model structure of perfectly graphitizable coiled carbon nanotubes

... properties of the nanotubes The symmetry groups for carbon nanotubes can be either symmorphic [such as armchair (n,n)and zigzag Physics of carbon nanotubes 29 Table Parameters of carbon nanotubes ... progress in research on carbon nanotubes and related materials 'The birth of the field of carbon nanotubes is marked by the publication by Iijima of the observation of multi-walled nanotubes with outer ... intrinsic structures are rather like that of the annual growth of trees The structure of VGCFs, especially those with hollow cores, are very similar to the structure of arc-formed carbon nanotubes...

Ngày tải lên: 05/03/2014, 15:21

... properties of the nanotubes The symmetry groups for carbon nanotubes can be either symmorphic [such as armchair (n,n)and zigzag Physics of carbon nanotubes 29 Table Parameters of carbon nanotubes ... progress in research on carbon nanotubes and related materials 'The birth of the field of carbon nanotubes is marked by the publication by Iijima of the observation of multi-walled nanotubes with outer ... intrinsic structures are rather like that of the annual growth of trees The structure of VGCFs, especially those with hollow cores, are very similar to the structure of arc-formed carbon nanotubes...

Ngày tải lên: 27/06/2014, 17:20

... properties of the nanotubes The symmetry groups for carbon nanotubes can be either symmorphic [such as armchair (n,n)and zigzag Physics of carbon nanotubes 29 Table Parameters of carbon nanotubes ... progress in research on carbon nanotubes and related materials 'The birth of the field of carbon nanotubes is marked by the publication by Iijima of the observation of multi-walled nanotubes with outer ... intrinsic structures are rather like that of the annual growth of trees The structure of VGCFs, especially those with hollow cores, are very similar to the structure of arc-formed carbon nanotubes...

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 films, ... size of titania symbols are representative of the lack (white) or abundance (yellow) of Ti3+ states and of the crystallite size obtained by XRD; the size of the arrows illustrate the magnitude of ... the identification of small changes in the patterns of the composite films; the narrower and more symmetric shape of the MWCNT peak at 2Â = 26◦ indicates the lost of amorphous carbon after functionalization...

Ngày tải lên: 20/03/2014, 13:07

... top It can also be stated that the edges of the Figure STM images of the edges of the graphene islands (a) 23 × 23 nm2 STM image of a monolayer on top of the (3 × 3) SiCreconstructed surface This ... 20 21 22 23 24 Page of atmospheric pressure graphitization of silicon carbide Nat Mater 2009, 8:203 Kim S, Ihm J, Choi HJ, Son YW: Origin of anomalous electronic structures of epitaxial graphene ... http://www.nanoscalereslett.com/content/6/1/171 Page of (a) (b) (c) (d) Figure STM images of a 6H-SiC(000-1) sample after graphitization (same sample as in figure 1) (a) 300 × 300 nm2 STM image of few layers of graphene grown...

Ngày tải lên: 21/06/2014, 05:20

... 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 ... dynamics of singlewalled carbon nanotubes Phys Rev B 2003, 67:045413 33 Esfarjani K, Zebarjadi M, Kawazoe Y: Thermoelectric properties of a nanocontact made of two-capped single-wall carbon nanotubes ... 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...

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 ... 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)...

Ngày tải lên: 09/09/2015, 18:54

... 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 Nanotubes 2 13 ... through these years ii Table of Contents Table of Contents ACKNOWLEDGEMENTS TABLE OF CONTENTS ABSTRACT I III VII LIST OF TABLES IX LIST OF FIGURES X LIST OF ABBREVIATIONS LIST OF SYMBOLS XV XVII CHAPTER ... Carbon Nanotubes 4.3.2 Catalytic Growth Mechanism of Carbon Nanotubes 4.3.3 Function of Metal Catalyst in CNT Growth 4.3.4 Growth Rate of Carbon Nanotubes with Fe Catalyst 56 56 60 62 66 4.4 Summary...

