Does natural frequency quantify the mass flow rate of fluid conveying single-walled carbon nanotubes?

Two configurations of perfect single walled carbon nanotubes (armchair and zigzag) were simulated based on the finite element method. Then, three most likely defects (Si-doping, carbon vacancy and perturbation) were introduced to the models to represent defective forms of single walled carbon nanotubes (SWCNTs). Finally, the vibrational properties of perfect and defective carbon nanotubes were evaluated and compared. The results showed that SWCNTs have a natural frequency with a rather high value between 18.69 and 24.01 GHz. In the consideration of the natural frequency of the defective SWCNTs, it was also observed that the existence of any type of defects or irregularities leads to a lower value of natural frequency and vibrational stability. Simple mathematical relations which express the change in natural frequency versus the percentage of the defect were also presented. This can be very useful to realistically estimate the influence of defects of different amounts on the vibrational behavior of carbon nanotubes.

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Combination Effect of Waviness and Vacancy Defects on the Natural Frequency of Single Walled Carbon Nanotubes

Journal of Computational and Theoretical Nanoscience ◽

10.1166/jctn.2016.5379 ◽

2016 ◽

Vol 13 (8) ◽

pp. 5031-5036

Author(s):

Mojtaba Amjadipour ◽

Dzung Viet Dao ◽

Nunzio Motta

Keyword(s):

Carbon Nanotubes ◽

Natural Frequency ◽

Single Walled Carbon Nanotubes ◽

Combination Effect ◽

Vacancy Defects ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes

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Process Design for the Flow of Ethanol Chemical Vapor Deposition Grown Vertically Aligned Single Walled Carbon Nanotubes

Volume 9: Micro- and Nano-Systems Engineering and Packaging, Parts A and B ◽

10.1115/imece2012-86650 ◽

2012 ◽

Author(s):

Hatem Abuhimd ◽

Abe Zeid ◽

Yung Joon Jung ◽

Sagar Kamarthi

Keyword(s):

Carbon Nanotubes ◽

Chemical Vapor Deposition ◽

Flow Rate ◽

Vapor Deposition ◽

Chemical Vapor ◽

Single Walled Carbon Nanotubes ◽

Growth Time ◽

Single Walled Carbon ◽

Vertically Aligned ◽

Walled Carbon Nanotubes

Carbon nanotubes (CNTs) have received much attention from both the scientific and industrial communities due to their structural properties and unique morphology. There has also been growing interest in vertically aligned single walled carbon nanotubes (VA-SWNTs) because of their suitability for building devices such as solar cells and nanomembrane. Various methods including chemical vapor deposition (CVD) have been developed for growing VA-SWNTs. Among them is alcohol catalytic CVD which is well known for its economic viability, comprehensive substrates selectivity and good yield of VA-SWNTs. This work studies the length assurance of VA-SWNTs growth by an experimental design and an artificial neural network (ANN) metamodel. Process analysis shows that the interaction between gas flow rate and growth time are the most significant input factors. In addition, with high probability flow rate less than 150 sccm and a growth time of 20 minutes are suitable for the repeatability of medium length VA-SWNTs.

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Effect of Temperature Gradient near the Target and Gas Flow Rate on the Diameter Distribution of Single-Walled Carbon Nanotubes Grown by the Laser Ablation Technique

MRS Proceedings ◽

10.1557/proc-633-a13.30 ◽

2000 ◽

Vol 633 ◽

Author(s):

Rahul Sen ◽

Hiromichi Kataura ◽

Yohsuke Ohtsuka ◽

Toshinobu Ishigaki ◽

Shinzo Suzuki ◽

...

