flexibility of graphene layers in carbon nanotubes

... SMALLEY and inated as broken fragments of sintered nanotubes, the amount of remaining material reflects the degree of sintering Our examinations of oxygen-purified deposits led to construction of a ... of the method is studied in detail The elimination of amorphous carbon is also investigated INTRODUCTION The catalytic growth of graphitic carbon nanofibers during the decomposition of hydrocarbons ... mapping of the two-dimensional lattice of a single sheet of graphite (graphene) , depicted as the honeycomb lattice of a single layer of graphite in Fig 1, onto the surface of a cylinder As pointed...

Ngày tải lên: 05/03/2014, 15:21

... SMALLEY and inated as broken fragments of sintered nanotubes, the amount of remaining material reflects the degree of sintering Our examinations of oxygen-purified deposits led to construction of a ... of the method is studied in detail The elimination of amorphous carbon is also investigated INTRODUCTION The catalytic growth of graphitic carbon nanofibers during the decomposition of hydrocarbons ... mapping of the two-dimensional lattice of a single sheet of graphite (graphene) , depicted as the honeycomb lattice of a single layer of graphite in Fig 1, onto the surface of a cylinder As pointed...

Ngày tải lên: 27/06/2014, 17:20

... SMALLEY and inated as broken fragments of sintered nanotubes, the amount of remaining material reflects the degree of sintering Our examinations of oxygen-purified deposits led to construction of a ... of the method is studied in detail The elimination of amorphous carbon is also investigated INTRODUCTION The catalytic growth of graphitic carbon nanofibers during the decomposition of hydrocarbons ... mapping of the two-dimensional lattice of a single sheet of graphite (graphene) , depicted as the honeycomb lattice of a single layer of graphite in Fig 1, onto the surface of a cylinder As pointed...

Ngày tải lên: 27/06/2014, 17:20

... images of some of the films obtained with both deposition techniques Coatings fabricated by screen-printing are depicted in Fig 1(a), while coatings obtained by the dipping technique are shown in ... CNT/Multiwall carbon nanotubes; A, anatase; B, brookite; R, rutile Discussion As explained in Section 2, films obtained by dip-coating and screen-printing techniques differ in the volume of HCl used in the ... shown in the inset Please cite this article in press as: M Sánchez, M.E Rincón, Sensor response of sol–gel multiwalled carbon nanotubes- TiO2 composites deposited by screen-printing and dip-coating...

Ngày tải lên: 20/03/2014, 13:07

... be explained by a high compressive strain of the graphene lattice This strain must originate from the strong difference in the in- plane thermal expansion coefficients of the SiC and the graphene ... 514-nm line of an Ar ion-laser was used for excitation The spot size was μm, with 1-mW incident power under the objective Using this original combination of techniques, a 16 × 16 μm2 mapping of the ... shown by the more intense spots (at 30° and predominantly around 14°) AES performed on this sample gives an average coverage of the surface of to graphene layers Scanning tunneling microscopy STM...

Ngày tải lên: 21/06/2014, 05:20

... carbon nanotubes Phys Rev Lett 2007, 98:186808 13 Prasher RS, Hu XJ, Chalopin Y, Mingo N, Lofgreen K, Volz S, Cleri F, Keblinski P: Turning carbon nanotubes from exceptional heat conductors into ... thermoelectric properties of a series of zigzag and chiral carbon nanotubes which exhibit interesting diameter and chirality dependence Our calculated results indicate that these carbon nanotubes could ... Thermal conductivity of carbon nanotubes Nanotechnology 2000, 11:65-69 30 Padgett CW, Brenner DW: Influence of chemisorption on the thermal conductivity of single-wall carbon nanotubes Nano Lett...

Ngày tải lên: 21/06/2014, 17:20

... the shape of a cylinder Depending on the geometry of CNT, the following categories of CNT can be found Single-walled and multi-walled carbon nanotubes CNTs as single-walled carbon nanotubes (SWNTs) ... affecting the buckling properties of CNTs Ru (2000a) concluded through a continuum shell model that inserting a tube into a MWNT, doesn’t increase the buckling strain but does increase the buckling ... which is initially derived by Timoshenko and Gere (1961) to determine buckling strain of 28 thin cylindrical shells subjected to non-axisymmetric buckling, to determine the buckling strain of SWNTs...

Ngày tải lên: 09/09/2015, 18:54

... CHAPTER INTRODUCTION 1.1 Background 1.2 Carbon Nanotubes 1.2.1 Discovery of Carbon Nanotubes 1.2.2 Bonding Structures of Carbon Nanotubes 1.2.3 Properties of Carbon Nanotubes 1.2.4 Applications of Carbon ... shown in the insert 132 Fig 6.9 Schematic illustration of effective potential area (shadowed parts) of electron tunneling varying with the change of the thickness of the coating ultrathin film ... groups [19] in 1993 A single-walled CNT is made up of a one-atom thick sheet of graphene and can be considered to form by cutting a C60 molecule in half and placing a graphene cylinder between...

Ngày tải lên: 11/09/2015, 10:17

... shown in Fig 2.2 The plot of ln(J/E2) versus 1/E (so called F-N plot) displayed in the inset comprised a linear region, emphasizing the quantum tunneling electron emission mechanism The slope of ... accordingly [35, 36] With the increase of anode-cathode spacing, the threshold voltage increased as well With the further increase of the applied voltage, large current density could be obtained ... twice the height of the emitters [48] In addition, the work function of the emitter also plays a crucial role in influencing its FE properties According to the F-N equation shown in Eq (2.10), the...

