Effect of growth conditions on B-doped carbon nanotubes

2006 ◽  
Vol 21 (12) ◽  
pp. 3058-3064 ◽  
Author(s):  
Sara M.C. Vieira ◽  
Odile Stéphan ◽  
David L. Carroll

The modified arc-discharge technique was used for the growth of boron-doped multiwalled carbon nanotubes. A variety of weight percentages of boron and sulfur were mixed (0.5–15 wt%) with graphite powder and packed in the consumable anode. Transmission electron microscopy, Raman spectroscopy, thermogravimetric analysis (TGA), and electron energy loss spectroscopy (EELS) were used to characterize the samples. EELS indicated a small percentage of boron present (<1 at.%) in the nanotubes. Sulfur was used primarily to enhance boron incorporation; however, Raman and TGA measurements indicated fewer defects and/or amorphous material present when sulfur was added.

2002 ◽  
Vol 737 ◽  
Author(s):  
D. Sarangi ◽  
A. Karimi

ABSTRACTCarbon nanotubes on metallic wires may be act as electrode for the field emission (FE) luminescent devices. Growing nanotubes on metallic wires with controlled density, length and alignment are challenging issues for this kind of devices. We, in the present investigation grow carbon nanotubes directly on the metal wires by a powerful but simple technique. A novel approach has been proposed to align nanotubes during growth. Methane, acetylene and dimethylamine have been used as source gases. With the same growth conditions (viz. pressure, growth temperature and plasma) methane does not produce any nanotube but nanotubes grown with dimethylamine show shorter length and radius than acetylene. The effect of temperature to control the radius, time to control the density, plasma conditions to align the nanotubes has been focused. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Rutherford Back Scattering (RBS) are used to characterize the nanotubes.


Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 669 ◽  
Author(s):  
Mariachiara Trapani ◽  
Antonino Mazzaglia ◽  
Anna Piperno ◽  
Annalaura Cordaro ◽  
Roberto Zagami ◽  
...  

The ability of multiwalled carbon nanotubes (MWCNTs) covalently functionalized with polyamine chains of different length (ethylenediamine, EDA and tetraethylenepentamine, EPA) to induce the J-aggregation of meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) was investigated in different experimental conditions. Under mild acidic conditions, protonated amino groups allow for the assembly by electrostatic interaction with the diacid form of TPPS, leading to hybrid nanomaterials. The presence of only one pendant amino group for a chain in EDA does not lead to any aggregation, whereas EPA (with four amine groups for chain) is effective in inducing J-aggregation using different mixing protocols. These nanohybrids have been characterized through UV/Vis extinction, fluorescence emission, resonance light scattering and circular dichroism spectroscopy. Their morphology and chemical composition have been elucidated through transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). TEM and STEM analysis evidence single or bundles of MWCNTs in contact with TPPS J-aggregates nanotubes. The nanohybrids are quite stable for days, even in aqueous solutions mimicking physiological medium (NaCl 0.15 M). This property, together with their peculiar optical features in the therapeutic window of visible spectrum, make them potentially useful for biomedical applications.


2012 ◽  
Vol 454 ◽  
pp. 63-66
Author(s):  
Xia Yuan ◽  
Yu Liang An ◽  
Chen Zhang ◽  
Hong Chao Sui

Single-walled carbon nanotubes (SWNTs) have been successfully prepared from starch by arc discharge technique. The SWNTs products were characterized by scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The growth mechanism of the SWNTs was discussed in terms of the starch. The results demonstrate that starch is one of the suitable precursor for making SWNTs by arc discharge method.


2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Yitian Peng ◽  
Zhonghua Ni

The oxidized multiwalled carbon nanotubes (MWCNTs) were modified with stearic acid (SA) molecules. The SA-modified MWCNTs were characterized with scanning electron microscopy, transmission electron microscopy, and Fourier transform-infrared spectroscopy. The tribological properties of the oxidized and SA-modified MWCNTs as additives in water were comparatively investigated with a four-ball tester. The results showed the SA-modified MWCNTs in water have better tribological properties including friction reduction and antiwear than oxidized MWCNTs. The possible mechanism of SA-modified MWCNT as an additive in water was discussed. This research provides the opportunity for the lubricant application of MWCNTs.


2016 ◽  
Vol 51 (16) ◽  
pp. 2291-2300 ◽  
Author(s):  
Shadpour Mallakpour ◽  
Samaneh Soltanian

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.


2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Liu ◽  
Chunli Guo ◽  
Xiaojian Ma ◽  
Changhui Sun ◽  
Fengxia Li ◽  
...  

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.


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

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.


1994 ◽  
Vol 359 ◽  
Author(s):  
Supapan Seraphin ◽  
Dan Zhou ◽  
Jun Jiao

ABSTRACTUsing a boron-containing composite anode in an arc discharge, we found in the soot on the reactor walls graphitic multiwalled carbon clusters that contained boron carbide crystals, as identified by high resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), and electron diffraction. The encapsulants are compounds of the lightest element that has yet been encapsulated, and the first of the non-metallic. The multiwalled graphitic cages partially encapsulating the boron compounds have rarely been observed in the soot of arc-discharge material produced from anodes not containing boron. We explain this exception by the known tendency of boron to catalyze graphitization.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Aasem Zeino ◽  
Abdalla Abulkibash ◽  
Mazen Khaled ◽  
Muataz Atieh

The raw carbon nanotubes (CNTs) were prepared by the floating catalyst chemical vapor deposition method. The raw carbon nanotubes were functionalized, impregnated with iron nanoparticles, and characterized using high resolution transmission electron microscopy (HRTEM), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). The three types of these multiwalled carbon nanotubes were applied as adsorbents for the removal of bromate from drinking water. The effects of the pH, the concentration ofBrO3-anion, the adsorbent dose, the contact time, and the coanions on the adsorption process have been investigated. The results concluded that the highest adsorption capacities were 0.3460 and 0.3220 mg/g through using CNTs-Fe and raw CNTs, respectively, at the same conditions. The results showed that the CNTs-Fe gives higher adsorption capacity compared with the raw CNTs and the functionalized CNTs. The presence of nitrate (NO3-) in the solution decreases the adsorption capacity of all CNTs compared with chloride (Cl-) associated with pH adjustment caused by nitric acid or hydrochloric acid, respectively. However, the adsorption of all MWNCTs types increases as the pH of solution decreases.


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