effects of parameters that influence the adsorption–elution process (such as pH, eluent volume and concentration, sampling and elution flow rates) and the atomic spectrometry conditions have been studied by means of different factorial design strategies. Under the optimized conditions, the detection and quantification limits obtained were 0.08 and 0.26 μg Pb L{sup −1}, respectively. The results demonstrate the absence of a urine matrix effect and this is the consequence of the SPE process carried out. Therefore, the developed method is useful for the analysis of Pb at low levels in real samples without the influence of other urine components. The proposed method was applied to the determination of lead in urine samples of unexposed healthy people and satisfactory results were obtained (in the range 3.64–22.9 μg Pb L{sup −1}). - Highlights: • Lead determination in urine using a solid phase extraction procedure followed by ETAAS • Carbon nanotubes as SPE adsorbent for Pb in urine • Matrix elimination for the Pb determination in urine by using SPE based on carbon nanotubes • The detection limit was 0.08 μg Pb L{sup −1}.

  18. Multiwalled carbon nanotubes as a sorbent material for the solid phase extraction of lead from urine and subsequent determination by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The determination of lead in urine is a way of monitoring the chemical exposure to this metal. In the present paper, a new method for the Pb determination by electrothermal atomic absorption spectrometry (ETAAS) in urine at low levels has been developed. Lead was separated from the undesirable urine matrix by means of a solid phase extraction (SPE) procedure. Oxidized multiwalled carbon nanotubes have been used as a sorbent material. Lead from urine was retained at pH 4.0 and was quantitatively eluted using a 0.7 M nitric acid solution and was subsequently measured by ETAAS. The effects of parameters that influence the adsorption–elution process (such as pH, eluent volume and concentration, sampling and elution flow rates) and the atomic spectrometry conditions have been studied by means of different factorial design strategies. Under the optimized conditions, the detection and quantification limits obtained were 0.08 and 0.26 μg Pb L−1, respectively. The results demonstrate the absence of a urine matrix effect and this is the consequence of the SPE process carried out. Therefore, the developed method is useful for the analysis of Pb at low levels in real samples without the influence of other urine components. The proposed method was applied to the determination of lead in urine samples of unexposed healthy people and satisfactory results were obtained (in the range 3.64–22.9 μg Pb L−1). - Highlights: • Lead determination in urine using a solid phase extraction procedure followed by ETAAS • Carbon nanotubes as SPE adsorbent for Pb in urine • Matrix elimination for the Pb determination in urine by using SPE based on carbon nanotubes • The detection limit was 0.08 μg Pb L−1

  19. A comparative study of EMI shielding properties of carbon nanofiber and multi-walled carbon nanotube filled polymer composites.

    Science.gov (United States)

    Yang, Yonglai; Gupta, Mool C; Dudley, Kenneth L; Lawrence, Roland W

    2005-06-01

    Electromagnetic interference shielding properties of carbon nanofiber- and multi-walled carbon nanotube-filled polystyrene composites were investigated in the frequency range of 8.2-12.4 GHz (X-band). It was observed that the shielding effectiveness of composites was frequency independent, and increased with the increase of carbon nanofiber or nanotube loading. At the same filler loading, multi-walled carbon nanotube-filled polystyrene composites exhibited higher shielding effectiveness compared to those filled with carbon nanofibers. In particular, carbon nanotubes were more effective than nanofibers in providing high EMI shielding at low filler loadings. The experimental data showed that the shielding effectiveness of the composite containing 7 wt% carbon nanotubes could reach more than 26 dB, implying that such a composite can be used as a potential electromagnetic interference shielding material. The dominant shielding mechanism of carbon nanotube-filled polystyrene composites was also discussed. PMID:16060155

  20. Carbon nanotube and conducting polymer composites for supercapacitors

    Institute of Scientific and Technical Information of China (English)

    Chuang Peng; Shengwen Zhang; Daniel Jewell; George Z. Chen

    2008-01-01

    Composites of carbon nanotubes and conducting polymers can be prepared via chemical synthesis, electrochemical deposition on pre-formed carbon nanotube electrodes, or by electrochemical co-deposition. The composites combine the large pseudocapacitance of the conducting polymers with the fast charging/discharging double-layer capacitance and excellent mechanical properties of the carbon nanotubes. The electrochemically co-deposited composites are the most homogeneous and show an unusual interaction between thepolymer and nanotubes, giving rise to a strengthened electron delocalisation and conjugation along the polymer chains. As a result they exhibit excellent electrochemical charge storage properties and fast charge/discharge switching, making them promising electrode mate-rials for high power supercapacitors.

  1. Parameterizing A Surface Water Model for Multiwalled Carbon Nanotubes

    Science.gov (United States)

    The unique electronic, mechanical, and structural properties of carbon nanotubes (CNTs) has lead to increasing production of these versatile materials; currently, the use of carbon-based nanomaterials in consumer products is second only to that of nano-scale silver. Although ther...

  2. Carbon Nanotubes: Printed Carbon Nanotube Electronics and Sensor Systems (Adv. Mater. 22/2016).

    Science.gov (United States)

    Chen, Kevin; Gao, Wei; Emaminejad, Sam; Kiriya, Daisuke; Ota, Hiroki; Nyein, Hnin Yin Yin; Takei, Kuniharu; Javey, Ali

    2016-06-01

    Printed electronics and sensors enable new applications ranging from low-cost disposable analytical devices to large-area sensor networks. Recent progress in printed carbon nanotube electronics in terms of materials, processing, devices, and applications is discussed on page 4397 by A. Javey and co-workers. The research challenges and opportunities regarding the processing and system-level integration are also discussed for enabling of practical applications. PMID:27273439

  3. Carbon Nanotubes: Printed Carbon Nanotube Electronics and Sensor Systems (Adv. Mater. 22/2016).

    Science.gov (United States)

    Chen, Kevin; Gao, Wei; Emaminejad, Sam; Kiriya, Daisuke; Ota, Hiroki; Nyein, Hnin Yin Yin; Takei, Kuniharu; Javey, Ali

    2016-06-01

    Printed electronics and sensors enable new applications ranging from low-cost disposable analytical devices to large-area sensor networks. Recent progress in printed carbon nanotube electronics in terms of materials, processing, devices, and applications is discussed on page 4397 by A. Javey and co-workers. The research challenges and opportunities regarding the processing and system-level integration are also discussed for enabling of practical applications.

  4. Chromatographic purification and size separation of carbon nanotubes

    Science.gov (United States)

    Duesberg, G. S.; Muster, J.; Krstic, V.; Burghard, M.; Roth, S.

    1998-08-01

    The efficient purification of single-wall and multi-wall carbon nanotubes (NTs) by columnar size exclusion chromatography (SEC) is reported. In this process, carbon nanospheres (polyhedra), amorphous carbon and metal particles are removed from aqueous surfactant-stabilised dispersions of NT raw material. TEM and AFM investigations revealed that more than 40-50% of the purified material consists of individual tubes. In addition, length separation of the tubes is achieved.

  5. Chromatographic size separation of single-wall carbon nanotubes

    Science.gov (United States)

    Duesberg, G. S.; Muster, J.; Krstic, V.; Burghard, M.; Roth, S.

    The efficient purification of single-wall carbon nanotubes (SWNTs) is reported. Carbon nanospheres, metal particles, and amorphous carbon could be successfully removed by size exclusion chromatography (SEC) applied to surfactant stabilised dispersions of SWNT raw material. In addition, length separation of the tubes was achieved. The SWNTs obtained can be adsorbed in high densities onto chemically modified substrates. As determined by AFM investigations, the purified material consists of about equal fractions of both individual SWNTS and ropes of SWNTs.

  6. Memory Effects on Iron Oxide Filled Carbon Nanotubes

    OpenAIRE

    Cava, Carlos

    2013-01-01

    In this Licentiate Thesis, the properties and effects of iron and iron oxide filled carbon nanotube (Fe-CNT) memories are investigated using experimental characterization and quantum physical theoretical models. Memory devices based on the simple assembly of Fe-CNTs between two metallic contacts are presented as a possible application involving the resistive switching phenomena of this material. It is known that the electrical conductivity of these nanotubes changes significantly when the mat...

  7. Carbon nanotubes as heat dissipaters in microelectronics

    DEFF Research Database (Denmark)

    Pérez Paz, Alejandro; García-Lastra, Juan María; Markussen, Troels;

    2013-01-01

    We review our recent modelling work of carbon nanotubes as potential candidates for heat dissipation in microelectronics cooling. In the first part, we analyze the impact of nanotube defects on their thermal transport properties. In the second part, we investigate the loss of thermal properties...... of nanotubes in presence of an interface with various substances, including air and water. Comparison with previous works is established whenever is possible....

  8. Hierarchical nickel sulfide/carbon nanotube nanocomposite as a catalytic material toward triiodine reduction in dye-sensitized solar cells

    Science.gov (United States)

    Lu, Man-Ning; Dai, Chao-Shuan; Tai, Sheng-Yen; Lin, Tsung-Wu; Lin, Jeng-Yu

    2014-12-01

    In this study, Ni3S2 nanoparticles are successfully decorated on the backbone of conductive multi-walled carbon nanotubes (denoted as Ni3S2/MWCNT-NC) via a facile glucose-assisted hydrothermal method and employed as a counter electrode (CE) in dye-sensitized solar cells (DSCs). It is noteworthy that the use of glucose in the hydrothermal reaction plays a crucial role in the formation of the nanocomposite structure. Nevertheless, a thick layer of amorphous carbon derived from the hydrothermal carbonization of glucose covers Ni3S2 nanoparticle surface, and thus may inhibit the contact of active sites in Ni3S2 nanoparticles with electrolyte. It is found that the partial amorphous carbon on Ni3S2/MWCNT-NC can be effectively removed after annealing at 400 °C in a nitrogen atmosphere, which further increases the active sites of Ni3S2 nanoparticles on MWCNTs and therefore improves the electrocatalytic activity of the Ni3S2/MWCNT-NC CE. As a result, the DSC with the Ni3S2/MWCNT-NC CE yields a cell efficiency of 6.87%, which is higher than those of DSCs based on the Ni3S2 CE (5.77%) and MWCNT CE (3.76%). Because the Ni3S2/MWCNT-NC CE based DSC shows a comparable photovoltaic performance to the DSC using the Pt CE (7.24%), Ni3S2/MWCNT-NC CE may serve as a promising alternative to Pt CE for DSCs.

  9. Fracture of Carbon Nanotube - Amorphous Carbon Composites: Molecular Modeling

    Science.gov (United States)

    Jensen, Benjamin D.; Wise, Kristopher E.; Odegard, Gregory M.

    2015-01-01

    Carbon nanotubes (CNTs) are promising candidates for use as reinforcements in next generation structural composite materials because of their extremely high specific stiffness and strength. They cannot, however, be viewed as simple replacements for carbon fibers because there are key differences between these materials in areas such as handling, processing, and matrix design. It is impossible to know for certain that CNT composites will represent a significant advance over carbon fiber composites before these various factors have been optimized, which is an extremely costly and time intensive process. This work attempts to place an upper bound on CNT composite mechanical properties by performing molecular dynamics simulations on idealized model systems with a reactive forcefield that permits modeling of both elastic deformations and fracture. Amorphous carbon (AC) was chosen for the matrix material in this work because of its structural simplicity and physical compatibility with the CNT fillers. It is also much stiffer and stronger than typical engineering polymer matrices. Three different arrangements of CNTs in the simulation cell have been investigated: a single-wall nanotube (SWNT) array, a multi-wall nanotube (MWNT) array, and a SWNT bundle system. The SWNT and MWNT array systems are clearly idealizations, but the SWNT bundle system is a step closer to real systems in which individual tubes aggregate into large assemblies. The effect of chemical crosslinking on composite properties is modeled by adding bonds between the CNTs and AC. The balance between weakening the CNTs and improving fiber-matrix load transfer is explored by systematically varying the extent of crosslinking. It is, of course, impossible to capture the full range of deformation and fracture processes that occur in real materials with even the largest atomistic molecular dynamics simulations. With this limitation in mind, the simulation results reported here provide a plausible upper limit on

  10. Carbon nanotubes as electrode substrate material for PEM fuel cells; Kohlenstoff-Nanoroehrchen als Elektrodenmaterial fuer PEM-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Soehn, Matthias

    2010-06-21

    This thesis reports an enhanced method to deposit nanoscaled noble metal catalysts (Pt/Ru) uniformly on carbon nanotubes based on wet chemical reduction of anorganic precursors via ethylene glycol. This well-known method is widely used to deposit noble metal catalyst particles on carbon black. Unfortunately, carbon nanotubes tend to agglomerate and therefore form bundles which cannot be penetrated by the precursor. Thus, effectiveness of the substrate is reduced. The new method prevents this by suspending the CNTs in butyl acetate by means of ultrasonic dispersion leading to a homogenous distribution. Because the butyl acetate is almost unpolar, it is nearly immiscible with the water-based ethylene glycol mixture. This problem has been solved by adding liquid Nafion {sup registered} which acts as an emulsifying agent. Thus an emulsion is created by ultrasonic treatment. This results in 30 {mu}m-sized droplets of butyl acetate with a layer of CNTs and Nafion {sup registered}. The large interface to the ethylene glycol phase yields a large surface for homogenous catalyst deposition. The prepared samples showed a narrow size distribution ({+-}0.5 nm) of small noble metal particles with loading up to 50% by weight and an average particle size of 3 nm. They are investigated using XRD, SEM, TEM, TGA-MS and CV. The added Nafion {sup registered} improves catalyst utilisation by establishing a proton conductive path to the catalyst particles. Furthermore, different manufacturing techniques for the CNT electrodes are evaluated. Thin layer Membrane-Electrode-Assemblies (MEAs) are prepared by the airbrush technique. Electrode thickness, composition and structure as well as membrane thickness is varied and the MEAs are tested in a single-cell hydrogen-oxygen-fed PEM fuel cell. The cells are characterised by cyclic IV curves which are recorded over an extended period of time, showing power densities up to 770mWcm-2 at a platinum loading of 0.3mgcm-2. Additionally, the MEAs are

  11. Carbon nanotubes and graphene towards soft electronics

    Science.gov (United States)

    Chae, Sang Hoon; Lee, Young Hee

    2014-04-01

    Although silicon technology has been the main driving force for miniaturizing device dimensions to improve cost and performance, the current application of Si to soft electronics (flexible and stretchable electronics) is limited due to material rigidity. As a result, various prospective materials have been proposed to overcome the rigidity of conventional Si technology. In particular, nano-carbon materials such as carbon nanotubes (CNTs) and graphene are promising due to outstanding elastic properties as well as an excellent combination of electronic, optoelectronic, and thermal properties compared to conventional rigid silicon. The uniqueness of these nano-carbon materials has opened new possibilities for soft electronics, which is another technological trend in the market. This review covers the recent progress of soft electronics research based on CNTs and graphene. We discuss the strategies for soft electronics with nano-carbon materials and their preparation methods (growth and transfer techniques) to devices as well as the electrical characteristics of transparent conducting films (transparency and sheet resistance) and device performances in field effect transistor (FET) (structure, carrier type, on/off ratio, and mobility). In addition to discussing state of the art performance metrics, we also attempt to clarify trade-off issues and methods to control the trade-off on/off versus mobility). We further demonstrate accomplishments of the CNT network in flexible integrated circuits on plastic substrates that have attractive characteristics. A future research direction is also proposed to overcome current technological obstacles necessary to realize commercially feasible soft electronics.

  12. Synthesis of carbon nanotubes using natural carbon precursor: Castor oil

    Science.gov (United States)

    Raziah, A. Z.; Junizah, A. R.; Saifuddin, N.

    2012-09-01

    Castor oil has long been an article of commerce due to its versatility as it is widely used as a starting material for many industrial chemical products because of its unique structure. In this study, carbon nanotubes has been synthesized by thermal decomposition of castor oil in nitrogen atmosphere at 300-400δC using custom-made microwave processing unit. The precursor material was catalyzed by iron clusters originating from the addition of ferrocene. The morphology and characterization of the CNTs were studied and discussed by transmission electron microscopy (TEM).

  13. Carbon Nanotube Paper-Based Electroanalytical Devices

    OpenAIRE

    Youngmi Koo; Vesselin N. Shanov; Yeoheung Yun

    2016-01-01

    Here, we report on carbon nanotube paper-based electroanalytical devices. A highly aligned-carbon nanotube (HA-CNT) array, grown using chemical vapor deposition (CVD), was processed to form bi-layered paper with an integrated cellulose-based Origami-chip as the electroanalytical device. We used an inverse-ordered fabrication method from a thick carbon nanotube (CNT) sheet to a thin CNT sheet. A 200-layered HA-CNT sheet and a 100-layered HA-CNT sheet are explored as a working electrode. The de...

  14. Ordered phases of cesium in carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jeong Won; Hwang, Ho Jung; Song, Ki Oh; Choi, Won Young; Byun, Ki Ryang [Chung-Ang University, Seoul (Korea, Republic of); Kwon, Oh Keun [Semyung University, Jecheon (Korea, Republic of); Lee, Jun Ha [Sangmyung University, Chonan (Korea, Republic of); Kim, Won Woo [Juseong College, Cheongwon (Korea, Republic of)

    2003-10-15

    We investigate the structural phases of Cs in carbon nanotubes by using a structural optimization process applied to an atomistic simulation method. As the radius of the carbon nanotubes is increased, the structures are found in various phases from an atomic strand to multishell packs composed of coaxial cylindrical shells. Both helical structures and layered structures are found. The numbers of helical atom rows composed of coaxial tubes and the orthogonal vectors of the circular rolling of a triangular network can explain the structural phases of Cs in carbon nanotubes.

  15. 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.

  16. Microcapsule carbon nanotube devices for therapeutic applications

    Science.gov (United States)

    Kulamarva, Arun; Raja, Pavan M. V.; Bhathena, Jasmine; Chen, Hongmei; Talapatra, Saikat; Ajayan, Pulickel M.; Nalamasu, Omkaram; Prakash, Satya

    2009-01-01

    Carbon nanotubes are a new class of nanomaterials that have immense potential in the field of biomedicine. Their ability to carry large quantities of therapeutic molecules makes them prime candidates for providing targeted delivery of therapeutics for use in various diseases. However, their utility is limited due to the problems faced during their delivery to target sites. This article for the first time describes the design of a novel microcapsule carbon nanotube targeted delivery device. This device has potential in the targeted delivery of carbon nanotubes in suitable membranes along with their cargo, safely and effectively to the target loci.

  17. Geometry Effect of Multi-Walled Carbon Nanotube on Elastic Modulus of Polymer Composites

    International Nuclear Information System (INIS)

    The high Young's modulus and tensile strength of carbon nanotubes has attracted great attention from the research community given the potential for developing super-strong, super-stiff composites with carbon nanotube reinforcements. Over the decades, the strength and stiffness of carbon nanotube-reinforced polymer nanocomposites have been researched extensively. However, unfortunately, such strong composite materials have not been developed yet. It has been reported that the efficiency of load transfer in such systems is critically dependent on the quality of adhesion between the nanotubes and the polymer chains. In addition, the waviness and orientation of the nanotubes embedded in a matrix reduce the reinforcement effectiveness. In this study, we carried out performed micromechanics-based numerical modeling and analysis by varying the geometry of carbon nanotubes including their aspect ratio, orientation, and waviness. The results of this analysis allow for a better understanding of the load transfer capabilities of carbon nanotube-reinforced polymer composites

  18. Geometry Effect of Multi-Walled Carbon Nanotube on Elastic Modulus of Polymer Composites

    Energy Technology Data Exchange (ETDEWEB)

    Suhn, Jonghwan [Sungkyunkwan Univ., Seoul (Korea, Republic of)

    2014-01-15

    The high Young's modulus and tensile strength of carbon nanotubes has attracted great attention from the research community given the potential for developing super-strong, super-stiff composites with carbon nanotube reinforcements. Over the decades, the strength and stiffness of carbon nanotube-reinforced polymer nanocomposites have been researched extensively. However, unfortunately, such strong composite materials have not been developed yet. It has been reported that the efficiency of load transfer in such systems is critically dependent on the quality of adhesion between the nanotubes and the polymer chains. In addition, the waviness and orientation of the nanotubes embedded in a matrix reduce the reinforcement effectiveness. In this study, we carried out performed micromechanics-based numerical modeling and analysis by varying the geometry of carbon nanotubes including their aspect ratio, orientation, and waviness. The results of this analysis allow for a better understanding of the load transfer capabilities of carbon nanotube-reinforced polymer composites.

  19. Assembly and Applications of Carbon Nanotube Thin Films

    Institute of Scientific and Technical Information of China (English)

    Hongwei ZHU; Bingqing WEI

    2008-01-01

    The ultimate goal of current research on carbon nanotubes (CNTs) is to make breakthroughs that advance nanotechnological applications of bulk CNT materials. Especially, there has been growing interest in CNT thin films because of their unique and usually enhanced properties and tremendous potential as components for use in nano-electronic and nano-mechanical device applications or as structural elements in various devices. If a synthetic or a post processing method can produce high yield of nanotube thin films, these structures will provide tremendous potential for fundamental research on these devices. This review will address the synthesis, the post processing and the device applications of self-assembled nanotube thin films.

  20. Defect-Free Carbon Nanotube Coils.

    Science.gov (United States)

    Shadmi, Nitzan; Kremen, Anna; Frenkel, Yiftach; Lapin, Zachary J; Machado, Leonardo D; Legoas, Sergio B; Bitton, Ora; Rechav, Katya; Popovitz-Biro, Ronit; Galvão, Douglas S; Jorio, Ado; Novotny, Lukas; Kalisky, Beena; Joselevich, Ernesto

    2016-04-13

    Carbon nanotubes are promising building blocks for various nanoelectronic components. A highly desirable geometry for such applications is a coil. However, coiled nanotube structures reported so far were inherently defective or had no free ends accessible for contacting. Here we demonstrate the spontaneous self-coiling of single-wall carbon nanotubes into defect-free coils of up to more than 70 turns with identical diameter and chirality, and free ends. We characterize the structure, formation mechanism, and electrical properties of these coils by different microscopies, molecular dynamics simulations, Raman spectroscopy, and electrical and magnetic measurements. The coils are highly conductive, as expected for defect-free carbon nanotubes, but adjacent nanotube segments in the coil are more highly coupled than in regular bundles of single-wall carbon nanotubes, owing to their perfect crystal momentum matching, which enables tunneling between the turns. Although this behavior does not yet enable the performance of these nanotube coils as inductive devices, it does point a clear path for their realization. Hence, this study represents a major step toward the production of many different nanotube coil devices, including inductors, electromagnets, transformers, and dynamos. PMID:26708150

  1. Charge Screening Effect in Metallic Carbon Nanotubes

    OpenAIRE

    Sasaki, K

    2001-01-01

    Charge screening effect in metallic carbon nanotubes is investigated in a model including the one-dimensional long-range Coulomb interaction. It is pointed out that an external charge which is being fixed spatially is screened by internal electrons so that the resulting object becomes electrically neutral. We found that the screening length is given by about the diameter of a nanotube.

