Radial Thermal Expansion of Purified Multiwall Carbon Nanotubes Measured by X-ray Diffraction

1997 ◽  
Vol 36 (Part 2, No. 10B) ◽  
pp. L1403-L1405 ◽  
Author(s):  
Shunji Bandow
Keyword(s):  
Carbon Nanotubes ◽  
Thermal Expansion ◽  
Multiwall Carbon Nanotubes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multiwall Carbon

scholarly journals Preparation and Microwave Absorbing Properties of an Electroless Ni-Co Coating on Multiwall Carbon Nanotubes Using [Ag(NH3)2]+as Activator

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Qiao-ling Li ◽  
Xiao-yong He ◽  
Yue-qing Zhang ◽  
Xiao-feng Yang
Keyword(s):  
Carbon Nanotubes ◽  
Energy Dispersive Spectrometry ◽  
Multiwall Carbon Nanotubes ◽  
Nucleation Site ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Electroless Ni ◽  
Coated Carbon ◽  
Multiwall Carbon

Ni-Co-coated carbon nanotubes (CNTs) composites with different molar ratios of Ni/Co were synthesized using [Ag(NH3)2]+as activator andH2PO2-as reductant, thereby replacing the conventional noble metal Pd salt activator and Sn2+reductant. Scanning electron microscopy, X-ray diffraction, and X-ray energy dispersive spectrometry analyses demonstrated that the CNTs were deposited with a dense, uniform Ni-Co coating. The possible mechanism of the electroless method was studied, which indicates that pure Ag0acted as a nucleation site for subsequent Ni-Co-P deposition. Network vector analyzer measurements indicated that the composite with only Ni coated had an absorbing value of −12.6 dB and the composite with a Ni/Co ratio of four had the maximum wave absorption (−15.6 dB) and the widest absorption bandwidth (800 MHz, RL < −10 dB), while the saturation magnetization (Ms) was 4.28 emu·g−1and the coercive force (Hc) was 31.33 Oe.

scholarly journals Free and partially encapsulated manganese ferrite nanoparticles in multiwall carbon nanotubes

2020 ◽  
Vol 11 ◽  
pp. 1891-1904
Author(s):  
Saja Al-Khabouri ◽  
Salim Al-Harthi ◽  
Toru Maekawa ◽  
Mohamed E Elzain ◽  
Ashraf Al-Hinai ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwall Carbon Nanotubes ◽  
Ferrite Nanoparticles ◽  
Photoemission Spectroscopy ◽  
Manganese Ferrite ◽  
X Ray Diffraction ◽  
Band Emission ◽  
Structure Surface ◽  
Diffraction Peaks ◽  
Multiwall Carbon

Free and partially encapsulated manganese ferrite (MnFe2O4) nanoparticles are synthesized and characterized regarding structure, surface, and electronic and magnetic properties. The preparation method of partially encapsulated manganese ferrite enables the formation of a hybrid nanoparticle/tube system, which exhibits properties of manganese ferrite nanoparticles inside and attached to the external surface of the tubes. The effect of having manganese ferrite nanoparticles inside the tubes is observed as a shift in the X-ray diffraction peaks and as an increase in stress, hyperfine field, and coercivity when compared to free manganese ferrite nanoparticles. On the other hand, a strong charge transfer from the multiwall carbon nanotubes is attributed to the attachment of manganese ferrite nanoparticles outside the tubes, which is detected by a significant decrease in the σ band emission of the ultraviolet photoemission spectroscopy signal. This is followed by an increase in the density of states at the Fermi level of the attached manganese ferrite nanoparticles in comparison to free manganese ferrite nanoparticles, which leads to an enhancement of the metallic properties.

Stacking Faults in SiC Nanowires

2008 ◽  
Vol 8 (7) ◽  
pp. 3504-3510 ◽  
Author(s):  
K. L. Wallis ◽  
M. Wieligor ◽  
T. W. Zerda ◽  
S. Stelmakh ◽  
S. Gierlotka ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Stacking Faults ◽  
Multiwall Carbon Nanotubes ◽  
Structural Defects ◽  
X Ray Diffraction ◽  
Ir Spectrometry ◽  
X Ray ◽  
Sic Nanowires ◽  
Transmission Electron ◽  
Multiwall Carbon

