hemi toroidal networks in pyrolytic carbon nanotubes

... Initial studies of the problem indicated that linking between the inner and outer walls is not, in general, a hindered process Pyrolytic carbon nanotubes from vapor-grown carbon fibers The toroidal ... on single nanotubes, characterized for their diameter and chirality Interesting effects can be observed in carbon nanotubes for diameters in the range 1-20 nm, depending Physics of carbon nanotubes ... PCNTs and VGCFs Since Iijima's original report[l], carbon nanotubes have been recognized as fascinating materials with nanometer dimensions promising exciting new areas of carbon chemistry and physics...

Ngày tải lên: 05/03/2014, 15:21

... Initial studies of the problem indicated that linking between the inner and outer walls is not, in general, a hindered process Pyrolytic carbon nanotubes from vapor-grown carbon fibers The toroidal ... on single nanotubes, characterized for their diameter and chirality Interesting effects can be observed in carbon nanotubes for diameters in the range 1-20 nm, depending Physics of carbon nanotubes ... PCNTs and VGCFs Since Iijima's original report[l], carbon nanotubes have been recognized as fascinating materials with nanometer dimensions promising exciting new areas of carbon chemistry and physics...

Ngày tải lên: 27/06/2014, 17:20

... Initial studies of the problem indicated that linking between the inner and outer walls is not, in general, a hindered process Pyrolytic carbon nanotubes from vapor-grown carbon fibers The toroidal ... on single nanotubes, characterized for their diameter and chirality Interesting effects can be observed in carbon nanotubes for diameters in the range 1-20 nm, depending Physics of carbon nanotubes ... PCNTs and VGCFs Since Iijima's original report[l], carbon nanotubes have been recognized as fascinating materials with nanometer dimensions promising exciting new areas of carbon chemistry and physics...

Ngày tải lên: 27/06/2014, 17:20

... 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 ... screen-printed films TiO2 (broken line), TiO2 :MWCNT (solid line) Inset: TiO2 (1), TiO2 –MWCNT (2) Behavior-type SR (%) tr (min) td (min) Screen-printed CNT as-prepared Screen-printed TiO2 Screen-printed ... screen-printing are depicted in Fig 1(a), while coatings obtained by the dipping technique are shown in Fig 1(b) It is clear the difference in thickness and reflectivity of the TiO2 films obtained...

Ngày tải lên: 20/03/2014, 13:07

... the presence of crystalline defects/disorder in the grown FLG The 2D band around 2750 cm-1 has a single Lorentzian shape that is the fingerprint of a turbostratic stacking Finally, both G and 2D ... and JYV participated in the writing of the manuscript All authors read and approved the final manuscript Competing interests The authors declare that they have no competing interests Received: ... Monitoring dopants by Raman scattering in electrochemically top-gated graphene transistor Nat Nanotechnol 2008, 3:210 Mohiuddin TMG, Lombardo A, Nair RR, Bonetti A, Savini G, Jalil R, Bonini N,...

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 ... the highest value of the pristine (10,0) tube The chemisorptions of hydrogen also increase the ZT value at other temperatures, as indicated in Figure 6c It is interesting to note that the temperature-dependent ... Y, Ding JW: Thermal conductivity of zigzag singlewalled carbon nanotubes: role of the umklapp process Phys Rev B 2004, 69:47 26 Gu Y, Chen Y: Thermal conductivities of single-walled carbon nanotubes...

Ngày tải lên: 21/06/2014, 17:20

... buckling strain decreases with the increase in aspect ratio within both shell and beam buckling ranges, however, the decrease of buckling strain was found to be higher within the beam buckling ... buckling load decreases with increasing inner diameter for MWNTs with low aspect ratios which shows shell buckling mode In contrary, the buckling load was found to increase as the inner diameter increases ... inserting a tube into a MWNT, doesn’t increase the buckling strain but does increase the buckling load due to the increase in cross-sectional area However, in a more detailed study using molecular...

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 ... ultrathin film coating, will be presented in specific in Chapter The fabrication process of FE devices is very complicated and involves many engineering issues However, it is not pertinent to ... making it possible of reduction or elimination of field-screening effect [4, 5] Application of lithographic technique in Chapter Introduction producing patterned CNTs may yield the most promising...

