The effect of a convection vortex on sock formation in the floating catalyst method for carbon nanotube synthesis

Hou, Guangfeng; Su, Ruitao; Wang, An‐Li; Ng, Vianessa; Liu, Weifeng; Song, Yi; Zhang, Lu; Sundaram, Murali M.; Shanov, Vesselin; Mast, David; Lashmore, D. S.; Schulz, Mark J.; Liu, Yijun

doi:10.1016/j.carbon.2016.02.087

Cited by 59 publications

(34 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As only feeding rate and carrier gas were altered in this case, we consider that it is the decrease of volume of carrier gas that accounts for the reduction of number of CNT loops. Theoretical studies have proposed the existence of back flow at the outlet of a quartz tube inside a high-temperature furnace [ 19 , 20 ]. The back flow boosted by the phenomenon of thermophoresis can trigger local convection vortex which might be more obvious when using a high flow rate, bringing about many CNT loops.…”

Section: Resultsmentioning

confidence: 99%

High-performance single-walled carbon nanotube transparent conducting film fabricated by using low feeding rate of ethanol solution

Ding¹,

Zhang²,

Wei³

et al. 2018

R. Soc. open sci.

View full text Add to dashboard Cite

We report floating catalyst chemical vapour deposition synthesis of single-walled carbon nanotubes (SWCNTs) for high-performance transparent conducting films (TCFs) using low feeding rate of precursor solution. Herein, ethanol acts as carbon source, ferrocene and thiophene as catalyst precursor and growth promoter, respectively. By adopting a low feeding rate of 4 µl min−1, the fabricated TCFs present one of the lowest sheet resistances of ca 78 Ω sq.−1. at 90% transmittance. Optical characterizations demonstrate that the mean diameter of high-quality SWCNTs is up to 2 nm. Additionally, electron microcopy observations provide evidence that the mean length of SWCNT bundles is as long as 28.4 µm while the mean bundle diameter is only 5.3 nm. Moreover, very few CNT loops can be found in the film. Remarkably, the fraction of individual SWCNTs reaches 24.6%. All those morphology data account for the superior optoelectronic performance of our SWCNT TCFs.

show abstract

Section: Resultsmentioning

confidence: 99%

High-performance single-walled carbon nanotube transparent conducting film fabricated by using low feeding rate of ethanol solution

Ding¹,

Zhang²,

Wei³

et al. 2018

R. Soc. open sci.

View full text Add to dashboard Cite

show abstract

“…While the conventional substrate-based CVD can tune the nanotube diameters by precisely controlling the catalyst sizes, significant batch-to-batch variations remain a drawback. On the other hand, the floating catalyst chemical vapor deposition (FCCVD) [2,[15][16][17][18] technique is attracting attention from both academia and industry. With the appropriate choice of reactants, precise condition control, and continuous winding collection of the CNT aerogel, the FCCVD process could achieve flexibility in product forms (e.g., yarns, sheets) providing mass production potential [19].…”

Section: Introductionmentioning

confidence: 99%

Continuous Synthesis of Double-Walled Carbon Nanotubes with Water-Assisted Floating Catalyst Chemical Vapor Deposition

et al. 2020

View full text Add to dashboard Cite

Double-walled carbon nanotubes (DWCNTs) were synthesized and continuously collected using a water-assisted floating catalyst chemical vapor deposition (FCCVD) method. Differing from the conventional water-assisted synthesis in which water vapor is one part of the carrier gas mixture, we included de-ionized water in the catalyst system, which achieved a more uniform and controlled distribution for efficient DWCNT production. Using a water-assisted FCCVD process with optimized conditions, a transition from multi- to double-walled CNTs was observed with a decrease in diameters from 19–23 nm to 10–15 nm in tandem with an elevated Raman IG/ID ratio up to 10.23, and corroborated from the decomposition peak shifts in thermogravimetric data. To characterize the mechanical and electrical improvements, the FCCVD-CNT/bismaleimide (BMI) composites with different water concentrations were manufactured, revealing high electrical conductivity of 1720 S/cm along the bundle alignment (collection) direction, and the nano-indentation tests showed an axial reduced modulus at 65 GPa. A consistent value of the anisotropic ratio at ~3 was observed comparing the longitudinal and transverse properties. The continuous capability of the presented method while maintaining high quality is expected to result in an improved DWCNT mass production process and potentially enhance the structural and electrical applications of CNT nanocomposites.

show abstract

“…Over the last two decades, carbon nanotubes (CNT) have attracted attention in the fields of sensors [ 1 ], filtering [ 2 , 3 ], energy storage [ 4 ], and other areas. There are various methods to synthesize CNTs, including arc-discharge [ 5 ], using plasma [ 6 ], laser ablation [ 7 ], chemical vapor deposition (CVD) [ 8 ], and the floating catalyst method [ 9 , 10 , 11 , 12 ]. Arc-discharge and the laser ablation process are high-temperature synthesis processes which can produce CNTs with fewer structural defects.…”

Section: Introductionmentioning

confidence: 99%

Carbon Nanotube Sheet-Synthesis and Applications

Chitranshi

Pujari

et al. 2020

Nanomaterials

Self Cite

View full text Add to dashboard Cite

Decades of extensive research have matured the development of carbon nanotubes (CNTs). Still, the properties of macroscale assemblages, such as sheets of carbon nanotubes, are not good enough to satisfy many applications. This paper gives an overview of different approaches to synthesize CNTs and then focuses on the floating catalyst method to form CNT sheets. A method is also described in this paper to modify the properties of macroscale carbon nanotube sheets produced by the floating catalyst method. The CNT sheet is modified to form a carbon nanotube hybrid (CNTH) sheet by incorporating metal, ceramic, or other types of nanoparticles into the high-temperature synthesis process to improve and customize the properties of the traditional nanotube sheet. This paper also discusses manufacturing obstacles and the possible commercial applications of the CNT sheet and CNTH sheet. Manufacturing problems include the difficulty of injecting dry nanoparticles uniformly, increasing the output of the process to reduce cost, and safely handling the hydrogen gas generated in the process. Applications for CNT sheet include air and water filtering, energy storage applications, and compositing CNTH sheets to produce apparel with anti-microbial properties to protect the population from infectious diseases. The paper also provides an outlook towards large scale commercialization of CNT material.

show abstract

The effect of a convection vortex on sock formation in the floating catalyst method for carbon nanotube synthesis

Cited by 59 publications

References 29 publications

High-performance single-walled carbon nanotube transparent conducting film fabricated by using low feeding rate of ethanol solution

High-performance single-walled carbon nanotube transparent conducting film fabricated by using low feeding rate of ethanol solution

Continuous Synthesis of Double-Walled Carbon Nanotubes with Water-Assisted Floating Catalyst Chemical Vapor Deposition

Carbon Nanotube Sheet-Synthesis and Applications

Contact Info

Product

Resources

About