Investigation about Synthesis of Carbon Nanotubes with Various Structures Governed by Temperature and Relevant Growth Mechanism

2012 ◽  
Vol 499 ◽  
pp. 35-39
Author(s):  
Hai Peng Li ◽  
Jia Wei Fan ◽  
Hong Shui Wang ◽  
Li Hui Wang
Keyword(s):  
Carbon Nanotubes ◽  
Growth Mechanism ◽  
Chemical Vapor ◽  
Composite Powders ◽  
Catalyst Carrier ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Synthesis Of Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (CNTs)/Al in-situ composite powders over Al as catalyst carrier had been synthesized successfully using transition metal Ni by chemical vapor deposition. CNTs were mainly characterized by transmission electron microscopy. It was found that reaction temperature had great influences on the structures of carbon products obtained. Detailed discussions according to the structures of CNTs at different reaction temperatures were given. A deduced model for explaining the growth mechanism of CNTs governed by temperature was developed.

Synthesis of Carbon Nanotubes from Polycyclic Compounds by CVD Method

2006 ◽  
Vol 320 ◽  
pp. 163-166 ◽  
Author(s):  
Koji Yamada ◽  
Kentaro Abe ◽  
Masafumi Mikami ◽  
Morihiro Saito ◽  
Jun Kuwano
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quartz Substrate ◽  
Chemical Vapor ◽  
Polycyclic Compounds ◽  
Cvd Method ◽  
Multi Walled Carbon Nanotubes ◽  
Synthesis Of Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWCNTs) were synthesized from camphor by a chemical vapor deposition (CVD) method in a range of 750-900. The catalyst was fed in three ways: (a) a sputtered Fe-film on a quartz substrate (b) vaporized ferrocene in an Ar flow; (c) both of (a) and (b). In the case (c), highly pure, dense and aligned MWCNT arrays formed on the quartz substrate at 850, whereas nonaligned MWCNTs formed in the cases (a) and (b).

Stacking Nature of the Catalytic Chemical Vapor Deposition-Derived Double-Walled Carbon Nanotubes

2006 ◽  
Vol 6 (11) ◽  
pp. 3321-3324 ◽  
Author(s):  
Yoong-Ahm Kim ◽  
Hiroyuki Muramatsu ◽  
Masahito Kojima ◽  
Takuya Hayashi ◽  
Yutaka Kaburagi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Method ◽  
Catalytic Chemical Vapor Deposition ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Double Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Here we described the synthesis of highly pure double walled carbon nanotube (DWNT) through a right combination of a catalytic chemical vapor deposition method and the two-step purification and evaluated their stacking infidelity when compared to multi-walled carbon nanotubes (MWNTs). Easy fabrication of thin and flexible, but mechanically tough DWNT-buckypaper was due to the long and large-sized bundled DWNT (up to 50 nm), where DWNTs with diameter below 2 nm were packed in hexagonal array. Through detailed transmission electron microscope, X-ray and Raman studies, we confirmed that the intershell spacing of our DWNT sample was ca. 0.36 nm, which was believed to strongly affect negative and small magnetoresistance absolute value of −0.09 at 77 K and 1 T.

In Situ Synthesis of CNTs/Mg Composite Powders by CVD at Low Temperatures

2012 ◽  
Vol 588-589 ◽  
pp. 1681-1684
Author(s):  
Fu Jun Sun ◽  
Chun Sheng Shi ◽  
En Zuo Liu ◽  
Chun Nian He ◽  
Nai Qin Zhao
Keyword(s):  
Mechanical Property ◽  
Carbon Nanotubes ◽  
Vapor Deposition ◽  
Low Temperatures ◽  
Chemical Vapor ◽  
In Situ Synthesis ◽  
Composite Powders ◽  
Co Catalyst ◽  
Synthesis Of Carbon Nanotubes