Ngày tải lên: 11/09/2015, 10:17

... characteristic plots are 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 ... [14] In contrast with metals, the external electrical field would penetrate into semiconductors and result in the band bending near the semiconductor surface as illustrated in Fig 2.3 This bending ... 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 emission...

Ngày tải lên: 11/09/2015, 10:17

... specimens 3.3 Thin Film Characterization Techniques Characterization techniques of thin films utilized in this project will be briefly introduced in this section, including scanning electron microscopy ... observed in a modern TEM, and the lattice spacing can be determined as well TEM is different with SEM in principle in that TEM emits an electron beam that transmits through an ultrathin specimen ... where n is the integer 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...

Ngày tải lên: 11/09/2015, 10:17

... vaporization methods Instead of beginning with a solid carbon, the carbon atoms are extracted from a carbon monoxide or hydrocarbon gas, which dissociates either thermally or in the presence 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 experiment ... that the heat balances were maintained in this process, the CNT would grow continuously However, if perturbations took place in the chemistry process or excess carbon on the metal surface could...

Ngày tải lên: 11/09/2015, 10:18

... amorphous carbon film can be produced in which a proportion of the carbon atoms are bonded as in diamond This amorphous carbon is called diamond-like carbon (DLC) DLC resembles diamond in many ... 80%) [4-6] DLC is applicable in many areas, within which the most prominent application is using it as a coating material to reduce the abrasive wear and extraordinarily increase the lifetime of ... the laser beam into the vacuum chamber with minimum energy loss The focusing lens was used to focus the laser beam to a minimum possible size attainable so as to obtain a maximum intensity for...

Ngày tải lên: 11/09/2015, 10:18

... Emission 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 ... From the top view it can be clearly observed that the nanotubes become increasing thinner as the duration of hydrogen plasma treatments was increased From the cross-sectional view it is obvious ... 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 were fully etched...

Ngày tải lên: 11/09/2015, 10:18

... 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 ... Tetrahedral Amorphous Carbon Coated Carbon Nanotubes Core-Shell Nanostructures confirming the proportional influence of the barrier height to the commencement of FE behavior In other words, the ... damaging the structures thereby making electron transport within the emitters become difficult 148 Chapter Field Emission Study of Hydrogenated Tetrahedral Amorphous Carbon Coated Carbon Nanotubes...

Ngày tải lên: 11/09/2015, 10:18

... through inducing the energy band bending on the emitter surface by coating the pristine emitters with lower work function materials while the latter one could be realized by appropriately adjusting ... have been attempted in CNT coating to investigate the influence on the FE performance A direct extension of this work is to explore some other materials for CNT coating For instance, Boron Nitride ... Electrochemical and Solid-State Letters (Accepted) Jun Yu, Pruthvi Anetab, Jovan Hsieh, Angel Ting Ting Koh and Daniel Hock Chuan Chua “Enhanced electron emission from integrated carbon nanotubes/ ...

Ngày tải lên: 11/09/2015, 10:18

... 81.05.Qk; 81.07.Pr Introduction Due to the increasing importance of energy dissipation in the electronic industry, thermal conductivity of cured epoxy resins has been widely investigated over ... existence of intertube Umklapp scattering processes In addition, SWNTs exhibit a higher number of phonon vibrational modes and a lower defect density in relation to MWNTs, leading to a higher intrinsic ... transferred from the nanotube crystalline structure into the insulating polymer matrix This behavior has already been observed in cured resins [27, 28], but not in the pre-cured state The addition...

Ngày tải lên: 20/06/2014, 23:20

... in atomically thin carbon films, Science 306, 666 (2004) Chapter QUANTUM THEORIES FOR CARBON NANOTUBES S Saito INTRODUCTION Carbon is a fascinating element One can construct in principle an in nite ... giving rise to many kinds of new crystalline carbon phases [3] In the case of carbon nanotubes, existence of many kinds of nanotubes in various samples has also been confirmed experimentally using ... 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 model combined with...

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 ... 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 ... considered for obtaining desired treatment effects The studied ways of CNT administration include oral and injections such as subcutaneous injection, abdominal injection, and intravenous injection There...

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