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Jean-louis Sauvajol - One of the best experts on this subject based on the ideXlab platform.

  • Production of bundles of Single Walled Nanotubes by a simple laser ablation technique
    The 13th international winterschool on electronic properties of novel materials- science and technology of molecular nanostructures, 1999
    Co-Authors: Wolfgang K. Maser, Edgar Muñoz, Ana M. Benito, M.t. Martínez, G.f. De La Fuente, Eric Anglaret, Jean-louis Sauvajol
    Abstract:

    High yield Single-Walled Nanotube (SWNT) material has been obtained by using a very simple laser-ablation experimental set-up. It significantly differs from the usually employed ones in three main points: a) Use of a CO2-laser (in continuous wave mode), b) a simple vertical evaporation-chamber with rotating graphite/metal composite rods, and c) the absence of a furnace around the graphite targets. The obtained SWNT material is characterized by electron microscopy (SEM, TEM) and Raman spectroscopy. We show that our simple laser system creates very favorable growth conditions and discuss the importance of certain experimental parameters during the formation of SWNTs.

  • Production of high-density Single-Walled Nanotube material by a simple laser-ablation method
    Chemical Physics Letters, 1998
    Co-Authors: Wolfgang K. Maser, Edgar Muñoz, Ana M. Benito, M.t. Martínez, G.f. De La Fuente, Eric Anglaret, Y. Maniette, Jean-louis Sauvajol
    Abstract:

    Abstract A continuous-wave 250 W CO2-laser operating at 10.6 μm has been employed to evaporate graphite/bi-metal targets in a vertical evaporation chamber. Without the help of an additional furnace, web-like soot material has been easily produced. This contains high densities of bundles of Single-Walled Nanotubes (SWNTs). Electron microscopy, Raman spectroscopy and neutron diffraction show the high quality of the SWNT material. The use of this simple laser-ablation system offers additional possibilities to study experimental parameters important for the formation of SWNTs leading to a better understanding of its growth mechanism.

Feng Peng - One of the best experts on this subject based on the ideXlab platform.

  • Effect of temperature on phonon amplification in a Single-Walled Nanotube
    Journal of University of Science and Technology Beijing, 2007
    Co-Authors: Feng Peng
    Abstract:

    The phonon amplification effect occurring in a Single-Walled Nanotube was discussed,and the change rates of phonon population at different temperatures were calculated by using a time-dependent-perturbation method.It is shown that the optical phonon population increases nonlinearly with increasing laser field and the rate decreases as the temperature increases.At a definite temperature,the more intense the laser field is,the more remarkable the phonon amplification effect is,and a reasonable interpretation on this phenomenon was presented.

  • Laser-induced phonon amplification in a Single-Walled Nanotube
    Europhysics Letters (EPL), 2006
    Co-Authors: Feng Peng
    Abstract:

    In this work, we present a phonon amplification effect occurring in a Single-Walled Nanotube in the presence of a laser field. We calculate the rate of change of the phonon population and obtain the field strength threshold for achieving the phonon amplification. The optical phonon population is seen to increase nonlinearly provided the phonon growth rate is greater than the phonon loss. We find that the intense laser field can open a window of generating phonon amplification in the one-dimensional wave vector space parallel to the tube axis.

Jihua Gou - One of the best experts on this subject based on the ideXlab platform.

  • STUDY OF AFFINITIES BETWEEN Single-Walled Nanotube AND EPOXY RESIN USING MOLECULAR DYNAMICS SIMULATION
    International Journal of Nanoscience, 2006
    Co-Authors: Jihua Gou, Bin Fan, Gangbing Song, A. Khan
    Abstract:

    In the processing of carbon Nanotube/polymer composites, the interactions between the Nanotube and polymer matrix will occur at the molecular level. Understanding their interactions before curing is crucial for nanocomposites processing. In this study, molecular dynamics (MD) simulations were employed to reveal molecular interactions between (10, 10) Single-Walled Nanotube and two kinds of epoxy resin systems. The two kinds of resin systems were EPON 862/EPI-CURE W curing agent (DETDA) and DGEBA (diglycidylether of bisphenol A)diethylenetriamine (DETA) curing agent. The MD simulation results show that the EPON 862, DETDA and DGEBA molecules had strong attractive interactions with Single-Walled Nanotubes and their molecules changed their conformation to align their aromatic rings parallel to the Nanotube surface due to π-stacking effect, whereas the DETA molecule had a repulsive interaction with the Single-Walled Nanotubes. The interaction energies of the molecular systems were also calculated. Furthermore, an affinity index (AI) of the average distance between the atoms of the resin molecule and Nanotube surface was defined to quantify the affinities between the Nanotubes and resin molecules. The MD simulation results show that the EPON 862/EPI-CURE W curing agent system has good affinities with Single-Walled Nanotubes.

