Search results for " Carbon nanotubes"

showing 10 items of 84 documents

Femtosecond four-wave-mixing spectroscopy of suspended individual semiconducting single-walled carbon nanotubes.

2010

Femtosecond four-wave-mixing (FWM) experiments of individual suspended semiconducting single-walled carbon nanotubes (SWCNTs) are presented. The chiral indices of the tubes were determined by electron diffraction as (28,14) and (24,14) having diameters of 2.90 and 2.61 nm, respectively. The diameter and semiconducting character of the tubes were additionally confirmed by resonance Raman measurements. The FWM signal showed electronic response from the SWCNTs. The results demonstrate that ultrafast dynamics of individual SWCNTs can be studied by FWM spectroscopies.

Materials scienceGeneral EngineeringAnalytical chemistryGeneral Physics and AstronomyResonanceCarbon nanotubelaw.inventionOptical properties of carbon nanotubessymbols.namesakeFour-wave mixingElectron diffractionlawFemtosecondsymbolsGeneral Materials ScienceRaman spectroscopySpectroscopyACS nano
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Simulation of electromagnetic properties in carbon nanotubes and graphene-based nanostructures

2012

As carbon nanotubes (CNT) and graphene nanostructures (GNR) constitute the basis of high-speed nanoelectronics and nanosensors, we examine the fundamental properties of var- ious CNT-metal (Me), GNR-Me, and CNT-graphene interconnects. The cluster approach based on the multiple scattering theory as well as effective medium approximation were used to model the dispersion law, electronic density of states (DOS), and conductivity, etc. Multiple scattering problems were solved for nanostructures with radial (quantum dots) and axial (nanowires, nano- tubes) symmetry. Interconnect capacitances and impedances have been evaluated in the GHz and THz regimes. Parametrical numerical simulations of cond…

Materials scienceGraphenebusiness.industryNanowireMechanical properties of carbon nanotubesNanotechnologyCarbon nanotubeCondensed Matter PhysicsElectronic Optical and Magnetic Materialslaw.inventionNanoelectronicslawNanosensorQuantum dotNano-OptoelectronicsbusinessJournal of Nanophotonics
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Cutting single-walled carbon nanotubes with an electron beam: evidence for atom migration inside nanotubes.

2006

Materials scienceMechanical properties of carbon nanotubesElectronsCarbon nanotubeElectronMolecular physicslaw.inventionBiomaterialsPotential applications of carbon nanotubesMicroscopy Electron TransmissionlawAtomMaterials TestingElectrochemistryNanotechnologyGeneral Materials ScienceNanotubesCarbon nanofiberNanotubes CarbonTemperatureGeneral ChemistryCarbonOptical properties of carbon nanotubesMicroscopy ElectronElectron microscopeCrystallizationBiotechnologySmall (Weinheim an der Bergstrasse, Germany)
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Parameters influencing the stiffness of composites reinforced by carbon nanotubes – A numerical–analytical approach

2014

Abstract Due to their high stiffness and strength, as well as their electrical conductivity, carbon nanotubes are under intense investigation as fillers in polymer matrix composites. The nature of the carbon nanotube/polymer bonding and the curvature of the carbon nanotubes may strongly reduce the reinforcing effect of the carbon nanotubes when added to a matrix to create composites. Here the effects of carbon nanotube waviness and the interaction with the matrix on the stiffness of the composite are investigated. Using a mixed numerical–analytical model, a parametric study of the waviness and volume fraction influence of CNTs on the elastic behavior of the nanocomposite is presented. The m…

Materials scienceNanocompositeCarbon nanotube Parametric study Modeling Composite Finite element methodWavinessCarbon nanotube actuatorsStiffnessMechanical properties of carbon nanotubesCarbon nanotubeCondensed Matter::Mesoscopic Systems and Quantum Hall Effectlaw.inventionCarbon nanotube metal matrix compositesSettore ING-IND/14 - Progettazione Meccanica E Costruzione Di MacchineCondensed Matter::Materials SciencelawVolume fractionCeramics and Compositesmedicinemedicine.symptomComposite materialCivil and Structural EngineeringComposite Structures
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Multifunctional properties of nanocomposites made by 1D and 2D graphene based fillers