SiC nanowires were obtained by a reaction between vapor silicon and multiwall carbon nanotubes, CNT, in vacuum at 1200 °C. Raman and IR spectrometry, X-ray diffraction and high resolution transmission electron microscopy, HRTEM, were used to characterize properties of SiC nanowires. Morphology and chemical composition of the nanowires was similar for all samples, but concentration of structural defects varied and depended on the origin of CNT. Stacking faults were characterized by HRTEM and Raman spectroscopy, and both techniques provided complementary results. Raman microscopy allowed studying structural defects inside individual nanowires. A thin layer of amorphous silicon carbide was detected on the surface of nanowires.

scholarly journals Composite Nanofibers Containing Multiwall Carbon Nanotubes as Biodegradable Membranes in Reconstructive Medicine

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 63 ◽  
Author(s):  
Andrzej Hudecki ◽  
Dorota Łyko-Morawska ◽  
Wirginia Likus ◽  
Magdalena Skonieczna ◽  
Jarosław Markowski ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Maxillofacial Surgery ◽  
Multiwall Carbon Nanotubes ◽  
Dermal Fibroblasts ◽  
Hydroxyl Groups ◽  
X Ray ◽  
Biological Responses ◽  
Transmission Electron ◽  
Multiwall Carbon

We have tested titanium (Ti) plates that are used for bone reconstruction in maxillofacial surgery, in combination with five types of novel long-resorbable biomaterials: (i) PCL0—polycaprolactone without additives, (ii) PCLMWCNT—polycaprolactone with the addition of multiwall carbon nanotubes (MWCNT), (iii) PCLOH—polycaprolactone doped with multiwall carbon nanotubes (MWCNT) containing –OH hydroxyl groups, (iv) PCLCOOH—polycaprolactone with the addition of multiwall carbon nanotubes (MWCNT) containing carboxyl groups, and (v) PCLTI—polycaprolactone with the addition of Ti nanoparticles. The structure and properties of the obtained materials have been examined with the use of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and/or X-ray powder diffraction (XRD). Titanium BR plates have been covered with: (i) PCL0 fibers (PCL0BR—connection plates), (ii) PCLMWCNT fibers (PCLMWCNTBR—plates), (iii) PCLOH fibers (PCLOHBR—plates), (iv) PCLCOOH (PCLCOOHBR—plates), (v) PCLTI fiber (PCLTIBR—connection plates). Such modified titanium plates were exposed to X-ray doses corresponding to those applied in head and neck tumor treatment. The potential leaching of toxic materials upon the irradiation of such modified titanium plates, and their effect on normal human dermal fibroblasts (NHDF) have been assessed by MTT assay. The presented results show variable biological responses depending on the modifications to titanium plates.

Structural Analysis of Al-CNT Nanocomposite Using X-Ray Diffraction

2021 ◽  
Vol 875 ◽  
pp. 138-145
Author(s):  
Muhammad Mansoor ◽  
Noveed Ejaz ◽  
Liaqat Ali ◽  
Hamid Zaigham
Keyword(s):  
Carbon Nanotubes ◽  
Structural Analysis ◽  
Matrix Material ◽  
Multiwall Carbon Nanotubes ◽  
Matrix Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mechanical And Physical Properties ◽  
Microscopic Studies ◽  
Size Crystallite

The development of metal-matrix composites (MMCs) has mainly been driven by the growing needs of modern applications for lightweight materials yet strong enough to withstand high service loading. On the other hand, carbon nanotubes (CNTs) presenting excellent combination of mechanical and physical properties have already performed as an excellent strengthening to reinforce MMCs. In present study, an air induction furnace was used to fabricate aluminum-multiwall carbon nanotubes (Al-MWCNTs) composite. The process was benefited for better dispersion of the CNTs, which was validated during microscopic studies. Additionally, the mechanical properties were significantly augmented i.e., the yield strength from 64±3 to 115±2 MPa, the tensile strength from 82±2 to 125±3 MPa for matrix material and Al-CNTs composite, respectively. The structural analysis including, grain size, crystallite strain and dislocation density were investigated using X-ray diffraction to relate with the improvement in the properties.