  2. The electrical conduction variation in stained carbon nanotubes

    Science.gov (United States)

    Sun, Shih-Jye; Wei Fan, Jun; Lin, Chung-Yi

    2012-01-01

    Carbon nanotubes become stained from coupling with foreign molecules, especially from adsorbing gas molecules. The charge exchange, which is due to the orbital hybridization, occurred in the stained carbon nanotube induces electrical dipoles that consequently vary the electrical conduction of the nanotube. We propose a microscopic model to evaluate the electrical current variation produced by the induced electrical dipoles in a stained zigzag carbon nanotube. It is found that stronger orbital hybridization strengths and larger orbital energy differences between the carbon nanotube and the gas molecules help increasing the induced electrical dipole moment. Compared with the stain-free carbon nanotube, the induced electrical dipoles suppress the current in the nanotube. In the carbon nanotubes with induced dipoles the current increases as a result of increasing orbital energy dispersion via stronger hybridization couplings. In particular, at a fixed hybridization coupling, the current increases with the bond length for the donor-carbon nanotube but reversely for the acceptor-carbon nanotube.

  3. Covalent enzyme immobilization onto carbon nanotubes using a membrane reactor

    Science.gov (United States)

    Voicu, Stefan Ioan; Nechifor, Aurelia Cristina; Gales, Ovidiu; Nechifor, Gheorghe

    2011-05-01

    Composite porous polysulfone-carbon nanotubes membranes were prepared by dispersing carbon nanotubes into a polysulfone solution followed by the membrane formation by phase inversion-immersion precipitation technique. The carbon nanotubes with amino groups on surface were functionalized with different enzymes (carbonic anhydrase, invertase, diastase) using cyanuric chloride as linker between enzyme and carbon nanotube. The composite membrane was used as a membrane reactor for a better dispersion of carbon nanotubes and access to reaction centers. The membrane also facilitates the transport of enzymes to active carbon nanotubes centers for functionalization (amino groups). The functionalized carbon nanotubes are isolated by dissolving the membranes after the end of reaction. Carbon nanotubes with covalent immobilized enzymes are used for biosensors fabrications. The obtained membranes were characterized by Scanning Electron Microscopy, Thermal analysis, FT-IR Spectroscopy, Nuclear Magnetic Resonance, and functionalized carbon nanotubes were characterized by FT-IR spectroscopy.

  4. Coulomb drag in multiwall armchair carbon nanotubes

    DEFF Research Database (Denmark)

    Lunde, A.M.; Jauho, Antti-Pekka

    2004-01-01

    We calculate the transresistivity rho(21) between two concentric armchair nanotubes in a diffusive multiwall carbon nanotube as a function of temperature T and Fermi level epsilon(F). We approximate the tight-binding band structure by two crossing bands with a linear dispersion near the Fermi...... surface. The cylindrical geometry of the nanotubes and the different parities of the Bloch states are accounted for in the evaluation of the effective Coulomb interaction between charges in the concentric nanotubes. We find a broad peak in rho(21) as a function of temperature at roughly T similar to 0.4T...

  5. Microfabricated electroactive carbon nanotube actuators

    Science.gov (United States)

    Ahluwalia, Arti; Baughman, Ray H.; De Rossi, Danilo; Mazzoldi, Alberto; Tesconi, Mario; Tognetti, Alessandro; Vozzi, Giovanni

    2001-07-01

    A variety of microfabrication techniques have been developed at the University of Pisa. They are based either on pressure or piston actuated microsyringes or modified ink-jet printers. This work present the results of a study aimed at fabricating carbon nanotube (NT) actuators using micro-syringes. In order to prevent the nanotubes from aggregating into clumps, they were enclosed in a partially cross-linked polyvinylalcohol - polyallylamine matrix. After sonication the solution remained homogenously dispersed for about 40 minutes, which was sufficient time for deposition. Small strips of NT, about 5 mm across and 15 mm long were deposited. Following deposition, the films were baked at 80 degree(s)C and their thickness, impedance and mechanical resistance measured. The results indicate that 50 minutes of baking time is sufficient to give a constant resistivity of 1.12 x 10-2 (Omega) m per layer similar to a typical semiconductor, and each layer has a thickness of about 6 micrometers .

  6. Fermentation based carbon nanotube multifunctional bionic composites

    Science.gov (United States)

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-06-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal.

  7. Fermentation based carbon nanotube multifunctional bionic composites

    Science.gov (United States)

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal. PMID:27279425

  8. Structure of single-wall carbon nanotubes: a graphene helix.

    Science.gov (United States)

    Lee, Jae-Kap; Lee, Sohyung; Kim, Jin-Gyu; Min, Bong-Ki; Kim, Yong-Il; Lee, Kyung-Il; An, Kay Hyeok; John, Phillip

    2014-08-27

    Evidence is presented in this paper that certain single-wall carbon nanotubes are not seamless tubes, but rather adopt a graphene helix resulting from the spiral growth of a nano-graphene ribbon. The residual traces of the helices are confirmed by high-resolution transmission electron microscopy and atomic force microscopy. The analysis also shows that the tubular graphene material may exhibit a unique armchair structure and the chirality is not a necessary condition for the growth of carbon nanotubes. The description of the structure of the helical carbon nanomaterials is generalized using the plane indices of hexagonal space groups instead of using chiral vectors. It is also proposed that the growth model, via a graphene helix, results in a ubiquitous structure of single-wall carbon nanotubes. PMID:24838196

  9. Purification of Carbon Nanotubes: Alternative Methods

    Science.gov (United States)

    Files, Bradley; Scott, Carl; Gorelik, Olga; Nikolaev, Pasha; Hulse, Lou; Arepalli, Sivaram

    2000-01-01

    Traditional carbon nanotube purification process involves nitric acid refluxing and cross flow filtration using surfactant TritonX. This is believed to result in damage to nanotubes and surfactant residue on nanotube surface. Alternative purification procedures involving solvent extraction, thermal zone refining and nitric acid refiuxing are used in the current study. The effect of duration and type of solvent to dissolve impurities including fullerenes and P ACs (polyaromatic compounds) are monitored by nuclear magnetic reasonance, high performance liquid chromatography, and thermogravimetric analysis. Thermal zone refining yielded sample areas rich in nanotubes as seen by scanning electric microscopy. Refluxing in boiling nitric acid seem to improve the nanotube content. Different procedural steps are needed to purify samples produced by laser process compared to arc process. These alternative methods of nanotube purification will be presented along with results from supporting analytical techniques.

  10. Deconvoluting hepatic processing of carbon nanotubes

    Science.gov (United States)

    Alidori, Simone; Bowman, Robert L.; Yarilin, Dmitry; Romin, Yevgeniy; Barlas, Afsar; Mulvey, J. Justin; Fujisawa, Sho; Xu, Ke; Ruggiero, Alessandro; Riabov, Vladimir; Thorek, Daniel L. J.; Ulmert, Hans David S.; Brea, Elliott J.; Behling, Katja; Kzhyshkowska, Julia; Manova-Todorova, Katia; Scheinberg, David A.; McDevitt, Michael R.

    2016-07-01

    Single-wall carbon nanotubes present unique opportunities for drug delivery, but have not advanced into the clinic. Differential nanotube accretion and clearance from critical organs have been observed, but the mechanism not fully elucidated. The liver has a complex cellular composition that regulates a range of metabolic functions and coincidently accumulates most particulate drugs. Here we provide the unexpected details of hepatic processing of covalently functionalized nanotubes including receptor-mediated endocytosis, cellular trafficking and biliary elimination. Ammonium-functionalized fibrillar nanocarbon is found to preferentially localize in the fenestrated sinusoidal endothelium of the liver but not resident macrophages. Stabilin receptors mediate the endocytic clearance of nanotubes. Biocompatibility is evidenced by the absence of cell death and no immune cell infiltration. Towards clinical application of this platform, nanotubes were evaluated for the first time in non-human primates. The pharmacologic profile in cynomolgus monkeys is equivalent to what was reported in mice and suggests that nanotubes should behave similarly in humans.

  11. Piezoresistive Sensors Based on Carbon Nanotube Films

    Institute of Scientific and Technical Information of China (English)

    L(U) Jian-wei; WANG Wan-lu; LIAO Ke-jun; WANG Yong-tian; LIU CHang-lin; Zeng Qing-gao

    2005-01-01

    Piezoresistive effect of carbon nanotube films was investigated by a three-point bending test.Carbon nanotubes were synthesized by hot filament chemical vapor deposition.The experimental results showed that the carbon nanotubes have a striking piezoresistive effect.The relative resistance was changed from 0 to 10.5×10-2 and 3.25×10-2 for doped and undoped films respectively at room temperature when the microstrain under stress from 0 to 500. The gauge factors for doped and undoped carbon nanotube films under 500 microstrain were about 220 and 67 at room temperature, respectively, exceeding that of polycrystalline silicon (30) at 35℃.The origin of the resistance changes in the films may be attributed to a strain-induced change in the band gap for the doped tubes and the defects for the undoped tubes.

  12. Self Assembled Carbon Nanotube Enhanced Ultracapacitors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this NASA STTR program is to develop single wall carbon nanotube (SWCNT) based ultracapacitors for energy storage devices (ESD) application, using...

  13. A Thermal Model for Carbon Nanotube Interconnects

    Directory of Open Access Journals (Sweden)

    Clay Mayberry

    2013-04-01

    Full Text Available In this work, we have studied Joule heating in carbon nanotube based very large scale integration (VLSI interconnects and incorporated Joule heating influenced scattering in our previously developed current transport model. The theoretical model explains breakdown in carbon nanotube resistance which limits the current density. We have also studied scattering parameters of carbon nanotube (CNT interconnects and compared with the earlier work. For 1 µm length single-wall carbon nanotube, 3 dB frequency in S12 parameter reduces to ~120 GHz from 1 THz considering Joule heating. It has been found that bias voltage has little effect on scattering parameters, while length has very strong effect on scattering parameters.

  14. 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.

  15. Carbon nanotube heat-exchange systems

    Science.gov (United States)

    Hendricks, Terry Joseph; Heben, Michael J.

    2008-11-11

    A carbon nanotube heat-exchange system (10) and method for producing the same. One embodiment of the carbon nanotube heat-exchange system (10) comprises a microchannel structure (24) having an inlet end (30) and an outlet end (32), the inlet end (30) providing a cooling fluid into the microchannel structure (24) and the outlet end (32) discharging the cooling fluid from the microchannel structure (24). At least one flow path (28) is defined in the microchannel structure (24), fluidically connecting the inlet end (30) to the outlet end (32) of the microchannel structure (24). A carbon nanotube structure (26) is provided in thermal contact with the microchannel structure (24), the carbon nanotube structure (26) receiving heat from the cooling fluid in the microchannel structure (24) and dissipating the heat into an external medium (19).

  16. Carbon nanotube electrodes for effective interfacing with retinal tissue

    Directory of Open Access Journals (Sweden)

    Asaf Shoval

    2009-04-01

    Full Text Available We have investigated the use of carbon nanotube microelectrodes as an interface material for retinal recording and stimulation applications. Test devices were micro-fabricated and consisted of 60 pristine 30 um electrodes coated with chemical vapor deposited carbon nanotubes, resulting in conducting, three dimensional surfaces with a high effective interfacial area. These attributes are important both for the quality of the cell-surface coupling as well as for electro-chemical interfacing efficiency. The entire chip was packaged to fit a commercial multielectrode recording and stimulation system. Electrical recordings of spontaneous spikes from whole-mount neonatal mouse retinas were consistently obtained minutes after retinas were placed over the electrodes, exhibiting typical bursting and propagating waves. Most importantly, the signals obtained with carbon nanotube electrodes have exceptionally high signal to noise ratio, reaching values as high as 75. Moreover, spikes are marked by a conspicuous gradual increase in amplitude recorded over a period of minutes to hours, suggesting improvement in cell-electrode coupling. This phenomenon is not observed in conventional commercial electrodes. Electrical stimulation using carbon nanotube electrodes was also achieved. We attribute the superior performances of the carbon nanotube electrodes to their three dimensional nature and the strong neuro-carbon nanotube affinity. The results presented here show the great potential of carbon nanotube electrodes for retinal interfacing applications. Specifically, our results demonstrate a route to achieve a reduction in the electrode size down to few micrometers in order to achieve high efficacy local stimulation needed in retinal prosthetic devices.

  17. Carbon nanotube temperature and pressure sensors

    Science.gov (United States)

    Ivanov, Ilia N; Geohegan, David Bruce

    2013-10-29

    The present invention, in one embodiment, provides a method of measuring pressure or temperature using a sensor including a sensor element composed of a plurality of carbon nanotubes. In one example, the resistance of the plurality of carbon nanotubes is measured in response to the application of temperature or pressure. The changes in resistance are then recorded and correlated to temperature or pressure. In one embodiment, the present invention provides for independent measurement of pressure or temperature using the sensors disclosed herein.

  18. Carbon nanotube temperature and pressure sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Ilia N.; Geohegan, David B.

    2016-10-25

    The present invention, in one embodiment, provides a method of measuring pressure or temperature using a sensor including a sensor element composed of a plurality of carbon nanotubes. In one example, the resistance of the plurality of carbon nanotubes is measured in response to the application of temperature or pressure. The changes in resistance are then recorded and correlated to temperature or pressure. In one embodiment, the present invention provides for independent measurement of pressure or temperature using the sensors disclosed herein.

  19. Analysis of Carbon Nanotube Field-Effect-Transistors (FETs)

    Science.gov (United States)

    Yamada, Toshishige

    1999-01-01

    This five page presentation is grouped into 11 numbered viewgraphs, most of which contain one or more diagrams. Some of the diagrams are accompanied by captions, including: 2) Nanotube FET by Delft, IBM; 3) Nanotube FET/Standard MOSFET; 5) Saturation with carrier-carrier; 7) Electronic properties of carbon nanotube; 8) Theoretical nanotube FET characteristics; 11) Summary: Delft and IBM nanotube FET analysis.

  20. 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

  1. On the elastic properties of carbon nanotube-based composites: modelling and characterization

    CERN Document Server

    Thostenson, E T

    2003-01-01

    The exceptional mechanical and physical properties observed for carbon nanotubes has stimulated the development of nanotube-based composite materials, but critical challenges exist before we can exploit these extraordinary nanoscale properties in a macroscopic composite. At the nanoscale, the structure of the carbon nanotube strongly influences the overall properties of the composite. The focus of this research is to develop a fundamental understanding of the structure/size influence of carbon nanotubes on the elastic properties of nanotube-based composites. Towards this end, the nanoscale structure and elastic properties of a model composite system of aligned multi-walled carbon nanotubes embedded in a polystyrene matrix were characterized, and a micromechanical approach for modelling of short fibre composites was modified to account for the structure of the nanotube reinforcement to predict the elastic modulus of the nanocomposite as a function of the constituent properties, reinforcement geometry and nanot...

  2. ON THE CONTINUUM MODELING OF CARBON NANOTUBES

    Institute of Scientific and Technical Information of China (English)

    张鹏; 黄永刚; Philippe H.Geubelle; 黄克智

    2002-01-01

    We have recently proposed a nanoscale continuum theory for carbonnanotubes. The theory links continuum analysis with atomistic modeling by incor-porating interatomic potentials and atomic structures of carbon nanotubes directlyinto the constitutive law. Here we address two main issues involved in setting upthe nanoscale continuum theory for carbon nanotubes, namely the multi-body in-teratomic potentials and the lack of centrosymmetry in the nanotube structure. Weexplain the key ideas behind these issues in establishing a nanoscale continuum theoryin terms of interatomic potentials and atomic structures.

  3. Combination of carbon nitride and carbon nanotubes: synergistic catalysts for energy conversion.

    Science.gov (United States)

    Gong, Yutong; Wang, Jing; Wei, Zhongzhe; Zhang, Pengfei; Li, Haoran; Wang, Yong

    2014-08-01

    Due to their versatile features and environmental friendliness, functionalized carbon materials show great potential in practical applications, especially in energy conversion. Developing carbon composites with properties that can be modulated by simply changing the ratio of the original materials is an intriguing synthetic strategy. Here, we took cyanamide and multiwalled carbon nanotubes as precursors and introduced a facile method to fabricate a series of graphitic carbon nitride/carbon nanotubes (g-C3 N4 /CNTs) composites. These composites demonstrated different practical applications with different weight ratios of the components, that is, they showed synergistic effects in optoelectronic conversion when g-C3 N4 was the main ingredient and in oxygen reduction reaction (ORR) when CNTs dominated the composites. Our experiments indicated that the high electrical conductivity of carbon nanotubes promoted the transmission of the charges in both cases.

  4. Electro-catalytic activity of multiwall carbon nanotube-metal (Pt or Pd) nanohybrid materials synthesized using microwave-induced reactions and their possible use in fuel cells

    Science.gov (United States)

    V, Lakshman Kumar; Ntim, Susana Addo; Sae-Khow, Ornthida; Janardhana, Chelli; Lakshminarayanan, V.; Mitra, Somenath

    2012-01-01

    Microwave induced reactions for immobilizing platinum and palladium nanoparticles on multiwall carbon nanotubes are presented. The resulting hybrid materials were used as catalysts for direct methanol, ethanol and formic acid oxidation in acidic as well as alkaline media. The electrodes are formed by simply mixing the hybrids with graphite paste, thus using a relatively small quantity of the precious metal. We report Tafel slopes and apparent activation energies at different potentials and temperatures. Ethanol electro-oxidation with the palladium hybrid showed an activation energy of 7.64 kJmol−1 which is lower than those observed for other systems. This system is economically attractive because Pd is significantly less expensive than Pt and ethanol is fast evolving as a commercial biofuel. PMID:23118490

  5. Electro-catalytic activity of multiwall carbon nanotube-metal (Pt or Pd) nanohybrid materials synthesized using microwave-induced reactions and their possible use in fuel cells.

    Science.gov (United States)

    V, Lakshman Kumar; Ntim, Susana Addo; Sae-Khow, Ornthida; Janardhana, Chelli; Lakshminarayanan, V; Mitra, Somenath

    2012-11-30

    Microwave induced reactions for immobilizing platinum and palladium nanoparticles on multiwall carbon nanotubes are presented. The resulting hybrid materials were used as catalysts for direct methanol, ethanol and formic acid oxidation in acidic as well as alkaline media. The electrodes are formed by simply mixing the hybrids with graphite paste, thus using a relatively small quantity of the precious metal. We report Tafel slopes and apparent activation energies at different potentials and temperatures. Ethanol electro-oxidation with the palladium hybrid showed an activation energy of 7.64 kJmol(-1) which is lower than those observed for other systems. This system is economically attractive because Pd is significantly less expensive than Pt and ethanol is fast evolving as a commercial biofuel.

  6. Functionalization of Multiwalled Carbon Nanotubes by Solution Plasma Processing in Ammonia Aqueous Solution and Preparation of Composite Material with Polyamide 6

    Science.gov (United States)

    Shirafuji, Tatsuru; Noguchi, Yohei; Yamamoto, Taibou; Hieda, Junko; Saito, Nagahiro; Takai, Osamu; Tsuchimoto, Akiharu; Nojima, Kazuhiro; Okabe, Youji

    2013-12-01

    Solution plasma processing (SPP) has been performed on multiwalled carbon nanotubes (MWCNTs) in ammonia aqueous solution. The MWCNTs, which do not disperse in aqueous solution, uniformly dispersed after the SPP. Only 2 h was required to obtain 10 g of the dispersed MWCNTs, while 7 days and additional chemicals were required for 185 mg in a previous study. The X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy of the SPP-treated MWCNTs revealed that nitrogen- and oxygen-containing groups are formed on the MWCNTs. Serious damage to the MWCNT structure was not observed in the Raman spectrum or transmission electron microscopy images of the SPP-treated MWCNTs. The composite materials prepared using polyamide 6 with the SPP-treated MWCNTs showed better tensile, bending, and impact strength than those prepared with nontreated MWCNTs.

  7. Improved synthesis of carbon nanotubes with junctions and of single-walled carbon nanotubes

    OpenAIRE

    Deepak, FL; Govindaraj, A.; Rao, CNR

    2006-01-01

    Pyrolysis of thiophene over nickel nanoparticles dispersed on silica is shown to yield Y-junction carbon nanotubes with smaller diameters than those obtained by the pyrolysis of organometallic-thiophene mixtures. In the presence of water vapour, the pyrolysis of organometallic-hydrocarbon mixtures yields single-walled nanotubes, as well as relatively narrow-diameter carbon nanotubes with Y-junctions. Pyrolysis-of organometallic-hydrocarbon mixtures, in the absence of water vapour, only gives ...

  8. Films, Buckypapers and Fibers from Clay, Chitosan and Carbon Nanotubes

    OpenAIRE

    Marc in het Panhuis; Holly Warren; Higgins, Thomas M.

    2011-01-01

    The mechanical and electrical characteristics of films, buckypapers and fiber materials from combinations of clay, carbon nanotubes (CNTs) and chitosan are described. The rheological time-dependent characteristics of clay are maintained in clay–carbon nanotube–chitosan composite dispersions. It is demonstrated that the addition of chitosan improves their mechanical characteristics, but decreases electrical conductivity by three-orders of magnitude compared to clay–CNT materials. We show that ...

  9. Method for nano-pumping using carbon nanotubes

    Science.gov (United States)

    Insepov, Zeke; Hassanein, Ahmed

    2009-12-15

    The present invention relates generally to the field of nanotechnology, carbon nanotubes and, more specifically, to a method and system for nano-pumping media through carbon nanotubes. One preferred embodiment of the invention generally comprises: method for nano-pumping, comprising the following steps: providing one or more media; providing one or more carbon nanotubes, the one or more nanotubes having a first end and a second end, wherein said first end of one or more nanotubes is in contact with the media; and creating surface waves on the carbon nanotubes, wherein at least a portion of the media is pumped through the nanotube.

  10. Carbon Nanotube Thin-Film Antennas.

    Science.gov (United States)

    Puchades, Ivan; Rossi, Jamie E; Cress, Cory D; Naglich, Eric; Landi, Brian J

    2016-08-17

    Multiwalled carbon nanotube (MWCNT) and single-walled carbon nanotube (SWCNT) dipole antennas have been successfully designed, fabricated, and tested. Antennas of varying lengths were fabricated using flexible bulk MWCNT sheet material and evaluated to confirm the validity of a full-wave antenna design equation. The ∼20× improvement in electrical conductivity provided by chemically doped SWCNT thin films over MWCNT sheets presents an opportunity for the fabrication of thin-film antennas, leading to potentially simplified system integration and optical transparency. The resonance characteristics of a fabricated chlorosulfonic acid-doped SWCNT thin-film antenna demonstrate the feasibility of the technology and indicate that when the sheet resistance of the thin film is >40 ohm/sq no power is absorbed by the antenna and that a sheet resistance of antenna. The dependence of the return loss performance on the SWCNT sheet resistance is consistent with unbalanced metal, metal oxide, and other CNT-based thin-film antennas, and it provides a framework for which other thin-film antennas can be designed.

  11. Non-covalent interactions between carbon nanotubes and conjugated polymers.

    Science.gov (United States)

    Tuncel, Dönüs

    2011-09-01

    Carbon nanotubes (CNTs) are interest to many different disciplines including chemistry, physics, biology, material science and engineering because of their unique properties and potential applications in various areas spanning from optoelectronics to biotechnology. However, one of the drawbacks associated with these materials is their insolubility which limits their wide accessibility for many applications. Various approaches have been adopted to circumvent this problem including modification of carbon nanotube surfaces by non-covalent and covalent attachments of solubilizing groups. Covalent approach modification may alter the intrinsic properties of carbon nanotubes and, in turn make them undesirable for many applications. On the other hand, a non-covalent approach helps to improve the solubility of CNTs while preserving their intrinsic properties. Among many non-covalent modifiers of CNTs, conjugated polymers are receiving increasing attention and highly appealing because of a number of reasons. To this end, the aim of this feature article is to review the recent results on the conjugated polymer-based non-covalent functionalization of CNTs with an emphasis on the effect of conjugated polymers in the dispersibility/solubility, optical, thermal and mechanical properties of carbon nanotubes as well as their usage in the purification and isolation of a specific single-walled nanotube from the mixture of the various tubes.

