scholarly journals Effects of Increasing Electrodes on CNTs Yield Synthesized by Using Arc-Discharge Technique

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Samy Yousef ◽  
A. Khattab ◽  
T. A. Osman ◽  
M. Zaki

A new design of fully automatic system was built up to produce multiwalled carbon nanotube (MWCNT) using arc discharge technique in deionized water and extra pure graphite multiple electrodes (99.9% pure). The goal of the experimental research is to determine the yield of CNT in two different cases: (a) single plasma electrodes and (b) multiplasma electrodes, particularly 10 electrodes. The experiments were performed at constant parameters (75 A, 238 V). The obtained CNT was examined by scanning electron microscope (SEM), transmission electron microscope (HRTEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results showed that the produced CNT is of type MWCNT, with a diameter of 5 nm, when using multiplasma electrodes and 13 nm when using single plasma electrodes. The yield of MWCNT was found to be 320% higher in case of comparing multielectrodes to that of single plasma electrodes. Under the experimental test conditions, a yield of 0.6 g/hr soot containing 40% by mass nanotube was obtained in case of single plasma electrodes and above 60% in case of multiplasma electrodes.

2021 ◽  
Vol 2114 (1) ◽  
pp. 012041
Author(s):  
Nada. K. Hussein ◽  
S.J. Kadhem

Abstract The aim of this research is to study the optical properties of carbon-magnesium plasma resulting from arc discharge with explosive wire technique, where the energy gap of each of carbon and magnesium and the carbon-magnesium bond for three values of the wire exploding current (50,75,100 amperes) was studied. It was found that the energy gap for each of carbon and magnesium decreases with increasing the current, the X-ray diffraction of magnesium and the carbon-magnesium suspension was studied, and FTIR of the carbon-magnesium suspended carbon was studied for three values of the exploding current (50, 75, 100 amperes) and the type of bonds for carbon and magnesium was determined. To obtain deeper insight about the morphology and size distribution of the nano rods obtained from the explosion of a magnesium strip in a carbon suspension images obtained from transmission electron microscope (TEM) image analysis confirmed that the formed nanomaterial is rod-shaped.


2021 ◽  
Author(s):  
Yan Chen ◽  
Yuemei Lan ◽  
Dong Wang ◽  
Guoxing Zhang ◽  
Wenlong Peng ◽  
...  

A series of Gd2-xMoO6:xEu3+(x=0.18-0.38) nanophosphors were synthesized by the solvothermal method. The properties of this nanophosphor were characterized by x-ray diffraction (XRD), transmission electron microscope (TEM), fluorescence spectra and diffuse...


2011 ◽  
Vol 80-81 ◽  
pp. 217-220 ◽  
Author(s):  
Xue Qing Yue ◽  
Hai Jun Fu ◽  
Da Jun Li

Graphite encapsulated nickel nanoparticles were prepared by ball milling andsubsequently annealing a mixture of expanded graphite with nickel powders. The products were characterized by transmission electron microscope and X-ray diffraction. The formation mechanism of the products was discussed. Results show that the products have a size range of 20-150 nm. The graphite and nickel in the products all exhibit a high crystallinity.


2011 ◽  
Vol 236-238 ◽  
pp. 1712-1716 ◽  
Author(s):  
Hai Tao Liu ◽  
Jun Dai ◽  
Jia Jia Zhang ◽  
Wei Dong Xiang

Bismuth selenide (Bi2Se3) hexagonal nanosheet crystals with uniform size were successfully prepared via a solvothermal method at 160°C for 22 h using bismuth trichloride(BiCl3) and selenium powder(Se) as raw materials, sodium bisulfite(NaHSO3) as a reducing agent, diethylene glycol(DEG) as solvent, and ammonia as pH regulator. Various techniques such as X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) were used to characterize the obtained products. Results show that the as-synthesized samples are pure Bi2Se3 hexagonal nanosheet crystals. A possible growth mechanism for Bi2Se3 hexagonal nanosheet crystals is also discussed based on the experiment.


2011 ◽  
Vol 311-313 ◽  
pp. 1713-1716 ◽  
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Chang An Wang ◽  
Li Guo Ma ◽  
Feng Liu

Nano-hydroxyapatite with different morphology was synthesized by the co-precipitation method coupled with biomineralization using Ca(NO3)2•4H2O and (NH4)2HPO4 as reagents, adding chondroitin sulfate, agarose and aspartic acid as template. The structure and morphology of the prepared powders were characterized by X-ray diffraction (XRD) and transmission electron microscope (TEM).


