The Effect of Calcination on Multi-Walled Carbon Nanotubes Produced by Dc-Arc Discharge

2008 ◽  
Vol 8 (7) ◽  
pp. 3539-3544 ◽  
Author(s):  
Sreejarani K. Pillai ◽  
Willem G. Augustyn ◽  
Margaretha H. Rossouw ◽  
Robert I. McCrindle
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Structural Integrity ◽  
Arc Discharge ◽  
Simple Method ◽  
Helium Atmosphere ◽  
Different Temperatures ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Dc Arc

Multi-walled carbon nanotubes were synthesized by dc-arc discharge in helium atmosphere and the effect of calcination at different temperatures ranging from 300–600 °C was studied in detail. The degree of degradation to the structural integrity of the multi-walled carbon nanotubes during the thermal process was studied by Raman spectroscopy, Scanning electron microscopy and High resolution transmission electron microscopy. The thermal behaviour of the as prepared and calcined samples was investigated by thermogravimetric analysis. Calcination in air at 400 °C for 2 hours was found to be an efficient and simple method to eliminate carbonaceous impurities from the nanotube bundles with minimal damage to the tube walls and length. The impurities were oxidized at a faster rate when compared to the nanotubes and gave good yield of about 50%. The nanotubes were observed to be damaged at temperature higher than 450 °C. The results show that this method is less destructive when compared liquid phase oxidation with 5 M HNO3.

Bulk synthesis of multi-walled carbon nanotubes by AC arc discharge method

2017 ◽  
Vol 231 (3) ◽  
pp. 141-151 ◽  
Author(s):  
KK Singh ◽  
SK Chaudhary ◽  
R Venugopal ◽  
A Gaurav
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Arc Discharge ◽  
Pure Graphite ◽  
Multi Walled Carbon Nanotubes ◽  
Different Shapes ◽  
Ac Arc ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This work proposes the production of multi-walled carbon nanotubes by AC arc discharging of spectroscopically pure graphite electrodes of different shapes, that is, movable cylindrical and stationary rectangular electrode by manual metal arc welding setup. Continuous arc was generated by maintaining the gap of about 3 mm between the electrodes which in turn formed the plasma zone. Vaporization of carbon cations followed by sudden quenching paved the way for formation of carbon nantotubes. Nanotubes produced were deposited on the stationary graphite electrode in the form of soot. Further extraction of the nanoparticles from the soot was performed by conducting series of purification processes which will be discussed in upcoming chapters. Morphology and purity of the extracted nanotubes were investigated by X-ray diffraction, scanning electron microscopy, field-emission scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. Following the characterization process, it was observed that the so-produced nanotubes were of different shapes, that is, carbon cone nanotubes, nanocapsules, nanoparticles and branching type and randomly oriented. The length of the nanotubes varied from 231 to 561 nm, whereas diameter was found to be in the range of 14–55 nm.

VERTICALLY ALIGNED CARBON NANOTUBES AT DIFFERENT TEMPERATURES BY SPRAY PYROLYSIS TECHNIQUES

2006 ◽  
Vol 20 (29) ◽  
pp. 4965-4972 ◽  
Author(s):  
RAKESH A. AFRE ◽  
T. SOGA ◽  
T. JIMBO ◽  
MUKUL KUMAR ◽  
Y. ANDO ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Spray Pyrolysis ◽  
Morphological Characteristics ◽  
Catalyst Precursor ◽  
Simple Method ◽  
Fe Catalyst ◽  
Different Temperatures ◽  
Multi Walled Carbon Nanotubes ◽  
Vertically Aligned ◽  
Walled Carbon Nanotubes

Vertically aligned arrays of multi-walled carbon nanotubes (VACNTs) were grown by spray pyrolysis of turpentine oil and ferrocene mixture at temperatures higher than 700°C. Using this simple method, we report the successful growth of vertically aligned nanotubes of ~300μm length and diameter in the range of ?20–80 nm on Si (100) substrate. The ferrocene acts as an in situ Fe catalyst precursor, forming the nano-sized metallic iron particles for formation of VACNTs on the Si substrate. The morphological characteristics of VACNTs are confirmed by SEM, TEM and Raman spectroscopy and growth mechanism is discussed in short.

Study on the Synthesis of Carbon Nanotubes using the Catalyst Metal Deposited Carbon Cathode Electrode in a DC Arc Discharge Process

2005 ◽  
Vol 900 ◽  
Author(s):  
Hyeon Hwan Kim ◽  
Hyeong Joon Kim
Keyword(s):  
Carbon Nanotubes ◽  
Arc Discharge ◽  
Metal Catalyst ◽  
Carbon Anode ◽  
Discharge Process ◽  
Carbon Cathode ◽  
Multi Walled Carbon Nanotubes ◽  
Usual Process ◽  
Walled Carbon Nanotubes ◽  
Dc Arc

ABSTRACTCarbon nanotubes (CNTs) were grown using a dc arc discharge process and relevant process parameters were investigated. Unlike the usual process in which a carbon anode is filled with metal catalyst powder, CNTs were prepared using a carbon cathode on which the metal catalyst had been deposited using an electroplating system. Various transition metals, Ni, Co and Ti, were used as a catalyst. The results show that multi-walled carbon nanotubes (MWNTs) and single-walled carbon nanotubes (SWNTs) can both be synthesized using this technique. And yield and morphology of the prepared CNTs varied depending on the experimental condition and catalyst. While MWNTs were produced in the deposit and soot sample, SWNTs with diameters near 1nm were only detected in the soot collects. When Ni film was used as a catalyst, the yield of SWNTs was higher than in case of using Co or Ti film as a catalyst. From these results, the optimized preparing condition of CNTs and the properties of a good catalyst are discussed.

