electronic structures of single walled carbon nanotubes

... spectroscopy applied to single- walled carbon nanotubes Chem Phys Lett 2005, 410:136 Hartschuh A, Qian H, Meixner AJ, Anderson AJ, Novotny L: Nanoscale optical imaging of single- walled carbon nanotubes J ... Nanoscale Optical Imaging of Excitons in Single- Walled Carbon Nanotubes Nano Lett 2005, 5:2310 11 Roy D, Williams C: High resolution Raman imaging of single wall carbon nanotubes using electrochemically ... probed the variation of the Raman signal of SWCNTs at seven different positions along a bundle The TERS intensity of G-mode in carbon nanotubes is strongly dependent on the height of the bundle Moreover,...

Ngày tải lên: 21/06/2014, 05:20

... poorly multi -walled carbon nanotubes (MWCNTs) and organized carbon in the sample The relatively high intensity of the D band relative to G band (ID/IG = 0.72) indicates mass amorphous carbon content ... in the results and are coated by plenty of amorphous carbons Conclusions A temperature window of SWCNTs growth by catalytic chemical vapor deposition of CH4 over Mo-Fe/MgO catalyst has been studied ... more and more amorphous carbons, and when the temperature increases to 950 °C, SWCNTs are hardly observed In order to study the influence of growth temperature on the purity of prepared tube samples,...

Ngày tải lên: 22/06/2014, 00:20

... carbon nanotubes: experiment and theory, J Chem Phys 119 (20) (2003) 10904–10910 [4] M.D Ellison, M.J Crotty, D.H Koh, R.L Spary, K.E Tate, Adsorption of NH3 and NO2 on single- walled carbon nanotubes, ... Hamers, M.A Eriksson, Effect of ozone oxidation on single- walled carbon nanotubes, J Phys Chem B 110 (2006) 7113–7118 J Li, Y Lu, Q Ye, M Cinke, J Han, M Meyyappan, Carbon nanotube sensors for ... Dickey, P.C Eklund, Debundling and dissolution of single- walled carbon nanotubes in amide solvents, J Am Chem Soc 126 (2004) 6095–6105 N Sano, F Ohtsuki, Carbon nanohorn sensor to detect ozone in...

Ngày tải lên: 19/03/2014, 16:47

... 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 ... 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 was 1.3, which was much lower than 5.0 of the PPA treated...

Ngày tải lên: 22/06/2014, 00:20

... Therefore, even with the addition of 20 vol.% H2 (H2/O2 of 10/40 (sccm/sccm)) in gas, there is still a significant removal of amorphous carbon and formation of oxygen-containing groups on the ... effect of gas composition on structural integrity of the nanotubes is insignificant in this case Conclusions In this article, the effects of various H2/O2 gas compositions on the functionalization of ... the amorphous carbon on the surface of the nanotubes Specifically, by using this gas condition to conduct the plasma treatment, the highest concentration of 31.1% (after exposure) of oxygenated...

Ngày tải lên: 22/06/2014, 01:20

... to b1, and TR2 to a2 An example of each type of BC2N nanotubes is given in Fig 1b–f Fig 2D projections of zigzag BC2N nanotubes (ZZ-1) z is a glide plane lack of horizontal symmetry axis/plane, ... symmetries at the C point of the 12 N (N is the number of unit cells in the tube and N = n for ZZ-1 BC2N nanotubes) of phonons in ZZ-1 BC2N nanotubes and the number of Raman- or IR-active modes, ... of BC2N nanotubes were discussed based on line group All BC2N nanotubes possess nonsymmorphic line groups, just like carbon nanotubes [8] and boron nitride nanotubes [11] Contrary to carbon and...

Ngày tải lên: 22/06/2014, 01:20

... diffusion layer porous carbon paper which consists of a macroporous layer of carbon fiber paper (SGL, Germany) and a microporous layer of carbon black powder and a hydrophobic agent The carbon black powder ... powder enhances an intimate electronic contact between the CNTs and the macroporous carbon paper The graphitized carbon paper was prepared by deposition of a mixture of carbon black and poly-tetrafluoroethylene ... scanning in the 2h range of 10–90°, in steps of 0.05° X-ray diffraction pattern of DyNi2 alloy shows the formation of single phase with a C 15 type cubic structure XRD pattern of as-prepared CNTs...

