scholarly journals Common Wet Chemical Agents for Purifying Multiwalled Carbon Nanotubes

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Rasel Das ◽  
Md. Eaqub Ali ◽  
Sharifah Bee Abd Hamid ◽  
M. S. M. Annuar ◽  
Seeram Ramakrishna
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Low Cost ◽  
Gravimetric Analysis ◽  
Electrode Arrays ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Pristine Mwcnts ◽  
Transmission Electron ◽  
Wet Chemical

Purification and functionalization of multiwalled carbon nanotubes (MWCNTs) are challenging but vital for their effective applications in various fields including water purification technologies, optoelectronics, biosensors, fuel cells, and electrode arrays. The currently available purification techniques, often complicated and time consuming, yielded shortened and curled MWCNTs that are not suitable for applications in certain fields such as membrane technologies, hybrid catalysis, optoelectronics, and sensor developments. Here we described the H2O2synergy on the actions of HCl and KOH in purifying and functionalizing pristine MWCNTs. The method (HCl/H2O2) showed 100% purification yield as compared to HCl and KOH/H2O2with purification yields 93.46 and 3.92%, respectively. We probed the findings using transmission electron microscope, energy dispersive X-ray spectroscope, attenuated total reflectance infrared spectroscope, Raman spectroscope, thermal gravimetric analysis, and X-ray powder diffraction. The study is a new avenue for simple, rapid, low cost, and scalable purification of pristine MWCNTs for application in versatile fields.

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.

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.

Synthesis of Three Dimensional Graphene/Multiwalled Carbon Nanotubes Nanocomposites Hydrogel and Investigation of their Electrochemical Properties as Electrodes of Supercapacitors

2015 ◽  
Vol 1094 ◽  
pp. 222-228
Author(s):  
Lei Zhou ◽  
Da Wei He ◽  
Hong Lu Wu ◽  
Zeng Hui Qiu
Keyword(s):  
Carbon Nanotubes ◽  
Specific Capacitance ◽  
Multiwalled Carbon Nanotubes ◽  
Synthesis Method ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene

A facile synthesis method of three dimensional reduced graphene oxide (RGO)/multiwalled carbon nanotubes (MWCNTs) hydrogel was introduced. Hydrogel samples which were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM) and examined by X-ray diffraction (XRD) have been used as the electrode of supercapacitor. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) were used to investigate the Supercapacitors which we have fabricated. Because MWCNTs inserting into layers of RGO homogeneously prevent the layers of RGO from stacking and enlarge the specific surface area of graphene, the specific capacitance of RGO/MWCNTs material has been greatly improved. At the current density of 0.2A/g, the specific capacitance of RGO/MWCNTs electrode is about 176F/g, which means a 52% increasement compared to which of pure RGO material electrode. And the specific capacitance of RGO/MWCNTs also achieves a good rate property.

Chemical splitting of multiwalled carbon nanotubes to enhance electrochemical capacitance for supercapacitors

2014 ◽  
Vol 07 (05) ◽  
pp. 1450057 ◽  
Author(s):  
Xinlu Li ◽  
Tongtao Li ◽  
Xinlin Zhang ◽  
Qineng Zhong ◽  
Hongyi Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Double Layers ◽  
X Ray Diffraction ◽  
Electrochemical Capacitance ◽  
Multiwalled Carbon ◽  
Pristine Mwcnts ◽  
Transmission Electron ◽  
Adsorption Desorption

Multiwalled carbon nanotubes (MWCNTs) were chemically split and self-assembled to a flexible porous paper made of graphene oxide nanoribbons (GONRs). The morphology and microstructure of the pristine MWCNTs and GONRs were analyzed by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy. And the specific surface area and porosity structure were measured by N 2 adsorption-desorption. The longitudinally split MWCNTs show an enhancement in specific capacitance from 21 F g-1 to 156 F g-1 compared with the pristine counterpart at 0.1 A g-1 in a 6 M KOH aqueous electrolytes. The electrochemical experiments prove that the chemical splitting of MWCNTs will make inner carbon layers opened and exposed to electrochemical double layers, which can effectively improve the electrochemical capacitance for supercapacitors.

ELECTROCONDUCTIVE ADHESIVES BASED ON POLYURETHANE WITH MULTIWALLED CARBON NANOTUBES

2009 ◽  
Vol 23 (31n32) ◽  
pp. 3739-3745 ◽  
Author(s):  
YESEUL KIM ◽  
SE YOUN CHO ◽  
YOUNG SOO YUN ◽  
HYOUNG-JOON JIN
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Multiwalled Carbon Nanotubes ◽  
Conductive Adhesives ◽  
Multiwalled Carbon ◽  
Electrically Conductive ◽  
Pristine Mwcnts ◽  
Transmission Electron ◽  
Polyurethane Matrix

In the present study, we prepared and characterized electrically conductive adhesives based on polyurethane filled with two kinds of multiwalled carbon nanotubes (MWCNTs), viz. pristine MWCNTs and acid treated MWCNTs, respectively. The influence of the type of filler on the dispersibility within the polyurethane matrix and the corresponding electrical conductivity is investigated. The electrical conductivity of the prepared specimens was measured using a four-point probe. The morphology and dispersibility of the fillers were observed by field emission scanning electron microscopy and transmission electron microscopy.