2015

High aspect ratio graphene based fillers with different dimensionalities showed the ability to greatly modify rheological, mechanical, thermal and electrical properties of polymers at very low content. In this work, the effect of filler dimensionality on the multifunctional properties of an epoxy matrix reinforced by both carbon nanotubes (1D) and graphite nanoplatelets (2D) have been investigated across the percolation region. Keywords-- Carbon nanotube, Graphite nanoplatelet, nanocomposites, mechanical properties, ...

Materials scienceNanocompositeCarbon nanotube; electrical conductivity; Graphite nanoplatelet; mechanical properties; nanocompositeselectrical conductivityGrapheneMechanical properties of carbon nanotubesCarbon nanotubeengineering.materialmechanical propertiesYoung's modulus carbon nanotubes glass transition graphene graphite nanocomposites rheology thermal expansionCarbon nanotubelaw.inventionCondensed Matter::Materials SciencelawFiller (materials)PercolationnanocompositesengineeringGraphite nanoplateletGraphiteComposite materialGraphene oxide paper
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Mechanics of deformation of single- and multi-wall carbon nanotubes

2004

Abstract An effective continuum/finite element (FE) approach for modeling the structure and the deformation of single- and multi-wall carbon nanotubes (CNTs) is presented. Individual tubes are modeled using shell elements, where a specific pairing of elastic properties and mechanical thickness of the tube wall is identified to enable successful modeling with shell theory. The incorporation and role of an initial internal distributed stress through the thickness of the wall, due to the cylindrical nature of the tube, are discussed. The effects of van der Waals forces, crucial in multi-wall nanotubes and in tube/tube or tube/substrate interactions, are simulated by the construction of special…

Materials scienceNanocompositeMechanical EngineeringShell (structure)Mechanical properties of carbon nanotubesBendingMechanicsCarbon nanotubeCondensed Matter Physicslaw.inventionStress (mechanics)symbols.namesakeMechanics of MaterialslawsymbolsDeformation (engineering)Composite materialvan der Waals forceJournal of the Mechanics and Physics of Solids
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The Engineering of Hot Carbon Nanotubes with a Focused Electron Beam

2004

Single-wall and multiwall carbon nanotubes at high temperature are irradiated with the focused electron beam in an electron microscope. Nanotubes can be tailored with monolayer precision, and new morphologies of nanotubes are created. Atoms from layers of multiwall tubes can be removed and the tubes can be bent by a predefined angle. Bundles of single-wall tubes are transformed locally to multiwall tubes with coherent transition between the two modifications.

Materials sciencePhysics::Instrumentation and DetectorsMechanical EngineeringNanostructured materialsBent molecular geometryBioengineeringMechanical properties of carbon nanotubesGeneral ChemistryCarbon nanotubeCondensed Matter::Mesoscopic Systems and Quantum Hall EffectCondensed Matter Physicslaw.inventionCondensed Matter::Materials SciencelawMonolayerCathode rayGeneral Materials ScienceIrradiationElectron microscopeComposite materialComputer Science::DatabasesNano Letters
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Second-harmonic Generation Microscopy of Carbon Nanotubes

2012

We image an individual single-walled carbon nanotube (SWNT) by second-harmonic generation (SHG) and transmission electron microscopy and propose that SHG microscopy could be used to probe the handedness of chiral SWNTs.