  12. Photovoltaic response of carbon nanotube-silicon heterojunctions: effect of nanotube film thickness and number of walls.

    Science.gov (United States)

    Castrucci, P; Del Gobbo, S; Camilli, L; Scarselli, M; Casciardi, S; Tombolini, F; Convertino, A; Fortunato, G; De Crescenzi, M

    2011-10-01

    We report on the multiwall carbon nanotube application as energy conversion material to fabricate thin film solar cells, with nanotubes acting as photogeneration sites as well as charge separators, collectors and carrier transporters. The device consists of a semitransparent thin film of nanotubes coating a n-type crystalline silicon substrate. Under illumination electron-hole (e-h) pairs, generated in the nanotubes and in the silicon substrate underneath, are split and charges are transported through the nanotubes (electrons) and the n-Si (holes). We found that a suitable thickness of the nanotube thin film, high density of Schottky junctions between nanotubes and n-Si and lowest number of nanotube walls are all fundamental parameters to improve the device incident photon to electron conversion efficiency. Multiwall carbon nanotubes have been synthesized by chemical vapour deposition in an ultra high vacuum chamber by evaporating a given amount of iron at room temperature and then exposing the substrate kept at 800 degrees C at acetylene gas. The amount of deposited iron is found to directly affect the nanotube size distribution (inner and outer diameter) and therefore the number of walls of the nanotubes. PMID:22400324

  13. Fast readout of carbon nanotube mechanical resonators

    Science.gov (United States)

    Meerwaldt, Harold; Singh, Vibhor; Schneider, Ben; Schouten, Raymond; van der Zant, Herre; Steele, Gary

    2013-03-01

    We perform fast readout measurements of carbon nanotube mechanical resonators. Using an electronic mixing scheme, we can detect the amplitude of the mechanical motion with an intermediate frequency (IF) of 46 MHz and a timeconstant of 1 us, up to 5 orders of magnitude faster than before. Previous measurements suffered from a low bandwidth due to the combination of the high resistance of the carbon nanotube and a large stray capacitance. We have increased the bandwidth significantly by using a high-impedance, close-proximity HEMT amplifier. The increased bandwidth should allow us to observe the nanotube's thermal motion and its transient response, approaching the regime of real-time detection of the carbon nanotube's mechanical motion.

  14. Fabrication of nylon-6/carbon nanotube composites

    Science.gov (United States)

    Xu, C.; Jia, Z.; Wu, D.; Han, Q.; Meek, T.

    2006-05-01

    A new technique to fabricate nylon-6/carbon nanotube (PA6/CNT) composites is presented. The method involves a pretreatment of carbon nanotubes synthesized by catalytic pyrolysis of hydrocarbon and an improved in-situ process for mixing nanotubes with the nylon 6 matrix. A good bond between carbon nanotubes and the nylon-6 matrix is obtained. Mechanical property measurements indicate that the tensile strength of PA6/CNT composites is improved significantly while the toughness and elongation are somewhat compromised. Scanning electron microscopy (SEM) analysis of the fractured tensile specimens reveals cracking initiated at the wrapping of the CNTs PA6 layer/PA6 matrix interface rather than at the PA6/CNT interface.

  15. Fabrication of 3D carbon nanotube networks

    Science.gov (United States)

    Laera, Anna Maria; Mirenghi, Luciana; Schioppa, Monica; Nobile, Concetta; Capodieci, Laura; Grazia Scalone, Anna; Di Benedetto, Francesca; Tapfer, Leander

    2016-08-01

    We report on the synthesis and characterization of a hyperbranched polymer englobing single-wall carbon nanotubes (SWCNTs). This new material was obtained by using SWCNTs functionalized with carboxylic groups as starting reagent. The acid groups were firstly converted in acyl chloride moieties and afterwards were bound to hexamethylenediamine (HMDA) via formation of amide functionality. The acquired spectra of attenuated total reflectance and the analysis performed through x-ray photoelectron spectroscopy confirmed the amide bond formation. The hyperbranched polymer characterization was completed by using scanning and transmission electron microscopy, thermo-gravimetric analysis and Raman spectroscopy. The electron microscopy analyses showed the formation of an amorphous polymeric material englobing a dense network of SWCNTs without phase segregation, demonstrating that the reaction with HMDA allows a reorganization of SWCNTs in a complex three-dimensional network.

  16. Enhancement of semiconducting single-wall carbon nanotubes photoluminescence

    OpenAIRE

    Gaufrès, Etienne; Izard, Nicolas; Vivien, Laurent; Kazaoui, Saïd; Marris-Morini, Delphine; Cassan, Eric

    2009-01-01

    International audience Photoluminescence properties of semiconducting single wall carbon nanotubes (s-SWNT) thin films with different metallic single wall carbon nanotubes (m-SWNT) concentrations are reported. s-SWNT purified samples are obtained by polymer assisted selective extraction. We show that a few m-SWNT in the sample generates a drastic quenching of the emission. Therefore, highly purified s-SWNT films are a strongly luminescent material and a good candidate for future applications in...

  17. Thermal Conductivity of Carbon Nanotubes Embedded in Solids

    Institute of Scientific and Technical Information of China (English)

    CAO Bing-Yang; HOU Quan-Wen

    2008-01-01

    @@ A carbon-nanotube-atom fixed and activated scheme of non-equilibrium molecular dynamics simulations is put forward to extract the thermal conductivity of carbon nanotubes (CNTs) embedded in solid argon. Though a 6.5% volume fraction of CNTs increases the composite thermal conductivity to about twice as much as that of the pure basal material, the thermal conductivity of CNTs embedded in solids is found to be decreased by 1/8-1/5with reference to that of pure ones. The decrease of the intrinsic thermal conductivity of the solid-embedded CNTs and the thermal interface resistance are demonstrated to be responsible for the results.

  18. Nickel Oxide/Carbon Nanotubes Nanocomposite for Electrochemical Capacitance

    Institute of Scientific and Technical Information of China (English)

    Kui LIANG; Kayhyeok AN; Younghee LEE

    2005-01-01

    A nanocomposite of nickel oxide/carbon nanotubes was prepared through a simple chemical precipitation followed by thermal annealing. The electrochemical capacitance of this electrode material was studied. When the mass fraction of CNTs (carbon nanotubes) in NiO/CNT composites increases, the electrical resistivity of nanocomposites decreases and becomes similar to that of pure CNTs when it reaches 30%. The specific surface area of composites increases with increasing CNT mass fraction and the specific capacitance reaches 160 F/g under 10 mA/g discharge current density at CNT mass fraction of 10%.

  19. The mechanism of selective molecular capture in carbon nanotube networks.

    Science.gov (United States)

    Wan, Yu; Guan, Jun; Yang, Xudong; Zheng, Quanshui; Xu, Zhiping

    2014-07-28

    Recently, air pollution issues have drawn significant attention to the development of efficient air filters, and one of the most promising materials for this purpose is nanofibers. We explore here the mechanism of selective molecular capture of volatile organic compounds in carbon nanotube networks by performing atomistic simulations. The results are discussed with respect to the two key parameters that define the performance of nanofiltration, i.e. the capture efficiency and flow resistance, which demonstrate the advantages of carbon nanotube networks with high surface-to-volume ratio and atomistically smooth surfaces. We also reveal the important roles of interfacial adhesion and diffusion that govern selective gas transport through the network.

  20. Tailored semiconducting carbon nanotube networks with enhanced thermoelectric properties

    Science.gov (United States)

    Avery, Azure D.; Zhou, Ben H.; Lee, Jounghee; Lee, Eui-Sup; Miller, Elisa M.; Ihly, Rachelle; Wesenberg, Devin; Mistry, Kevin S.; Guillot, Sarah L.; Zink, Barry L.; Kim, Yong-Hyun; Blackburn, Jeffrey L.; Ferguson, Andrew J.

    2016-04-01

    Thermoelectric power generation, allowing recovery of part of the energy wasted as heat, is emerging as an important component of renewable energy and energy efficiency portfolios. Although inorganic semiconductors have traditionally been employed in thermoelectric applications, organic semiconductors garner increasing attention as versatile thermoelectric materials. Here we present a combined theoretical and experimental study suggesting that semiconducting single-walled carbon nanotubes with carefully controlled chirality distribution and carrier density are capable of large thermoelectric power factors, higher than 340 μW m‑1 K‑2, comparable to the best-performing conducting polymers and larger than previously observed for carbon nanotube films. Furthermore, we demonstrate that phonons are the dominant source of thermal conductivity in the networks, and that our carrier doping process significantly reduces the thermal conductivity relative to undoped networks. These findings provide the scientific underpinning for improved functional organic thermoelectric composites with carbon nanotube inclusions.

  1. Investigation of interlaminar shear strength in carbon epoxy and carbon epoxy carbon nanotubes using experimental and finite element technique

    Directory of Open Access Journals (Sweden)

    P. Rama Lakshmi

    2012-05-01

    Full Text Available The present study concerns experimental and finite element analysis of carbon epoxy and carbon epoxy carbon nanotube composites to estimate interlaminar shear strength. Mechanical properties such as elastic ratios, thickness are varied for double notched specimen and the corresponding deflections and interlaminar shear strengths are estimated by ANSYS. From simple rule of mixtures, equivalent orthotropic material properties are estimated. These properties are provided as input in ANSYS to generate finite element model. Solid layered element is used to model double notch specimen. To estimate the properties of carbon epoxy carbon nanotube composite, initially finite element model of matrix and carbon nanotube is generated by properties individual material properties of both the materials. From the obtained stretch and stress, the equivalent material property of combined matrix and carbon nanotube is achieved. This property is provided as input in simple rule of mixtures to find out the equivalent orthotropic materials are determined. It is inferred that experiment results are in good agreement with results generated by ANSYS. The superiority of the presence of carbon nanotube in the composite is proved from experimental and finite element technique from the estimated fracture parameters.

  2. Carbon Nanotube Microarrays Grown on Nanoflake Substrates

    Science.gov (United States)

    Schmidt, Howard K.; Hauge, Robert H.; Pint, Cary; Pheasant, Sean

    2013-01-01

    This innovation consists of a new composition of matter where single-walled carbon nanotubes (SWNTs) are grown in aligned arrays from nanostructured flakes that are coated in Fe catalyst. This method of growth of aligned SWNTs, which can yield well over 400 percent SWNT mass per unit substrate mass, exceeds current yields for entangled SWNT growth. In addition, processing can be performed with minimal wet etching treatments, leaving aligned SWNTs with superior properties over those that exist in entangled mats. The alignment of the nanotubes is similar to that achieved in vertically aligned nanotubes, which are called "carpets. " Because these flakes are grown in a state where they are airborne in a reactor, these flakes, after growing SWNTs, are termed "flying carpets. " These flakes are created in a roll-to-roll evaporator system, where three subsequent evaporations are performed on a 100-ft (approx. =30-m) roll of Mylar. The first layer is composed of a water-soluble "release layer, " which can be a material such as NaCl. After depositing NaCl, the second layer involves 40 nm of supporting layer material . either Al2O3 or MgO. The thickness of the layer can be tuned to synthesize flakes that are larger or smaller than those obtained with a 40-nm deposition. Finally, the third layer consists of a thin Fe catalyst layer with a thickness of 0.5 nm. The thickness of this layer ultimately determines the diameter of SWNT growth, and a layer that is too thick will result in the growth of multiwalled carbon nanotubes instead of single-wall nanotubes. However, between a thickness of 0.5 nm to 1 nm, single-walled carbon nanotubes are known to be the primary constituent. After this three-layer deposition process, the Mylar is rolled through a bath of water, which allows catalyst-coated flakes to detach from the Mylar. The flakes are then collected and dried. The method described here for making such flakes is analogous to that which is used to make birefringent ink that is

  3. Applications and Nanotoxicity of Carbon Nanotubes and Graphene in Biomedicine

    Directory of Open Access Journals (Sweden)

    Caitlin Fisher

    2012-01-01

    Full Text Available Owing to their unique mechanical, electrical, optical, and thermal properties, carbon nanostructures including carbon nanotubes and graphenes show great promise for advancing the fields of biology and medicine. Many reports have demonstrated the promise of these carbon nanostructures and their hybrid structures (composites with polymers, ceramics, and metal nanoparticles, etc. for a variety of biomedical areas ranging from biosensing, drug delivery, and diagnostics, to cancer treatment, tissue engineering, and bioterrorism prevention. However, the issue of the safety and toxicity of these carbon nanostructures, which is vital to their use as diagnostic and therapeutic tools in biomedical fields, has not been completely resolved. This paper aims to provide a summary of the features of carbon nanotube and graphene-based materials and current research progress in biomedical applications. We also highlight the current opinions within the scientific community on the toxicity and safety of these carbon structures.

  4. New Method Developed To Purify Single Wall Carbon Nanotubes for Aerospace Applications

    Science.gov (United States)

    Lebron, Marisabel; Meador, Michael A.

    2003-01-01

    Single wall carbon nanotubes have attracted considerable attention because of their remarkable mechanical properties and electrical and thermal conductivities. Use of these materials as primary or secondary reinforcements in polymers or ceramics could lead to new materials with significantly enhanced mechanical strength and electrical and thermal conductivity. Use of carbon-nanotube-reinforced materials in aerospace components will enable substantial reductions in component weight and improvements in durability and safety. Potential applications for single wall carbon nanotubes include lightweight components for vehicle structures and propulsion systems, fuel cell components (bipolar plates and electrodes) and battery electrodes, and ultra-lightweight materials for use in solar sails. A major barrier to the successful use of carbon nanotubes in these components is the need for methods to economically produce pure carbon nanotubes in large enough quantities to not only evaluate their suitability for certain applications but also produce actual components. Most carbon nanotube synthesis methods, including the HiPCO (high pressure carbon monoxide) method developed by Smalley and others, employ metal catalysts that remain trapped in the final product. These catalyst impurities can affect nanotube properties and accelerate their decomposition. The development of techniques to remove most, if not all, of these impurities is essential to their successful use in practical applications. A new method has been developed at the NASA Glenn Research Center to purify gram-scale quantities of single wall carbon nanotubes. This method, a modification of a gas phase purification technique previously reported by Smalley and others, uses a combination of high-temperature oxidations and repeated extractions with nitric and hydrochloric acid. This improved procedure significantly reduces the amount of impurities (catalyst and nonnanotube forms of carbon) within the nanotubes, increasing

  5. Skeletal myotube formation enhanced by electrospun polyurethane carbon nanotube scaffolds

    OpenAIRE

    Sirivisoot S; Harrison BS

    2011-01-01

    Sirinrath Sirivisoot, Benjamin S Harrison Wake Forest Institute for Regenerative Medicine, Wake Forest University Health Sciences, Medical Center Boulevard, Winston-Salem, NC, USA Background: This study examined the effects of electrically conductive materials made from electrospun single- or multiwalled carbon nanotubes with polyurethane to promote myoblast differentiation into myotubes in the presence and absence of electrical stimulation. Methods and results: After electrical stimulation,...

  6. Ultrafast Photoconductivity of Graphene Nanoribbons and Carbon Nanotubes

    DEFF Research Database (Denmark)

    Jensen, Søren A.; Ulbricht, Ronald; Narita, Akimitsu;

    2013-01-01

    carbon nanotubes (CNTs) with a similar bandgap energy. Transient photoconductivities of both materials were measured using time-resolved terahertz spectroscopy, allowing for contact-free measurements of complex-valued photoconductivity spectra with subpicosecond time-resolution. We show that, while...

  7. Structural and biological properties of carbon nanotube composite films

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Roger J. [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States)]. E-mail: roger.narayan@mse.gatech.edu; Berry, C.J. [Environmental Biotechnology Section, Savannah River National Laboratory, Aiken, SC 29808 (United States); Brigmon, R.L. [Environmental Biotechnology Section, Savannah River National Laboratory, Aiken, SC 29808 (United States)

    2005-11-20

    Carbon nanotube composite films have been developed that exhibit unusual structural and biological properties. These novel materials have been created by pulsed laser ablation of graphite and bombardment of nitrogen ions at temperatures between 600 and 700 deg. C. High-resolution transmission electron microscopy and radial distribution function analysis demonstrate that this material consists of sp{sup 2}-bonded concentric ribbons that are wrapped approximately 15 deg. normal to the silicon substrate. The interlayer order in this material extends to approximately 15-30 A. X-ray photoelectron spectroscopy and Raman spectroscopy data suggest that this material is predominantly trigonally coordinated. The carbon nanotube composite structure results from the use of energetic ions, which allow for non-equilibrium growth of graphitic planes. In vitro testing has revealed significant antimicrobial activity of carbon nanotube composite films against Staphylococcus aureus and Staphylococcus warneri colonization. Carbon nanotube composite films may be useful for inhibiting microorganism attachment and biofilm formation in hemodialysis catheters and other medical devices.

  8. Carbon nanotube ecotoxicity in amphibians: assessment of multiwalled carbon nanotubes and comparison with double-walled carbon nanotubes.

    Science.gov (United States)

    Mouchet, Florence; Landois, Perine; Puech, Pascal; Pinelli, Eric; Flahaut, Emmanuel; Gauthier, Laury

    2010-08-01

    The potential impact of industrial multiwalled carbon nanotubes (MWNTs) was investigated under normalized laboratory conditions according to the International Standard micronucleus assay ISO 21427-1 for 12 days of half-static exposure to 0.1, 1, 10 and 50 mg/l of MWNTs in water. Three different end points were carried out for 12 days of exposure: mortality, growth inhibition and micronuclei induction in erythrocytes of the circulating blood of larvae. Raman spectroscopy analysis was used to study the presence of carbon nanotubes in the biological samples. Considering the high diversity of carbon nanotubes according to their different characteristics, MWNTs were analyzed in Xenopus larvae, comparatively to double-walled carbon nanotubes used in a previous study in similar conditions. Growth inhibition in larvae exposed to 50 mg/l of MWNTs was evidenced; however, no genetoxicity (micronucleus assay) was noticed, at any concentration. Carbon nanotube localization in the larvae leads to different possible hypothesis of mechanisms explaining toxicity in Xenopus.

  9. Carbon Nanotube-Based Synthetic Gecko Tapes

    Science.gov (United States)

    Dhinojwala, Ali

    2008-03-01

    Wall-climbing geckos have unique ability to attach to different surfaces without the use of any viscoelastic glues. On coming in contact with any surface, the micron-size gecko foot-hairs deform, enabling molecular contact over large areas, thus translating weak van der Waals (vdW) interactions into enormous shear forces. We will present our recent results on the development of synthetic gecko tape using aligned carbon nanotubes to mimic the keratin hairs found on gecko feet. The patterned carbon nanotube-based gecko tape can support a shear stress (36 N/cm^2) nearly four times higher than the gecko foot and sticks to a variety of surfaces, including Teflon. Both the micron-size setae (replicated by nanotube bundles) and nanometer-size spatulas (individual nanotubes) are necessary to achieve macroscopic shear adhesion and to translate the weak vdW interactions into high shear forces. The carbon nanotube based tape offers an excellent synthetic option as a dry conductive reversible adhesive in microelectronics, robotics and space applications. The mechanism behind these large shear forces and self-cleaning properties of these carbon nanotube based synthetic gecko tapes will be discussed. This work was performed in collaboration with graduate students Liehui Ge, and Sunny Sethi, and collaborators from RPI; Lijie Ci and Professor Pulickel Ajayan.

  10. Materials for carbon dioxide separation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qingqing

    2014-10-01

    The CO{sub 2} adsorption capacities at room temperature have been investigated by comparing carbon nanotubes, fullerene, graphenes, graphite and granular activated carbons. It turned out that the amount of the micropore surface area was dominating the CO{sub 2} adsorption ability. Another promising class of materials for CO{sub 2} capture and separation are CaO derived from the eggshells. Two aspects were studied in present work: a new hybrid materials synthesized by doping the CaTiO{sub 3} and the relationship between physisorption and chemisorption properties of CaO-based materials.

  11. Synthesis of single wall carbon nanotubes from a lamellar type aluminophosphate (AlPO4-L)

    Indian Academy of Sciences (India)

    N Venkatathri

    2008-08-01

    Single wall carbon nanotubes are synthesized from a lamellar type aluminophosphate, AlPO4-L. The lamellar aluminophosphate was synthesized from hexamethyleneimine template. The latter was calcined at argon atmosphere for 12 h at 600°C. The resulting carbonaceous material was treated with 1 N H2SO4 to remove the aluminophosphate skeleton. Characterization of the resulting carbon revealed to contain single walled nanotubes. These nanotubes are applicable to store more hydrogen.

  12. 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 ...

  13. Methods for Gas Sensing with Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Kaul, Anupama B. (Inventor)

    2013-01-01

    Methods for gas sensing with single-walled carbon nanotubes are described. The methods comprise biasing at least one carbon nanotube and exposing to a gas environment to detect variation in temperature as an electrical response.

  14. Carbon Nanotube-Based Permeable Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Holt, J K; Park, H G; Bakajin, O; Noy, A; Huser, T; Eaglesham, D

    2004-04-06

    A membrane of multiwalled carbon nanotubes embedded in a silicon nitride matrix was fabricated for use in studying fluid mechanics on the nanometer scale. Characterization by fluorescent tracer diffusion and scanning electron microscopy suggests that the membrane is void-free near the silicon substrate on which it rests, implying that the hollow core of the nanotube is the only conduction path for molecular transport. Assuming Knudsen diffusion through this nanotube membrane, a maximum helium transport rate (for a pressure drop of 1 atm) of 0.25 cc/sec is predicted. Helium flow measurements of a nanoporous silicon nitride membrane, fabricated by sacrificial removal of carbon, give a flow rate greater than 1x10{sup -6} cc/sec. For viscous, laminar flow conditions, water is estimated to flow across the nanotube membrane (under a 1 atm pressure drop) at up to 2.8x10{sup -5} cc/sec (1.7 {micro}L/min).

  15. Carbon Nanotubes and Chronic Granulomatous Disease

    Directory of Open Access Journals (Sweden)

    Barbara P. Barna

    2014-06-01

    Full Text Available Use of nanomaterials in manufactured consumer products is a rapidly expanding industry and potential toxicities are just beginning to be explored. Combustion-generated multiwall carbon nanotubes (MWCNT or nanoparticles are ubiquitous in non-manufacturing environments and detectable in vapors from diesel fuel, methane, propane, and natural gas. In experimental animal models, carbon nanotubes have been shown to induce granulomas or other inflammatory changes. Evidence suggesting potential involvement of carbon nanomaterials in human granulomatous disease, has been gathered from analyses of dusts generated in the World Trade Center disaster combined with epidemiological data showing a subsequent increase in granulomatous disease of first responders. In this review we will discuss evidence for similarities in the pathophysiology of carbon nanotube-induced pulmonary disease in experimental animals with that of the human granulomatous disease, sarcoidosis.