Ngày tải lên: 11/09/2015, 10:17

... space charge effects, overheating of the emitter tips or the low concentration of the carriers in the tips, conduction band of semiconductors [15-17] FE properties of semiconductors could on 17] ... concentration of carriers would influence the band structures of the semiconductors, resulting in varied emission barrier height and heights thus diverse FE performance [20, 21] Furthermore, the origin of ... lifetime of the emitters [53] Therefore, one primary issue about FE devices is to improve the corrosion resistance of the emitters One of the methods, i.e., coating the emitters with materials of high...

Ngày tải lên: 11/09/2015, 10:17

... spectrum of a mixture of elements is approximately the sum of the peaks of the individual constituents Generally, identification of chemical states can be made from exact measurements of peak ... 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, ... Schematic setup of the PECVD system used 55    Chapter Synthesis of Vertically-Aligned Carbon Nanotubes 4.3 Results and Discussion 4.3.1 Characterization of the As-Grown Carbon Nanotubes Fig 4.2 ... the hollow part of   Fig 4.4 TEM images of the as-grown CNTs obtained with Fe catalyst 58    Chapter Synthesis of Vertically-Aligned Carbon Nanotubes the nanotube that a few layers of graphene sheets...

Ngày tải lên: 11/09/2015, 10:18

... Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures neighbors giving rise to three-dimensional interconnected structure of carbon atoms [1] This structure ... energy (BE) of 284.5 and 285.2 eV confirm a high sp3 content of 126 Chapter Field Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures ... Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures 6.3.4 FE Performance of the Composite Emitters with Varied Thicknesses of Coating Films...

Ngày tải lên: 11/09/2015, 10:18

... 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 ... 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 Fig 6.10 ... 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...

Ngày tải lên: 11/09/2015, 10:18

... Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures 6.4.2 FE Properties of the Hydrogenated Composite Emitters The FE J-E curves of the pristine ... Chapter Field 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 ... 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

... characteristics of tetrahedral amorphous carbon coated carbon nanotubes Journal of Physical Chemistry C (Accepted) Jun Yu, Kuan He Choo, Lifang Niu, and Daniel H C Chua “Synthesis of three-dimensional ... 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 ... molybdenum oxide-coated carbon nanotubes core-shell nanostructures” Journal of Materials Science 46, 4858 (2011) Jun Yu, and Daniel H C Chua “Enhanced field emission properties of hydrogenated tetrahedral...

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 ... 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 ... indicate that MWNTs are the most effective carbon nanofillers to improve the K of liquid resins Indeed, the K of the nanofluids gradually increased as a function of MWNT content, reaching a 70% improvement...

Ngày tải lên: 20/06/2014, 23:20

... addition to isolated individual carbon nanotubes, condensed phases of nanotubes, i.e., bundles of single-walled carbon nanotubes and concentric multiwalled carbon nanotubes, are very important ... applications 3.3 Electronic Structure of Chiral Carbon Nanotubes First-principles electronic structure studies of chiral carbon nanotubes other than achiral zigzag and armchair nanotubes have scarcely ... role of essential importance in the field of carbon nanotubes as will be reviewed in this chapter, in which an overview of theories applied to carbon nanotubes is presented and the advantages of...

Ngày tải lên: 04/06/2014, 14:43

... 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 nanotubes ... applications of single walled carbon nanotubes Curr Med Chem 2010, 17:10-24 Ito Y, Venkatesan N, Hirako N, Sugioka N, Takada K: Effect of fiber length of carbon nanotubes on the absorption of erythropoietin ... properties of CNTs Carbon nanotubes are a huge cylindrical large molecules consisting of a hexagonal arrangement of sp2 hybridized carbon atoms (C-C distance is about 1.4 Ǻ) The wall of CNTs is...

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 ... 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 and metal catalysts ... present in the tubular wall structure and the G-band in the 1550–1600 cm-1 region of spectrum is due to the tangential C–C stretching of SWCNT carbon atoms [25] The ID/IG value of the TMPBA-g-SWCNT...

Ngày tải lên: 22/06/2014, 00:20