Optical Studies on Multiwalled Carbon Nanotubes via Modified Wolff-Kishner Reduction Process

2011 ◽  
Vol 194-196 ◽  
pp. 618-624 ◽  
Author(s):  
Kim Han Tan ◽  
Bey Fen Leo ◽  
Meng Nee Ng ◽  
Roslina Ahmad ◽  
Mohd Rafie Johan
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Empirical Relationship ◽  
Reduction Process ◽  
Refraction Index ◽  
Optical Studies ◽  
Multiwalled Carbon ◽  
Simple Method ◽  
Transmission Electron ◽  
First Time

Multiwalled carbon nanotubes (MWCNTs) have been successfully synthesized by using a relatively simple method, known as modified Wolff-Kishner reduction process. Transmission electron microscopy (TEM) has shown the as-prepared MWCNTs possess straight morphologies with average inner and outer diameters, between 2 to 7 nm and 5 to 15 nm, respectively. Ultraviolet-visible (UV-Vis) absorption measurement has been conducted for the first time. The correlation between energy of the π plasmon absorbance (Eπ) and nanotube diameter (dCNT) for the as-prepared MWCNTs shows contradiction to the empirical relationship as Eπ = 4.8 + 0.7 / (dCNT)2. Other optical characteristics like transmittance, reflectance and refraction index also have been studied. This work explores the optical property of the as-prepared MWCNTs and thus provides better understanding about the feasibility of this synthesis technique.

UNUSUAL ELECTROCHEMICAL RESPONSE OF ELECTROCHEMICAL ETCHING ON MULTIWALLED CARBON NANOTUBES

NANO ◽  
2008 ◽  
Vol 03 (06) ◽  
pp. 461-467 ◽  
Author(s):  
JIAN-SHAN YE ◽  
GUANGQUAN MO ◽  
WEI DE ZHANG ◽  
XIAO LIU ◽  
FWU-SHAN SHEU
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Electrochemical Impedance ◽  
Electrochemical Etching ◽  
Current Response ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Oxidation Of Glucose ◽  
Total Disappearance ◽  
Electrocatalytic Effects

Multiwalled carbon nanotubes (MWNTs) can be etched at potentials more positive than 1.7 V versus Ag / AgCl (3 M KCl ) in 0.2 M HNO 3. The electrochemically etched MWNTs show an increase in electrochemical impedance and sluggish electron transfer kinetics, and lose the electrocatalytic effects toward the oxidation of glucose, H 2 O 2, uric acid (UA) and L-ascorbic acid (L-AA). Transmission electron microscope (TEM) images reveal that the nanotube tips are cut off by electrochemical oxidation. This may lead to the degradation of electrocatalytic ability in the MWNTs. Furthermore, the current response after different electrochemically etched cycles shows that the electrocatalytic ability of the MWNTs toward different molecules can be tuned by etched cycles. For example, five etched cycles leads to the total disappearance of the oxidative response to L-AA, with the remaining over 50% of the UA current response in the L-AA and UA mixture. Thus, electrochemical etching is a simple yet novel way to tune the electrocatalytic reactivity and improve the selectivity of the MWNTs.

scholarly journals Characteristics of multiwalled carbon nanotubes-rhenium nanocomposites with varied rhenium mass fractions

2017 ◽  
Vol 7 ◽  
pp. 184798041770717 ◽  
Author(s):  
Anna D Dobrzańska-Danikiewicz ◽  
Weronika Wolany ◽  
Dariusz Łukowiec ◽  
Karolina Jurkiewicz ◽  
Paweł Niedziałkowski
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Multiwalled Carbon Nanotubes ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Multiwalled Carbon ◽  
Weight Percentage ◽  
Transmission Electron ◽  
Scanning Transmission

The purpose of the article is to discuss the process of oxidation of carbon nanotubes subsequently subjected to the process of decoration with rhenium nanoparticles. The influence of functionalization in an oxidizing medium is presented and the results of investigations using Raman spectroscopy and infrared spectroscopy are discussed. Multiwalled carbon nanotubes rhenium-type nanocomposites with the weight percentage of 10%, 20% and 30% of rhenium are also presented in the article. The structural components of such nanocomposites are carbon nanotubes decorated with rhenium nanoparticles. Microscopic examinations under transmission electron microscope and scanning transmission electron microscope using the bright and dark field confirm that nanocomposites containing about 20% of rhenium have the most homogenous structure.