Keyword(s):

Carbon Nanotubes ◽

Laser Ablation ◽

Temperature Gradient ◽

Flow Rate ◽

Gas Flow ◽

Single Walled Carbon Nanotubes ◽

Diameter Distribution ◽

Gas Flow Rate ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes

AbstractGas dynamic and time resolved imaging studies have been performed on the growth of single-walled carbon nanotubes (SWNTs) in the laser ablation process. SWNTs were synthesized by laser ablation of Ni-Co catalyzed graphite targets at 1200°C under argon flow. The effects of the temperature gradient near the target and the gas flow rate were studied in order to understand the effect of gas dynamics over the diameter distribution of SWNTs. The gas flow rate affects the diameter distribution of SWNTs especially when the growth species flow through a large temperature gradient. Scattering images from the growth species at different flow rates was recorded by high-speed video imaging. The results indicate that the velocities of these species are dependent on the gas flow rate but this dependence is evident 30 ms after the laser ablation. These findings are used to estimate the time period for the nucleation and the growth of SWNTs.

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Effects of argon flow rate and reaction temperature on synthesizing single-walled carbon nanotubes from ethanol

Physica E Low-dimensional Systems and Nanostructures ◽

10.1016/j.physe.2009.02.001 ◽

2009 ◽

Vol 41 (7) ◽

pp. 1204-1209 ◽

Cited By ~ 18

Author(s):

QiXin Liu ◽

Yu Ouyang ◽

LuYin Zhang ◽

Yan Xu ◽

Yan Fang

Keyword(s):

Carbon Nanotubes ◽

Reaction Temperature ◽

Flow Rate ◽

Single Walled Carbon Nanotubes ◽

Argon Flow Rate ◽

Single Walled Carbon ◽

Argon Flow ◽

Walled Carbon Nanotubes

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Feedstock-dependent nitrogen configurations of nitrogen-doped single-walled carbon nanotubes in a CVD process

Nanoscale ◽

10.1039/c8nr02850h ◽

2018 ◽

Vol 10 (30) ◽

pp. 14579-14585 ◽

Cited By ~ 1

Author(s):

Theerapol Thurakitseree ◽

Christian Kramberger ◽

Shigeo Maruyama

Keyword(s):

Carbon Nanotubes ◽

Flow Rate ◽

Single Walled Carbon Nanotubes ◽

Flow Rates ◽

Nitrogen Doped ◽

Single Walled Carbon ◽

Walled Carbon Nanotubes

We demonstrate the modification of nitrogen configurations through a CVD process. Lowering the mixed C/N feedstock flow rate could promote a predominance of pyridinic and graphitic nitrogen structures, while higher flow rates give rise to the formation of trapped N2 molecules.

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Selective Diameter Control of Single-Walled Carbon Nanotubes in the Gas-Phase Synthesis

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.sw23 ◽

2008 ◽

Vol 8 (11) ◽

pp. 6153-6157 ◽

Cited By ~ 149

Author(s):

Takeshi Saito ◽

Satoshi Ohshima ◽

Toshiya Okazaki ◽

Shigekazu Ohmori ◽

Motoo Yumura ◽

...

Keyword(s):

Carbon Nanotubes ◽

Carbon Source ◽

Gas Phase ◽

Flow Rate ◽

Carbon Sources ◽

Single Walled Carbon Nanotubes ◽

Diameter Distribution ◽

Single Walled Carbon ◽

Diameter Control ◽

Walled Carbon Nanotubes

A novel approach for selective diameter control of single-walled carbon nanotubes (SWNTs) is performed in the gas-phase growth using two kinds of carbon sources with different decomposition properties; the one carbon source (1st carbon source) is the organic solvent which is difficult to decompose in the reactor and the another carbon source (2nd carbon source) is facile to decompose. The diameter distributions of SWNTs synthesized with various conditions of the flow rate of the 2nd carbon source were investigated by resonant Raman scattering, optical absorption, and photoluminescence (PL) mapping measurements. It was found that increasing the flow rate of the ethylene tends to decrease the diameter of synthesized SWNTs, probably due to the earlier nucleation of SWNTs induced by the ethylene addition. The controlling the flow rate of the ethylene used as a 2nd carbon source can selectively tune the diameter distribution of SWNTs in our growth system.

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