  16. Optical trapping of carbon nanotubes and graphene

    OpenAIRE

    Vasi, S.; M. A. Monaca; Donato, M. G.; Bonaccorso, F.; Privitera, G; Trushkevych, O.; G. Calogero; Fazio, B.; Irrera, A.; M.A. Iati'; Saija, R.; Denti, P.; F. Borghese; Jones, P H; Ferrari, A. C.

    2011-01-01

    We study optical trapping of nanotubes and graphene. We extract the distribution of both centre-of-mass and angular fuctuations from three-dimensional tracking of these optically trapped carbon nanostructures. The optical force and torque constants are measured from auto and cross-correlation of the tracking signals. We demonstrate that nanotubes enable nanometer spatial, and femto-Newton force resolution in photonic force microscopy by accurately measuring the radiation pressure in a double ...

  17. Efficiently Dispersing Carbon Nanotubes in Polyphenylene Sulfide

    OpenAIRE

    Sommer, Kevin M; Pipes, R. Byron

    2013-01-01

    Thermal plastics are replacing conventional metals in the aerospace, sporting, electronics, and other industries. Thermal plastics are able to withstand relatively high temperatures, have good fatigue properties, and are lighter than metals. Unfortunately, they are not very electrically conductive. However, adding carbon nanotubes to thermal plastics such as polyphenylene sulfide (PPS) can drastically increase the plastic's conductivity at a low weight percent of nanotubes called the percolat...

  18. Charge-carrier transport mechanisms in composites containing carbon-nanotube inclusions

    Energy Technology Data Exchange (ETDEWEB)

    Usanov, D. A., E-mail: UsanovDA@info.sgu.ru; Skripal’, A. V.; Romanov, A. V. [Saratov State University (Russian Federation)

    2015-12-15

    From the microwave-radiation transmittance and reflectance spectra, the temperature dependence of the complex permittivity of carbon nanotubes, subjected to high-temperature annealing, and composite materials produced on their basis is determined. The electron transport mechanisms in composites with inclusions of unannealed carbon nanotubes and nanotubes subjected to high-temperature annealing are determined. The influence of the annealing temperature on the parameters that are characteristic of these mechanisms and control the temperature dependence of the conductivity of multiwall carbon nanotubes is established.

  19. Charge-carrier transport mechanisms in composites containing carbon-nanotube inclusions

    International Nuclear Information System (INIS)

    From the microwave-radiation transmittance and reflectance spectra, the temperature dependence of the complex permittivity of carbon nanotubes, subjected to high-temperature annealing, and composite materials produced on their basis is determined. The electron transport mechanisms in composites with inclusions of unannealed carbon nanotubes and nanotubes subjected to high-temperature annealing are determined. The influence of the annealing temperature on the parameters that are characteristic of these mechanisms and control the temperature dependence of the conductivity of multiwall carbon nanotubes is established

  20. Thermal Transport in Carbon Nanotubes

    Science.gov (United States)

    Christman, Jeremy; Moore, Andrew; Khatun, Mahfuza

    2011-10-01

    Recent advances in nanostructure technology have made it possible to create small devices at the nanoscale. Carbon nanotubes (CNT's) are among the most exciting building blocks of nanotechnology. Their versatility and extremely desirable properties for electronic and other devices have driven intense research and development efforts in recent years. A review of electrical and thermal conduction of the structures will be presented. The theoretical investigation is mainly based on molecular dynamics. Green Kubo relation is used for the study of thermal conductivity. Results include kinetic energy, potential energy, heat flux autocorrelation function, and heat conduction of various CNT structures. Most of the computation and simulation has been conducted on the Beowulf cluster at Ball State University. Various software packages and tools such as Visual Molecular Dynamics (VMD), Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS), and NanoHUB, the open online resource at Purdue University have been used for the research. The work has been supported by the Indiana Academy of Science Research Fund, 2010-2011.

  1. Does water dope carbon nanotubes?

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Robert A.; Payne, Michael C. [Theory of Condensed Matter Group, Cavendish Laboratory, Cambridge (United Kingdom); Mostofi, Arash A. [Department of Materials and Department of Physics, and the Thomas Young Centre for Theory and Simulation of Materials, Imperial College London, London SW7 2AZ (United Kingdom)

    2014-10-28

    We calculate the long-range perturbation to the electronic charge density of carbon nanotubes (CNTs) as a result of the physisorption of a water molecule. We find that the dominant effect is a charge redistribution in the CNT due to polarisation caused by the dipole moment of the water molecule. The charge redistribution is found to occur over a length-scale greater than 30 Å, highlighting the need for large-scale simulations. By comparing our fully first-principles calculations to ones in which the perturbation due to a water molecule is treated using a classical electrostatic model, we estimate that the charge transfer between CNT and water is negligible (no more than 10{sup −4} e per water molecule). We therefore conclude that water does not significantly dope CNTs, a conclusion that is consistent with the poor alignment of the relevant energy levels of the water molecule and CNT. Previous calculations that suggest water n-dopes CNTs are likely due to the misinterpretation of Mulliken charge partitioning in small supercells.

  2. Elastomer Reinforced with Carbon Nanotubes

    Science.gov (United States)

    Hudson, Jared L.; Krishnamoorti, Ramanan

    2009-01-01

    Elastomers are reinforced with functionalized, single-walled carbon nanotubes (SWNTs) giving them high-breaking strain levels and low densities. Cross-linked elastomers are prepared using amine-terminated, poly(dimethylsiloxane) (PDMS), with an average molecular weight of 5,000 daltons, and a functionalized SWNT. Cross-link densities, estimated on the basis of swelling data in toluene (a dispersing solvent) indicated that the polymer underwent cross-linking at the ends of the chains. This thermally initiated cross-linking was found to occur only in the presence of the aryl alcohol functionalized SWNTs. The cross-link could have been via a hydrogen-bonding mechanism between the amine and the free hydroxyl group, or via attack of the amine on the ester linage to form an amide. Tensile properties examined at room temperature indicate a three-fold increase in the tensile modulus of the elastomer, with rupture and failure of the elastomer occurring at a strain of 6.5.

  3. Mechanical strength of carbon nanotube nickel nanocomposites

    Science.gov (United States)

    Sun, Ying; Sun, Jianren; Liu, Miao; Chen, Quanfang

    2007-12-01

    Carbon nanotubes (CNTs), including single-walled CNT (SWCNT) and multi-walled CNT (MWCNT), have been regarded as the stiffest and strongest materials ever developed and are promising reinforcement fillers for developing nanocomposites. However, the scientific community has been puzzled about the reinforcement efficiency. Here we report CNT-reinforced nickel nanocomposites fabricated with an innovative electrochemical co-deposition process for achieving good interfacial bonding between CNT and metallic matrices. Test results show that Ni/SWCNT composite produces a tensile strength as high as 2 GPa, which is more than three times stronger than that of pure nickel. The mechanical strength of Ni/CNT nanocomposites is dependent on CNT addition, while the fracture strain remains similar or better than that of pure nickel. The good reinforcement of CNT/metal nanocomposites is attributed to the good interfacial bonding as well as the stiffer matrix nature.

  4. Preparation and characterization of carbon nanotube-hybridized carbon fiber to reinforce epoxy composite

    International Nuclear Information System (INIS)

    Highlights: → CNTs were uniformly grown onto the carbon fibers. → No obvious mechanical properties of carbon fiber were observed after CNT growth. → The IFSS of multiscale epoxy composite was measured by single fiber pull-out tests. → Observing fractography of composite, the fracture modes of CNTs were discussed. -- Abstract: The multiscale carbon nanotube-hybridized carbon fiber was prepared by a newly developed aerosol-assisted chemical vapour deposition. Scanning electron microscopy and transmission electron microscope were carried out to characterize this multiscale material. Compared with the original carbon fibers, the fabrication of this hybrid fiber resulted in an almost threefold increase of BET surface area to reach 2.22 m2/g. Meanwhile, there was a slight degradation of fiber tensile strength within 10%, while the fiber modulus was not significantly affected. The interfacial shearing strength of a carbon fiber-reinforced polymer composite with carbon nanotube-hybridized carbon fiber and an epoxy matrix was determined from the single fiber pull-out tests of microdroplet composite. Due to an efficient increase of load transfer at the fiber/matrix interfaces, the interracial shear strength of composite reinforced by carbon nanotube-hybridized carbon fiber is almost 94% higher than that of one reinforced by the original carbon fiber. Based on the fractured morphologies of the composites, the interfacial reinforcing mechanisms were discussed through proposing different types of carbon nanotube fracture modes along with fiber pulling out from epoxy composites.

  5. Edge effects in finite elongated carbon nanotubes

    CERN Document Server

    Hod, O; Scuseria, G E; Hod, Oded; Peralta, Juan E.; Scuseria, Gustavo E.

    2006-01-01

    The importance of finite-size effects for the electronic structure of long zigzag and armchair carbon nanotubes is studied. We analyze the electronic structure of capped (6,6), (8,0), and (9,0) single walled carbon nanotubes as a function of their length up to 60 nm, using a divide and conquer density functional theory approach. For the metallic nanotubes studied, most of the physical features appearing in the density of states of an infinite carbon nanotube are recovered at a length of 40 nm. The (8,0) semi-conducting nanotube studied exhibits pronounced edge effects within the energy gap that scale as the inverse of the length of the nanotube. As a result, the energy gap reduces from the value of ~1 eV calculated for the periodic system to a value of ~0.25 eV calculated for a capped 62 nm long CNT. These edge effects are expected to become negligible only at tube lengths exceeding 6 micrometers. Our results indicate that careful tailoring of the nature of the system and its capping units should be applied w...

  6. Chitosan-mediated synthesis of carbon nanotube-gold nanohybrids

    Institute of Scientific and Technical Information of China (English)

    GRAVEL; Edmond; FOILLARD; Stéphanie; DORIS; Eric

    2010-01-01

    Metal-nanotube nanohybrids were produced by in situ synthesis and stabilization of gold nanoparticles on chitosan-functionalized carbon nanotubes.The formation of gold nanoparticles from tetrachloroauric acid was observed after only a few minutes of contact with the functionalized nanotubes,at room temperature.These results suggest that adsorption of chitosan at the surface of carbon nanotubes permits smooth reduction of the metallic salt and efficient anchoring of gold nanoparticles to the nanotubes.

  7. WIMP detection and slow ion dynamics in carbon nanotube arrays

    OpenAIRE

    Cavoto, G.; Cirillo, E. N. M.; Cocina, F.; Ferretti, J.; Polosa, A.D.

    2016-01-01

    Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy lo...

  8. Transport Properties of Carbon-Nanotube/Cement Composites

    NARCIS (Netherlands)

    Han, B.; Yang, Z.; Shi, X.; Yu, X.

    2012-01-01

    This paper preliminarily investigates the general transport properties (i.e., water sorptivity, water permeability, and gas permeability) of carbon-nanotube/cement composites. Carboxyl multi-walled carbon nanotubes (MWNTs) are dispersed into cement mortar to fabricate the carbon nanotubes (CNTs) rei

  9. Deposition of the platinum crystals on the carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new technique and the affecting factors for depositing platinum on the carbon nanotubes were investigated. The results show that the deposited platinum crystals in the atmosphere of hydrogen or nitrogen have a small size and a homogeneous distribution on the surface of the carbon nanotubes. The pretreatment would decrease the platinum particles on the carbon nanotubes significantly.

  10. Improvements in Production of Single-Walled Carbon Nanotubes

    Science.gov (United States)

    Balzano, Leandro; Resasco, Daniel E.

    2009-01-01

    A continuing program of research and development has been directed toward improvement of a prior batch process in which single-walled carbon nanotubes are formed by catalytic disproportionation of carbon monoxide in a fluidized-bed reactor. The overall effect of the improvements has been to make progress toward converting the process from a batch mode to a continuous mode and to scaling of production to larger quantities. Efforts have also been made to optimize associated purification and dispersion post processes to make them effective at large scales and to investigate means of incorporating the purified products into composite materials. The ultimate purpose of the program is to enable the production of high-quality single-walled carbon nanotubes in quantities large enough and at costs low enough to foster the further development of practical applications. The fluidized bed used in this process contains mixed-metal catalyst particles. The choice of the catalyst and the operating conditions is such that the yield of single-walled carbon nanotubes, relative to all forms of carbon (including carbon fibers, multi-walled carbon nanotubes, and graphite) produced in the disproportionation reaction is more than 90 weight percent. After the reaction, the nanotubes are dispersed in various solvents in preparation for end use, which typically involves blending into a plastic, ceramic, or other matrix to form a composite material. Notwithstanding the batch nature of the unmodified prior fluidized-bed process, the fluidized-bed reactor operates in a continuous mode during the process. The operation is almost entirely automated, utilizing mass flow controllers, a control computer running software specific to the process, and other equipment. Moreover, an important inherent advantage of fluidized- bed reactors in general is that solid particles can be added to and removed from fluidized beds during operation. For these reasons, the process and equipment were amenable to

  11. Lithium ion batteries made of electrodes with 99 wt% active materials and 1 wt% carbon nanotubes without binder or metal foils

    Science.gov (United States)

    Hasegawa, Kei; Noda, Suguru

    2016-07-01

    Herein, we propose lithium ion batteries (LIBs) without binder or metal foils, based on a three-dimensional carbon nanotube (CNT) current collector. Because metal foils occupy 20-30 wt% of conventional LIBs and the polymer binder has no electrical conductivity, replacing such non-capacitive materials is a valid approach for improving the energy and power density of LIBs. Adding only 1 wt% of few-wall CNTs to the active material enables flexible freestanding sheets to be fabricated by simple dispersion and filtration processes. Coin cell tests are conducted on full cells fabricated from a 99 wt% LiCoO2-1 wt% CNT cathode and 99 wt% graphite-1 wt% CNT anode. Discharge capacities of 353 and 306 mAh ggraphite-1 are obtained at charge-discharge rates of 37.2 and 372 mA ggraphite-1, respectively, with a capacity retention of 65% at the 500th cycle. The suitability of the 1 wt% CNT-based composite electrodes for practical scale devices is demonstrated with laminate cells containing 50 × 50 mm2 electrodes. Use of metal combs instead of metal foils enables charge-discharge operation of the laminate cell without considerable IR drop. Such electrodes will minimize the amount of metal and maximize the amount of active materials contained in LIBs.

  12. Current-Voltage Characteristics of the Composites Based on Epoxy Resin and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Iwona Pełech

    2015-01-01

    Full Text Available Polymer composites based on epoxy resin were prepared. Multiwalled carbon nanotubes synthesized on iron-cobalt catalyst were applied as a filler in a polymer matrix. Chlorine or hydroxyl groups were incorporated on the carbon nanotubes surface via chlorination or chlorination followed by hydroxylation. The effect of functionalized carbon nanotubes on the epoxy resin matrix is discussed in terms of the state of CNTs dispersion in composites as well as electrical properties. For the obtained materials current-voltage characteristics were determined. They had a nonlinear character and were well described by an exponential-type equation. For all the obtained materials the percolation threshold occurred at a concentration of about 1 wt%. At a higher filler concentration >2 wt%, better conductivity was demonstrated by polymer composites with raw carbon nanotubes. At a lower filler concentration <2 wt%, higher values of electrical conductivity were obtained for polymer composites with modified carbon nanotubes.

  13. Decoration of activated carbon nanotubes by assembling nano-silver

    Institute of Scientific and Technical Information of China (English)

    Chen-sha Li; Bin-song Wang; Ying-jie Qiao; Wei-zhe Lu; Ji Liang

    2009-01-01

    A facile solution processed strategy of synthesizing nano silver assembled on carbon nanotubes (CNTs) at room tempera-ture was put forward. Activated carbon nanotubes were used as precursors for preparing silver-decorated nanotubes. The nature of the decorated nanotubes was studied using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and en-ergy-dispersive X-ray spectroscopy (EDX). The inert surfaces of carbon nanotubes were activated by introducing catalytic nuclei via an oxidation-sensitization-activation approach. Activated carbon nanotubes catalyzed the metal deposition specifically onto their surfaces upon immersion in electroless plating baths. The method produced nanotubes decorated with silver. The extent of silver decoration was found to be dependent on fabrication conditions. Dense nano silver assembled on nanotube surfaces could be ob-tained by keeping a low reaction rate in the solution phase. The results here show that this method is an efficient and simple means of achieving carbon nanotubes being assembled by nano metal.

  14. Geometric and electronic structure of carbon nanotube networks: 'super'-carbon nanotubes

    Science.gov (United States)

    Coluci, V. R.; Galvão, D. S.; Jorio, A.

    2006-02-01

    Structures of the so-called super-carbon nanotubes are proposed. These structures are built from single walled carbon nanotubes connected by Y-like junctions forming a 'super'-sheet that is then rolled into a seamless cylinder. Such a procedure can be repeated several times, generating a fractal structure. This procedure is not limited to carbon nanotubes, and can be easily modified for application to other systems. Tight binding total energy and density of states calculations showed that the 'super'-sheets and tubes are stable and predicted to present metallic and semiconducting behaviour.

  15. Nanocrystalline cobalt oxides for carbon nanotube growth

    Science.gov (United States)

    Guo, Kun; Jayatissa, Ahalapitiya H.; Jayasuriya, Ambalangodage C.

    2007-09-01

    Thin Films of nanocrystalline cobalt oxide were formed by sol-gel method. Structure, optical properties and surface properties of these films were investigated by numerous characterization techniques. These films were successfully fabricated on glass substrates below 500°C. . Micropatterns of cobalt oxide thin films were also fabricated on glass and silicon substrates by employing a lift-off method. Crystal size of these nanocrystalline cobalt films could be successfully controllable by varying the amount of cobalt precursors and number of layers. These films were used as the seeding layers for carbon nanotube growth in a CVD process By changing the concentration of monomer precursors in the solgel coating solutions, different size nanoclusters hence different size carbon nanotubes could be synthesized in CVD process. This method can be used for controlled growth of carbon nanotubes for many different applications. In this paper, detail of these experimental results will be presented.

  16. Modelling Carbon Nanotubes-Based Mediatorless Biosensor

    Directory of Open Access Journals (Sweden)

    Julija Razumiene

    2012-07-01

    Full Text Available This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments: a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate.

  17. Modelling carbon nanotubes-based mediatorless biosensor.

    Science.gov (United States)

    Baronas, Romas; Kulys, Juozas; Petrauskas, Karolis; Razumiene, Julija

    2012-01-01

    This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments): a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate. PMID:23012537

  18. Detection of gas atoms with carbon nanotubes

    Science.gov (United States)

    Arash, B.; Wang, Q.

    2013-05-01

    Owning to their unparalleled sensitivity resolution, nanomechanical resonators have excellent capabilities in design of nano-sensors for gas detection. The current challenge is to develop new designs of the resonators for differentiating distinct gas atoms with a recognizably high sensitivity. In this work, the characteristics of impulse wave propagation in carbon nanotube-based sensors are investigated using molecular dynamics simulations to provide a new method for detection of noble gases. A sensitivity index based on wave velocity shifts in a single-walled carbon nanotube, induced by surrounding gas atoms, is defined to explore the efficiency of the nano-sensor. The simulation results indicate that the nano-sensor is able to differentiate distinct noble gases at the same environmental temperature and pressure. The inertia and the strengthening effects by the gases on wave characteristics of carbon nanotubes are particularly discussed, and a continuum mechanics shell model is developed to interpret the effects.

  19. High frequency conductivity in carbon nanotubes

    Directory of Open Access Journals (Sweden)

    S. S. Abukari

    2012-12-01

    Full Text Available We report on theoretical analysis of high frequency conductivity in carbon nanotubes. Using the kinetic equation with constant relaxation time, an analytical expression for the complex conductivity is obtained. The real part of the complex conductivity is initially negative at zero frequency and become more negative with increasing frequency, until it reaches a resonance minimum at ω ∼ ωB for metallic zigzag CNs and ω < ωB for armchair CNs. This resonance enhancement is indicative for terahertz gain without the formation of current instabilities induced by negative dc conductivity. We noted that due to the high density of states of conduction electrons in metallic zigzag carbon nanotubes and the specific dispersion law inherent in hexagonal crystalline structure result in a uniquely high frequency conductivity than the corresponding values for metallic armchair carbon nanotubes. We suggest that this phenomenon can be used to suppress current instabilities that are normally associated with a negative dc differential conductivity.

  20. Investigating the effect of carbon nanotube diameter and wall number in carbon nanotube/silicon heterojunction solar cells

    OpenAIRE

    Tom Grace; LePing Yu; Christopher Gibson; Daniel Tune; Huda Alturaif; Zeid Al Othman; Joseph Shapter

    2016-01-01

    Suspensions of single-walled, double-walled and multi-walled carbon nanotubes (CNTs) were generated in the same solvent at similar concentrations. Films were fabricated from these suspensions and used in carbon nanotube/silicon heterojunction solar cells and their properties were compared with reference to the number of walls in the nanotube samples. It was found that single-walled nanotubes generally produced more favorable results; however, the double and multi-walled nanotube films used in...

  1. Molecular Dynamics Modeling of Carbon Nanotubes and Their Composites

    Science.gov (United States)

    Jensen, Lars R.; Pyrz, Ryszard

    2004-06-01

    The tensile modulus of individual nanotubes and nanotube-polypropylene composites has been determined using molecular dynamics simulations. Simulations of individual single-walled carbon nanotubes showed that their tensile modulus was dependent on the tube structure and the diameter if the diameter was below 1,6 nm. The tensile modulus was determined for an infinite single-walled carbon nanotube embedded in an amorphous polypropylene matrix and for a finite and capped single-walled carbon nanotube embedded in a polypropylene matrix. For the infinite nanotube-polypropylene system the modulus was found to correspond to the one given by the Voigt approximation. For the finite nanotube-polypropylene system the reinforcing effect of the nanotube was not very pronounced. A pull out simulation showed that the length of the nanotube in the simulation was much smaller than the critical length and hence no load transfer between the nanotube and the matrix existed.

  2. Development of carbon nanotubes/CoFe{sub 2}O{sub 4} magnetic hybrid material for removal of tetrabromobisphenol A and Pb(II)

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Lincheng, E-mail: zhoulc@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000 (China); Ji, Liqin [State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000 (China); Ma, Peng-Cheng [The Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Shao, Yanming; Zhang, He; Gao, Weijie; Li, Yanfeng [State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000 (China)

    2014-01-30

    Highlights: • Amino-functionalized CoFe{sub 2}O{sub 4} nanoparticles were deposited on MWCNTs in one-pot. • Novel chitosan modified MWCNTs/CoFe{sub 2}O{sub 4} hybrid material were successfully synthesized. • The hybrid material had high specific surface area and abundant functional groups. • The hybrid material exhibited high adsorption properties for TBBPA and Pb(II). • The hybrid material was an efficient, eco-friendly and reusable adsorbent. -- Abstract: Multi-walled carbon nanotubes (MWCNTs) coated with magnetic amino-modified CoFe{sub 2}O{sub 4} (CoFe{sub 2}O{sub 4}–NH{sub 2}) nanoparticles (denoted as MNP) were prepared via a simple one-pot polyol method. The MNP composite was further modified with chitosan (CTS) to obtain a chitosan-functionalized MWCNT/CoFe{sub 2}O{sub 4}–NH{sub 2} hybrid material (MNP–CTS). The obtained hybrid materials were characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectrogram (FT-IR) Analysis and X-ray Photoelectron Spectroscopy (XPS) Analysis, Vibrating Sample Magnetometer (VSM) Analysis and the Brunauer–Emmett–Teller (BET) surface area method, respectively. The composites were tested as adsorbents for tetrabromobisphenol A (TBBPA) and Pb(II), and were investigated using a pseudo-second-order model. The adsorption of TBBPA was well represented by the Freundlich isotherm; the Langmuir model better described Pb(II) absorption. MNP–CTS adsorbed both TBBPA and Pb(II) (maximum adsorption capacities of 42.48 and 140.1 mg g{sup −1}, respectively) better than did MNP without CTS. Magnetic composite particles with adsorbed TBBPA and Pb(II) could be regenerated using 0.2 M NaOH solution and were separable from liquid media using a magnetic field.

