DISPERSION OF PRISTINE MULTI-WALLED CARBON NANOTUBES IN COMMON ORGANIC SOLVENTS

NANO ◽  
2010 ◽  
Vol 05 (02) ◽  
pp. 103-109 ◽  
Author(s):  
GUOXING SUN ◽  
ZHENGPING LIU ◽  
GUANGMING CHEN

The dispersion of pristine multi-walled carbon nanotubes in various common organic solvents and water has been investigated. Sedimentation tests, optical microscopy, transmission electron microscopy and Tyndall effect tests are employed. The results clearly show that N-methyl-2-pyrrolodone, acetone, tetrahydrofuran and dichloromethane are good solvents to debundle and disperse the multi-walled carbon nanotubes. In contrast, much precipitation can be obviously observed for systems of the carbon nanotubes in water, ethanol and toluene. Additionally, Tyndall effect tests suggest that the upper dispersions of the carbon nanotubes in acetone, tetrahydrofuran and dichloromethane with a concentration of 0.1 mg/mL and the dispersion of carbon nanotubes in N-methyl-2-pyrrolodone with a concentration of 0.05 mg/mL are colloidal systems rather than solutions. Finally, based on the above results, a possible mechanism is briefly discussed.

2009 ◽  
Vol 81 (12) ◽  
pp. 2317-2325 ◽  
Author(s):  
Wei-De Zhang ◽  
Jin Chen

Strongly bonded arrays of vertically aligned, multi-walled carbon nanotubes (MWNTs) have been successfully grown on Ta foils, and provide a convenient basis for fabricating electrodes with high conductivity and stability. The MWNT arrays were further coated by nanostructured MnO2 through reacting with KMnO4 solution at room temperature. The morphology of the MnO2/MWNT nanocomposite was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the MnO2 is a beehive-like nanostructure that is homogeneously and densely coated on the surface of the MWNTs. The capacitance of the MWNT electrode was significantly increased from 0.14 to 6.81 mF cm–2 after being modified with nanostructured MnO2, that is, the mass-specific capacitance of the bare and MnO2-modified MWNTs was about 33 and 446 F g–1, respectively. The MnO2/MWNT nanocomposite on Ta foils could be potential for developing a supercapacitor.


2013 ◽  
Vol 365-366 ◽  
pp. 1122-1127
Author(s):  
Shao Wei Lu ◽  
Xian Jun Zeng ◽  
Peng Nie ◽  
Chun Xu Zhang

Achieving the monodispersion of Multi-walled carbon nanotubes (MWCNTs) is a challenging work for CNTs application. Centrifugation as a standard procedure was employed to remove remaining large bundles and leaving primarily individual nanotubes and small bundles in the supernatant. The optimum centrifugation time and force were 30min and 12×103g, respectively , which were determined by UV-vis absorbance, transmission electron microscopy (TEM), Zeta potential and the residual MWCNTs concentration after centrifugation. Through centrifugation treatments, the uniform and stable MWCNTs monodispersion can be obtained and the Zeta potential was as high as-53.8mv after one month. The film formed from optimized MWCNTs monodispersed solution is smooth and flexible.


2016 ◽  
Vol 879 ◽  
pp. 442-447
Author(s):  
A.D. Dobrzańska-Danikiewicz ◽  
D. Cichocki ◽  
D. Łukowiec

In the framework of the made researches nanocomposite of CNT-NPs type (Carbon Nanotube-Nanoparticles) consisting of multiwalled carbon nanotubes coated by rhodium nanoparticles and/or palladium using the two-step indirect method: chemical reduction have been produced. In the researches high-quality multi-walled carbon nanotubes MWCNTs with a length of 100 to 500 nm and a diameter of 8 to 20 nm previously obtained in the catalytic-chemical vapour deposition CCVD have been used. Nanotubes produced within the framework of own researches contain minor amounts of metallic impurities and amorphous carbon deposits. In order to deposit the noble metal nanoparticles on the surface of carbon nanotubes functionalization of multi-walled carbon nanotubes in a mixture of H2SO4 and HNO3 acids have been used. The prepared material has been subjected chemical reduction using noble metal precursors (RhCI3, PdCl2). The characterization of the produced material including the examination of the structure, morphology, chemical composition and evaluation of the size and distribution of rhodium and/or palladium nanoparticles on the surface of carbon nanotubes has been performed using: scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS). The produced nanomaterials may be used as the active layer of sensors of chemical/biological agents.


2006 ◽  
Vol 21 (4) ◽  
pp. 1012-1018 ◽  
Author(s):  
Seamus A. Curran ◽  
Jiri Cech ◽  
Donghui Zhang ◽  
James L. Dewald ◽  
Aditya Avadhanula ◽  
...  

We have used transmission electron microscopy to observe the structural changes that have occurred in multi-walled carbon nanotubes (MWCNTs) because of acid treatment. After a thiolation reaction of the acid-treated MWCNTs using P4S10 in refluxing toluene, we have also used electron energy loss spectroscopy to characterize the changes on the nanotubes from sidewall functionalization. We have determined that the sulfur content bonded to the nanotubes is 0.6% in terms of the atomic content of the samples. Raman spectroscopy was used to examine the vibrational changes that occurred to the nanotubes as well as identifying new vibrational modes around 500 cm−1 characteristic of carbon-sulfur bonds.


2020 ◽  
pp. 74-78
Author(s):  
V. V. Bolotov ◽  
◽  
V. E. Kan ◽  
E. V. Knyazev ◽  
◽  
...  

The structure of multi-walled carbon nanotubes exposed to a pulsed high-power ion beam is investigated using the methods of Raman spectroscopy and transmission electron microscopy. It has been shown that irradiation with an ion beam generates significant defects in the structure of nanotubes. With an increase in the number of pulses, processes associated with the annealing of defects in the internal structure of the samples are observed. Electron microscopy data make it possible to distinguish two types of defects leading to a decrease in the interlayer distance of the carbon nanotube wall


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Jung-Eun Park ◽  
Yong-Seok Jang ◽  
Tae-Sung Bae ◽  
Min-Ho Lee

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.


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