Nanopages ◽  
2019 ◽  
pp. 1-11
Author(s):  
G. M. Taha ◽  
M. N. Rashed ◽  
M. S. El-Sadek ◽  
M. A. Moghazy

Abstract BiFeO3 (BFO) nanopowder was synthesized in a pure form via a sol- gel method based on glycol gel reaction. Effect of drying and preheating temperature on preventing other phases was studied. Many parameters were studied as calcination temperature and time & stirring temperature as well. The prepared powder was characterized by X-Ray Diffraction of powder (XRD) and Transmission Electron Microscope (TEM). High pure BiFeO3 was obtained by preheated process at 400 °C for 0.5 h and calcination at 600 °C for 0.5 h without any impurities compared to dry at110 °C.


NANO ◽  
2013 ◽  
Vol 08 (04) ◽  
pp. 1350038 ◽  
Author(s):  
JIANQUAN LI ◽  
HUASHI LIU ◽  
JIANING LI ◽  
GUOZHONG LI

Zn was firstly used to improve wear resistance of a TA7 (Ti–5Al–2.5Sn) titanium alloy surface by mean of a laser alloying (LA) technique. The synthesis of the hard coating on a TA7 titanium alloy by LA of Co–Ti–Cr–TiB2–Zn–CeO2 pre-placed powders was investigated by means of scanning electron microscope (SEM), X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM). Experimental results indicated lot of the nanocrystals, such as Ti–B/CoZn13 and the amorphous phases were produced in such LA coating. The nucleation and growth of the amorphous phases were retarded by the nanocrystals in a certain extent during the crystallization process of the amorphous phases. Compared with a TA7 alloy substrate, an improvement of the wear resistance was obtained for such LA composite coating.


2018 ◽  
Vol 42 (19) ◽  
pp. 16307-16328 ◽  
Author(s):  
Mohammad Hassan Omidi ◽  
Mohammad Hossein Ahmadi Azqhandi ◽  
Bahram Ghalami-Choobar

In this study, branched polyethylenimine (PEI) loaded on magnetic multiwalled carbon nanotubes (MWCNT/CoFe2O4) was synthesized and characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) analysis and Fourier transform infrared spectroscopy (FTIR).


2021 ◽  
Vol 16 (3) ◽  
pp. 363-367
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Tao Tian ◽  
Shanyu Liu ◽  
...  

Accurate and real-time detection of formaldehyde (HCHO) in indoor air is urgently needed for human health. In this work, a ceramic material (WO3·H2O) with unique structure was successfully prepared using an efficient hydrothermal method. The crystallinity, morphology and microstructure of the as-prepared sensing material were analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) as well as transmission electron microscope (TEM). The characterization results suggest that the as-prepared sample is composed of square-like nanoplates with uneven surface. Formaldehyde vapor is utilized as the target gas to investigate gas sensing properties of the synthesized novel nanoplates. The testing results indicate that the as-fabricated gas sensor exhibit high gas response and excellent repeatability to HCHO gas. The response value (Ra/Rg) is 24.5 towards 70 ppm HCHO gas at 350 °C. Besides, the gas sensing mechanism was described.


1999 ◽  
Vol 14 (5) ◽  
pp. 1782-1790 ◽  
Author(s):  
X. L. Dong ◽  
Z. D. Zhang ◽  
S. R. Jin ◽  
W. M. Sun ◽  
X. G. Zhao ◽  
...  

Ultrafine Fe–Ni(C) particles of various compositions were prepared by arc discharge synthesis in a methane atmosphere. The particles were characterized by x-ray diffraction, transmission electron microscopy, energy disperse spectroscopy, chemical analysis, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and magnetization measurement. The carbon atoms solubilizing at interstitial sites in γ–(Fe, Ni, C) solution particles have the effects of forming austenite structure and changing microstructures as well as magnetic properties. A carbon layer covers the surface of Fe–Ni(C) particles to form the nanocapsules and protect them from oxidization. The mechanism of forming Fe–Ni(C) nanocapsules in the methane atmosphere was analyzed.


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