  • Single-Walled Nanotube bucky paper and nanocomposite
    Polymer International, 2006
    Co-Authors: Jihua Gou
    Abstract:

    A new processing method for the fabrication of Single-Walled Nanotube (SWNT)-reinforced nanocomposites was developed to achieve uniform dispersion and high composition of the Nanotubes in the nanocomposites. In this method, SWNTs were preformed as bucky paper by multi-step dispersion and micro-filtration of a suspension of Nanotubes. The nanocomposites were then fabricated by infiltration of diluted epoxy resin through the bucky paper and hot pressing. The wetting of the nanocomposites was examined using scanning electron microscopy and atomic force microscopy. The results showed that the epoxy resin completely penetrated the bucky paper through the nanoporous structures. The results of dynamic mechanical analysis of the nanocomposites showed that the storage moduli of the nanocomposites increased by 200–250%. The tan δ curves indicated that the Nanotubes had a strong influence on the damping properties of the nanocomposites. This processing technique is an effective method for fabricating nanocomposites with uniform dispersion and high composition of SWNTs. Copyright © 2006 Society of Chemical Industry

  • Computational and experimental study of interfacial bonding of Single-Walled Nanotube reinforced composites
    Computational Materials Science, 2004
    Co-Authors: Jihua Gou, Bob Minaie, Ben Wang, Zhiyong Liang, Chuck Zhang
    Abstract:

    Abstract In the development of Nanotube reinforced polymer composites, one of the fundamental issues that scientists and engineers are confronting is the Nanotube/polymer interfacial bonding, which will determine load transfer capability from the polymer matrix to the Nanotube. In this paper, the interfacial bonding of Single-Walled Nanotube (SWNT) reinforced epoxy composites was investigated using a combination of computational and experimental methods. The interfacial bonding was predicted using molecular dynamics (MD) simulations based on a cured epoxy resin model, which was constructed by incorporating three-dimensional cross-links formed during curing reaction. Based on the pullout simulations, the interfacial shear strength between the Nanotube and the cured epoxy resin was calculated to be up to 75 MPa, indicating that there could be an effective stress transfer from the epoxy resin to the Nanotube. In the experiments, Single-Walled Nanotube reinforced epoxy composites were fabricated, characterized and analyzed. The uniform dispersion and good interfacial bonding of the Nanotubes in the epoxy resin resulted in a 250–300% increase in storage modulus with the addition of 20–30 wt% Nanotubes. These experimental results provided evidence of stress transfer in agreement with the simulation results.

  • Nanoscale Modeling and Simulation of Interfacial Bonding of Single-Walled Nanotube Reinforced Composites
    Electronic and Photonic Packaging Electrical Systems and Photonic Design and Nanotechnology, 2003
    Co-Authors: Jihua Gou, Bob Minaie, Zhiyong Liang, Chuck Zhang, Shunliang Jiang, Ben Wang
    Abstract:

    Owning to the extraordinary mechanical, electrical and thermal properties of Single-Walled Nanotubes (SWNTs), SWNT reinforced composites can be used for various applications. In the development of SWNT reinforced composites, one of the fundamental issues that scientists and engineers are confronting is the SWNT-polymer interfacial bonding, which will determine the load transfer capability from the polymer matrix to the Nanotube. In Single-Walled Nanotube (SWNT) reinforced epoxy composites, the epoxy resin molecules and the Nanotubes are at the nano scale. the interaction at the SWNT/epoxy resin interface is highly dependent on their local molecular structures and bonding. At this small length scale, the lattice structures of the Nanotube and the epoxy resin cannot be considered continuous, and their interfacial properties cannot be determined through continuum mechanics. In this paper, the interfacial bonding of SWNT reinforced epoxy composites is investigated using molecular mechanics and molecular dynamics simulations based on a cured epoxy resin model, which is constructed by incorporating three-dimensional crosslinks formed with Shell EPON 862 epoxy resin and EPI CURE W curing agent during polymerization. The interfacial bonding energy between the SWNT and the cured epoxy resin is analyzed using molecular mechanics. Furthermore, the pullout of a SWNT from the cured epoxy resin is investigated using molecular dynamics simulations. Based on the pullout simulation, the interfacial shear strength between the SWNT and the cured epoxy resin is calculated to be up to 75MPa. These analysis results indicate that there could be an effective stress transfer from the epoxy resin to the Nanotube.Copyright © 2003 by ASME

Wolfgang K. Maser - One of the best experts on this subject based on the ideXlab platform.