Ngày tải lên: 22/06/2014, 18:20

... energy between the singlet and doublet states The + sign means the triplet state has lower energy than the singlet state Fig (a) Optimized structure of C68B2 armchair single walled carbon nanotube ... walled carbon nanotube (b) optimized structure of zig-zag C68B2 single walled carbon nanotube Methods and Results The structures at minimum energy of zig-zag (7,0) and armchair (5,5) tubes are ... (2007) 2:447–449 Table Calculated total energy of singlet and triplet state for boron and nitrogen doped single wall zig-zag and armchair carbon nanotubes Formula Type C68B2 Armchair Method Total...

Ngày tải lên: 22/06/2014, 18:20

... transformation process of this bacterium is unknown This work aimed at the use of multi -walled carbon nanotubes (MWCNT) for the study of the nanostructures action on the transformation process of meningococci, ... action of MWCNT in the transformation of serogroup C N meningitidis against two different DNA obtained from isogenic mutants of this microorganism Methods Synthesis of multi -walled carbon nanotubes ... verifying the action of multi -walled carbon nanotubes (MWCNT) under the naturally transformable Neisseria meningitidis against two different DNA obtained from isogenic mutants of this microorganism,...

Ngày tải lên: 11/08/2014, 08:20

... Raman spectrum of our PECVD MWCNTs (Fig curve a) shows a strong D band, indicating the existence of defects on the tube wall Compared to MWCNTs, the surfaces of the single- walled carbon nanotubes ... of PECVD-grown CNTs b TEM image of ALD ZnO-coated CNTs c and d SEM images of ALD ZnO-coated CNTs e TEM image of ALD AlxOy-coated CNTs Fig Raman spectrum of CNTs before (a) and after (b) ALD of ... Figure 1a shows the TEM image of the typical morphology of the PECVD CNTs prior to deposition Most of the nanotubes are multiwall tubes, and the average diameter of the CNTs is about nm Figure...

Ngày tải lên: 21/06/2014, 08:20

... structure and electronic properties of single- walled carbon nanotubes Nature, 391(6662), 62–64 Santos, C.V., Hernandez, A.L.M., Fisher, F.T., Ruoff, R & Castano, V.M (2003) Improvement of thermal ... of benzoid at 1476 cm–1 and the quinoid ring vibration at 1557 cm–1, indicating the oxidation state of emaraldine salt of PANI.15 The strong band around 1141 cm–1 is the characteristic peak of ... -MnO2 Polymerisation of PANI/MWCNTs-MnO2 30 Figure 2: FTIR spectrum of HCl-doped PANI that can be observed is the intensity ratio of the benzoid and quinoid bands The spectrum of pure PANI (Fig...

Ngày tải lên: 07/08/2014, 14:20

... was shown that albumin which was bound to single- walled carbon nanotubes (SWCNTs) altered the inflammatory response of RAW264.7 macrophages by a reduction of LPS-mediated Cox-2 induction [20] These ... 2Institute of Anatomy, Division of Histology, University of Bern, Bern, Switzerland Division Neonatology, Department of Paediatrics, Inselspital and University of Bern, Bern, Switzerland 4Department of ... handling of unrefined single- walled carbon nanotube material Journal of Toxicology and Environmental Health-Part A 2004, 67:87-107 Kaiser JP, Krug HF, Wick P: Nanomaterial cell interactions: how carbon...

Ngày tải lên: 11/08/2014, 00:22

... two main types: single- walled carbon nanotubes (SWNTs), which consist of one single layer of graphene sheet seamlessly rolled into a cylindrical tube, and multi -walled carbon nanotubes (MWNTs), ... Biomedical Applications of Functionalised Carbon Nanotubes 25 Fig 2.1 Transmission electron microscopy (TEM) images of pristine single- walled (a) and multiwalled carbon nanotubes (b) Several methods ... Pharmacological Potential of Fullerenes and Carbon Nanotubes CARBON MATERIALS: CHEMISTRY AND PHYSICS A comprehensive book series which encompasses the complete coverage of carbon materials and carbon- rich...

Ngày tải lên: 17/02/2014, 05:20

... Research on the precise control of synthesis of composite nano -structures has become increasingly important as the functionality, processability, size, and morphology of nano -structures play a crucial ... optical, and electrical properties of the composites the characteristic peaks of PANI and the peaks of CNTs In addition, the intensity of the diffraction peak of PANI in MWCNTs-f-PANI at 26◦ was ... procedure of MWCNTs-f-PANI was as follows: MWCNTs-DABSA was dispersed in 20 mL of a 0.5 M HCl containing 2.7 mmol of aniline and stirred under ultrasonication conditions for 15 Next, 10 mL of APS...