Immobilization of Metal Sulfide Nanocrystals on Multiwalled Carbon Nanotubes Facilitated by Infrared Irradiation

2017 ◽  
Vol 13 (2) ◽  
pp. 17-32
Author(s):  
Venugopal B R
Keyword(s):  
Carbon Nanotubes ◽  
Metal Ions ◽  
Multiwalled Carbon Nanotubes ◽  
Photoelectron Spectroscopy ◽  
Metal Sulfide ◽  
Multiwalled Carbon ◽  
Ir Radiation ◽  
X Ray ◽  
Transmission Electron ◽  
Sulfide Nanocrystals

Uniformly distributed metal sulfide nanocrystals are immobilized on the surface of oxygenated multiwalled carbon nanotubes (MWCNTs) by reacting metal ions (Cu 2+ / Zn 2+ /Cd 2+ ) anchored to MWCNTs with hydrogen sulfide while irradiating with infrared (IR) radiation. The IR irradiation is the key step in the effective immobilization of metal sulfide nanocrystals on MWCNTs. The photoabsorption and photothermal properties of MWCNTs in the presence of IR irradiation raises the temperature of the CNTs in solution, facilitating the interaction between the acidic groups on CNTs and the metal ions, which results in effective immobilization of the nanocrystals. The metal sulfide-MWCNT hybrids are characterized by X-ray powder diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy.

scholarly journals Effect of Size of Multiwalled Carbon Nanotubes Dispersed in Gear Oils for Improvement of Tribological Properties

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Kodanda Rama Rao Chebattina ◽  
V. Srinivas ◽  
N. Mohan Rao
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Ball Milling ◽  
Multiwalled Carbon Nanotubes ◽  
Tribological Properties ◽  
Extreme Pressure ◽  
Multiwalled Carbon ◽  
Pristine Mwcnts ◽  
Gear Oil ◽  
The Stability

The aim of the paper is to investigate the effect of size of multiwalled carbon nanotubes (MWCNTs) as additives for dispersion in gear oil to improve the tribological properties. Since long pristine MWCNTs tend to form clusters compromising dispersion stability, they are mildly processed in a ball mill to shorten the length and stabilized with a surfactant before dispersing in lubricant. Investigations are made to assess the effect of ball milling on the size and structure of MWCNTs using electron microscopy and Raman spectroscopy. The long and shortened MWCNTs are dispersed in EP 140 gear oil in 0.5% weight. The stability of the dispersed multiwalled carbon nanotubes is evaluated using light scattering techniques. The antiwear, antifriction, and extreme pressure properties of test oils are evaluated on a four-ball wear tester. It is found that ball milling of MWCNTs has a strong effect on the stability and tribological properties of the lubricant. From Raman spectroscopy, it is found that ball milling time of up to 10 hours did not produce any defects on the surface of MWCNTs. The stability of the lubricant and the antiwear, antifriction, and extreme pressure properties have improved significantly with dispersion shortened MWCNTs. Ball milling for longer periods produces defects on the surface of MWCNTs reducing their advantage as oil additives.

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.

Synthesis of Nanocomposites of V2OO5©Selenium Nanoparticles and Multiwalled Carbon Nanotubes for Antimicrobial Activity

2021 ◽  
Vol 21 (11) ◽  
pp. 5673-5680
Author(s):  
Muthukrishnan Francklin Philips ◽  
Jothirathinam Thangarathinam ◽  
Jayakumar Princy ◽  
Cyril Arockiaraj Crispin Tina ◽  
Cyril Arockiaraj Crispin Tina ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Antimicrobial Activity ◽  
Multiwalled Carbon Nanotubes ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
Uv Visible ◽  
Micro Organisms

The authors report the preparation of the nanocomposite comprising of vanadium pentoxide (V2O5) and selenium (Se) nanoparticles and functionalized multiwalled carbon nanotubes (MWCNTs) (V2O5@Se NPs/MWCNTs). Since Se NPs possesses extraordinary physicochemical properties including larger surface area with higher adsorption capacity, V2O5 NPs were adsorbed onto Se NPs surface through physisorption process (designated as V2O5@Se NPs). The nanocomposite synthesized hydrothermally was evaluated for its antimicrobial activity. The morphology and microstructure of the nanocomposite were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, respectively. Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy (UV-Vis) were employed to analyze the spectral properties of nanocomposite. The microbicidal efficacy of nanocomposite was tested against Gram-negative (G-)ZGram-positive (G+) bacteria and fungus. This is the first report on the synthesis of V2O5@Se NPs/MWCNTs nanocomposites by chemical method that showed microbicidal effect on micro-organisms. The thiol (-SH) units facilitates the enrichment of V2O5@Se NPs onto MWCNTs surface. Ultimately, it reflects on the significant antimicrobial activity of V2O5@Se NPs/MWCNTs.

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