  • Production of bundles of Single Walled Nanotubes by a simple laser ablation technique
    The 13th international winterschool on electronic properties of novel materials- science and technology of molecular nanostructures, 1999
    Co-Authors: Wolfgang K. Maser, Edgar Muñoz, Ana M. Benito, M.t. Martínez, G.f. De La Fuente, Eric Anglaret, Jean-louis Sauvajol
    Abstract:

    High yield Single-Walled Nanotube (SWNT) material has been obtained by using a very simple laser-ablation experimental set-up. It significantly differs from the usually employed ones in three main points: a) Use of a CO2-laser (in continuous wave mode), b) a simple vertical evaporation-chamber with rotating graphite/metal composite rods, and c) the absence of a furnace around the graphite targets. The obtained SWNT material is characterized by electron microscopy (SEM, TEM) and Raman spectroscopy. We show that our simple laser system creates very favorable growth conditions and discuss the importance of certain experimental parameters during the formation of SWNTs.

  • Production of high-density Single-Walled Nanotube material by a simple laser-ablation method
    Chemical Physics Letters, 1998
    Co-Authors: Wolfgang K. Maser, Edgar Muñoz, Ana M. Benito, M.t. Martínez, G.f. De La Fuente, Eric Anglaret, Y. Maniette, Jean-louis Sauvajol
    Abstract:

    Abstract A continuous-wave 250 W CO2-laser operating at 10.6 μm has been employed to evaporate graphite/bi-metal targets in a vertical evaporation chamber. Without the help of an additional furnace, web-like soot material has been easily produced. This contains high densities of bundles of Single-Walled Nanotubes (SWNTs). Electron microscopy, Raman spectroscopy and neutron diffraction show the high quality of the SWNT material. The use of this simple laser-ablation system offers additional possibilities to study experimental parameters important for the formation of SWNTs leading to a better understanding of its growth mechanism.

Edgar Muñoz - One of the best experts on this subject based on the ideXlab platform.

  • Production of bundles of Single Walled Nanotubes by a simple laser ablation technique
    The 13th international winterschool on electronic properties of novel materials- science and technology of molecular nanostructures, 1999
    Co-Authors: Wolfgang K. Maser, Edgar Muñoz, Ana M. Benito, M.t. Martínez, G.f. De La Fuente, Eric Anglaret, Jean-louis Sauvajol
    Abstract:

    High yield Single-Walled Nanotube (SWNT) material has been obtained by using a very simple laser-ablation experimental set-up. It significantly differs from the usually employed ones in three main points: a) Use of a CO2-laser (in continuous wave mode), b) a simple vertical evaporation-chamber with rotating graphite/metal composite rods, and c) the absence of a furnace around the graphite targets. The obtained SWNT material is characterized by electron microscopy (SEM, TEM) and Raman spectroscopy. We show that our simple laser system creates very favorable growth conditions and discuss the importance of certain experimental parameters during the formation of SWNTs.

  • Production of high-density Single-Walled Nanotube material by a simple laser-ablation method
    Chemical Physics Letters, 1998
    Co-Authors: Wolfgang K. Maser, Edgar Muñoz, Ana M. Benito, M.t. Martínez, G.f. De La Fuente, Eric Anglaret, Y. Maniette, Jean-louis Sauvajol
    Abstract:

    Abstract A continuous-wave 250 W CO2-laser operating at 10.6 μm has been employed to evaporate graphite/bi-metal targets in a vertical evaporation chamber. Without the help of an additional furnace, web-like soot material has been easily produced. This contains high densities of bundles of Single-Walled Nanotubes (SWNTs). Electron microscopy, Raman spectroscopy and neutron diffraction show the high quality of the SWNT material. The use of this simple laser-ablation system offers additional possibilities to study experimental parameters important for the formation of SWNTs leading to a better understanding of its growth mechanism.