Synthesis and Performance of Dopa-Modified Multiwalled Carbon Nanotubes

2012 ◽  
Vol 184-185 ◽  
pp. 1289-1293
Author(s):  
Lu Zhi Wang ◽  
Lin Yu ◽  
Xiao Ling Cheng ◽  
Jun He ◽  
Le Jia Lin ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Multiwalled Nanotubes ◽  
Mixed Acid ◽  
Transmission Electron ◽  
Ft Ir ◽  
And Performance

The Dopamine-modified multiwalled carbon nanotubes (MWNT-Dopa) were synthesized by chemical reaction between dopamine (Dopa) and multiwalled carbon nanotubes which oxidazed by mixed-acid (MWNT-COOH). The structure of MWNT-Dopa were analyzed by Fourier transform infrared spectroscopy (FT-IR), Thermogravimetric (TG), Transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques and the dispersity of MWNT-Dopa were studied by Dispersion stability analyzer. The results show that dopamine has been grafted on multiwalled carbon nanotubes successfully, and a dopamine layer which wraps on the surface of multiwalled nanotubes make multiwalled nanotubes have outstanding dispersity in water.

Benzoyl Peroxide Initiated Grafting of 3-Aminopropyltriethoxysilane to Multiwalled Carbon Nanotubes

2011 ◽  
Vol 364 ◽  
pp. 489-493
Author(s):  
Abdul Shukor Junidah ◽  
Aziz Azizan ◽  
Mariatti Jaafar
Keyword(s):  
Carbon Nanotubes ◽  
Free Radicals ◽  
Benzoyl Peroxide ◽  
Multiwalled Carbon Nanotubes ◽  
Radical Reaction ◽  
Covalent Bond ◽  
Free Radical Reaction ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Transmission Electron

A new method to functionalize multiwalled carbon nanotubes (MWCNT) with 3-aminopropyltriethoxysilane (APTES) has been established using benzoyl peroxide (BPO) as initiator. The functionalization was carried out through free radical reaction by thermal decomposition of benzoyl peroxide at 110°C. The reaction liberated carbon dioxide and generated phenyl free radicals. The phenyl free radicals initiated in-situ functionalization represent a simple means of creating reactive site on the surface of MWNT as well as on APTES. The functionalized MWNT was characterized using X-ray photoelectron microscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM results showed that the APTES has been successfully grafted onto MWNT. Due to the high radical reactive trap of MWNT, APTES radical are easily grafted onto MWNT surface to form covalent bond. XPS results clearly indicate alkoxylsilane and amide groups of APTES were grafted on the MWNT surface with the formation of C-O-Si and C-N bonds as evidence. From the XRD results, it was found that the surface functionalized does not give any effect on the MWNT graphitic structure.

Morphology and thermal properties of nanocomposites based on chiral poly(ester-imide) matrix reinforced by vitamin B1 functionalized multiwalled carbon nanotubes

2016 ◽  
Vol 51 (16) ◽  
pp. 2291-2300 ◽  
Author(s):  
Shadpour Mallakpour ◽  
Samaneh Soltanian
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Multiwalled Carbon Nanotubes ◽  
Vitamin B1 ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
Scanning Electron

Chemical functionalization of carboxylated multiwalled carbon nanotubes with vitamin B1 was carried out under ultrasonic irradiation. The functionalized nanotubes were embedded in a chiral and biodegradable poly(ester-imide) to prepare multiwalled carbon nanotubes reinforced polymer nanocomposites. Optically active poly(ester-imide) was synthesized by step-growth polymerization of aromatic diol and amino acid based diacid. The vitamin B1 functionalized multiwalled carbon nanotubes and the resulting nanocomposites were examined using Fourier-transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, transmission electron microscopy, and field-emission scanning electron microscopy. Thermogravimetric analysis results indicated that temperature at 10% weight loss was increased from 409℃ for pure PEI to 419℃, 427℃, and 430℃ for nanocomposites containing 5%, 10%, and 15% functionalized multiwalled carbon nanotubes, respectively. The Fourier-transform scanning electron microscopy and transmission electron microscopy images exhibited that the functionalized multiwalled carbon nanotubes were separated individually and enwrapped by polymer chains.

