raman spectroscopy on double walled carbon nanotubes

... in carbon nanotubes based on resonant Raman scattering Phys Status Solidi B 2005, 242:1802 13 Popov VN, Henrard L, Lambin P: Electron-phonon and electron-photon interactions and resonant Raman ... of single -walled carbon nanotubes J Luminesc 2006, 119-120:204 10 Hartschuh A, Qian H, Meixner AJ, Anderson N, Novotny L: Nanoscale Optical Imaging of Excitons in Single -Walled Carbon Nanotubes ... AC, Robertson J: Phonon linewidths and electron-phonon coupling in graphite and nanotubes Phys Rev B 2006, 73:155426 16 Dubay O, Kresse G, Kuzmany H: Phonon Softening in Metallic Nanotubes by...

Ngày tải lên: 21/06/2014, 05:20

... the ALD ZnO shell on CNTs The first one is the surface configuration of the CNTs As a micromolecular form of carbon, CNT can be regarded as graphitic layers (sp2hybridized carbon atoms) rolled up ... the weak UV emission, will hinder the photonic application of such hybrid nanostructures [12] In this work, we report the direct ALD of ZnO on vertical-aligned multi -walled carbon nanotube arrays ... The 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...

Ngày tải lên: 21/06/2014, 08:20

... solution (1 wt% lithium dodecyl sulfate) and purified by centrifugation Thereafter they were deposited on a highly n-doped silicon wafer with 100 nm SiO2 layer by putting one droplet of suspension on ... distribution in the interwall region, and then the configuration of DWCNTs When the inner tube vibrates normal to the tube axis, the inner tube is close to the outer tube on one side and far away on ... interaction between layers with the elastic force of the graphene layers There may be orientational dislocations or twist frozen in DWCNTs during their synthesis High resolution transmission electron...

Ngày tải lên: 22/06/2014, 01:20

... 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 functional ... could be because the ion bombardment under this gas condition can heavily etch the surface of the nanotubes to the extent that the concentration of amorphous carbon coated on the Table The MWCNT ... 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 MWCNTs...

Ngày tải lên: 22/06/2014, 01:20

... 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 ... 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 ... 14 S.C Lim, H.K Choi, H.J Jeong, Y.I Song, G.Y Kim, K.T Jung, Y.H Lee, Carbon 44, 2809 (2006) 15 H.J Jeong, H.K Choi G.Y Kim, Y.I Song, Y Tong, S.C Lim, Y.H Lee, Carbon 44, 2689 (2006) 123 Nanoscale...

Ngày tải lên: 22/06/2014, 18:20

... to obtain different concentration The ozone generator that we used produced ozone by projecting UV to dry air The concentration of the ozone could be controlled by the ozone generator up to ppm ... (2004) 1466–1470 J.M Simmons, B.M Nichols, S.E Baker, M.S Marcus, O.M Castellini, C.S Lee, R.J Hamers, M.A Eriksson, Effect of ozone oxidation on single -walled carbon nanotubes, J Phys Chem B ... Ellison, M.J Crotty, D.H Koh, R.L Spary, K.E Tate, Adsorption of NH3 and NO2 on single -walled carbon nanotubes, J Phys Chem B 108 (2004) 7938–7943 [5] M Penza, F Antolini, M Vittori Antisari, Carbon...

Ngày tải lên: 19/03/2014, 16:47

... coated carbon nanotubes were obtained Transition-metal ions were added to the SiO2 coated carbon nanotubes by mixing the carbon nanotubes in a TEOS/ethanol solution containing transition-metal ... rate constant [133] Degradation and mineralization can be monitored by determining sulfate ion and total organic carbon concentrations in the reaction solution In this study, the reduction in ... excited electrons of TiO2 conduction band can be readily scavenges through multi -walled carbon nanotubes when they are coupled (Figure 1-3) Moreover, carbon nanotubes may modify the electronic structure...

Ngày tải lên: 20/03/2014, 13:06

... synthesized via spontaneous redox reaction of corresponding monomers with AuCl3 or AgNO3 using a one step polymerization method where the monomer acts as reductant of the metal ions [31,32] The ... them due to the absence of strong covalent bonds Strong bonding is essential to ensure efficient transfer from the CEP matrix to the carbon nanotube lattice, and is thus one of the critical issues ... / Synthetic Metals xxx (2009) xxx–xxx are one of the most important, based on their electron donor and acceptor interactions Research on the precise control of synthesis of composite nano-structures...

Ngày tải lên: 05/05/2014, 15:26

... dielectric constants have contributions from interband transitions (IB) and the excitation of the plasmon (P): ε1 = ε1IB + ε1,P ε2 = ε2IB + ε2P (3) The plasmon contributions to the components of ... identical experimental conditions The absorption and emission spectra of carbon nanotubes have been the subject of various studies [13,14] Light absorption is a response of the electronic properties ... Adsorption on carbon nanotubes studied using polarization-modulated infrared reflection-absorption spectroscopy J Phys Chem B 2005, 109(20):9970-9979 15 Hartschuh A, Pedrosa HN, Peterson J, Huang...

Ngày tải lên: 20/06/2014, 22:20

... 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 or more defect concentration in the MWCNTs ... region (100–300 cm-1), the radial breath modes (RBM) which represent the existence of SWCNTs are hardly shown The data show no SWCNTs are formed and there are only poorly multi -walled carbon nanotubes ... when the diameter distribution of SWCNTs is more narrow, the application values of SWCNTs are higher At this growth temperature, only one strong band at 160 cm-1 in the Raman spectrum, this shows...