  3. A Taste Sensor Based on a Carbon Nanotube

    Science.gov (United States)

    Takagi, Keisuke; Hirata, Takamichi; Akiya, Masahiro

    A taste sensor consisting of a back-gate type field effect transistor(FET) chip based on carbon nanotube compound materials[poly(ethylene glycol)(PEG)-grafted single-walled carbon nanotubes(PEG-SWNTs)] was developed. The results of impedance measurements for five tastes (sourness, saltiness, bitterness, sweetness, and umami), are shown much difference for specific tastes which are difficult to identify by using Langmuir-Blodgett(LB)film. Moreover, the sensor is able to distinguish most of the experimental taste materials with a short response time. Characteristics of the sensor involve in taste material concentration , initial impedance and frequency characteristics. A clear difference is observed over five basic taste materials.

  4. Center for Applications of Single-Walled Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Resasco, Daniel E

    2008-02-21

    This report describes the activities conducted under a Congressional Direction project whose goal was to develop applications for Single-walled carbon nanotubes, under the Carbon Nanotube Technology Center (CANTEC), a multi-investigator program that capitalizes on OU’s advantageous position of having available high quality carbon nanotubes. During the first phase of CANTEC, 11 faculty members and their students from the College of Engineering developed applications for carbon nanotubes by applying their expertise in a number of areas: Catalysis, Reaction Engineering, Nanotube synthesis, Surfactants, Colloid Chemistry, Polymer Chemistry, Spectroscopy, Tissue Engineering, Biosensors, Biochemical Engineering, Cell Biology, Thermal Transport, Composite Materials, Protein synthesis and purification, Molecular Modeling, Computational Simulations. In particular, during this phase, the different research groups involved in CANTEC made advances in the tailoring of Single-Walled Carbon Nanotubes (SWNT) of controlled diameter and chirality by Modifying Reaction Conditions and the Nature of the catalyst; developed kinetic models that quantitatively describe the SWNT growth, created vertically oriented forests of SWNT by varying the density of metal nanoparticles catalyst particles, and developed novel nanostructured SWNT towers that exhibit superhydrophobic behavior. They also developed molecular simulations of the growth of Metal Nanoparticles on the surface of SWNT, which may have applications in the field of fuell cells. In the area of biomedical applications, CANTEC researchers fabricated SWNT Biosensors by a novel electrostatic layer-by-layer (LBL) deposition method, which may have an impact in the control of diabetes. They also functionalized SWNT with proteins that retained the protein’s biological activity and also retained the near-infrared light absorbance, which finds applications in the treatment of cancer.

  5. A carbon nanotube optical rectenna

    Science.gov (United States)

    Sharma, Asha; Singh, Virendra; Bougher, Thomas L.; Cola, Baratunde A.

    2015-12-01

    An optical rectenna—a device that directly converts free-propagating electromagnetic waves at optical frequencies to direct current—was first proposed over 40 years ago, yet this concept has not been demonstrated experimentally due to fabrication challenges at the nanoscale. Realizing an optical rectenna requires that an antenna be coupled to a diode that operates on the order of 1 PHz (switching speed on the order of 1 fs). Diodes operating at these frequencies are feasible if their capacitance is on the order of a few attofarads, but they remain extremely difficult to fabricate and to reliably couple to a nanoscale antenna. Here we demonstrate an optical rectenna by engineering metal-insulator-metal tunnel diodes, with a junction capacitance of ˜2 aF, at the tip of vertically aligned multiwalled carbon nanotubes (˜10 nm in diameter), which act as the antenna. Upon irradiation with visible and infrared light, we measure a d.c. open-circuit voltage and a short-circuit current that appear to be due to a rectification process (we account for a very small but quantifiable contribution from thermal effects). In contrast to recent reports of photodetection based on hot electron decay in a plasmonic nanoscale antenna, a coherent optical antenna field appears to be rectified directly in our devices, consistent with rectenna theory. Finally, power rectification is observed under simulated solar illumination, and there is no detectable change in diode performance after numerous current-voltage scans between 5 and 77 °C, indicating a potential for robust operation.

  6. Nitrogen in highly crystalline carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ducati, C; Koziol, K; Stavrinadis, A; Friedrichs, S; Windle, A H; Midgley, P A [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom)

    2006-02-22

    Multiwall carbon nanotubes (MWCNTs) with an unprecedented degree of internal order were synthesised by chemical vapour deposition (CVD) adding a nitrogen-containing compound to the hydrocarbon feedstock. Ferrocene was used as the metal catalyst precursor. The remarkable crystallinity of these nanotubes lies both in the isochirality and in the crystallographic register of their walls, as demonstrated by electron diffraction and high resolution electron microscopy experiments. High resolution transmission electron microscopy analysis shows that the walls of the nanotubes consist of truncated stacked cones, instead of perfect cylinders, with a range of apex angles that appears to be related to the nitrogen concentration in the synthesis process. The structure of armchair, zigzag and chiral nanotubes is modelled and discussed in terms of density of topological defects, providing an interesting comparison with our microscopy experiments. A growth mechanism based on the interplay of base- and tip-growth is proposed to account for our experimental observations.

  7. Magnetoresistance of Multiwalled Carbon Nanotube Yarns

    Institute of Scientific and Technical Information of China (English)

    SHENG Lei-Mei; GAO Wei; CAO Shi-Xun; ZHANG Jin-Cang

    2008-01-01

    We measure zero-field resistivity and magnetoresistance of multiwalled carbon nanotube yarns (CNTYs). The CNTYs are drawn from superaligned multiwalled carbon nanotube arrays synthesized by the low-pressure chemical vapour deposition method. The zero-field resistivity shows a logarithmic decrease from 2 K to 300 K. In the presence of a magnetic field applied perpendicular to the yarn axis, a pronounced negative magnetoresistance is observed. A magnetoresistance ratio of 22% is obtained. These behaviours can be explained by the weak localization effect.

  8. A carbon nanotube-based sensing element

    Institute of Scientific and Technical Information of China (English)

    YANG Xing; ZHOU Zhao-ying; WU Ying; ZHANG Jin; ZHANG Ying-ying

    2007-01-01

    A carbon nanotube-based(CNT) sensing element is presented, which consists of substrate, insulating layer, electrodes,carbon nanotube and measuring circuit. The sensing components are a single or array of CNTs, which are located on the two electrodes. The CNT-based sensing element is fabricated by CVD (chemical vapor deposition)-direct-growth on microelectrodes. The sensing model and measurement method of electromechanical property are also presented. Finally, the voltage-current characteristics are measured, which show that the CNT-based sensing element has good electrical properties.

  9. Carbon nanotubes for in vivo cancer nanotechnology

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The latest progress of using carbon nanotubes(CNTs) for in vivo cancer nanotechnology is reviewed.CNTs can be functionalized by either covalent or non-covalent chemistry to produce functional bioconjugates for many in vivo applications.In vivo behaviors and toxicology studies of CNTs are summarized,suggesting no significant toxicity of well functionalized CNTs to the treated mice.Owing to their unique chemical and physical properties,CNTs,especially single-walled carbon nanotubes(SWNTs),have been widely used for various modalities of in vivo cancer treatment and imaging.Future development of CNT-based nanomedicine may bring novel opportunities to cancer diagnosis and therapy.

  10. Laser ablative synthesis of carbon nanotubes

    Science.gov (United States)

    Smith, Michael W.; Jordan, Kevin; Park, Cheol

    2010-03-02

    An improved method for the production of single walled carbon nanotubes that utilizes an RF-induction heated side-pumped synthesis chamber for the production of such. Such a method, while capable of producing large volumes of carbon nanotubes, concurrently permits the use of a simplified apparatus that allows for greatly reduced heat up and cool down times and flexible flowpaths that can be readily modified for production efficiency optimization. The method of the present invention utilizes a free electron laser operating at high average and peak fluence to illuminate a rotating and translating graphite/catalyst target to obtain high yields of SWNTs without the use of a vacuum chamber.

  11. Piezoresistive effect in carbon nanotube films

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The piezoresistive effect of the pristine carbon nanotube (CNT) films has been studied. Carbon nanotubes were synthesized by hot filament chemical vapor deposition. The piezoresistive effect in the pristine CNT films was studied by a three-point bending test. The gauge factor for the pristine CNT films under 500 microstrains was found to be at least 65 at room temperature, and increased with temperature, exceeding that of polycrystalline silicon (30) at 35℃. The origin of the piezoresistivity in CNT films may be ascribed to a pressure-induced change in the band gap and the defects.

  12. Enhanced graphitization of carbon around carbon nanotubes during the formation of carbon nanotube/graphite composites by pyrolysis of carbon nanotube/polyaniline composites.

    Science.gov (United States)

    Nam, Dong Hoon; Cha, Seung Il; Jeong, Yong Jin; Hong, Soon Hyung

    2013-11-01

    The carbon nanotubes (CNTs) are actively applied to the reinforcements for composite materials during last decade. One of the attempts is development of CNT/Carbon composites. Although there are some reports on the enhancement of mechanical properties by addition of CNTs in carbon or carbon fiber, it is far below the expectation. Considering the microstructure of carbon materials such as carbon fiber, the properties of them can be modified and enhanced by control of graphitization and alignment of graphene planes. In this study, enhanced graphitization of carbon has been observed the vicinity of CNTs during the pyrolysis of CNT/Polyaniline composites. As a result, novel types of composite, consisting of treading CNTs and coated graphite, can be fabricated. High-resolution transmission electron microscopy revealed a specific orientation relationship between the graphene layers and the CNTs, with an angle of 110 degrees between the layers and the CNT axis. The possibility of graphene alignment control in the carbon by the addition of CNTs is demonstrated.

  13. Hierarchical MoS2 tubular structures internally wired by carbon nanotubes as a highly stable anode material for lithium-ion batteries

    Science.gov (United States)

    Chen, Yu Ming; Yu, Xin Yao; Li, Zhen; Paik, Ungyu; Lou, Xiong Wen (David)

    2016-01-01

    Molybdenum disulfide (MoS2), a typical two-dimensional material, is a promising anode material for lithium-ion batteries because it has three times the theoretical capacity of graphite. The main challenges associated with MoS2 anodes are the structural degradation and the low rate capability caused by the low intrinsic electric conductivity and large strain upon cycling. Here, we design hierarchical MoS2 tubular structures internally wired by carbon nanotubes (CNTs) to tackle these problems. These porous MoS2 tubular structures are constructed from building blocks of ultrathin nanosheets, which are believed to benefit the electrochemical reactions. Benefiting from the unique structural and compositional characteristics, these CNT-wired MoS2 tubular structures deliver a very high specific capacity of ~1320 mAh g−1 at a current density of 0.1 A g−1, exceptional rate capability, and an ultralong cycle life of up to 1000 cycles. This work may inspire new ideas for constructing high-performance electrodes for electrochemical energy storage. PMID:27453938

  14. Hierarchical MoS2 tubular structures internally wired by carbon nanotubes as a highly stable anode material for lithium-ion batteries.

    Science.gov (United States)

    Chen, Yu Ming; Yu, Xin Yao; Li, Zhen; Paik, Ungyu; Lou, Xiong Wen David

    2016-07-01

    Molybdenum disulfide (MoS2), a typical two-dimensional material, is a promising anode material for lithium-ion batteries because it has three times the theoretical capacity of graphite. The main challenges associated with MoS2 anodes are the structural degradation and the low rate capability caused by the low intrinsic electric conductivity and large strain upon cycling. Here, we design hierarchical MoS2 tubular structures internally wired by carbon nanotubes (CNTs) to tackle these problems. These porous MoS2 tubular structures are constructed from building blocks of ultrathin nanosheets, which are believed to benefit the electrochemical reactions. Benefiting from the unique structural and compositional characteristics, these CNT-wired MoS2 tubular structures deliver a very high specific capacity of ~1320 mAh g(-1) at a current density of 0.1 A g(-1), exceptional rate capability, and an ultralong cycle life of up to 1000 cycles. This work may inspire new ideas for constructing high-performance electrodes for electrochemical energy storage. PMID:27453938

  15. A concise review of carbon nanotube's toxicology

    Directory of Open Access Journals (Sweden)

    Seyed Yazdan Madani

    2013-12-01

    Full Text Available Carbon nanotubes can be either single-walled or multi-walled, each of which is known to have a different electron arrangement and as a result have different properties. However, the shared unique properties of both types of carbon nanotubes (CNT allow for their potential use in various biomedical devices and therapies. Some of the most common properties of these materials include the ability to absorb near-infra-red light and generate heat, the ability to deliver drugs in a cellular environment, their light weight, and chemical stability. These properties have encouraged scientists to further investigate CNTs as a tool for thermal treatment of cancer and drug delivery agents. Various promising data have so far been obtained about the usage of CNTs for cancer treatment; however, toxicity of pure CNTs represents a major challenge for clinical application. Various techniques both in vivo and in in vitro have been conducted by a number of different research groups to establish the factors which have a direct effect on CNT-mediated cytotoxicity. The main analysis techniques include using Alamar blue, MTT, and Trypan blue assays. Successful interpretation of these results is difficult because the CNTs can significantly disrupt the emission of the certain particles, which these assays detect. In contrast, in vivo studies allow for the measurement of toxicity and pathology caused by CNTs on an organismal level. Despite the drawbacks of in vitro studies, they have been invaluable in identifying important toxicity factors, such as size, shape, purity, and functionalisation, the latter of which can attenuate CNT toxicity.

  16. Consideration of critical axial properties of pristine and defected carbon nanotubes under compression.

    Science.gov (United States)

    Ranjbartoreh, A R; Su, D; Wang, G

    2012-06-01

    Carbon nanotubes are hexagonally configured carbon atoms in cylindrical structures. Exceptionally high mechanical strength, electrical conductivity, surface area, thermal stability and optical transparency of carbon nanotubes outperformed other known materials in numerous advanced applications. However, their mechanical behaviors under practical loading conditions remain to be demonstrated. This study investigates the critical axial properties of pristine and defected single- and multi-walled carbon nanotubes under axial compression. Molecular dynamics simulation method has been employed to consider the destructive effects of Stone-Wales and atom vacancy defects on mechanical properties of armchair and zigzag carbon nanotubes under compressive loading condition. Armchair carbon nanotube shows higher axial stability than zigzag type. Increase in wall number leads to less susceptibility of multi-walled carbon nanotubes to defects and higher stability of them under axial compression. Atom vacancy defect reveals higher destructive effect than Stone-Wales defect on mechanical properties of carbon nanotubes. Critical axial strain of single-walled carbon nanotube declines by 67% and 26% due to atom vacancy and Stone-Wales defects.

  17. Study on the application of reduced graphene oxide and multiwall carbon nanotubes hybrid materials for simultaneous determination of catechol, hydroquinone, p-cresol and nitrite

    Energy Technology Data Exchange (ETDEWEB)

    Hu Fangxin [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Chen Shihong, E-mail: cshong@swu.edu.cn [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Wang Chengyan [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yuan Ruo, E-mail: yuanruo@swu.edu.cn [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yuan Dehua; Wang Cun [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2012-04-29

    Graphical abstract: In this paper, the reduced graphene oxide and multiwall carbon nanotubes hybrid materials (RGO-MWNTs) were prepared and a novel strategy for the simultaneous determination of multiple environmental contaminations has been proposed on the basis of RGO-MWNTs hybrid materials modified electrode. The hybrid materials were characterized by the scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and N{sub 2} sorption-desorption isotherms. Due to the excellent catalytic activity, enhanced electrical conductivity, high surface area and porous structure of the RGO-MWNTs, the RGO-MWNTs/GCE achieved the simultaneous measurement of hydroquinone (HQ), catechol (CC), p-cresol (PC) and nitrite (NO{sub 2}{sup -}) with well-separate four peaks. Scheme 1a illuminated the preparation process of the RGO-MWNTs hybrid materials. Scheme 1b explains the electron mediating properties of RGO-MWNTs/GCE towards the oxidation of HQ, CC, PC and NO{sub 2}{sup -}. Scheme 1c presented the SEM image of RGO-MWNTs hybrid materials. Scheme 1d and e showed the 2D and 3D AFM images of RGO-MWNTs films, respectively. Highlights: Black-Right-Pointing-Pointer The novel RGO-MWNTs hybrid materials were synthesized. Black-Right-Pointing-Pointer The simultaneous detection of four environmental contaminations was achieved. Black-Right-Pointing-Pointer SEM, AFM, XPS was employed to characterize the RGO-MWNTs hybrid materials. - Abstract: In this paper, the reduced graphene oxide and multiwall carbon nanotubes hybrid materials (RGO-MWNTs) were prepared and a strategy for detecting environmental contaminations was proposed on the basis of RGO-MWNTs modified electrode. The hybrid materials were characterized by the scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and N{sub 2} sorption-desorption isotherms. Due to the excellent catalytic activity, enhanced electrical conductivity and high

  18. Study on the application of reduced graphene oxide and multiwall carbon nanotubes hybrid materials for simultaneous determination of catechol, hydroquinone, p-cresol and nitrite

    International Nuclear Information System (INIS)

    Graphical abstract: In this paper, the reduced graphene oxide and multiwall carbon nanotubes hybrid materials (RGO–MWNTs) were prepared and a novel strategy for the simultaneous determination of multiple environmental contaminations has been proposed on the basis of RGO–MWNTs hybrid materials modified electrode. The hybrid materials were characterized by the scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and N2 sorption–desorption isotherms. Due to the excellent catalytic activity, enhanced electrical conductivity, high surface area and porous structure of the RGO–MWNTs, the RGO–MWNTs/GCE achieved the simultaneous measurement of hydroquinone (HQ), catechol (CC), p-cresol (PC) and nitrite (NO2−) with well-separate four peaks. Scheme 1a illuminated the preparation process of the RGO–MWNTs hybrid materials. Scheme 1b explains the electron mediating properties of RGO–MWNTs/GCE towards the oxidation of HQ, CC, PC and NO2−. Scheme 1c presented the SEM image of RGO–MWNTs hybrid materials. Scheme 1d and e showed the 2D and 3D AFM images of RGO–MWNTs films, respectively. Highlights: ► The novel RGO–MWNTs hybrid materials were synthesized. ► The simultaneous detection of four environmental contaminations was achieved. ► SEM, AFM, XPS was employed to characterize the RGO–MWNTs hybrid materials. - Abstract: In this paper, the reduced graphene oxide and multiwall carbon nanotubes hybrid materials (RGO–MWNTs) were prepared and a strategy for detecting environmental contaminations was proposed on the basis of RGO–MWNTs modified electrode. The hybrid materials were characterized by the scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and N2 sorption–desorption isotherms. Due to the excellent catalytic activity, enhanced electrical conductivity and high surface area of the RGO–MWNTs, the simultaneous measurement of hydroquinone

  19. Titanium dioxide, single-walled carbon nanotube composites

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yuan; Li, Gonghu; Gray, Kimberly; Lueptow, Richard M.

    2015-07-14

    The present invention provides titanium dioxide/single-walled carbon nanotube composites (TiO.sub.2/SWCNTs), articles of manufacture, and methods of making and using such composites. In certain embodiments, the present invention provides membrane filters and ceramic articles that are coated with TiO.sub.2/SWCNT composite material. In other embodiments, the present invention provides methods of using TiO.sub.2/SWCNT composite material to purify a sample, such as a water or air sample.

  20. Structure and Strength of Iron-Copper-Carbon Nanotube Nanocomposites

    OpenAIRE

    Boshko, Oleh; Dashevskyi, Mykola; Mykhaliuk, Olga; Ivanenko, Kateryna; Hamamda, Smail; Revo, Sergiy

    2016-01-01

    Nanocomposite materials of the Fe-Cu system with/without small addition of carbon nanotubes have been synthesized by mechanochemical activation of elemental Fe and Cu powders in a high-energy planetary ball mill and have been examined by the X-ray diffraction method, SEM and the thermopower methods; the tensile strength of the materials obtained has been estimated. The metastable (Fe, Cu) supersaturated solid solution is formed in the Fe-Cu nanocomposites during milling process. The coherent ...

  1. Strain Sensors Based on Carbon Nanotube - Polymer Coatings

    OpenAIRE

    Grabowski, Krzysztof; Zbyrad, Paulina; Wilmański, Alan; Uhl, Tadeusz

    2014-01-01

    In this work there have been investigated the potential usage of the CNT's as strain sensors for the structural health monitoring based on the spray coatings. Experimental work was performed on the metal and glass-reinforced composites. Multiwalled Carbon Nanotubes (MWCNTs) were mixed with different matrix materials (acrylic and epoxy) and then applied to the test material with the use of two techniques (screen printing and spray coating). Futhermore, sensors were investigated using SEM. Resp...

  2. DNA Based Carbon Nanotube Porphyrin Nanohybrids Molecular Recognization and Regeneration

    OpenAIRE

    Riccitelli, Molly M; Zhang, Hanyu; Choi, Jong Hyun

    2013-01-01

    In the search to improve solar cells, scientists are exploring new materials that will provide better current transfer. One material that has emerged as a strong contender is the single walled carbon nanotube (SWNT). Current DNA-SWNT based films combined with chromophores have poor operational lifetimes compared to commercial solar cells. Once exposed to light the chromophore begins to degrade, eventually rendering the solar cell unusable. To solve this problem, we used a method involving mul...

  3. High Volume Fraction Carbon Nanotube Composites for Aerospace Applications

    Science.gov (United States)

    Siochi, E. J.; Kim, J.-W.; Sauti, G.; Cano, R. J.; Wincheski, R. A.; Ratcliffe, J. G.; Czabaj, M.

    2016-01-01

    Reported mechanical properties of carbon nanotubes (CNTs) at the nanoscale suggest their potential to enable significantly lighter structures of interest for space applications. However, their utility depends on the retention of these properties in bulk material formats that permit practical fabrication of large structures. This presentation summarizes recent progress made to produce carbon nanotube composites with specific tensile properties that begin to rival those of carbon fiber reinforced polymer composites. CNT content in these nanocomposites was greater than 70% by weight. Tested nanocomposite specimens were fabricated from kilometers or tens of square meters of CNT, depending on the starting material format. Processing methods to yield these results, and characterization and testing to evaluate the performance of these composites will be discussed. The final objective is the demonstration of a CNT composite overwrapped pressure vessel to be flight tested in the Fall of 2016.

  4. Nonlinear dynamics of bi-layered graphene sheet, double-walled carbon nanotube and nanotube bundle

    Science.gov (United States)

    Gajbhiye, Sachin O.; Singh, S. P.