scholarly journals Biocompatibility Characteristics of Titanium Coated with Multi Walled Carbon Nanotubes—Hydroxyapatite Nanocomposites

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Jung-Eun Park ◽  
Yong-Seok Jang ◽  
Tae-Sung Bae ◽  
Min-Ho Lee
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Sol Gel ◽  
Pure Titanium ◽  
Cell Proliferation And Differentiation ◽  
Transmission Electron ◽  
Proliferation And Differentiation ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi walled carbon nanotubes-hydroxyapatite (MWCNTs-HA) with various contents of MWCNTs was synthesized using the sol-gel method. MWCNTs-HA composites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). HA particles were generated on the surface of MWCNT. Produced MWCNTs-HA nanocomposites were coated on pure titanium (PT). Characteristic of the titanium coated MWCNTs-HA was evaluated by field-emission scanning electron microscopy (FE-SEM) and XRD. The results show that the titanium surface was covered with MWCNTs-HA nanoparticles and MWCNTs help form the crystalized hydroxyapatite. Furthermore, the MWCNTs-HA coated titanium was investigated for in vitro cellular responses. Cell proliferation and differentiation were improved on the surface of MWCNT-HA coated titanium.

Kinetics and thermodynamics of the sorption of furaltadone from aqueous solutions on magnetic multi-walled carbon nanotubes

2014 ◽  
Vol 70 (6) ◽  
pp. 964-971
Author(s):  
Xu Chen ◽  
Zhen-hu Xiong
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Sorption Data ◽  
Multi Wall Carbon Nanotubes ◽  
Adsorption Behaviors ◽  
Different Temperatures ◽  
Multi Walled Carbon Nanotubes ◽  
Pseudo Second Order ◽  
Experimental Data Analysis ◽  
Walled Carbon Nanotubes

Magnetic multi-wall carbon nanotubes (M-MWCNTs) were used as an adsorbent for removal of furaltadone from aqueous solutions, and the adsorption behaviors were investigated by varying pH, sorbent amount, sorption time and temperature. The results showed that the adsorption efficiency of furaltadone reached 97% when the dosage of M-MWCNT was 0.45 g · L−1, the pH was 7 and the adsorption time was 150 min. The kinetic data showed that the pseudo-second-order model can fit the adsorption kinetics. The sorption data could be well explained by the Langmuir model under different temperatures. The adsorption process was influenced by both intraparticle diffusion and external mass transfer. The experimental data analysis indicated that the electrostatic attraction and π–π stacking interactions between M-MWCNT and furaltadone might be the adsorption mechanism. Thermodynamic analysis reflected that adsorption of furaltadone on the M-MWCNT was spontaneous and exothermic. Our study showed that M-MWCNTs can be used as a potential adsorbent for removal of furaltadone from water and wastewater.

Continuous Fixed-Bed Column Studies of Textile Effluent Treatment using Multi-Walled Carbon Nanotubes Originated from Rosmarinus officinalis Oil

2022 ◽  
Vol 10 (4) ◽  
pp. 22-30
Author(s):  
S. Valliammai ◽  
K. Gopal ◽  
R. Nithya ◽  
L. Rama Priya ◽  
D. Kavitha
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Service Time ◽  
Fixed Bed ◽  
Rosmarinus Officinalis ◽  
Time Model ◽  
Fixed Bed Column ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Bed Depth Service Time

A continuous adsorption study in a fixed-bed column was carried out using Multi-walled Carbon Nanotubes derived from Rosmarinus officinalis oil as an adsorbent for removing the textile dye Acid blue 40 from an aqueous solution. The adsorbent, MWNTs were prepared from Rosmarinus officinalis oil as a precursor to Fe/Mo catalyst supported on silica at 650 ºC under N2 atmosphere by spray pyrolysis process characterized by scanning electron microscopy, Transmission Electron microscopy, and Raman spectroscopy. The effects of adsorbent bed height (2–6 cm), initial ion concentration (20– 60 mg/L), and flow rate (10–30 mL/min) on the column performance were analyzed. The breakthrough curve was analyzed using the mathematical models of Thomas, Yoon-Nelson, and bed depth service time. The Thomas model at different conditions defined the behaviors of the breakthrough curves. The bed depth service time model showed good agreement with the experimental data. The high values of correlation coefficients (R2 0.9875) obtained indicate the validity of the bed depth service time model for the present column system.

Electron Microscopy Characterization of Platinum Catalysts Supported on Multi-walled Carbon Nanotubes

2012 ◽  
Vol 18 (S2) ◽  
pp. 1316-1317
Author(s):  
M.J. Guinel ◽  
N. Brodusch ◽  
R. Gauvin ◽  
Y. Verde-Gomez ◽  
B. Escobar-Morales
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Platinum Catalysts ◽  
Multi Walled Carbon Nanotubes ◽  
Microscopy Characterization ◽  
Walled Carbon Nanotubes

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

scholarly journals Polymeric Composites Based on Polyurea Matrix Reinforced with Carbon Nanotubes

2017 ◽  
Vol 54 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Maria Adina Vulcan ◽  
Celina Damian ◽  
Paul Octavian Stanescu ◽  
Eugeniu Vasile ◽  
Razvan Petre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.

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