Ngày tải lên: 11/09/2015, 10:17

... behind crystal diffraction is Bragg’ law: [23] nλ = 2d sinθ (3.1) where n is the integer representing the order of diffraction, λ is the wavelength, d is the interplanar spacing of the reflecting ... Characterization Techniques Characterization techniques of thin films utilized in this project will be briefly introduced in this section, including scanning electron microscopy (SEM), transmission electron ... three types of heating methods have been used to heat the susceptor: RF induction heating, radioactive heating and resistance heating Most MOCVD reactions occur in the temperature range of 300 -...

Ngày tải lên: 11/09/2015, 10:17

... Synthesis of Vertically-Aligned Carbon Nanotubes 4.3.4 Growth Rate of Carbon Nanotubes with Fe Catalyst In order to investigate the growth rate of CNTs under the conditions mentioned in the preceding ... CNTs obtained with Fe catalyst 58    Chapter Synthesis of Vertically-Aligned Carbon Nanotubes the nanotube that a few layers of graphene sheets formed randomly in the hollow tube This kind of CNT ... alternating current controlled power supply [2, 6-8] Some of these methods are innovative and effective in CNT growth However, the main problem of these methods is the incapability of producing vertically-aligned...

Ngày tải lên: 11/09/2015, 10:18

... vertically in the PLD chamber, facing to the carbon target with a constant distance of 50 mm in between The carbon target was prepared of high purity carbon powder (99.9%) with the particle size of 325 ... combine the advantages of the DLC and CNTs, i.e., the low electron affinity and strong mechanical properties of DLC and the one-dimensional free-standing geometry of CNTs by coating the DLC thin ... first stage of pumping was done with a rotary pump to bring the pressure in the chamber 123 Chapter Field Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell...

Ngày tải lên: 11/09/2015, 10:18

... Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures with the increase of ambient temperature during emission process, the work function of the ... Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures of the pristine CNTs Hence, it is reasonable to assume that the coated tips of these nanotubes ... flat and the average diameter of these nanotubes is comparable to that 136 Chapter Field Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures...

Ngày tải lên: 11/09/2015, 10:18

... of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures confirming the proportional influence of the barrier height to the commencement of FE behavior In ... three kinds of samples As the ta-C coated CNTs and the hydrogenated samples are merely the pristine CNTs with ultrathin film coating on the tube surface, the β values of these three kinds of samples ... corresponding F-N plots are shown in the insert 141 Chapter Field Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures original ta-C coated...

Ngày tải lên: 11/09/2015, 10:18

... discussion of this study have provided a better understanding of the FE enhancement mechanism of the multilayer structured field emitters The main factors influencing the FE properties of the composite ... fabrication process of FE devices is not taken into account since it is very complicated and not pertinent to the topic of this study However, to achieve the mass production of this kind of emitters, ... amorphous carbon films containing nano -graphene clusters” Submitted to Applied Physics Letters H Y Wang, Z Tan, J Yu, and Daniel H C Chua “Enhancement of field emission by coating carbon nanotubes...

Ngày tải lên: 11/09/2015, 10:18

... coupling of the vibrational modes of the graphene and of the polymeric matrix plays a dominant role on the thermal conductivities of the liquid and solid states Keywords: carbon nanotubes; graphene; ... properties of the system Thus, we aimed at studying the effect of two types of carbon- based nanofillers, in particular, nanotubes and graphene sheets, on the thermal conductivity of an uncured ... single wall carbon nanotubes Carbon 2002, 40:2043-2061 24 Deng F, Zheng QS, Wang LF: Effects of anisotropy, aspect ratio, and nonstraightness of carbon nanotubes on thermal conductivity of carbon...

Ngày tải lên: 20/06/2014, 23:20

... soot in macroscopic amounts and have been chromatographically purified, giving rise to many kinds of new crystalline carbon phases [3] In the case of carbon nanotubes, existence of many kinds of nanotubes ... the chirality of the nanotube using the tight-binding model In addition to isolated individual carbon nanotubes, condensed phases of nanotubes, i.e., bundles of single-walled carbon nanotubes and ... of electronic properties in carbon nanotubes as will be given in other chapters of this volume 2.3 Tight-Binding Model for Geometries and Energetics In the case of carbon, the pÀs tight-binding...

Ngày tải lên: 04/06/2014, 14:43

... thinking Because of the synthesis impairment, acetylcholine is decreased in the neurons in the Alzheimer disease brain, leading to the incapability of learning, memory, and thinking Providing ... hybridized carbon atoms (C-C distance is about 1.4 Ǻ) The wall of CNTs is single or multiple layers of graphene sheets, of which those formed by rolling up of single sheet are called single-walled carbon ... targeting of carbon nanotubes in mice Nat Nanotechnol 2007, 2:47-52 56 Liu Z, Tabakman S, Welsher K, Dai H: Carbon nanotubes in biology and medicine in vitro and in vivo detection, imaging and...

Ngày tải lên: 20/06/2014, 22:20

... samples were imbedded in KBr disks Elemental analysis (EA) was performed by using a CE Instruments EA1110 The melting points (mp) were determined on a Mel-Temp melting point apparatus and are ... was conducted both in air and nitrogen atmospheres with a heating rate of 10 °C/min using a Perkin–Elmer TGA7 The field emission scanning electron microscopy (FE-SEM) used in this work was a LEO ... without causing the sidewall opening and breaking of the stable crystalline carbon particles This implies that PPA can selectively destroy the amorphous carbons Unlike SWCNTs treated in hydrochloric...

Ngày tải lên: 22/06/2014, 00:20