Ngày tải lên: 22/06/2014, 00:20

... dispersion The reaction condition in PPA/P2O5 medium at 130 °C has been utilized in both the polymerization of phenoxybenzoic acids [11] and functionalization of closely related carbon materials ... chemical reaction(s) between SWCNT and carbonium ion to heavily and uniformly functionalize entire SWCNT (see Fig 2b) [19, 28] The proposed functionalization mechanism of TMPBA onto SWCNTs is ... framework In addition, the amide functionality on TMPBA is versatile for the covalent functionalization of SWCNTs via a simple one-step ‘‘direct’’ electrophilic substitution reaction Thus, our approach...

Ngày tải lên: 22/06/2014, 00:20

... noteworthy that the triplet state is considerably lower than the singlet in the nitrogen doped carbon nanotubes by 4.23 eV compared to the boron doped tubes which is only 0.75 eV lower While the existence ... minimum energy showing the location of the boron substitutions Similar structures are obtained for SWNTs doped with nitrogen at the same locations as the borons Table compares the energy difference ... is a single point calculation on the optimized 6-31G structure This approach rather than a DFT model is used so as to minimize computer computation time The calculations were performed using the...

Ngày tải lên: 22/06/2014, 18:20

... Polymerisation of PANI/MWCNTs-MnO2 28 the original polymer.5 Among these polymer/CNTs nanocomposites, many have focused on the combination of CNTs and conducting polymers.6, PANI is one of the conducting ... properties of carbon nanotube composites through chemical functionalization Chem Mater., 15(23), 4470–4475 Ajayan, P.M., Stephan, O., Colliex, C & Trauth, D (1994) Alligned carbon nanotubes arrays ... (1991) Helical microtubules of graphitic carbon Nature, 354 (6348), 56–58 De Heer, W.A., Chatelain, A & Ugarte, D (1995) A carbon nanotube field emission electron source Sci., 1270(5239), 1179–1180...

Ngày tải lên: 07/08/2014, 14:20

... organized secondary structure upon adsorption onto a hydrophobic surface [51] By looking at the proteins function, it was shown that albumin which was bound to single -walled carbon nanotubes (SWCNTs) ... components foster adhesion among MWCNTs; a phenomenon that was also similarly described in a previous study on carbon black [11] Such an effect may become more relevant when Table Characterization ... 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 nanotubes...

Ngày tải lên: 11/08/2014, 00:22

... transformation of serogroup C N meningitidis against two different DNA obtained from isogenic mutants of this microorganism Methods Synthesis of multi -walled carbon nanotubes The carbon nanotubes ... using Raman Spectroscopy Conclusion: These increases in the transformation capacity mediated by MWCNT, in meningococci, indicate the interaction of these particles with the virulence acquisition ... mutant strain M2 (figure 2) Construction of serogroup W135 mutants in transcriptional fusion synG::ermAM As the mutant M2, this mutant construction follows the specifications described in Hollanda...

Ngày tải lên: 11/08/2014, 08:20

... $900°C, carbon multilayers were formed on the surface of carbonized Si NWs At a higher reaction temperature ($1000°C), the silicon cores reacted with carbon and transformed into b-SiC cores Carbon ... tube-like carbon shell structure and a carbonization e€ect for the transformation of Si NWs to SiC nanowires At a relatively low substrate temperature ($900°C), the deposition rate of carbon on the ... carbon nucleation happened on a nanowire surface, it was possible that a carbon tube-like network formed around the nanowire As the diameters of the nanowires were very small, tube-like carbon...

Ngày tải lên: 16/03/2014, 15:04

... can be contained The above two-step simulation focuses all the computational consumption on the concerned information Results and discussion Figure shows the relative viscosity of water confined ... 9:674 Corry B: Designing Carbon Nanotube Membranes for Efficient Water Desalination J Phys Chem B 2008, 112:1427 Zhu FQ, Schulten K: Water and Proton Conduction through Carbon Nanotubes as Models ... JP: Water Conduction through the 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...

Ngày tải lên: 21/06/2014, 06:20

... electronics and optoelectronic devices Carbon nanotubes, especially single -walled carbon nanotubes (SWCNTs), are among the most promising nanoscale materials that have a broad range of applications, ... alternative interpretations regarding the toxicity of carbon nanotubes for both in vivo and in vitro generated data Some experimental results indicate that introduction of carbon nanotubes into the ... incubation to generate a measurable signal (1–2 h for the CellTiter 96 Aqueous One Solution), there could be some interactions of the nanotubes as well as their conjugates with the assay components...

Ngày tải lên: 22/06/2014, 00:20

... size of Pt NPs on N-doped CNTs is smaller than that on undoped ones Fig X-Ray diffraction pattern of Pt nanoparticles (NPs) immobilized on N-doped carbon nanotubes (CNTs) and undoped ones To understand ... field-emission scanning electron microscope (FESEM), a JEOL JEM-2100F field-emission transmission electron microscope (FETEM), X-ray diffractometry (XRD) (PHILIPS PW1700), and X-ray photoelectron spectroscopy ... found that the formation of N bonding is evident in Pt NPs deposited on N-doped CNTs In general, the N 1s XPS spectrum can be deconvoluted with four N-based bonding configurations inclusive of pyridinic...

Ngày tải lên: 22/06/2014, 00:20

... decomposition of hydrocarbon gas at the surface of the catalyst nanoparticles; (2) diffusion of resultant carbon atom in the nanoparticles to form the nucleation seed; and (3) precipitation of carbon ... vibrations of carbon atoms with dangling bonds in plane terminations of ‘‘disordered graphite’’ or glassy carbons The G-band corresponds to the E2g mode of graphite and is related to the vibration ... scanning electron microscopy (SEM) and transmission electron microscopy (TEM) Raman spectroscopy equipped with a charge-coupled device detector is used to study the effect of flow rate on the intensity...

Ngày tải lên: 22/06/2014, 01:20