scholarly journals One-Step Route to Synthesize Multiwalled Carbon Nanotubes Filled with MgO Nanorods

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Liu ◽  
Chunli Guo ◽  
Xiaojian Ma ◽  
Changhui Sun ◽  
Fengxia Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Multiwalled Carbon Nanotubes ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
One Step ◽  
Walled Cnts

Multiwalled carbon nanotubes filled with MgO nanorods were synthesized through the reaction of ethanol and Mg powder in the presence ofTiO2at 400C°. X-ray powder diffraction indicated that the sample was composed of graphite and cubic MgO. Transmission electron microscopy studies showed that multi-walled CNTs with the outer diameters of 70–130 nm were filled with discontinuous MgO nanorods whose diameter was in the range of 25–40 nm. The ratios of the band intensities(ID/IG=0.67)in Raman spectrum implied that carbon nanotubes had good crystallinity. The influence of correlative reaction factors on the morphology of the sample and the possible formation mechanism were discussed.

Integration of Multiwalled Carbon Nanotubes in Bulk Heterojunction CdSe/PCPDTBT Hybrid Solar Cells

2018 ◽  
Vol 929 ◽  
pp. 150-157
Author(s):  
Alfian Ferdiansyah Madsuha ◽  
Nofrijon Sofyan ◽  
Akhmad Herman Yuwono ◽  
Michael Krueger
Keyword(s):  
Carbon Nanotubes ◽  
Solar Cells ◽  
Multiwalled Carbon Nanotubes ◽  
Bulk Heterojunction ◽  
Photovoltaic Performance ◽  
Hybrid Solar Cells ◽  
Cdse Qds ◽  
Multiwalled Carbon ◽  
Simple Method

In this work, the development of solution-processed bulk heterojunction hybrid solar cells based on CdSe quantum dot (QD) and conjugated polymer poly [2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta [2,1-b;3,4-b] dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)], PCPDTBT was performed. The photoactive layer was formed by integrating CdSe QDs onto multiwalled carbon nanotubes (CNTs). A simple method of thiol functionalization in the interface CNTs and CdSe QDs has been investigated. Integration of CNTs enhances long-term performance of solar cells devices. Initial PCE values of about 1.9 % under AM1.5G illumination have been achieved for this hybrid CNT-CdSe photovoltaic device. In addition, the long-term stability of the photovoltaic performance of the devices was investigated and found superior to CdSe QD only based devices. About 84 % of the initial PCE remained after storage in a glove box for one year without any further encapsulation. It is concluded that the improvement is mainly due to a strong binding between thiol functionalized CNTs and CdSe QDs, resulting preservation of the nanomorphology of the hybrid film over time.

Experimental and theoretical studies on the mechanism for chemical oxidation of multiwalled carbon nanotubes

RSC Advances ◽  
2014 ◽  
Vol 4 (55) ◽  
pp. 28826-28831 ◽  
Author(s):  
B. M. Maciejewska ◽  
M. Jasiurkowska-Delaporte ◽  
A. I. Vasylenko ◽  
K. K. Kozioł ◽  
S. Jurga
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Multiwalled Carbon Nanotubes ◽  
Chemical Oxidation ◽  
Theoretical Studies ◽  
Multiwalled Carbon ◽  
Transmission Electron ◽  
Experimental And Theoretical Studies

In this study, the oxidation of multiwalled carbon nanotubes (MWCNTs) sonicated and/or refluxed in acids (H2SO4/HNO3) was investigated using a combination of high-resolution transmission electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and ab initio computational methods.

Nanoactuation of Telescoping Multiwalled Carbon Nanotubes inside Transmission Electron Microscope

2007 ◽  
Vol 46 (No. 42) ◽  
pp. L1035-L1038 ◽  
Author(s):  
Masahiro Nakajima ◽  
Shigeo Arai ◽  
Yahachi Saito ◽  
Fumihito Arai ◽  
Toshio Fukuda
Keyword(s):  
Carbon Nanotubes ◽  
Electron Microscope ◽  
Multiwalled Carbon Nanotubes ◽  
Transmission Electron Microscope ◽  
Multiwalled Carbon ◽  
Transmission Electron
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