    2016-05-01

    Due to strong van der Waals (vdW) interactions, the graphene sheets and nanotubes stick to each other and form clusters of these corresponding nanostructures, viz. bi-layered graphene sheet (BLGS), double-walled carbon nanotube (DWCNT) and nanotube bundle (NB) or ropes. This research work is concerned with the study of nonlinear dynamics of BLGS, DWCNT and NB due to nonlinear interlayer vdW forces using multiscale atomistic finite element method. The energy between two adjacent carbon atoms is represented by the multibody interatomic Tersoff-Brenner potential, whereas the nonlinear interlayer vdW forces are represented by Lennard-Jones 6-12 potential function. The equivalent nonlinear material model of carbon-carbon bond is used to model it based on its force-deflection relation. Newmark's algorithm is used to solve the nonlinear matrix equation governing the motion of the BLGS, DWCNT and NB. An impulse and harmonic excitations are used to excite these nanostructures under cantilevered, bridged and clamped boundary conditions. The frequency responses of these nanostructures are computed, and the dominant resonant frequencies are identified. Along with the forced vibration of these structures, the eigenvalue extraction problem of armchair and zigzag NB is also considered. The natural frequencies and corresponding mode shapes are extracted for the different length and boundary conditions of the nanotube bundle.

  5. Improved Method of Purifying Carbon Nanotubes

    Science.gov (United States)

    Delzeit, Lance D.

    2004-01-01

    An improved method of removing the residues of fabrication from carbon nanotubes has been invented. These residues comprise amorphous carbon and metal particles that are produced during the growth process. Prior methods of removing the residues include a variety of processes that involved the use of halogens, oxygen, or air in both thermal and plasma processes. Each of the prior methods entails one or more disadvantages, including non-selectivity (removal or damage of nanotubes in addition to removal of the residues), the need to dispose of toxic wastes, and/or processing times as long as 24 hours or more. In contrast, the process described here does not include the use of toxic chemicals, the generation of toxic wastes, causes little or no damage to the carbon nanotubes, and involves processing times of less than 1 hour. In the improved method, purification is accomplished by flowing water vapor through the reaction chamber at elevated temperatures and ambient pressures. The impurities are converted to gaseous waste products by the selective hydrogenation and hydroxylation by the water in a reaction chamber. This process could be performed either immediately after growth or in a post-growth purification process. The water used needs to be substantially free of oxygen and can be obtained by a repeated freeze-pump-thaw process. The presence of oxygen will non-selectively attach the carbon nanotubes in addition to the amorphous carbon.

  6. Carbon Nanotube Membranes: Carbon Nanotube Membranes for Energy-Efficient Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-03-01

    Broad Funding Opportunity Announcement Project: Porifera is developing carbon nanotube membranes that allow more efficient removal of CO2 from coal plant exhaust. Most of today’s carbon capture methods use chemical solvents, but capture methods that use membranes to draw CO2 out of exhaust gas are potentially more efficient and cost effective. Traditionally, membranes are limited by the rate at which they allow gas to flow through them and the amount of CO2 they can attract from the gas. Smooth support pores and the unique structure of Porifera’s carbon nanotube membranes allows them to be more permeable than other polymeric membranes, yet still selective enough for CO2 removal. This approach could overcome the barriers facing membrane-based approaches for capturing CO2 from coal plant exhausts.

  7. Catalytic CVD Synthesis of Carbon Nanotubes: Towards High Yield and Low Temperature Growth

    Directory of Open Access Journals (Sweden)

    Marijana Mionić

    2010-11-01

    Full Text Available The catalytic chemical vapor deposition (CCVD is currently the most flexible and economically attractive method for the growth of carbon nanotubes. Although its principle is simple, the precisely controlled growth of carbon nanotubes remains very complex because many different parameters influence the growth process. In this article, we review our recent results obtained on the synthesis of carbon nanotubes via CCVD. We discuss the role of the catalyst and the catalyst support. Our recent results obtained from the water assisted growth and the equimolar C2H2-CO2 reaction are also discussed. Both procedures lead to significantly enhanced carbon nanotube growth. In particular, the latter allows growing carbon nanotubes on diverse substrate materials at low temperatures.

  8. The mechanical properties measurement of multiwall carbon nanotube reinforced nanocrystalline aluminum matrix composite

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Manjula, E-mail: manjula.physics@gmail.com; Pal, Hemant; Sharma, Vimal [Department of Physics, NIT Hamirpur (HP) - 177005 (India)

    2015-05-15

    Nanocrystalline aluminum matrix composite containing carbon nanotubes were fabricated using physical mixing method followed by cold pressing. The microstructure of the composite has been investigated using X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy techniques. These studies revealed that the carbon nanotubes were homogeneously dispersed throughout the metal matrix. The consolidated samples were pressureless sintered in inert atmosphere to further actuate a strong interface between carbon nanotubes and aluminum matrix. The nanoindentation tests carried out on considered samples showed that with the addition of 0.5 wt% carbon nanotubes, the hardness and elastic modulus of the aluminum matrix increased by 21.2 % and 2 % repectively. The scratch tests revealed a decrease in the friction coefficient of the carbon nanotubes reinforced composite due to the presence of lubricating interfacial layer. The prepared composites were promising entities to be used in the field of sporting goods, construction materials and automobile industries.

  9. Fabrication And Properties Of Silver Based Multiwall Carbon Nanotube Composite Prepared By Spark Plasma Sintering Method

    Directory of Open Access Journals (Sweden)

    Lis M.

    2015-06-01

    Full Text Available The paper presents results of investigations of the obtained nanocomposite materials based on silver with addition of multiwall carbon nanotubes. The powder of carbon nanotubes content from 0.1 to 3 wt. % was produced by application of powder metallurgy methods, through mixing and high-energetic milling, and also chemical methods. Modification of carbon nanotubes included electroless deposition of silver particles on the carbon nanotube active surfaces and chemical reduction with strong reducing agent – sodium borohydride (NaBH4. The obtained powder mixtures were consolidated by SPS – Spark Plasma Sintering method. The formed composites were subjected to tests of relative density, electrical conductivity and electro-erosion properties. Detailed examinations of the structure with application of X-ray microanalysis, with consideration of carbon nanotubes distribution, were also carried out. The effect of manufacturing methods on properties of the obtained composites was observed.

  10. Films, Buckypapers and Fibers from Clay, Chitosan and Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Marc in het Panhuis

    2011-04-01

    Full Text Available The mechanical and electrical characteristics of films, buckypapers and fiber materials from combinations of clay, carbon nanotubes (CNTs and chitosan are described. The rheological time-dependent characteristics of clay are maintained in clay–carbon nanotube–chitosan composite dispersions. It is demonstrated that the addition of chitosan improves their mechanical characteristics, but decreases electrical conductivity by three-orders of magnitude compared to clay–CNT materials. We show that the electrical response upon exposure to humid atmosphere is influenced by clay-chitosan interactions, i.e., the resistance of clay–CNT materials decreases, whereas that of clay–CNT–chitosan increases.

  11. Carbon nanotube stationary phases for microchip electrochromatography

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; Bøggild, Peter; Kutter, Jörg Peter

    nanotubes are very interesting for integration in especially microfluidic devices, because they can readily be grown on planar substrates by means of chemical vapour deposition. In this way the cumbersome process of packing of the stationary phase in the finished microfluidic channels is avoided and the CNT...... surface can furthermore be used directly as a stationary phase in reverse-phase separations, thereby avoiding subsequent functionalization of the nanostructures. This significantly reduces the fabrication time and possibly also increases the reproducibility of the column performance. In this presentation......, microfluidic devices with microfabricated carbon nanotube columns for electrochromatographic separations will be presented. The electrically conductive carbon nanotube layer has been patterned into hexoganol micropillars in order to support electroosmotic flow without forming gas bubbles from electrolysis...

  12. Carbon Nanotube Composites for Electronic Packaging Applications: A Review

    Directory of Open Access Journals (Sweden)

    Lavanya Aryasomayajula

    2013-01-01

    Full Text Available Composite engineering comprises of metal matrix composites. They have high strength-weight ratio, better stiffness, economical production, and ease of availability of raw materials. The discovery of carbon nanotubes has opened new possibilities to face challenges better. Carbon Nanotubes are known for their high mechanical strength, excellent thermal and electrical properties. Recent research has made progress in fabricating carbon nanotube metal matrix and polymer-based composites. The methods of fabrication of these composites, their properties and possible applications restricted to the field of electronic packaging have been discussed in this paper. Experimental and theoretical calculations have shown improved mechanical and physical properties like tensile stress, toughness, and improved electrical and thermal properties. They have also demonstrated the ease of production of the composites and their adaptability as one can tailor their properties as per the requirement. This paper reviews work reported on fabricating and characterizing carbon- nanotube-based metal matrix and polymer composites. The focus of this paper is mainly to review the importance of these composites in the field of electronics packaging.

  13. Large spin-orbit coupling in carbon nanotubes

    Science.gov (United States)

    Steele, G. A.; Pei, F.; Laird, E. A.; Jol, J. M.; Meerwaldt, H. B.; Kouwenhoven, L. P.

    2013-03-01

    It has recently been recognised that the strong spin-orbit interaction present in solids can lead to new phenomena, such as materials with non-trivial topological order. Although the atomic spin-orbit coupling in carbon is weak, the spin-orbit coupling in carbon nanotubes can be significant due to their curved surface. Previous works have reported spin-orbit couplings in reasonable agreement with theory, and this coupling strength has formed the basis of a large number of theoretical proposals. Here we report a spin-orbit coupling in three carbon nanotube devices that is an order of magnitude larger than previously measured. We find a zero-field spin splitting of up to 3.4 meV, corresponding to a built-in effective magnetic field of 29 T aligned along the nanotube axis. Although the origin of the large spin-orbit coupling is not explained by existing theories, its strength is promising for applications of the spin-orbit interaction in carbon nanotubes devices.

  14. Large spin-orbit coupling in carbon nanotubes.

    Science.gov (United States)

    Steele, G A; Pei, F; Laird, E A; Jol, J M; Meerwaldt, H B; Kouwenhoven, L P

    2013-01-01

    It has recently been recognised that the strong spin-orbit interaction present in solids can lead to new phenomena, such as materials with non-trivial topological order. Although the atomic spin-orbit coupling in carbon is weak, the spin-orbit coupling in carbon nanotubes can be significant due to their curved surface. Previous works have reported spin-orbit couplings in reasonable agreement with theory, and this coupling strength has formed the basis of a large number of theoretical proposals. Here we report a spin-orbit coupling in three carbon nanotube devices that is an order of magnitude larger than previously measured. We find a zero-field spin splitting of up to 3.4 meV, corresponding to a built-in effective magnetic field of 29 T aligned along the nanotube axis. Although the origin of the large spin-orbit coupling is not explained by existing theories, its strength is promising for applications of the spin-orbit interaction in carbon nanotubes devices.

  15. Modeling of carbon nanotubes, graphene and their composites

    CERN Document Server

    Silvestre, Nuno

    2014-01-01

    This book contains ten chapters, authored by world experts in the field of simulation at nano-scale and aims to demonstrate the potentialities of computational techniques to model the mechanical behavior of nano-materials, such as carbon nanotubes, graphene and their composites. A large part of the research currently being conducted in the fields of materials science and engineering mechanics is devoted to carbon nanotubes, graphene and their applications. In this process, computational modeling is a very attractive research tool due to the difficulties in manufacturing and testing of nano-materials. Both atomistic modeling methods, such as molecular mechanics and molecular dynamics, and continuum modeling methods are being intensively used. Continuum modeling offers significant advantages over atomistic modeling such as the reduced computational effort, the capability of modeling complex structures and bridging different analysis scales, thus enabling modeling from the nano- to the macro-scale. On the oth...

  16. Physically unclonable cryptographic primitives using self-assembled carbon nanotubes

    Science.gov (United States)

    Hu, Zhaoying; Comeras, Jose Miguel M. Lobez; Park, Hongsik; Tang, Jianshi; Afzali, Ali; Tulevski, George S.; Hannon, James B.; Liehr, Michael; Han, Shu-Jen

    2016-06-01

    Information security underpins many aspects of modern society. However, silicon chips are vulnerable to hazards such as counterfeiting, tampering and information leakage through side-channel attacks (for example, by measuring power consumption, timing or electromagnetic radiation). Single-walled carbon nanotubes are a potential replacement for silicon as the channel material of transistors due to their superb electrical properties and intrinsic ultrathin body, but problems such as limited semiconducting purity and non-ideal assembly still need to be addressed before they can deliver high-performance electronics. Here, we show that by using these inherent imperfections, an unclonable electronic random structure can be constructed at low cost from carbon nanotubes. The nanotubes are self-assembled into patterned HfO2 trenches using ion-exchange chemistry, and the width of the trench is optimized to maximize the randomness of the nanotube placement. With this approach, two-dimensional (2D) random bit arrays are created that can offer ternary-bit architecture by determining the connection yield and switching type of the nanotube devices. As a result, our cryptographic keys provide a significantly higher level of security than conventional binary-bit architecture with the same key size.

  17. Carbon nanotube based biomedical agents for heating, temperature sensoring and drug delivery

    CERN Document Server

    Klingeler, Ruediger; Buechner, Bernd

    2009-01-01

    Due to their extraordinary physical and chemical properties carbon nanotubes reveal a promising potential as biomedical agents for heating, temperature sensoring and drug delivery on the cellular level. Filling carbon nanotubes with tailored materials realises nanoscaled containers in which the active content is encapsulated by a protecting carbon shell. We describe different synthesis routes and show the structural and magnetic properties of carbon nanotubes. In particular, the filling with magnetic materials offers the potential for hyperthermia applications while the insertion of NMR active substances allows the usage as markers and sensors. The potential of carbon nanotubes for biomedical applications is highlighted by hyperthermia studies which prove their applicability for local in-situ heating. In addition we have shown that a non-invasive temperature control by virtue of a carbon-wrapped nanoscaled thermometer and filling with anti-cancer drugs is possible.

  18. Structure Stability of Ⅰ-Type Carbon Nanotube Junctions

    Institute of Scientific and Technical Information of China (English)

    夏丹; 袁喆; 李家明

    2002-01-01

    Carbon nanotubes with junctions may play an important role in future ‘nanoelectronics' and future ‘nano devices'.In particular, junctions constructed with metal and semiconducting nanotubes have potential applications. Basedon the orthogonal tight-binding molecular dynamics method, we present our study of the structure stability ofI-type carbon nanotube junctions.

  19. Aligned carbon nanotube sheet piezoresistive strain sensors

    Science.gov (United States)

    Li, Ang; Bogdanovich, Alexander E.; Bradford, Philip D.

    2015-09-01

    Carbon nanotubes (CNTs) have a unique set of properties that may be useful in the production of next generation structural health monitoring composites. This research introduces a novel CNT based material system for strain and damage sensing applications. An aligned sheet of interconnected CNTs was drawn from a chemical vapor deposition grown CNT array and then bonded to the surface of glass fiber/epoxy composite coupons. Various types of mechanical tests were conducted, accompanied by real-time electrical data acquisition, in order to evaluate the electro-mechanical behavior of the developed sensing material. Specimens were loaded in the longitudinal and transverse CNT sheet orientations to investigate the anisotropy of the piezoresistive effect. The CNT sheets exhibited good sensing stability, linearity, sensitivity and repeatability within a practical strain range; which are crucial sensor features for health monitoring. It was also demonstrated that the CNT orientation in the sheet had a dramatic effect on the sensitivity, thus validating the usefulness of this sensing material for directional strain/damage monitoring. Finally, pre-straining of the CNT sheet sensors was conducted to further enhance the linearity of electro-mechanical response and long-term stability of the sensors during cyclic loading.

  20. Deconvoluting hepatic processing of carbon nanotubes.

    Science.gov (United States)

    Alidori, Simone; Bowman, Robert L; Yarilin, Dmitry; Romin, Yevgeniy; Barlas, Afsar; Mulvey, J Justin; Fujisawa, Sho; Xu, Ke; Ruggiero, Alessandro; Riabov, Vladimir; Thorek, Daniel L J; Ulmert, Hans David S; Brea, Elliott J; Behling, Katja; Kzhyshkowska, Julia; Manova-Todorova, Katia; Scheinberg, David A; McDevitt, Michael R

    2016-01-01

    Single-wall carbon nanotubes present unique opportunities for drug delivery, but have not advanced into the clinic. Differential nanotube accretion and clearance from critical organs have been observed, but the mechanism not fully elucidated. The liver has a complex cellular composition that regulates a range of metabolic functions and coincidently accumulates most particulate drugs. Here we provide the unexpected details of hepatic processing of covalently functionalized nanotubes including receptor-mediated endocytosis, cellular trafficking and biliary elimination. Ammonium-functionalized fibrillar nanocarbon is found to preferentially localize in the fenestrated sinusoidal endothelium of the liver but not resident macrophages. Stabilin receptors mediate the endocytic clearance of nanotubes. Biocompatibility is evidenced by the absence of cell death and no immune cell infiltration. Towards clinical application of this platform, nanotubes were evaluated for the first time in non-human primates. The pharmacologic profile in cynomolgus monkeys is equivalent to what was reported in mice and suggests that nanotubes should behave similarly in humans. PMID:27468684

  1. Making junctions between carbon nanotubes using an ion beam

    CERN Document Server

    Krasheninnikov, A V; Keinonen, J; Banhart, F

    2003-01-01

    Making use of empirical potential molecular dynamics, we study ion bombardment of crossed single-walled carbon nanotubes as a tool to join the nanotubes. We demonstrate that ion irradiation should result in welding of crossed nanotubes, both suspended and deposited on substrates. We further predict optimum ion doses and energies for ion-mediated nanotube welding which may potentially be used for developing complicated networks of joined nanotubes.

  2. A new mechanism for carbon nanotube evolution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Key discoveries on the growth mechanism of carbon nanotubes(CNTs) have recently been achieved by CAS researcher ZHU Zhenping and his research group at the State Key Laboratory of Coal Conversion,the Institute of Coal Chemistry of CAS, funded by the National Natural Science Foundation of China and the CAS Bairen Program.

  3. Chiral Anomaly in Toroidal Carbon Nanotubes

    OpenAIRE

    Sasaki, K.

    2001-01-01

    It is pointed out that the chiral anomaly in 1+1 dimensions should be observed in toroidal carbon nanotubes on a planar geometry with varying magnetic field. We show that the chiral anomaly is closely connected with the persistent current in a one-dimensional metallic ring.

  4. Synthesis of Carbon Nanotube (CNT Composite Membranes

    Directory of Open Access Journals (Sweden)

    Dusan Losic

    2010-12-01

    Full Text Available Carbon nanotubes are attractive approach for designing of new membranes for advanced molecular separation because of their unique transport properties and ability to mimic biological protein channels. In this work the synthetic approach for fabrication of carbon nanotubes (CNTs composite membranes is presented. The method is based on growth of multi walled carbon nanotubes (MWCNT using chemical vapour deposition (CVD on the template of nanoporous alumina (PA membranes. The influence of experimental conditions including carbon precursor, temperature, deposition time, and PA template on CNT growth process and quality of fabricated membranes was investigated. The synthesis of CNT/PA composites with controllable nanotube dimensions such as diameters (30–150 nm, and thickness (5–100 µm, was demonstrated. The chemical composition and morphological characteristics of fabricated CNT/PA composite membranes were investigated by various characterisation techniques including scanning electron microscopy (SEM, energy-dispersive x-ray spectroscopy (EDXS, high resolution transmission electron microscopy (HRTEM and x-ray diffraction (XRD. Transport properties of prepared membranes were explored by diffusion of dye (Rose Bengal used as model of hydrophilic transport molecule.

  5. Single electron-ics with carbon nanotubes

    NARCIS (Netherlands)

    Götz, G.T.J.

    2010-01-01

    We experimentally investigate Quantum Dots, formed in Carbon Nanotubes. The first part of this thesis deals with charge sensing on such quantum dots. The charge sensor is a metallic Single-electron-transistor, sensitive to the charge of a single electron on the quantum dot. We use this technique for

  6. Spatially resolved spectroscopy on carbon nanotubes

    NARCIS (Netherlands)

    Janssen, J.W.

    2001-01-01

    Carbon nanotubes are small cylindrical molecules with a typical diameter of 1 nm and lengths of up to micrometers. These intriguing molecules exhibit, depending on the exact atomic structure, either semiconducting or metallic behavior. This makes them ideal candidates for possible future molecular e

  7. Effective models for excitons in carbon nanotubes

    DEFF Research Database (Denmark)

    Cornean, Horia; Duclos, Pierre; Ricaud, Benjamin

    We analyse the low lying spectrum of a model of excitons in carbon nanotubes. Consider two particles with a Coulomb self-interaction, placed on an infinitely long cylinder. If the cylinder radius becomes small, the low lying spectrum is well described by a one-dimensional effective Hamiltonian...

  8. Effective models for excitons in carbon nanotubes

    DEFF Research Database (Denmark)

    Cornean, Horia; Duclos, Pierre; Ricaud, Benjamin

    2007-01-01

    We analyse the low lying spectrum of a model of excitons in carbon nanotubes. Consider two particles with opposite charges and a Coulomb self-interaction, placed on an infinitely long cylinder. If the cylinder radius becomes small, the low lying spectrum of their relative motion is well described...

  9. A New Resistance Formulation for Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Ji-Huan He

    2008-01-01

    Full Text Available A new resistance formulation for carbon nanotubes is suggested using fractal approach. The new formulation is also valid for other nonmetal conductors including nerve fibers, conductive polymers, and molecular wires. Our theoretical prediction agrees well with experimental observation.

  10. Bioaccumulation and ecotoxicity of carbon nanotubes

    DEFF Research Database (Denmark)

    Jackson, Petra; Jacobsen, Nicklas Raun; Baun, Anders;

    2013-01-01

    Carbon nanotubes (CNT) have numerous industrial applications and may be released to the environment. In the aquatic environment, pristine or functionalized CNT have different dispersion behavior, potentially leading to different risks of exposure along the water column. Data included in this review...

  11. In-line manufacture of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Brambilla, Nicol Michele; Signorelli, Riccardo; Martini, Fabrizio; Corripio Luna, Oscar Enrique

    2015-04-28

    Mass production of carbon nanotubes (CNT) are facilitated by methods and apparatus disclosed herein. Advantageously, the methods and apparatus make use of a single production unit, and therefore provide for uninterrupted progress in a fabrication process. Embodiments of control systems for a variety of CNT production apparatus are included.

  12. Development of a novel composite material with carbon nanotubes assisted by self-assembled peptides designed in conjunction with β-sheet formation.

    Science.gov (United States)

    Hashida, Yasuhiko; Umeyama, Tomokazu; Mihara, Junya; Imahori, Hiroshi; Tsujimoto, Masahiko; Isoda, Seiji; Takano, Mikio; Hashida, Mitsuru

    2012-09-01

    A novel composite material is developed with single-walled carbon nanotubes (SWCNTs) and artificially designed peptides, and its chemical and physicochemical characteristics are evaluated with an aim toward biomedical application. The peptides were designed to form a β-sheet structure that would be suitable for wrapping SWCNTs. The complex of SWCNTs and peptide (SWCNT-peptide) showed good dispersibility in aqueous media and was considerably stable even in the absence of an excess amount of peptide in the media. The formation of SWCNT-peptide was confirmed by its performance in water, atomic force microscopy and transmission electron microscopy observation, and molecular modeling. The possibility of introducing various functions to SWCNT-peptide was also demonstrated by several methods, such as introduction of special amino acids, chemical modification, and additional complex formation based on electrostatic interaction. These results suggest the potential of the SWCNT-peptide complex as a molecular platform on which a desirable structure and/or function can be constructed for biomedical and industrial application.

