helically coiled and toroidal cage forms of graphitic carbon

... microscopy of carbon nanotubes and nanocones 65 T W EBBESEN and T TAKADA: Topological and SP3 defect structures in nanotubes 71 S IHARA and S ITOH: Helically coiled and torodial cage forms of graphitic ... on carbon nanotubes We hope this book will contribute to the dissemination of present understanding of the subject and to future developments in the science and technology of carbon nanotubes and ... by Ebbesen and Takada The review by Ihara and Itoh of the many helical and toroidal forms of carbon nanostructures that may be realized provides insight into the potential breadth of this field...

Ngày tải lên: 05/03/2014, 15:21

... microscopy of carbon nanotubes and nanocones 65 T W EBBESEN and T TAKADA: Topological and SP3 defect structures in nanotubes 71 S IHARA and S ITOH: Helically coiled and torodial cage forms of graphitic ... on carbon nanotubes We hope this book will contribute to the dissemination of present understanding of the subject and to future developments in the science and technology of carbon nanotubes and ... by Ebbesen and Takada The review by Ihara and Itoh of the many helical and toroidal forms of carbon nanostructures that may be realized provides insight into the potential breadth of this field...

Ngày tải lên: 27/06/2014, 17:20

... microscopy of carbon nanotubes and nanocones 65 T W EBBESEN and T TAKADA: Topological and SP3 defect structures in nanotubes 71 S IHARA and S ITOH: Helically coiled and torodial cage forms of graphitic ... on carbon nanotubes We hope this book will contribute to the dissemination of present understanding of the subject and to future developments in the science and technology of carbon nanotubes and ... by Ebbesen and Takada The review by Ihara and Itoh of the many helical and toroidal forms of carbon nanostructures that may be realized provides insight into the potential breadth of this field...

Ngày tải lên: 27/06/2014, 17:20

... sensor response, and times of adsorption/desorption of screenprinted and dip-coated films sensing a flux of 150 mL of N2 with a charge of 1% NH3 Material Fig Optical properties of: (a) dip-coated ... adsorption/desorption, and the direction and amount of charge transfer Fig Photocurrent ratio of dip-coated TiO2 –MWCNT films and TiO2 films as a function of wavelenght The spectral response of TiO2 (broken line) and ... electrochemical and photoelectrochemical energy conversion and storage, synthesis and characterization of composites based in inorganic and organic semiconductors, and nanocarbon materials in energy and...

Ngày tải lên: 20/03/2014, 13:07

... to 60 nm (c, d) Raman shift of the G and 2D bands, respectively The positions of both bands are shifted to higher energies The G band is around 1610 cm-1 and the 2D band around 2750 cm-1 This high ... centered at 1582 cm-1, and a 2D band at 2690 cm-1 The average up shift is then of 28 cm-1 for the G band, and of 60 (30) cm-1 for the 2D (D) band, respectively The G and 2D band Raman shift maps are ... D band lies around 1380 cm-1, the G band around 1610 cm-1, and the 2D band around 2750 cm-1 whereas neutral relaxed graphene has a D band around 1350 cm-1, a G band centered at 1582 cm-1, and...

Ngày tải lên: 21/06/2014, 05:20

... performance of zigzag and chiral carbon nanotubes Xiaojian Tan1, Huijun Liu*1, Yanwei Wen1, Hongyan Lv1, Lu Pan1, Jing Shi*1, and Xinfeng Tang2 Key Laboratory of Artificial Micro- and Nano-structures of ... the NEGF and NEMD calculations HJL participated in the design of the study and discussions of the theoretical results YWW, HYL, and LP participated in the implementation of the LAMMPS and ATK ... dispersion and separation of carbon nanotubes Nat Mater 2003, 2:338-342 Figure Lattice thermal conductivity of tube (4,2) as a function of temperature Results from the Callaway-Holland model and the...

Ngày tải lên: 21/06/2014, 17:20

... properties of carbon nanotubes 1.1.3 Applications of carbon nanotubes 1.2 Motivation 1.3 Objective and scope of work 11 1.4 Layout of the thesis 13 CHAPTER 2: LITERATURE REVIEW 2.1 Buckling of CNTs ... achiral carbon nanotubes The latter comprises of both zigzag and armchair carbon nanotubes This categorization is done based on the orientation of carbon- carbon (C-C) bonds Orientation of C-C ... of different configurations of vacancy defects, such as the number of missing atoms and the shape of defects, on the buckling properties of SWNTs and DWNTs are studied The cumulative effect of...

Ngày tải lên: 09/09/2015, 18:54

... ABBREVIATIONS LIST OF SYMBOLS XV XVII 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 ... the tube axis, and a1 and a2 are the unit vectors of graphene in real space Fig 1.4 Schematic illustration of sp1, sp2 and sp3 hybrid carbon orbitals Fig 1.5 Illustration of energy of the electrons ... Schematic illustration of sp1, sp2 and sp3 hybrid carbon orbitals Hybridization determines the type of bonding of the carbon atoms with their types n neighbors, and different types of bonding are responsible...

Ngày tải lên: 11/09/2015, 10:17

... emission mass, barrier height of the emitter F is the local field, ε0 is the permittivity of free space, emitters, 21 Chapter Physics of Field Emission and t(y) and υ(y) are the Nordheim elliptic ... electron emission mechanism The slope of the linear region of the F-N plot is a function of both β and Ø, which can be expressed as below by transformation of the Eq (2.3): φ3/ Slope = −6.83 × ... low and high electrical field This deviation might be due to the space charge effects, overheating of the emitter tips or the low concentration of the carriers in the tips, conduction band of...