The emphasis of this study was in-situ synthesis of carbon nanotubes (CNTs) on Mg matrix at 480°C. The process involves homogeneous deposition of Co catalyst onto Mg by deposition-precipitation route with low Co content (1.0 wt.%) and in situ synthesis of CNTs by chemical vapor deposition. The morphologies and microstructure of the as-obtained CNTs/Mg composite powders was characterized by SEM, TEM, Raman spectrum, and XRD. The results indicated that CNTs were well graphitized and uniformly distributed on the surface of Mg powders, which would be beneficial to the mechanical property of CNTs/Mg composites.

scholarly journals The Reduction Temperature Effect of Fe–Co/MgO Catalyst on Characteristics of Multi-Walled Carbon Nanotubes

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 361 ◽  
Author(s):  
Paul Kim ◽  
Cheol Lee
Keyword(s):  
Carbon Nanotubes ◽  
Sol Gel ◽  
Chemical Vapor ◽  
Diameter Distribution ◽  
Metal Catalyst ◽  
Reduction Temperature ◽  
Raman Analysis ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Diameters and crystallinity of multi-walled carbon nanotubes (MWCNTs) dependent on reduction temperature of the Fe–Co/MgO catalyst were investigated. MWCNTs were synthesized by catalytic chemical vapor depositing and the Fe–Co/MgO catalyst was fabricated by using a sol-gel method. According to Raman analysis, transmission electron microscopy and thermogravimetric analysis, the diameter distribution of MWCNTs was broadened with increasing reduction temperature of the Fe–Co/MgO catalyst and crystallinity was improved. The above results are attributed to an increased size and enhanced crystallinity of metal catalyst particles by increasing reduction temperature.

Rapid Structural Improvement of CVD-Grown Multi-Walled Carbon Nanotubes by Drastic Thermite Reaction

NANO ◽  
2015 ◽  
Vol 10 (08) ◽  
pp. 1550112
Author(s):  
Jiang Zhao ◽  
Jing Chen ◽  
Pengcheng Zhang ◽  
Haofeng Yu ◽  
Jie Chen
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Electric Fields ◽  
Chemical Vapor ◽  
Reaction Process ◽  
Thermite Reaction ◽  
Structural Improvement ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon nanotubes (MWCNTs) produced by chemical vapor deposition (CVD) are the most common commercial products at extremely low price in the market. However, due to the inherent drawbacks of CVD surroundings at temperature below [Formula: see text][Formula: see text]1000[Formula: see text]C, CVD-grown nanotubes usually have very disordered structure, resulting in most of their properties being much below expectations. Herein, we present a simple and energy-efficient method for improving rapidly the structure of CVD-grown MWCNTs via a drastic thermite reaction process. Direct observations from scan electron microscope (SEM) and transmission electron microscope (TEM) images, decrease of [Formula: see text] ratios in Raman spectra, increase of the starting oxidation temperatures observed in thermogravimetric analysis (TGA), decrease of the volumetric electrical resistivity and decrease of the turn-on electric fields from 3.64 to 2.88[Formula: see text]V/[Formula: see text]m in field emission measurements suggest that the graphitization of MWCNTs can be effectively enhanced and the structure of nanotubes becomes more ordered after the drastic thermite reaction process.

Synthesis and Characteristics of Multi-Walled Carbon Nanotubes-Polyimide Nanocomposite Films

2008 ◽  
Vol 8 (5) ◽  
pp. 2671-2675 ◽  
Author(s):  
Mei-Hui Tsai ◽  
Dong-Sen Chen ◽  
Pei-Chun Chiang ◽  
Hsin-Chuan Lin ◽  
Jih-Mirn Jehng
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Nanocomposite Film ◽  
Chemical Vapor ◽  
Mechanical Analysis ◽  
Nanocomposite Films ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Polyimide Nanocomposite ◽  
Walled Carbon Nanotubes

The polyimide/multi-walled carbon nanotubes (PI/MWNTs) nanocomposite film has been successfully synthesized in this study. The source of MWNTs is prepared by chemical vapor deposition (CVD) method. Then the MWNTs are washed with acid for purification before being added into the polymer matrix. The acid-modified procedure aids in dispersing MWNTs in N,N-dimethylacetamide (DMAc) solvent. Based on the results of field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), the MWNTs are embedded in PI and well-dispersed within the PI matrix. The dynamic mechanical analysis (DMA) shows that the storage modulus of nanocomposite film is increased by 68% with the addition of 1 wt% MWNTs into PI. The nanocomposite films start to decompose at or above 400 °C and lose 5% of its weight at 545 °C according to thermogravimetric analysis (TGA). Meanwhile, the electrical conductivity of the nanocomposite film with 3 wt% MWNTs, is raised more than 10 orders of magnitude from 10−15 to 10−5 S/cm.