  13. Ultrasonication-assisted ultrafast preparation of multiwalled carbon nanotubes/Au/Co3O4 tubular hybrids as superior anode materials for oxygen evolution reaction

    Science.gov (United States)

    Fang, Yiyun; Li, Xinzhe; Hu, Yiping; Li, Feng; Lin, Xiaoqing; Tian, Min; An, Xingcai; Fu, Yan; Jin, Jun; Ma, Jiantai

    2015-12-01

    Efficient and simple operation electrocatalysts for the oxygen evolution reaction (OER) are essential components of renewable energy technologies. Here, a novel, simple, and efficient routine is presented for the first time by constructing a high-efficiency anode catalyst for OER. With the aid of high intensity ultrasound, a uniformly loading, conductive multiwalled carbon nanotubes/metal/transition metal-oxide (CNTs-Au@Co3O4) tubular hybrids is synthesized. In alkaline media, the materials catalyze OER with an onset potential of 1.56 V vs. reversible hydrogen electrode (RHE) and overpotential only of 350 mV to achieve a stable current density of 10 mA cm-2 for at least 25 h. The unusual catalytic activity and stability is due to the following elements. Firstly, the tubular architecture not only provides sufficient active centers for OER, but also improves rapid mass/charge transport. Secondly, Co3O4 layer protects Au nanoparticles (NPs) against detachment. In addition, we also prove that the highest electronegativity metal Au accelerate the formation of catalytic active sites of CoIV species for OER. It is believed that this simple preparation method paves a way to fabricate a range of CNTs/metal/metal-oxide based composites as superior OER catalysts.

  14. In Situ-Grown ZnCo2O4 on Single-Walled Carbon Nanotubes as Air Electrode Materials for Rechargeable Lithium–Oxygen Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Bin; Xu, Wu; Yan, Pengfei; Bhattacharya, Priyanka; Cao, Ruiguo; Bowden, Mark E.; Engelhard, Mark H.; Wang, Chong M.; Zhang, Jiguang

    2015-10-12

    Although lithium-oxygen (Li-O2) batteries have great potential to be used as one of the next generation energy storage systems due to their ultrahigh theoretical specific energy, there are still many significant barriers before their practical applications. These barriers include electrolyte and electrode instability, poor ORR/OER efficiency and cycling capability, etc. Development of a highly efficient catalyst will not only enhance ORR/OER efficiency, it may also improve the stability of electrolyte because the reduced charge voltage. Here we report the synthesis of nano-sheet-assembled ZnCo2O4 spheres/single walled carbon nanotubes (ZCO/SWCNTs) composites as high performance air electrode materials for Li-O2 batteries. The ZCO catalyzed SWCNTs electrodes delivered high discharge capacities, decreased the onset of oxygen evolution reaction by 0.9 V during charge processes, and led to more stable cycling stability. These results indicate that ZCO/SWCNTs composite can be used as highly efficient air electrode for oxygen reduction and evolution reactions. The highly enhanced catalytic activity by uniformly dispersed ZnCo2O4 catalyst on nanostructured electrodes is expected to inspire

  15. Evolution of Electronic Circuits using Carbon Nanotube Composites

    Science.gov (United States)

    Massey, M. K.; Kotsialos, A.; Volpati, D.; Vissol-Gaudin, E.; Pearson, C.; Bowen, L.; Obara, B.; Zeze, D. A.; Groves, C.; Petty, M. C.

    2016-01-01

    Evolution-in-materio concerns the computer controlled manipulation of material systems using external stimuli to train or evolve the material to perform a useful function. In this paper we demonstrate the evolution of a disordered composite material, using voltages as the external stimuli, into a form where a simple computational problem can be solved. The material consists of single-walled carbon nanotubes suspended in liquid crystal; the nanotubes act as a conductive network, with the liquid crystal providing a host medium to allow the conductive network to reorganise when voltages are applied. We show that the application of electric fields under computer control results in a significant change in the material morphology, favouring the solution to a classification task. PMID:27558444

  16. Evolution of Electronic Circuits using Carbon Nanotube Composites.

    Science.gov (United States)

    Massey, M K; Kotsialos, A; Volpati, D; Vissol-Gaudin, E; Pearson, C; Bowen, L; Obara, B; Zeze, D A; Groves, C; Petty, M C

    2016-01-01

    Evolution-in-materio concerns the computer controlled manipulation of material systems using external stimuli to train or evolve the material to perform a useful function. In this paper we demonstrate the evolution of a disordered composite material, using voltages as the external stimuli, into a form where a simple computational problem can be solved. The material consists of single-walled carbon nanotubes suspended in liquid crystal; the nanotubes act as a conductive network, with the liquid crystal providing a host medium to allow the conductive network to reorganise when voltages are applied. We show that the application of electric fields under computer control results in a significant change in the material morphology, favouring the solution to a classification task. PMID:27558444

  17. Evolution of Electronic Circuits using Carbon Nanotube Composites

    Science.gov (United States)

    Massey, M. K.; Kotsialos, A.; Volpati, D.; Vissol-Gaudin, E.; Pearson, C.; Bowen, L.; Obara, B.; Zeze, D. A.; Groves, C.; Petty, M. C.

    2016-08-01

    Evolution-in-materio concerns the computer controlled manipulation of material systems using external stimuli to train or evolve the material to perform a useful function. In this paper we demonstrate the evolution of a disordered composite material, using voltages as the external stimuli, into a form where a simple computational problem can be solved. The material consists of single-walled carbon nanotubes suspended in liquid crystal; the nanotubes act as a conductive network, with the liquid crystal providing a host medium to allow the conductive network to reorganise when voltages are applied. We show that the application of electric fields under computer control results in a significant change in the material morphology, favouring the solution to a classification task.

  18. Synthesis of chemically bonded graphene/carbon nanotube composites and their application in large volumetric capacitance supercapacitors.

    Science.gov (United States)

    Jung, Naeyoung; Kwon, Soongeun; Lee, Dongwook; Yoon, Dong-Myung; Park, Young Min; Benayad, Anass; Choi, Jae-Young; Park, Jong Se

    2013-12-17

    Chemically bonded graphene/carbon nanotube composites as flexible supercapacitor electrode materials are synthesized by amide bonding. Carbon nanotubes attached along the edges and onto the surface of graphene act as spacers to increase the electrolyte-accessible surface area. Our lamellar structure electrodes demonstrate the largest volumetric capacitance (165 F cm(-3) ) ever shown by carbon-based electrodes.

  19. Degradation of multiwall carbon nanotubes by bacteria

    International Nuclear Information System (INIS)

    Understanding the environmental transformation of multiwall carbon nanotubes (MWCNTs) is important to their life cycle assessment and potential environmental impacts. We report that a bacterial community is capable of degrading 14C-labeled MWCNTs into 14CO2 in the presence of an external carbon source via co-metabolism. Multiple intermediate products were detected, and genotypic characterization revealed three possible microbial degraders: Burkholderia kururiensis, Delftia acidovorans, and Stenotrophomonas maltophilia. This result suggests that microbe/MWCNTs interaction may impact the long-term fate of MWCNTs. Highlights: •Mineralization of MWCNTs by a bacterial community was observed. •The mineralization required an external carbon source. •Multiple intermediate products were identified in the MWCNT degrading culture. •Three bacterial species were found likely responsible for MWCNT degradation. -- The 14C-labeled multiwall carbon nanotubes can be degraded to 14CO2 and other byproducts by a bacteria community under natural conditions

  20. Processing and Characterization of Carbon Nanotube Composites

    Science.gov (United States)

    Can, Roberto J.; Grimsley, Brian W.; Czabaj, Michael W.; Siochi, Emilie J.; Hull, Brandon

    2014-01-01

    Recent advances in the synthesis of large-scale quantities of carbon nanotubes (CNT) have provided the opportunity to study the mechanical properties of polymer matrix composites using these novel materials as reinforcement. Nanocomp Technologies, Inc. currently supplies large sheets with dimensions up to 122 cm x 244 cm containing both single-wall and few-wall CNTs. The tubes are approximately 1 mm in length with diameters ranging from 8 to 12 nm. In the present study being conducted at NASA Langley Research Center (LaRC), single and multiple layers of CNT sheets were infused or coated with various polymer solutions that included commercial toughened-epoxies and bismaleimides, as well as a LaRC developed polyimide. The resulting CNT composites were tested in tension using a modified version of ASTM D882-12 to determine their strength and modulus values. The effects of solvent treatment and mechanical elongation/alignment of the CNT sheets on the tensile performance of the composite were determined. Thin composites (around 50 wt% CNT) fabricated from acetone condensed and elongated CNT sheets with either a BMI or polyimide resin solution exhibited specific tensile moduli approaching that of toughened epoxy/ IM7 carbon fiber unidirectional composites.

  1. Purification Procedures for Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Gorelik, Olga P.; Nikolaev, Pavel; Arepalli, Sivaram

    2001-01-01

    This report summarizes the comparison of a variety of procedures used to purify carbon nanotubes. Carbon nanotube material is produced by the arc process and laser oven process. Most of the procedures are tested using laser-grown, single-wall nanotube (SWNT) material. The material is characterized at each step of the purification procedures by using different techniques including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), Raman, X-ray diffractometry (XRD), thermogravimetric analysis (TGA), nuclear magnetic resonance (NMR), and high-performance liquid chromatography (HPLC). The identified impurities are amorphous and graphitic carbon, catalyst particle aggregates, fullerenes, and hydrocarbons. Solvent extraction and low-temperature annealing are used to reduce the amount of volatile hydrocarbons and dissolve fullerenes. Metal catalysts and amorphous as well as graphitic carbon are oxidized by reflux in acids including HCl, HNO3 and HF and other oxidizers such as H2O2. High-temperature annealing in vacuum and in inert atmosphere helps to improve the quality of SWNTs by increasing crystallinity and reducing intercalation.

  2. Covalently bonded three-dimensional carbon nanotube solids via boron induced nanojunctions

    OpenAIRE

    Hashim, Daniel P.; Narayanan, Narayanan T.; Romo-Herrera, Jose M.; Cullen, David A.; Myung Gwan Hahm; Peter Lezzi; Suttle, Joseph R.; Doug Kelkhoff; E. Muñoz-Sandoval; Sabyasachi Ganguli; Roy, Ajit K.; Smith, David J.; Robert Vajtai; Sumpter, Bobby G.; Vincent Meunier

    2012-01-01

    The establishment of covalent junctions between carbon nanotubes (CNTs) and the modification of their straight tubular morphology are two strategies needed to successfully synthesize nanotube-based three-dimensional (3D) frameworks exhibiting superior material properties. Engineering such 3D structures in scalable synthetic processes still remains a challenge. This work pioneers the bulk synthesis of 3D macroscale nanotube elastic solids directly via a boron-doping strategy during chemical va...

  3. A Nanomechanical Approach on the Measurement of the Elastic Properties of Epoxy Reinforced Carbon Nanotube Nanocomposites

    OpenAIRE

    Mansour, G; D. Tzetzis; K.D. Bouzakis

    2013-01-01

    The mechanical behavior of nanocomposite materials with multiwallcarbon nanotube ( MWCNT ) reinforcements is investigated in the present paper. Epoxy nanocomposites with different weight percentages of carbon nanotubes have been characterized following tensile tests and nanoindentations. The objective of this work was to investigate the efficiency of the reinforcement provided by nanotubes and to examine the agreement between the mechanical properties of the epoxynanocomposites obtained via a...

  4. Carbon nanotube composites for glucose biosensor incorporated with reverse iontophoresis function for noninvasive glucose monitoring

    OpenAIRE

    Sun, Tai-ping; Shieh, Hsiu-Li; Ching, Congo Tak-Shing; Yao, Yan-Dong; Huang, Su-Hua; Liu, Chia-Ming; Liu, Wei-Hao; Chen, Chung-Yuan

    2010-01-01

    This study aims to develop an amperometric glucose biosensor, based on carbon nanotubes material for reverse iontophoresis, fabricated by immobilizing a mixture of glucose oxidase (GOD) and multiwalled carbon nanotubes (MWCNT) epoxy-composite, on a planar screen-printed carbon electrode. MWCNT was employed to ensure proper incorporation into the epoxy mixture and faster electron transfer between the GOD and the transducer. Results showed this biosensor possesses a low detection potential (+50...

  5. Preparation of double-walled carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    JIANG Bin; WEI Jinquan; CI Lijie; WU Dehai

    2004-01-01

    Double-walled carbon nanotubes were prepared using the floating chemical vapor deposition with methane as carbon source and adding small amount of sulfur into the ferrocene catalyst. The optimized technological parameters are: the reaction temperature is 1200℃; the catalyst vapor temperature is 80℃; the flow rate of argon is 2000 SCCM; the flow rate of methane is 5 SCCM. The purified DWNTs under these optimized technological parameters have high purity above 90 wt%.

  6. Thermal stability and formation barrier of a high-energetic material N8 polymer nitrogen encapsulated in (5,5) carbon nanotube

    Science.gov (United States)

    Ji, Wei; Timoshevskii, V.; Guo, H.; Abou-Rachid, Hakima; Lussier, Louis-Simon

    2009-07-01

    We report the density functional theory total energy calculations of thermal stability and formation barrier of polymer nitrogen confined in carbon nanotubes (CNT). The analysis suggests that N8 polymer nitrogen encapsulated in (5,5) carbon nanotube [N8@CNT(5,5)] is thermally (meta)stable at a finite temperature up to energy scale of at least 5000 K, similar to nitrogen molecule gas phase confined in CNT [N2@CNT(5,5)]. The energetic difference between these two phases of N does not significantly change with temperature. A barrier of 1.07 eV was found for the formation of N8@CNT(5,5) from N2@CNT(5,5), while the dissociation barrier was found to be 0.2 eV. Snapshots of the reaction pathway show that the transition state is composed by a N2 and a N6 inside a CNT(5,5).

  7. Carbon Nanotube-based Super Nanotube: Tailorable Thermal Conductivity at Three-dimensional

    CERN Document Server

    Zhan, Haifei; Gu, Yuantong

    2015-01-01

    The advancements of nanomaterials or nanostructures have enabled the possibility of fabricating multifunctional materials that hold great promises in engineering applications. The carbon nanotube (CNT)-based nanostructure is one representative building block for such multifunctional materials. Based on a series of in silico studies, we report the tailorability of the thermal conductivity of a three-dimensional CNT-based nanostructure, i.e., the single wall CNT (SWNT)-based super nanotube (ST). It is shown that the thermal conductivity of STs varies with different connecting carbon rings, and the ST with longer constituent SWNTs and larger diameter yield to a smaller thermal conductivity. Further results reveal that the inverse of the ST thermal conductivity exhibits a good linear relationship with the inverse of its length. Particularly, it is found that the thermal conductivity exhibits an approximately proportional relationship with the inverse of the temperature, but appears insensitive to the axial strain...

  8. 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.

  9. Facile scalable synthesis of Co{sub 3}O{sub 4}/carbon nanotube hybrids as superior anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhiguo; Xu, Weiwei [Key Lab of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, and the College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Huang, Tao [Department of Chemistry, Fudan University, Shanghai 210024 (China); Li, Maolin; Wang, Wanren; Liu, Yanping; Mao, Chaochao; Meng, Fanli; Wang, Mengjiao [Key Lab of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, and the College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Cheng, Minghai [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China); Yu, Aishui [Department of Chemistry, Fudan University, Shanghai 210024 (China); Guo, Xiaohui, E-mail: guoxh2009@nwu.edu.cn [Key Lab of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, and the College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China)

    2013-10-15

    Graphical abstract: Co{sub 3}O{sub 4}/MWCNT hybrids were synthesized via strong ultra-sonication assisted shaking processes. The resultant samples as anode electrode display enhanced cycling performance and rate capability compared with pure Co{sub 3}O{sub 4} particle. - Highlights: • Co{sub 3}O{sub 4}/MWCNT hybrids were synthesized via ultra-sonication assisted shaking process. • The resulting Co{sub 3}O{sub 4} nanoparticles are highly dispersed onto MWCNT network backbone. • Co{sub 3}O{sub 4}/MWCNT hybrid displays highly enhanced lithium storage properties. • The present synthetic approach is facile, controllable, and scalable. - Abstract: In this report, Co{sub 3}O{sub 4}/multiple-wall carbon nanotube (MWCNT) hybrid materials were synthesized via strong ultrasonication-assisted shaking and magnetic stirring processes. The prepared samples were well characterized by utilizing powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy techniques. Results indicated that the resulting Co{sub 3}O{sub 4} nanoparticles were highly dispersed in the MWCNT network backbone and further form Co{sub 3}O{sub 4}/MWCNT hybrid materials. The obtained Co{sub 3}O{sub 4}/MWCNT hybrids can be employed as anode electrode in Lithium-ion batteries and deliver as high as discharge capacity of 1250 mA h g{sup −1} at a current density of 0.2 C, additionally, 81% of the discharge capacity for sample 2 with 20 wt.% MWCNT loading could be retained after 70 cycles, which could be associated with the specific hybrid structure of the electrode as well as the addition of MWCNT. Most importantly, the present synthetic approach is facile, controllable, and scalable, which allowing it more easily adapted to prepare other hybrid materials with specific architectures.

  10. Multi-walled carbon nanotubes integrated in microcantilevers for application of tensile strain

    DEFF Research Database (Denmark)

    Dohn, Søren; Kjelstrup-Hansen, Jakob; Madsen, D.N.;

    2005-01-01

    Individual multi-walled carbon nanotubes were positioned on silicon oxide microcantilevers using nanomanipulation tools. A silicon nanowire with a diameter of 200nm is positioned across the nanotube, and serves as shadow mask during deposition of conducting electrode material, leading to a 200 ru...

  11. Excitation transfer and luminescence in porphyrin-carbon nanotube complexes

    CERN Document Server

    Magadur, G; Alain-Rizzo, V; Voisin, C; Roussignol, Ph; Deleporte, E; Delaire, J A

    2007-01-01

    Functionalization of carbon nanotubes with hydrosoluble porphyrins (TPPS) is achieved by "$\\pi$-stacking". The porphyrin/nanotube interaction is studied by means of optical absorption, photoluminescence and photoluminescence excitation spectroscopies. The main absorption line of the porphyrins adsorbed on nanotubes exhibits a 120 meV red shift, which we ascribe to a flattening of the molecule in order to optimize $\\pi-\\pi$ interactions. The porphyrin-nanotube complex shows a strong quenching of the TPPS emission while the photoluminescence intensity of the nanotubes is enhanced when the excitation laser is in resonance with the porphyrin absorption band. This reveals an efficient excitation transfer from the TPPS to the carbon nanotube.

  12. Ion Exclusion by Sub 2-nm Carbon Nanotube Pores

    Energy Technology Data Exchange (ETDEWEB)

    Fornasiero, F; Park, H G; Holt, J K; Stadermann, M; Grigoropoulos, C P; Noy, A; Bakajin, O

    2008-04-09

    Carbon nanotubes offer an outstanding platform for studying molecular transport at nanoscale, and have become promising materials for nanofluidics and membrane technology due to their unique combination of physical, chemical, mechanical, and electronic properties. In particular, both simulations and experiments have proved that fluid flow through carbon nanotubes of nanometer size diameter is exceptionally fast compared to what continuum hydrodynamic theories would predict when applied on this length scale, and also, compared to conventional membranes with pores of similar size, such as zeolites. For a variety of applications such as separation technology, molecular sensing, drug delivery, and biomimetics, selectivity is required together with fast flow. In particular, for water desalination, coupling the enhancement of the water flux with selective ion transport could drastically reduce the cost of brackish and seawater desalting. In this work, we study the ion selectivity of membranes made of aligned double-walled carbon nanotubes with sub-2 nm diameter. Negatively charged groups are introduced at the opening of the carbon nanotubes by oxygen plasma treatment. Reverse osmosis experiments coupled with capillary electrophoresis analysis of permeate and feed show significant anion and cation rejection. Ion exclusion declines by increasing ionic strength (concentration) of the feed and by lowering solution pH; also, the highest rejection is observed for the A{sub m}{sup Z{sub A}} C{sub n}{sup Z{sub C}} salts (A=anion, C=cation, z= valence) with the greatest Z{sub A}/Z{sub C} ratio. Our results strongly support a Donnan-type rejection mechanism, dominated by electrostatic interactions between fixed membrane charges and mobile ions, while steric and hydrodynamic effects appear to be less important. Comparison with commercial nanofiltration membranes for water softening reveals that our carbon nanotube membranes provides far superior water fluxes for similar ion

  13. Thermal characterization of carbon nanotube foam using MEMS microhotplates and thermographic analysis

    OpenAIRE

    Silvestri, C.; Riccio, M.; Poelma, R. H.; B. Morana; Vollebregt, S.; Santagata, F.; Irace, A.; Zhang, G Q; Sarro, P.M.

    2016-01-01

    Thermal material properties play a fundamental role in the thermal management of microelectronic systems. The porous nature of carbon nanotube (CNT) arrays results in a very high surface area to volume ratio, which makes the material attractive for surface driven heat transfer mechanisms. Here, we report on the heat transfer performance of lithographically defined micropins made of carbon nanotube (CNT) nanofoam, directly grown on microhotplates (MHPs). The MHP is used as an in situ character...

  14. Enhancement of carbon nanotube photoluminescence by photonic crystal nanocavities

    OpenAIRE

    Watahiki, R.; Shimada, T; Zhao, P; Chiashi, S.; Iwamoto, S.; Arakawa, Y; Maruyama, S.; Kato, Y. K.

    2012-01-01

    Photonic crystal nanocavities are used to enhance photoluminescence from single-walled carbon nanotubes. Micelle-encapsulated nanotubes are deposited on nanocavities within Si photonic crystal slabs and confocal microscopy is used to characterize the devices. Photoluminescence spectra and images reveal nanotube emission coupled to nanocavity modes. The cavity modes can be tuned throughout the emission wavelengths of carbon nanotubes, demonstrating the ability to enhance photoluminescence from...

  15. Enhancement of carbon nanotube photoluminescence by photonic crystal nanocavities

    OpenAIRE

    Watahiki, R.; Shimada, T; Zhao, P; Chiashi, S.; Iwamoto, S.; Arakawa, Y; Maruyama, S.; Kato, Y. K.

    2012-01-01

    Photonic crystal nanocavities are used to enhance photoluminescence from single-walled carbon nanotubes. Micelle-encapsulated nanotubes are deposited on nanocavities within Si photonic crystal slabs and confocal microscopy is used to characterize the devices.Photoluminescencespectra and images reveal nanotube emission coupled to nanocavity modes. The cavity modes can be tuned throughout the emission wavelengths of carbon nanotubes, demonstrating the ability to enhance photoluminescence from a...