Ngày tải lên: 11/09/2015, 10:17

... various materials, including carbon and carbon related materials (diamond, nanocrystalline diamond and CNTs, etc.) and non -carbon advanced materials, such as GaN, SiC, Ga2O3 and silicon whiskers [18] ... representing the order of diffraction, λ is the wavelength, d is the interplanar spacing of the reflecting (diffracting) plane, and θ is the angle of the incidence and of the diffraction of the radiation ... measurements of the work functions and band structures of the solid, the surface and adsorbed layers [27, 28] In this study, UPS technique was used to measure the work functions of the samples Photons of...

Ngày tải lên: 11/09/2015, 10:17

... covered with amorphous carbon, which is the product of the thermal deposition of hydrocarbon [3] 52    Chapter Synthesis of Vertically-Aligned Carbon Nanotubes In terms of other CNT growth approaches, ... the growth of CNTs The catalytic CVD growth of CNTs is an entirely different process with the arc discharge and laser vaporization methods Instead of beginning with a solid carbon, the carbon atoms ... growth of CNTs by plasma-enhanced chemical vapor deposition (PECVD) technique There are some advantages of growing CNTs by PECVD technique: [4] (1) Dissociation of hydrocarbon gas and formation of...

Ngày tải lên: 11/09/2015, 10:18

... primarily c composed of carbon Fig 6.5 shows the carbon 1s core level XPS spectrum of the film Two peaks with the binding energy (BE) of 284.5 and 285.2 eV confirm a high sp3 content of 126 Chapter ... low electron affinity and strong mechanical properties of DLC and the one-dimensional free-standing geometry of CNTs by coating the DLC thin films directly onto the surface of the vertically-aligned ... other and form a thick canopy composed of clustered particles on the top surface of CNTs eventually 128 Chapter Field Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon...

Ngày tải lên: 11/09/2015, 10:18

... Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures Fig 6.11 Top and cross-sectional view SEM images of composite emitters (a) and (b) 100 ... surface is rather 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 ... Top and cross-sectional view SEM images of composite emitters (a) and (b) 50 nm sectional ta-C coated CNTs; (c) and (d) 50 nm ta coated CNTs with a 10 s hydrogenation treatment; C ta-C (e) and...

Ngày tải lên: 11/09/2015, 10:18

... water layer in air and result in a raised valence band maximum of diamond, in other words, a 143 Chapter Field Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes ... Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures Fig 6.15 Carbon 1s core level XPS spectra of the (a) 50 nm ta C coated CNTs and (b) 10 ... Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures performance of the emitters and there exists an optimum thickness of the ta-C coating...

Ngày tải lên: 11/09/2015, 10:18

... “Hydrogenation and its effects on the field emission characteristics of tetrahedral amorphous carbon coated carbon nanotubes” Journal of Physical Chemistry C (Accepted) Jun Yu, Kuan He Choo, Lifang Niu, and ... List of Publications J Yu, C H Sow, Andrew T S Wee, and Daniel H C Chua “Enhanced field emission of vertically-aligned core-shell carbon nanotubes with molybdenum oxide encapsulation” Journal of ... 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,...

Ngày tải lên: 11/09/2015, 10:18

... 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 ... cross-link density and hence, on the final properties of the system Thus, we aimed at studying the effect of two types of carbon- based nanofillers, in particular, nanotubes and graphene sheets, ... Young's modulus of TPa and ultimate strength of 130 GPa [11] In addition to these outstanding properties, the recent developments on graphene synthesis routes and on -2- the understanding of their unique...

Ngày tải lên: 20/06/2014, 23:20

... T.F Kelly and R.S Ruoff, Strength and breaking mechanism of multiwalled carbon nanotubes under tensile load, Science 287, 637 (2000) [40] J Cumings, P.G Collins and A Zettl, Peeling and sharpening ... Fleming, J Liu and O Zhou, Fabrication and properties of composites of poly(ethylene-oxide) and functionalized carbon nanotubes, Adv Mater 14, 1387 (2002) [85] M Zhang, K.R Atkinson and R.H Baughman, ... 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 in...

Ngày tải lên: 04/06/2014, 14:43

... mixing and heating of CNTs and urea to initiate a polymerization reaction of the isocyanic acid and/ or cyanate ion to yield modified CNTs [45] As a summary, there have been a lot of literatures and ... details Institute of Pharmacology and Toxicology and Key Laboratory of Nanopharmacology and Nanotoxicology, Beijing Academy of Medical Science, Zhengzhou, Henan, People’s Republic of China 2Nanotechnology ... energy of singlewalled carbon nanotubes Appl Phys Lett 1999, 16:2307-2309 Peigney A, Laurent C, Flahaut E, Bacsa RR, Rousset A: Specific surface area of carbon nanotubes and bundles of carbon...

Ngày tải lên: 20/06/2014, 22:20

... polymerization of phenoxybenzoic acids [11] and functionalization of closely related carbon materials such as vapor-grown multi-walled carbon nanofibers (MWCNFs) [12, 13] and multi-walled carbon nanotubes ... Results and Discussion Without purification, most of the as-prepared SWCNTs contain approximately 60–70 wt% of impurities such as carbonaceous fragments, amorphous carbons, and small amount of graphite ... contact each other and forms larger bundles Apparently, the surface of PPA treated SWCNT bundles is seamless and smooth, whereas the surface of as-received SWCNT bundles is furry and rough due to...

Ngày tải lên: 22/06/2014, 00:20