Materials sciencePhysics::Medical PhysicsPhysics::OpticsSecond-harmonic generationScanning gate microscopyNanotechnologyCarbon nanotubeSecond Harmonic Generation MicroscopyCondensed Matter::Mesoscopic Systems and Quantum Hall Effectlaw.inventionOptical properties of carbon nanotubesCondensed Matter::Materials ScienceTransmission electron microscopylawEnergy filtered transmission electron microscopyPhotoconductive atomic force microscopyConference on Lasers and Electro-Optics 2012
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Thermo-oxidative resistant nanocomposites containing novel hybrid-nanoparticles based on natural polyphenol and carbon nanotubes

2015

Abstract Quercetin (Q), a natural antioxidant molecule, is physically immobilized onto multi-walled carbon nanotubes (CNTs) bearing covalently-linked long-chain alkyl functional groups, and the so obtained hybrid-nanoparticles are used to prepare Ultra High Molecular Weight PolyEthylene-based nanocomposite films with enhanced thermo-oxidation resistance. The effective immobilization of the Q molecules is confirmed by spectroscopic (micro-Raman, ATR-FTIR, and FTIR) and thermo-gravimetric analyses, and the influence of the nanoparticles on the rheological behaviour and thermo-oxidative stability of the nanocomposites are investigated. Rheological analyses (linear viscoelasticity and stress re…

Materials sciencePolymers and PlasticsNanoparticleMulti-walled carbon nanotubesCarbon nanotubeNanocompositeslaw.inventionchemistry.chemical_compoundUltra-high molecular weight polyethylene (UHMWPE)lawMaterials ChemistryMoleculeMechanics of MaterialSolubilityComposite materialAlkylMaterials Chemistry2506 Metals and AlloyUltra-high-molecular-weight polyethylenechemistry.chemical_classificationPolymers and PlasticNanocompositeNanocompositeMetals and AlloysMulti-walled carbon nanotubes; Nanocomposites; Quercetin; Thermo-oxidation resistance; Ultra-high molecular weight polyethylene (UHMWPE); Condensed Matter Physics; Mechanics of Materials; Polymers and Plastics; Materials Chemistry; 2506; Metals and AlloysPolyethyleneCondensed Matter PhysicsMulti-walled carbon nanotubeSettore ING-IND/22 - Scienza E Tecnologia Dei MaterialiChemical engineeringchemistryMechanics of MaterialsQuercetin2506Thermo-oxidation resistancePolymer Degradation and Stability
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Multi-functional polyhedral oligomeric silsesquioxane-functionalized carbon nanotubes for photo-oxidative stable Ultra-High Molecular Weight Polyethy…

2016

Abstract Nanohybrid (phPOSS- f -CNTs) based on Carbon Nanotubes (CNTs) and Phenyl Polyhedral Olygomenric Silsesquioxane (phPOSS) have been synthesized to be used as multifunctional filler for polymer nanocomposites. The success of the functionalization procedure has been demonstrated via accurate spectroscopic, spectrometric and thermo-gravimetric analyses. The results reveal that a large portion of phPOSS is covalently linked to CNTs, while a small amount of phPOSS remains physically adsorbed due to the strong interactions coming from π electron coupling between the CNTs and phenyl rings in phPOSS. Small amounts (1 wt.%) of phPOSS- f -CNTs have been dispersed in Ultra High Molecular Weight…

Materials sciencePolymers and PlasticsPolymer nanocompositeCarbon NanotubeUHMWPEPOSS Carbon Nanotubes Functionalization UHMWPE Photo-oxidation resistanceGeneral Physics and Astronomy02 engineering and technologyCarbon nanotube010402 general chemistry01 natural scienceslaw.inventionPhysics and Astronomy (all)chemistry.chemical_compoundlawMaterials ChemistryMoleculeComposite materialFunctionalizationPOSSUltra-high-molecular-weight polyethylenePolymers and PlasticNanocompositeOrganic ChemistryCarbon Nanotubes; Functionalization; Photo-oxidation resistance; POSS; UHMWPE; Physics and Astronomy (all); Polymers and Plastics; Organic ChemistryPhoto-oxidation resistance021001 nanoscience & nanotechnologySilsesquioxane0104 chemical scienceschemistryChemical engineeringCovalent bondSurface modificationCarbon Nanotubes0210 nano-technologyEuropean Polymer Journal
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