Terahertz transmission ellipsometry of vertically aligned multi-walled carbon nanotubes

2012 ◽  
Vol 101 (11) ◽  
pp. 111107 ◽  
Author(s):  
M. J. Paul ◽  
N. A. Kuhta ◽  
J. L. Tomaino ◽  
A. D. Jameson ◽  
L. P. Maizy ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multi Walled Carbon Nanotubes ◽  
Vertically Aligned ◽  
Terahertz Transmission ◽  
Walled Carbon Nanotubes

scholarly journals PRELIMINARY STUDY OF ELECTROPHORETIC DEPOSITION OF VERTICALLY ALIGNED MWCNT ON METALLIC ELECTRODE

2012 ◽  
Vol 05 ◽  
pp. 704-711
Author(s):  
SIAVASH KHABAZIAN ◽  
SOHRAB SANJABI
Keyword(s):  
Carbon Nanotubes ◽  
Metallic Electrode ◽  
Aqueous Solvent ◽  
Multi Walled Carbon Nanotubes ◽  
Dc Electric Field ◽  
Ft Ir ◽  
Vertically Aligned ◽  
Preliminary Study ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

Multi-walled carbon nanotubes films formed randomly aligned laterally by electrophoresis. Multi-walled carbon nanotubes with lengths of about 10 μ was shortened and functionalized by a mixture of sulfuric and nitric acid. The functional groups on carbon nanotubes were elaborated by FT-IR. Chemically shortened MWCNTs disperse in organic and aqueous solvent and deposited on electrode vertically-aligned by applying a constant DC electric field. The alignment of MWCNTs was observed by scanning electron microscopy. It also the effect of various substrates on alignment of multi-walled carbon nanotubes was investigated.

scholarly journals Conjugated polyelectrolyte nano field emission adlayers

2016 ◽  
Vol 1 (4) ◽  
pp. 304-312 ◽  
Author(s):  
M. T. Cole ◽  
R. J. Parmee ◽  
A. Kumar ◽  
C. M. Collins ◽  
M. H. Kang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Field Emission ◽  
Electron Emission ◽  
Field Electron Emission ◽  
Conjugated Polyelectrolyte ◽  
Emission Performance ◽  
Field Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Vertically Aligned ◽  
Walled Carbon Nanotubes

Here we report on a straightforward and rapid means of enhancing the field electron emission performance of nascent vertically aligned multi-walled carbon nanotubes by introducing a polar zwitterionic conjugated polyelectrolyte adlayer at the vacuum–emitter interface.

Effect of Ferrocene Catalyst and Hydrogen Feed on Microstructures of Vertically Aligned MWCNTs

2016 ◽  
Vol 701 ◽  
pp. 8-12
Author(s):  
Shazia Shukrullah ◽  
Norani Muti Mohamed ◽  
Maizatul Shima Shaharun ◽  
Muhammad Yasar
Keyword(s):  
Carbon Nanotubes ◽  
Vapour Deposition ◽  
Chemical Vapour ◽  
Areal Density ◽  
Optimum Conditions ◽  
Catalyst Amount ◽  
Multi Walled Carbon Nanotubes ◽  
Cvd Growth ◽  
Vertically Aligned ◽  
Walled Carbon Nanotubes

This study investigated the effect of catalyst amount on chemical vapour deposition (CVD) growth of multi-walled carbon nanotubes (MWCNTs) with and without hydrogen feed. The ferrocene weight was varied from 100 mg to 200 mg for CNTs growth over Si/SiO2/Al2O3 substrate. Very few CNTs were seen in micrographs of the samples produced in the absence of the hydrogen feed. Most of the carbon atoms precipitated into amorphous carbon due to existence of inactive catalyst particles. However, CNT structures grown with hydrogen feed were more distinct; the nanotubes were thinner, straight and highly crystalline. MWCNTs arrays/forest length was also increased from 120 µm to 850 µm with hydrogen feed. An increase in catalyst weight significantly affected the diameter, crystallinity, alignment and growth of nanotubes. The lowest inner-shell spacing of 0.348 nm was obtained with 150 mg of ferrocene, which is an indication of growth of relatively pure CNTs. Under the optimum conditions, the areal density of the ferrocene particles was sufficiently increased to get required alignment and crystallinity of MWCNTs.

