properties of buckytubes and derivatives

... DRAVID, J B KETTERSON and R P H CHANG: Properties of buckytubes and derivatives 111 J.-P ISSI, L LANGER, J HEREMANS and C H OLK: Electronic properties of carbon nanotubes: Experimental ... contribute to the dissemination of present understanding of the subject and to future developments in the science and technology of carbon nanotubes and fullerenes, and of carbon science more generally ... properties of carbon nanotubes Most of these unusual properties are a direct consequence of their 1D quantum behavior and symmetry properties, including their unique conduction properties[ l and...

Ngày tải lên: 05/03/2014, 15:21

... DRAVID, J B KETTERSON and R P H CHANG: Properties of buckytubes and derivatives 111 J.-P ISSI, L LANGER, J HEREMANS and C H OLK: Electronic properties of carbon nanotubes: Experimental ... contribute to the dissemination of present understanding of the subject and to future developments in the science and technology of carbon nanotubes and fullerenes, and of carbon science more generally ... properties of carbon nanotubes Most of these unusual properties are a direct consequence of their 1D quantum behavior and symmetry properties, including their unique conduction properties[ l and...

Ngày tải lên: 27/06/2014, 17:20

... DRAVID, J B KETTERSON and R P H CHANG: Properties of buckytubes and derivatives 111 J.-P ISSI, L LANGER, J HEREMANS and C H OLK: Electronic properties of carbon nanotubes: Experimental ... contribute to the dissemination of present understanding of the subject and to future developments in the science and technology of carbon nanotubes and fullerenes, and of carbon science more generally ... properties of carbon nanotubes Most of these unusual properties are a direct consequence of their 1D quantum behavior and symmetry properties, including their unique conduction properties[ l and...

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 ... dip-coated and screen-printed composites with their sensing performance The color and size of titania symbols are representative of the lack (white) or abundance (yellow) of Ti3+ states and of the...

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

... 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 ... Nano-structures of Ministry of Education and School of Physics and Technology, Wuhan University, Wuhan, 430072, China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan ... simulations and nonequilibrium Green's function method, we investigate the thermoelectric properties of a series of zigzag and chiral carbon nanotubes which exhibit interesting diameter and chirality...

Ngày tải lên: 21/06/2014, 17:20

... missing atoms and the shape of defects, on the buckling properties of SWNTs and DWNTs are studied The cumulative effect of defects and temperature on SWNTs is also assessed 12 1.4 Layout of the thesis ... the buckling of defective freestanding CNTs Here, effects of different defect parameters, such as number of missing atoms, number of dangling bonds, asymmetry of defects and number of vacancy clusters, ... effect of SW defects on tensile behavior and fracture of achiral and chiral SWNTs They found that the effect of SW defect on the tensile properties of armchair tubes is higher than that of zigzag...

Ngày tải lên: 09/09/2015, 18:54

... support and great confidence in me all 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 ... 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 ... the conduction band minimum, and VBM is the valence band maximum 134 Fig 6.10 Top and cross-sectional view SEM images of composite emitters (a) and (b) 50 nm ta-C coated CNTs; (c) and (d) 50 nm...

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

... 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 ... Santos, Principles and Applications of NanoMEMS Physics (Springer, Netherlands, 2005) pp 15 S Zhang and N Ali, Nanocomposite Thin Films and Coatings: Processing, Properties and Performance (Imperial...

Ngày tải lên: 11/09/2015, 10:17

... application of an 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 ... 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 ... portion TEM images of the as-grown CNTs are shown in Fig 4.4 It can be observed from the images that the CNT is multiwalled and consists of 35 layers of graphene sheets with spacing of around 0.31...

Ngày tải lên: 11/09/2015, 10:18

... 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 ... and extraordinarily increase the lifetime of components [7] Diamond and DLC are potential in FE applications due to their low-field electron emission, hardness to withstand ion bombardment, and ... power of 500 Watt was applied for the hydrogenation The chamber pressure was set to be 15 Torr and the H2 flow rate was set to be 300 sccm 6.3 Thickness Effect of Ta-C Films on FE Properties of...

Ngày tải lên: 11/09/2015, 10:18

... 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 ... thin films, which look like a layer of whiskers formed with the average diameter larger than that of the pristine CNTs and the whiskers extended from the tips of the CNTs With a 10 s surface hydrogenation ... the tips of these whiskers seem to protrude out and stand freely rather than exhibiting curly shape at the tips like the pristine ta-C coated CNTs With 20 s hydrogenation, the surface of the sample...

Ngày tải lên: 11/09/2015, 10:18

... Illustration of the band bending of the ta-C film in equilibrium with the absorbed water layer in air Evac represents the vacuum level, Ec refers to the conduction band minimum and Ev is the valence band ... assumption of equal β values is reasonable Namely, the geometry of these three kinds of samples has nearly equal contribution to the electron emission The mechanism of the FE enhancement of the 10 ... 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...

Ngày tải lên: 11/09/2015, 10:18

... electron injection from the Fermi level of the CNTs to the conduction band of metal oxides followed by the electron emission from the conduction band minimum of metal oxides to the vacuum The considerably ... durations of hydrogen plasma treatments FE characteristics of these specimens were tested to study whether these steps could enhance the FE properties of the pristine CNTs Results showed that the FE properties ... fabricated and these emitters may be considered as alternative choices for the present commercial FE devices Moreover, the results and discussion of this study have provided a better understanding of...

Ngày tải lên: 11/09/2015, 10:18

... 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, ... mechanical properties with 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- ... on -2- the understanding of their unique properties have prompted the development and study of graphene filled nanocomposites [12, 13] This communication analyzes the epoxy-nanofiller blend in...

Ngày tải lên: 20/06/2014, 23:20

... rolled up sheets of graphene, and, as might be expected, many of the mechanical and electronic properties of nanotubes are derived from or closely related to corresponding properties of graphene (Amusingly, ... mechanical properties of individual nanotubes [37]; the examination of ‘‘sword and sheath’’ failure modes of MWNTs under axial strain [39]; sharpening, peeling, and ‘‘telescoping’’ of nanotubes ... 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,...

Ngày tải lên: 04/06/2014, 14:43

... polymers and their derivatives for noncovalent functionalization of the nanotubes which increases solubility and enhances other properties of interest Pseudorotaxanes are grafted along the walls of ... 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...

Ngày tải lên: 20/06/2014, 22:20

... mechanism of functionalization of SWCNT with benzamide functional group SWCNT diameters of 1.37–2.62 nm It is a strong indication that the framework of SWCNTs was not damaged The ratio of D/G-band ... for covalent attachment of TMPBA onto SWCNTs Conclusions The purification of SWCNTs and the covalent attachment of TMPBA onto the surface of SWCNTs were conducted in a mild and thus less destructive ... implies the higher purity of SWCNTs The TEM image of the as-received SWCNTs shows that there are large portions of carbonaceous and metallic impurities (Fig 1c) On the other hand, the PPA treated...

Ngày tải lên: 22/06/2014, 00:20