Effects of acid treatment duration and sulfuric acid molarity on purification of multi-walled carbon nanotubes

Open Physics ◽  
2010 ◽  
Vol 8 (6) ◽  
Author(s):  
Seyedeh Mortazavi ◽  
Abdul Novinrooz ◽  
Ali Reyhani ◽  
Soghra Mirershadi
Keyword(s):  
Carbon Nanotubes ◽  
Sulfuric Acid ◽  
Acid Solution ◽  
Treatment Duration ◽  
Acid Treatment ◽  
Bimetallic Catalyst ◽  
Chemical Vapor ◽  
Destructive Effect ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

AbstractMulti-walled carbon nanotubes were synthesized using a Fe-Ni bimetallic catalyst supported by MgO using thermal chemical vapor deposition. Purification processes to remove unwanted carbon structures and other metallic impurities were carried out by boiling in sulfuric acid solution. Various analytical techniques such as TGA/DSC, Raman spectroscopy, SEM, HRTEM and EDAX were employed to investigate the morphology, graphitization and quality of the carbon nanotubes. The obtained results reveal the molarity of sulfuric acid and immersed time of the carbon nanotubes in the acid solution is very effective at purifying multi-walled carbon nanotubes. It was also found that 5 M concentration of boiling sulfuric acid for a 3 h treatment duration led to the highest removal of the impurities with the least destructive effect. Moreover, it was observed that acid treatment results in decreasing of CNTs’ diameter.

Preparation of Aspect Ratio-Controlled Carbon Nanotubes

2008 ◽  
Vol 47-50 ◽  
pp. 1101-1104 ◽  
Author(s):  
Don Young Kim ◽  
Hyoung Joon Jin
Keyword(s):  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Acid Treatment ◽  
Treatment Time ◽  
Chemical Vapor ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Carbon Impurities ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Commercially, multi-walled carbon nanotubes (MWCNTs) production methods are based on the use of transition metal catalysts such as chemical vapor deposition (CVD). Raw MWCNTs usually contain metal catalysts and other carbon impurities. A common route to eliminate these impurities is an acid treatment. In addition, this route induces cutting of MWCNTs which can control the aspect ratio of MWCNTs. The aspect ratio controlled MWCNTs can use many applications such as the electrode material, biological imaging and sensing, etc. In this study, the aspect ratio of MWCNTs was controlled using an acid treatment with a 3:1 concentrated H2SO4/HNO3 mixture by varying the treatment time. Results show that an acid treatment can control the aspect ratio of MWCNTs. The aspect ratio controlled MWCNTs were observed by TEM and Raman spectra.

Electron Microscopy and Raman Characterization of Multi-Walled Carbon Nanotubes Grown by Chemical Vapor Deposition

2008 ◽  
Vol 14 (S2) ◽  
pp. 304-305
Author(s):  
M Ellis ◽  
T Jutarosaga ◽  
S Smith ◽  
Y Wei ◽  
S Seraphin
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
New Mexico ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Raman Characterization

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

The Effect of Inoculum in the Preparation of Fermented Tapioca for Nanotechnology Applications Based on FT-IR Studies

2013 ◽  
Vol 667 ◽  
pp. 534-537
Author(s):  
M.Z. Nuraini ◽  
S. Aishah ◽  
S.F. Nik ◽  
Mohamad Rusop
Keyword(s):  
Carbon Nanotubes ◽  
Gas Flow ◽  
Deposition Time ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Ir Studies ◽  
Multi Walled Carbon Nanotubes ◽  
Ft Ir ◽  
Walled Carbon Nanotubes ◽  
Ft Ir Spectroscopy

Fermented tapioca which is a new starting material was used as a carbon precursor. Carbon nanotubes (CNTs) were deposited on silicon wafer (Si) by Thermal Chemical Vapor Deposition (TCVD). The gas flow of Argon (Ar) was constant at 70 bubbles per minute and 20 minutes of deposition time. Before the deposition process, silicon was coated with Nickel using spin coater. Various parameters such as amount of inoculums have been studied. Chemical functional groups of carbon nanotubes were characterized using FT-IR Spectroscopy. The FT-IR result shows peaks attributed to multi–walled carbon nanotubes (MWCNT) vibration modes.

Defect-induced vibrational response of multi-walled carbon nanotubes using resonance Raman spectroscopy

2005 ◽  
Vol 20 (12) ◽  
pp. 3368-3373 ◽  
Author(s):  
S.A. Curran ◽  
J.A. Talla ◽  
D. Zhang ◽  
D.L. Carroll
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Acid Treatment ◽  
Defect Formation ◽  
Double Resonance ◽  
Resonance Raman ◽  
The Body ◽  
Structural Defects ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

We systematically introduced defects onto the body of multi-walled carbon nanotubes through an acid treatment, and the evolution of these defects was examined by Raman spectroscopy using different excitation wavelengths. The D and D′ modes are most prominent and responsive to defect formation caused by acid treatment and exhibit dispersive behavior upon changing the excitation wavelengths as expected from the double resonance Raman (DRR) mechanism. Several weaker Raman resonances including D″ and L1 (L2) + D′ modes were also observed at the lower excitation wavelengths (633 and 785 nm). In addition, specific structural defects including the typical pentagon-heptagon structure (Stone–Wales defects) were identified by Raman spectroscopy. In a closer analysis we also observed Haeckelite structures, specifically Ag mode response in R5,7 and O5,6,7.

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).

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