Ngày tải lên: 05/05/2014, 15:26

... synthesis of high-purity single- walled carbon nanotubes from alchohol Chem Phys Lett 2002, 360:229-234 -7- Murakami Y, Miyauchi Y, Chiashi S, Maruyama S: Characterization of singlewalled carbon nanotubes ... synthesis of thin multiwalled carbon nanotubes J Phys Chem B 2004, 108:17695-17698 Singh BK, Ryu H: The effect of Ni-Co catalyst composition on the yield and nanostructure of carbon nanofibers ... to carbon nanotubes Figure 8b shows an overlap of reflections from the carbon nanotubes and crystal structure related to the particles encapsulated into the nanotubes The detailed analysis of...

Ngày tải lên: 20/06/2014, 20:20

... Novotny L, Krauss TD: Single carbon nanotube optical spectroscopy ChemPhysChem 2005, 6:1-6 16 Weisman RB: Optical spectroscopy of single- walled carbon nanotubes Department of Chemistry, Center ... deposition of silver on the SWCNT surface Simulations of absorption spectra of spheres and elongate structures Figure illustrates simulations of the dependence of g as a function of wavelength ... formation of one-dimensional silver nanostructures from the alignment of particle-like structures Dry deposits from samples with a larger silver content resulted in the formation of structures...

Ngày tải lên: 20/06/2014, 22:20

... -hybridized carbons of the nanotubes, whereas the G band corresponds to a splitting of the E g stretching mode of graphite, which reflects the structural intensity of the sp2-hybridized carbon atoms ... functionalized carbon nanotubes Prog Polym Sci 2010, 35:837 14 Jin J, Dong Z, He J, Li R, Ma J: Synthesis of novel porphyrin and its complexes covalently linked to multi -walled carbon nanotubes and study of ... Functionalization of single- walled carbon nanotubes with well-defined polystyrene by “click” coupling J Am Chem Soc 2005, 127:14518 18 Leu CM, Chang YT, Wei KH: Synthesis and dielectric properties of polyimide...

Ngày tải lên: 21/06/2014, 05:20

... Hydrophobic Channel of a Carbon Nanotube Nature 2001, 414:188 Holt JK: Carbon Nanotubes and Nanofluidic Transport Adv Mater 2009, 21:3542 Hanaski I, Yonebayashi T, Kawano S: Molecular dynamics of a water ... Transport Properties of Single- File Water Molecules inside a Carbon Nanotube Biomimicking Water Channel ACS Nano 2010, 4:205 Bianco A, Kostarelos K, Prato M: Applications of Carbon Nanotubes in Drug ... amount of the hydrogen bonds of the confined water to the amount in the bulk water In this study, the geometrical definition of the hydrogen bond is adopted [25] The amounts of the hydrogen bonds of...

Ngày tải lên: 21/06/2014, 06:20

... deposition of single- wall carbon nanotube inks J Am Chem Soc 2007, 129:10088-10089 Avouris P, Chen ZH, Perebeinos V: Carbon- based electronics Nat Nanotechnol 2007, 2:605-615 Leonard F: The Physics of Carbon ... conductance of multiwall carbon nanotubes Phys Rev B 2002, 66:073407, (1-4) Abrikosov AA Jr, Livanov DV, Varlamov AA: Electronic spectrum and tunneling properties of multiwall carbon nanotubes ... thresholds of 20 and 30 mV on both bias polarities and both temperatures (20 and 298 K) are given by the conductance minima Abbreviations CNTs: carbon nanotubes; MWCNTs: multi -walled carbon nanotubes; ...

Ngày tải lên: 21/06/2014, 06:20

... very different values of ON/OFF ratio, i.e smaller ON/OFF ratio at room temperature or larger ON/OFF ratio at low temperature Indeed, at low temperature (red circles), the ON/OFF ratio increases ... characteristic of this device does not show noticeable change after the test The retention times of both the ON and OFF states are tested by continuously recording the drain current in the ON (OFF) state ... deterioration of the charge trapping mechanisms causing hysteresis after the stress test in air, probably due to the formation of additional defects on the oxide surface or to loss of adhesion of the...

Ngày tải lên: 21/06/2014, 08:20