Catalytic growth of multi-walled carbon nanotubes using NiFe2O4 nanoparticles and incorporation into epoxy matrix for enhanced mechanical properties

2016 ◽  
Vol 36 (1) ◽  
pp. 53-64 ◽  
Author(s):  
Hassan Javed ◽  
Mohammad Islam ◽  
Nasir Mahmood ◽  
Amine Achour ◽  
Asad Hameed ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Chemical Vapor ◽  
Weight Percent ◽  
Impact Testing ◽  
Maximum Increase ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Abstract Mechanical properties of multi-walled carbon nanotubes (CNT) reinforced epoxy nanocomposites, with and without any structural defect, were investigated using different weight percent values of pristine and covalently functionalized CNT. First, nickel ferrite (NiFe2O4) catalyst nanoparticles were prepared using the co-precipitate method followed by CNT growth via chemical vapor deposition, using acetylene as carbon feedstock. Through a combination of magnetic stirring and ultrasound vibration treatments in acetone, pristine, COOH-, or NH2-functionalized CNTs at 0.15, 0.60, 1.10 and 1.50 wt% were added to the Epon 828 epoxy. During each stage, extensive materials characterization was carried out using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA)/differential thermal analysis (DTA) techniques. Tensile testing of the specimens revealed an increase in the elastic modulus and tensile strength values with maximum increase registered in the case of nanocomposites made from 1.1 wt% CNT-NH2 (+73%) or CNT-COOH (67%) addition. The energy absorbed during impact testing also increased by 86% upon addition of 1.50 wt% CNT-NH2. The presence of a small notch in the nanocomposite specimens yielded superior mechanical properties to those of the neat epoxy. Such enhancement in the mechanical properties can be attributed to better CNT dispersion in the nanocomposites and good interfacial bonding, as confirmed from microstructural examination of the fractured surfaces.

Chemical Vapor Deposition Growth of Multi-Walled Carbon Nanotubes on Metallic Substrates

2007 ◽  
Vol 121-123 ◽  
pp. 101-104
Author(s):  
Xiao Ping Zou ◽  
H. Abe ◽  
Toru Shimizu ◽  
A. Ando ◽  
H. Tokumoto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Chemical Vapor Deposition Growth ◽  
Large Current ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A simple thermal chemical vapor deposition (STCVD) growth technique of multi-walled carbon nanotubes (MWCNTs) is present. Carbon nanotube film was synthesized on the Pt plate substrates by pyrolysis of ethyl alcohol as carbon source at lower reaction temperature at atmospheric pressure by using simple apparatus. The as-synthesized MWCNTs were characterized by both scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The electrical property of an individual MWCNT was evaluated by I-V measurement. The electrical resistance of single MWCNT is about 450 k/ in linear region under bias voltage between 2 to 4 V. It can undergo a large current of 6 2A at 4 V

scholarly journals A self-supported electrode for supercapacitors based on nanocellulose/multi-walled carbon nanotubes/polypyrrole composite

RSC Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 1109-1114
Author(s):  
Peng Lv ◽  
Yeyun Meng ◽  
Lingxia Song ◽  
Hao Pang ◽  
Weiqu Liu
Keyword(s):  
Carbon Nanotubes ◽  
Ultrasonic Dispersion ◽  
Multi Walled Carbon Nanotubes ◽  
Polypyrrole Composite ◽  
Walled Carbon Nanotubes

A robust self-supported electrode was prepared by a facile combination of ultrasonic dispersion and consequent in situ polymerization.

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