Comparing Field Emission Stability of Lithography-free, Modified Multi-walled Carbon Nanotubes

2009 ◽  
Vol 1204 ◽  
Author(s):  
Archana Pandey ◽  
Abhishek Prasad ◽  
Jason Moscatello ◽  
Yoke Khin Yap
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Constant ◽  
Methyl Methacrylate ◽  
Field Emission ◽  
Field Emission Properties ◽  
Emission Stability ◽  
Multi Walled Carbon Nanotubes ◽  
Vertically Aligned ◽  
Walled Carbon Nanotubes ◽  
Stable Field

AbstractField emission from carbon nanotubes (CNTs) has been known for more than a decade but there is no commercialized product available in the market. Apparently, we need to improve our basics understanding on stable field emission from CNTs. Here we compared the field emission properties of as grown vertically-aligned multi-walled carbon nanotubes (MWCNTs) to two types of modified MWCNTs: 1) Conical bundles of opened-tip MWCNTs, and 2) Opened-tip MWCNTs embedded in poly-methyl methacrylate (PMMA). We found that both types of modified MWCNTs have lower emission thresholds and better emission stability than the as grown samples. Among these modified samples, MCNTs embedded in PMMA has lower emission thresholds and better emission stability. We attributed these improvements to the filling of spacing between MWCNTs with PMMA that has higher dielectric constant than vacuum.

Vertically aligned laser sliced MWCNTs

Nanoscale ◽  
2019 ◽  
Vol 11 (44) ◽  
pp. 21394-21403 ◽  
Author(s):  
Thaar M. D. Alharbi ◽  
Kasturi Vimalanathan ◽  
Ibrahim K. Alsulami ◽  
Colin L. Raston
Keyword(s):  
Carbon Nanotubes ◽  
Multi Walled Carbon Nanotubes ◽  
Vertically Aligned ◽  
Walled Carbon Nanotubes

Applications of multi-walled carbon nanotubes (MWCNTs) benefit from the availability of specific lengths of the material while keeping the outer walls pristine, for example, for applications requiring vertically aligned tubes.

Carbon Nanotubes Blended Nematic Liquid Crystal for Display and Electro-Optical Applications

2021 ◽  
Vol 2 (4) ◽  
pp. 466-481
Author(s):  
Bhupendra Pratap Singh ◽  
Samiksha Sikarwar ◽  
Kamal Kumar Pandey ◽  
Rajiv Manohar ◽  
Michael Depriester ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Nematic Liquid Crystal ◽  
Orientational Order ◽  
Isotropic Phase ◽  
Multi Walled Carbon Nanotubes ◽  
Vertically Aligned ◽  
Higher Temperature ◽  
Optical Applications ◽  
Walled Carbon Nanotubes

In this paper, we investigate a commercial nematic liquid crystal (LC) mixture namely E7 dispersed with small concentrations of multi-walled carbon nanotubes (MWCNTs). The dielectric and electro-optical characterizations have been carried out in the homogeneously and vertically aligned LC cells. The electro-optical response of LC molecules has been enhanced by 60% after the addition of MWCNTs, which is attributed to the reduced rotational viscosity in the composites. MWCNTs act like barricades for ionic impurities by reducing them up to ∼34.3% within the dispersion limit of 0.05 wt%. The nematic–isotropic phase transition temperature (TNI) of the E7 LC has also been shifted towards the higher temperature, resulting in a more ordered nematic phase. The enhanced birefringence and orientational order parameter in the LC-MWCNTs are attributed to π-π electron stacking between the LC molecules and the MWCNTs. The outlined merits of the LC-MWCNTs composites evince their suitability for ultrafast nematic-based electro-optical devices.

Sign in / Sign up

Export Citation Format

Share Document