  16. Nonlinear Optical Properties of Carbon Nanotube Hybrids in Polymer Dispersions

    OpenAIRE

    Wang, Jun; Liao, Kang-Shyang; Früchtl, Daniel; Tian, Ying; Gilchrist, Aisling, , T; Alley, Nigel; Andreoli, Enrico; Aitchison, Brad; Nasibulin, Albert; Byrne, Hugh; Kauppinen, Esko I.; Zhang, Long; Blau, Werner; Curran, Seamus

    2012-01-01

    A series of double-walled carbon nanotubes (DWNTs) and multi-walled nanotubes (MWNTs) functionalized with selected organic chromophores, fluorescein 5(6)-isothiocyanate (FITC), rhodamine B isothiocyanate (RITC) and fullerene (C60) were synthesized by covalently linking these electron-donor groups to the metallic nanotubes. These versatile carbon nanotube composites show remarkable nonlinear optical (NLO) performance, due to a merged effect of the complementary NLO characteristics of the moiet...

  17. Mechanical properties of carbon nanotube/polymer composites

    OpenAIRE

    B. Arash; Wang, Q.(The University of Kansas, Lawrence, USA); Varadan, V. K.

    2014-01-01

    The remarkable mechanical properties of carbon nanotubes, such as high elastic modulus and tensile strength, make them the most ideal and promising reinforcements in substantially enhancing the mechanical properties of resulting polymer/carbon nanotube composites. It is acknowledged that the mechanical properties of the composites are significantly influenced by interfacial interactions between nanotubes and polymer matrices. The current challenge of the application of nanotubes in the compos...

  18. Carbon nanotube based gecko inspired self-cleaning adhesives

    Science.gov (United States)

    Sethi, Sunny; Ge, Liehui; Ajayan, Pulickel; Ali, Dhinojwala

    2008-03-01

    Wall climbing organisms like geckos have unique ability to attach to different surfaces without use of any viscoelastic material. The hairy structure found in gecko feet allows them to obtain intimate contact over a large area thus allowing then to adhere using van der Waals interactions. Not only high adhesion, the geometry of the hairs makes gecko feet self cleaning, thus allowing them to walk continuously without worrying about loosing adhesive strength. Such properties if mimicked synthetically could form basis of a new class of materials, which, unlike conventional adhesives would show two contradictory properties, self cleaning and high adhesion. Such materials would form essential component of applications like wall climbing robot. We tried to synthesize such material using micropatterened vertically aligned carbon nanotubes. When dealing with large areas, probability of defects in the structure increase, forming patterns instead of using uniform film of carbon nanotubes helps to inhibit crack propagation, thus gives much higher adhesive strength than a uniform film. When carbon nanotube patterns with optimized aspect ratio are used, both high adhesion and self cleaning properties are observed.

  19. Field emission properties of the graphenated carbon nanotube electrode

    Energy Technology Data Exchange (ETDEWEB)

    Zanin, H., E-mail: hudson.zanin@bristol.ac.uk [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Faculdade de Engenharia Elétrica e Computação, Departamento de Semicondutores, Instrumentos e Fotônica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N. 400, CEP 13 083-852 Campinas, São Paulo (Brazil); Ceragioli, H.J.; Peterlevitz, A.C.; Baranauskas, Vitor [Faculdade de Engenharia Elétrica e Computação, Departamento de Semicondutores, Instrumentos e Fotônica, Universidade Estadual de Campinas, UNICAMP, Av. Albert Einstein N. 400, CEP 13 083-852 Campinas, São Paulo (Brazil); Marciano, F.R.; Lobo, A.O. [Laboratory of Biomedical Nanotechnology/Institute of Research and Development at UNIVAP, Av. Shishima Hifumi, 2911, CEP 12244-000 Sao Jose dos Campos, SP (Brazil)

    2015-01-01

    Graphical abstract: - Highlights: • Facile method to prepare graphenated carbon nanotubes (g-CNTs). • The electric field emission behaviour of g-CNTs was studied. • g-CNTs show better emission current stability than non-graphenated CNTs. - Abstract: Reduced graphene oxide-coated carbon nanotubes (RGO-CNT) electrodes have been prepared by hot filament chemical vapour deposition system in one-step growth process. We studied RGO-CNT electrodes behaviour as cold cathode in field emission test. Our results show that RGO-CNT retain the low threshold voltage typical of CNTs, but with greatly improved emission current stability. The field emission enhancement value is significantly higher than that expected being caused by geometric effect (height divided by the radius of nanotube). This suggested that the field emission of this hybrid structure is not only from a single tip, but eventually it is from several tips with contribution of graphene nanosheets at CNT's walls. This phenomenon explains why the graphenated carbon nanotubes do not burn out as quickly as CNT does until emission ceases completely. These preliminaries results make nanocarbon materials good candidates for applications as electron sources for several devices.

  20. EB treatment of carbon nanotube-reinforced polymer composites

    Science.gov (United States)

    Szebényi, G.; Romhány, G.; Vajna, B.; Czvikovszky, T.

    2012-09-01

    A small amount — less than 0.5% — carbon nanotube reinforcement may improve the mechanical properties of epoxy based composite materials significantly. The basic technical problem on one side is the dispersion of the nanotubes into the viscous matrix resin, namely, the fine powder-like — less than 100 nanometer diameter — nanotubes are prone to form aggregates. On the other side, the good connection between the nanofiber and matrix, which is determining the success of the reinforcement, requires some efficient adhesion promoting treatment. The goal of our research was to give one such treatment capable of industrial size application. A two step curing epoxy/vinylester resin process technology has been developed where the epoxy component has been cured conventionally, while the vinylester has been cured by electron treatment afterwards. The sufficient irradiation dose has been selected according to Raman spectroscopy characterization. Using the developed hybrid resin system hybrid composites containing carbon fibers and multiwalled carbon nanotubes have been prepared. The effect of the electron beam induced curing of the vinylester resin on the mechanical properties of the composites has been characterized by three point bending and interlaminar shear tests, which showed clearly the superiority of the developed resin system. The results of the mechanical tests have been supported by AFM studies of the samples, which showed that the difference in the viscoelastic properties of the matrix constituents decreased significantly by the electron beam treatment.

  1. Designing novel nano materials through functionalization of carbon nanotubes with supramolecules for the application in nuclear waste management

    International Nuclear Information System (INIS)

    Very recently, researchers are now interested to know whether CNT can play a role in the field of nuclear waste management. Some experimental studies were carried out to understand the interactions between nanotubes and uranyl ions. Although poor solubility of CNT restricts the use of it in aqueous environment, introduction of functional groups to CNT can overcome the solubility issues. On the other hand, supramolecule such as cucurbituril (CB) are efficient cation binders. Here again, solubility issues (in aqueous phase) are there for lower members of CB (CB-(5) and CB-(6)). Fortunately, direct functionalization of CB through hydroxyl and cyclohexyl groups can solve the solubility issues. The aim of the present work is to functionalize the CNT with molecule through electronic structure calculations. Further, the uranyl binding affinities to these functionalized sites have been identified such that these models can be used as a viable route for nuclear waste management

  2. Analytical modeling of glucose biosensors based on carbon nanotubes

    OpenAIRE

    Pourasl, Ali H; Ahmadi, Mohammad Taghi; Rahmani, Meisam; Chin, Huei Chaeng; Lim, Cheng Siong; Ismail, Razali; Tan, Michael Loong Peng

    2014-01-01

    In recent years, carbon nanotubes have received widespread attention as promising carbon-based nanoelectronic devices. Due to their exceptional physical, chemical, and electrical properties, namely a high surface-to-volume ratio, their enhanced electron transfer properties, and their high thermal conductivity, carbon nanotubes can be used effectively as electrochemical sensors. The integration of carbon nanotubes with a functional group provides a good and solid support for the immobilization...

  3. A new method of preparing single-walled carbon nanotubes

    OpenAIRE

    Vivekchang, SRC; Govindaraj, A.

    2003-01-01

    A novel method of purification for single-walled carbon nanotubes, prepared by an arc-discharge method, is described. The method involves a combination of acid washing followed by high temperature hydrogen treatment to remove the metal nanoparticles and amorphous carbon present in the as-synthesized single-walled carbon nanotubes. The purified single-walled carbon nanotubes have been characterised by low-angle X-ray diffraction, electron microscopy, thermo-gravimetric analysis and Raman spect...

  4. A new method of preparing single-walled carbon nanotubes

    Indian Academy of Sciences (India)

    S R C Vivekchand; A Govindaraj

    2003-10-01

    A novel method of purification for single-walled carbon nanotubes, prepared by an arc-discharge method, is described. The method involves a combination of acid washing followed by high temperature hydrogen treatment to remove the metal nanoparticles and amorphous carbon present in the as-synthesized singlewalled carbon nanotubes. The purified single-walled carbon nanotubes have been characterised by low-angle X-ray diffraction, electron microscopy, thermo-gravimetric analysis and Raman spectroscopy.

  5. Functionalization of vertically aligned carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Eloise Van Hooijdonk

    2013-02-01

    Full Text Available This review focuses and summarizes recent studies on the functionalization of carbon nanotubes oriented perpendicularly to their substrate, so-called vertically aligned carbon nanotubes (VA-CNTs. The intrinsic properties of individual nanotubes make the VA-CNTs ideal candidates for integration in a wide range of devices, and many potential applications have been envisaged. These applications can benefit from the unidirectional alignment of the nanotubes, the large surface area, the high carbon purity, the outstanding electrical conductivity, and the uniformly long length. However, practical uses of VA-CNTs are limited by their surface characteristics, which must be often modified in order to meet the specificity of each particular application. The proposed approaches are based on the chemical modifications of the surface by functionalization (grafting of functional chemical groups, decoration with metal particles or wrapping of polymers to bring new properties or to improve the interactions between the VA-CNTs and their environment while maintaining the alignment of CNTs.

  6. Functional Carbon Nanotubes for Electrical Conductors

    Science.gov (United States)

    Schauerman, Christopher Mark

    Carbon nanotube (CNT) conductors are an enabling technology for advancing the efficacy of sustainable energy systems. In parallel, proactive consideration for each of the phases in the material life cycle can enhance device performance while minimizing unwanted impacts. Increasing the yield of CNTs through advances in synthesis will help reduce the electricity, chemicals, and costs associated with their production. Modifications to the nanoscale morphology (alignment, bundling, density and lower contact resistances) are needed to improve the CNT material properties to meet or exceed those of conventional metallic conductors. Also, a robust evaluation of methods for contacting carbon-based wires is needed when interfacing with metallic contacts. Finally, it's important to begin looking at upstream options for proper treatment of waste streams containing CNT conductors when they reach the end of their useable life. Therefore, the subject of this dissertation focuses on the development of functional CNT conductors and considers approaches to improve each phase of their life cycle. Specifically, progress towards using more efficient catalysts in the laser vaporization process has led to a 50% increase in SWCNT yield and simplified the purification procedure. The use of chemical dopants such as KAuCl4 has increased the electrical conductivity up to 1x10 6 S/m which is over an order of magnitude higher than the pre-doping baseline value. Alternatively, chlorosulfonic acid was used to disperse high weight loadings of SWCNTs and modify the nanoscale morphology through the use of selective coagulation and mechanical extrusions of binder free SWCNT wires. The highly dense and aligned wires have electrical conductivities as high as 4.9x106 S/m and are in agreement with the highest CNT conductivities reported. The ability to contact bulk CNT conductors through ultrasonic welding was demonstrated for the first time and exhibit low carbon-copper contact resistances of 4.3 mO-cm2

  7. Structure and Strength of Iron-Copper-Carbon Nanotube Nanocomposites

    Science.gov (United States)

    Boshko, Oleh; Dashevskyi, Mykola; Mykhaliuk, Olga; Ivanenko, Kateryna; Hamamda, Smail; Revo, Sergiy

    2016-02-01

    Nanocomposite materials of the Fe-Cu system with/without small addition of carbon nanotubes have been synthesized by mechanochemical activation of elemental Fe and Cu powders in a high-energy planetary ball mill and have been examined by the X-ray diffraction method, SEM and the thermopower methods; the tensile strength of the materials obtained has been estimated. The metastable (Fe, Cu) supersaturated solid solution is formed in the Fe-Cu nanocomposites during milling process. The coherent scattering block size of the materials obtained is decreased with increase of milling time. The duration of mechanochemical activation affects the physical properties of nanocomposites studied. Addition of a small amount of nanotubes into Fe-Cu charge results in a significant increase of strength of the Fe-Cu (4:1) + CNT nanocomposite materials (NCMs) obtained.

  8. Structure and Strength of Iron-Copper-Carbon Nanotube Nanocomposites.

    Science.gov (United States)

    Boshko, Oleh; Dashevskyi, Mykola; Mykhaliuk, Olga; Ivanenko, Kateryna; Hamamda, Smail; Revo, Sergiy

    2016-12-01

    Nanocomposite materials of the Fe-Cu system with/without small addition of carbon nanotubes have been synthesized by mechanochemical activation of elemental Fe and Cu powders in a high-energy planetary ball mill and have been examined by the X-ray diffraction method, SEM and the thermopower methods; the tensile strength of the materials obtained has been estimated. The metastable (Fe, Cu) supersaturated solid solution is formed in the Fe-Cu nanocomposites during milling process. The coherent scattering block size of the materials obtained is decreased with increase of milling time. The duration of mechanochemical activation affects the physical properties of nanocomposites studied. Addition of a small amount of nanotubes into Fe-Cu charge results in a significant increase of strength of the Fe-Cu (4:1) + CNT nanocomposite materials (NCMs) obtained. PMID:26858160

  9. "Drawing with nanotubes": creating nanowires with complex geometries by pulsed electrodeposition on self-organized carbon nanotube patterns.

    Science.gov (United States)

    Yarden, Tohar S; Joselevich, Ernesto

    2010-11-10

    We present a new approach for the creation of nanowires with well-defined complex geometries by electrodeposition onto self-organized single-walled carbon nanotubes. The concept is demonstrated by generation of continuous Au nanowires with various geometries, including parallel arrays, serpentines, and coils. The generality of this approach is further illustrated by synthesizing Bi(2)Te(3) nanowires. Our concept of "drawing with nanotubes" offers to combine different material properties with complex geometries on the route to new functional nanosystems.

  10. A three-dimensional LiFePO{sub 4}/carbon nanotubes/graphene composite as a cathode material for lithium-ion batteries with superior high-rate performance

    Energy Technology Data Exchange (ETDEWEB)

    Lei, Xingling [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Zhang, Haiyan, E-mail: hyzhang@gdut.edu.cn [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, Guangzhou 510006 (China); Chen, Yiming, E-mail: chenym@gdut.edu.cn [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, Guangzhou 510006 (China); Wang, Wenguang [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, Guangzhou 510006 (China); Ye, Yipeng; Zheng, Chuchun; Deng, Peng [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Shi, Zhicong [School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, Guangzhou 510006 (China)

    2015-03-25

    Graphical abstract: The excellent electrochemical performances can be attributed to the synergistic effect of CNTs and graphene. - Highlights: • The LFP–CNT–G composite was successfully prepared by solid station method. • The interlaced CNTs reduced the crumple of graphene and improved tap density of the composite. • The LFP–CNT–G electrode exhibited superior electrochemical performance. - Abstract: A three-dimensional lithium iron phosphate (LiFePO{sub 4})/carbon nanotubes (CNTs)/graphene composite was successfully synthesized via solid-state reaction. The LiFePO{sub 4}/carbon nanotubes/graphene (LFP–CNT–G) composite used as Li-ions battery cathode material exhibits superior high-rate capability and favorable charge–discharge cycle performance under relative high current density compared with that of LiFePO{sub 4}/carbon nanotubes (LFP–CNT) composite and LiFePO{sub 4}/graphene (LFP–G) composite. Graphene nanosheets and CNTs construct 3D conducting networks are favor for faster electron transfer, higher Li-ions diffusion coefficient and lower resistance during the Li-ions reversible reaction. The synergistic effect of graphene nanosheets and CNTs improves the rate capability and cycling stability of LiFePO{sub 4}-based cathodes. The LFP–CNT–G electrode shows reversible capacity of 168.9 mA h g{sup −1} at 0.2 C and 115.8 mA h g{sup −1} at 20 C. The electrochemical impedance spectroscopy demonstrate that the LFP–CNT–G electrode has the smallest charge-transfer resistance, indicating that the fast electron transfer from the electrolyte to the LFP–CNT–G active materials in the Li-ions intercalation/deintercalation reactions owing to the three-dimensional networks of graphene and carbon nanotubes.

  11. Diffusion through Carbon Nanotube Semipermeable membranes

    Energy Technology Data Exchange (ETDEWEB)

    Bakajin, O

    2006-02-13

    The goal of this project is to measure transport through CNTs and study effects of confinement at molecular scale. This work is motivated by several simulation papers in high profile journals that predict significantly higher transport rates of gases and liquids through carbon nanotubes as compared with similarly-sized nanomaterials (e.g. zeolites). The predictions are based on the effects of confinement, atomically smooth pore walls and high pore density. Our work will provide the first measurements that would compare to and hopefully validate the simulations. Gas flux is predicted to be >1000X greater for SWNTs versus zeolitesi. A high flux of 6-30 H2O/NT/ns {approx} 8-40 L/min for a 1cm{sup 2} membrane is also predicted. Neutron diffraction measurements indicate existence of a 1D water chain within a cylindrical ice sheet inside carbon nanotubes, which is consistent with the predictions of the simulation. The enabling experimental platform that we are developing is a semipermeable membrane made out of vertically aligned carbon nanotubes with gaps between nanotubes filled so that the transport occurs through the nanotubes. The major challenges of this project included: (1) Growth of CNTs in the suitable vertically aligned configuration, especially the single wall carbon nanotubes; (2) Development of a process for void-free filling gaps between CNTs; and (3) Design of the experiments that will probe the small amounts of analyte that go through. Knowledge of the behavior of water upon nanometer-scale confinement is key to understanding many biological processes. For example, the protein folding process is believed to involve water confined in a hydrophobic environment. In transmembrane proteins such as aquaporins, water transport occurs under similar conditions. And in fields as far removed as oil recovery and catalysis, an understanding of the nanoscale molecular transport occurring within the nanomaterials used (e.g. zeolites) is the key to process optimization

  12. Advances in mechanisms and signaling pathways of carbon nanotube toxicity

    OpenAIRE

    Dong, Jie; Ma, Qiang

    2015-01-01

    Carbon nanotubes (CNT) have been developed into new materials with a variety of industrial and commercial applications. In contrast, the physicochemical properties of CNT at the nanoscale render them the potency to generate toxic effects. Indeed, the potential health impacts of CNT have drawn a great deal of attention in recent years, owing to their identified toxicological and pathological consequences including cytotoxicity, inflammation, fibrosis, genotoxicity, tumorigenesis, and immunotox...

  13. Towards carbon nanotube growth into superconducting microwave resonator geometries

    OpenAIRE

    Blien, S.; Götz, K. J. G.; Stiller, P. L.; Mayer, T.; Huber, T.; Vavra, O.; Hüttel, A. K.

    2016-01-01

    The in-place growth of suspended carbon nanotubes facilitates the observation of both unperturbed electronic transport spectra and high-Q vibrational modes. For complex structures integrating, e.g., superconducting rf elements on-chip, selection of a chemically and physically resistant material that survives the chemical vapor deposition (CVD) process provides a challenge. We demonstrate the implementation of molybdenum-rhenium coplanar waveguide resonators that exhibit clear resonant behavio...

  14. Actuation mechanisms of carbon nanotube-based architectures

    OpenAIRE

    Geier, Sebastian; Mahrholz, Thorsten; Wierach, Peter; Sinapius, Michael

    2016-01-01

    State of the art smart materials such as piezo ceramics or electroactive polymers cannot feature both, mechanical stiffness and high active strain. Moreover, properties like low density, high mechanical stiffness and high strain at the same time driven by low energy play an increasingly important role for their future application. Carbon nanotubes (CNT), show this behavior. Their active behavior was observed 1999 the first time using paper-like mats made of CNT. Therefore the CNT-...

  15. Transparent, conductive and flexible single-walled carbon nanotube films

    OpenAIRE

    Kaskela, Antti

    2013-01-01

    Single-walled carbon nanotube (SWCNT) networks have a large application potential for future electronics as transparent conductive films. SWCNT networks (SWCNT-N) offer improved flexibility when compared to the current industry standard transparent conductive films (TCF), an example of which is indium tin oxide (ITO). SWCNTs can be synthesised from abundant raw materials, whereas indium supply is limited and has been a target of aggressive trade policies, thus increasing supply risks and price v...

  16. Smart Polymer/Carbon Nanotube Nanocomposites and Their Electrorheological Response

    Directory of Open Access Journals (Sweden)

    Ke Zhang

    2014-04-01

    Full Text Available This review article summarizes the preparation of polymer/carbon nanotube (CNT nanocomposites and their applications as electrorheological (ER fluids. These ER fluids exhibited a controllable electro-response under an applied electric field due to the presence of well-dispersed CNTs. The background, morphology, preparations, and characteristics of these materials are discussed, specifically focusing on the various approaches in the preparation of polymer/CNT nanocomposites, morphology, and their effects on the ER characteristics.

  17. Microstructure and Properties of Polypropylene/Carbon Nanotube Nanocomposites

    OpenAIRE

    Dimitrios Bikiaris

    2010-01-01

    In the last few years, great attention has been paid to the preparation of polypropylene (PP) nanocomposites using carbon nanotubes (CNTs) due to the tremendous enhancement of the mechanical, thermal, electrical, optical and structural properties of the pristine material. This is due to the unique combination of structural, mechanical, electrical, and thermal transport properties of CNTs. However, it is well-known that the properties of polymer-based nanocomposites strongly depend on the disp...

  18. Impact Excitation by Hot Carriers in Carbon Nanotubes

    OpenAIRE

    Perebeinos, Vasili; Avouris, Phaedon

    2006-01-01

    We investigate theoretically the efficiency of intra-molecular hot carrier induced impact ionization and excitation processes in carbon nanotubes. The electron confinement and reduced screening lead to drastically enhanced excitation efficiencies over those in bulk materials. Strong excitonic coupling favors neutral excitations over ionization, while the impact mechanism populates a different set of states than that produced by photoexcitation. The excitation rate is strongly affected by opti...

  19. Optical trapping of carbon nanotubes and graphene

    Directory of Open Access Journals (Sweden)

    S. Vasi

    2011-09-01

    Full Text Available We study optical trapping of nanotubes and graphene. We extract the distribution of both centre-of-mass and angular fluctuations from three-dimensional tracking of these optically trapped carbon nanostructures. The optical force and torque constants are measured from auto and cross-correlation of the tracking signals. We demonstrate that nanotubes enable nanometer spatial, and femto-Newton force resolution in photonic force microscopy by accurately measuring the radiation pressure in a double frequency optical tweezers. Finally, we integrate optical trapping with Raman and photoluminescence spectroscopy demonstrating the use of a Raman and photoluminescence tweezers by investigating the spectroscopy of nanotubes and graphene flakes in solution. Experimental results are compared with calculations based on electromagnetic scattering theory.

  20. On the Nanoindentation of the Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Petre P. Teodorescu

    2010-01-01

    Full Text Available A new inverse approach is proposed in this paper, which combines elements of nonlocal theory and molecular mechanics, based on the experimental results available in the nanoindentation literature. The effect of the inlayer van der Waals atomistic interactions for carbon nanotubes with multiple walls (MWCNT is included by means of the Brenner-Tersoff potential and experimental results. The neighboring walls of MWCNT are coupled through van der Waals interactions, and the shell buckling would initiate in the outermost shell, when nanotubes are short. The nanoindentation technique is simulated for the axially compressed of individual nanotubes, in order to evaluate the load-unloaded-displacement, the curve critical buckling and the appropriate values for local Lamé constants.