Bimetallic PtRu Nanoparticles Supported on Functionalized Multiwall Carbon Nanotubes as High Performance Electrocatalyst for Direct Methanol Fuel Cells

NANO ◽  
2016 ◽  
Vol 11 (02) ◽  
pp. 1650022 ◽  
Author(s):  
Chunhui Tan ◽  
Juhui Sa ◽  
Feipeng Cai ◽  
Bo Jiang ◽  
Gai Yang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cells ◽  
Methanol Oxidation ◽  
Direct Methanol Fuel Cells ◽  
Multiwall Carbon Nanotubes ◽  
X Ray ◽  
Direct Methanol ◽  
Methanol Fuel Cells ◽  
Multiwall Carbon ◽  
Ptru Nanoparticles

PtRu nanoparticles (NPs) supported on acid treated multiwall carbon nanotubes (Pt1Ru1/MWCNTs) were prepared by a modified polyol method without adding any other surfactant or protective agent. The structural and compositional properties of the as-obtained samples were characterized by transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and X-ray photoelectron (XPS) spectroscopy. The electrocatalytic performance of the catalyst was evaluated by cyclic voltammetry (CV), CO stripping voltammetry and chronoamperometry, indicating a high catalytic activity, excellent CO tolerance and stability for methanol oxidation. Interestingly, a series of accurate controllable experiments have been designed to explore the enhancement mechanism of Pt1Ru1/MWCNTs for methanol oxidation reaction. Most importantly, Pt1Ru1/MWCNTs composites were used as an anode catalyst in the direct methanol fuel cells (DMFCs) exhibiting outstanding power density (126.1 mW/cm[Formula: see text] 1.7 times higher than that of the commercial catalyst of Pt1Ru1/C (74.1 mW/cm[Formula: see text] (E-TEK).

X-RAY PROPAGATION IN MULTIWALL CARBON NANOTUBES

2010 ◽  
Vol 25 (supp01) ◽  
pp. 208-216
Author(s):  
P A CHILDS ◽  
S Y ONG ◽  
D C HERBERT ◽  
A G O'NEILL
Keyword(s):  
Carbon Nanotubes ◽  
Bragg Reflection ◽  
Semiconductor Industry ◽  
Grazing Angle ◽  
Multiwall Carbon Nanotubes ◽  
Angle Of Incidence ◽  
Bragg Structure ◽  
X Ray ◽  
Extreme Uv ◽  
Multiwall Carbon

There is considerable interest in the development of inexpensive lithography techniques for applications in the area of nanoscale electronics. The semiconductor industry is pursuing the development of photolithography techniques such as extreme UV and x-ray. However these techniques are extremely expensive and not suitable for smaller scale applications. In this paper we describe research on the feasibility of exploiting x-ray propagation within carbon nanotubes (CNTs) for the fabrication and characterisation of nanoscale devices. A description is given of a test structure designed to explore experimentally the possibility of x-ray propagation in carbon nanotubes. As x-ray propagation requires a grazing angle of incidence the nanotubes need to be straight and reproducible. In order to alleviate this problem the possibility of using Bragg reflection is investigated. This approach to the problem is stimulated by the inherent Bragg structure of multiwall carbon nanotubes. It is further encouraged by the recent development of coatings using materials such as WS2. Results from simulations presented in this paper show that although Bragg reflection in as-grown multiwall carbon nanotubes is weak the potential for exploitation of this phenomenon in suitably coated nanotubes exists.

Effect of Urea on the Shape and Structure of Carbon Nanotubes

2018 ◽  
Vol 73 (2) ◽  
pp. 113-120 ◽  
Author(s):  
M. R. Elamin ◽  
Babiker Y. Abdulkhair ◽  
Kamal K. Taha
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapour ◽  
Multiwall Carbon Nanotubes ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Adsorption Analysis ◽  
Bet Analysis ◽  
Multiwall Carbon

AbstractCoiled multiwall carbon nanotubes (MWCNTs) were prepared on Fe, Co, and Ni metal oxides supported on α-Al2O3 using urea as fuel and catalyst surface modifying agent by catalytic chemical vapour deposition (CCVD). The shape of the nanotubes was influenced by the addition of urea, where coiled and uncoiled tubes were obtained in the presence and absence of urea, respectively. The MWCNTs were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and nitrogen adsorption analysis. The coiling/uncoiling of the nanotubes was visualized from the SEM and TEM images of the prepared specimens. The XRD data showed the characteristic peaks of the nanotubes. BET analysis of the coiled tubes revealed 85.57 m2 g−1 surface area with a pore diameter 102.2–110.8 Å. A mechanism for the nanotubes coiling is suggested.

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