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Synthesis and characterization of carbon-stabilized magnesium nanoparticles
, Article Journal of Cluster Science ; 2016 , Pages 1-9 ; 10407278 (ISSN) ; Asgari, F ; Arzi, M ; Hojaji, A ; Sadrnezhaad, S. K ; Sharif University of Technology
Springer New York LLC
2016
Abstract
Magnesium nanopowder has attracted many interests in the recent years, which has a very difficult and costly synthesis process because of its high activity. In this work, magnesium nanoparticles stabilized with amorphous carbon (Mg–C nanoparticles) were synthesized by submerged arc discharge technique in kerosene. The arc discharge was generated between two electrodes of magnesium at the arc current of 1 A and arc voltage of 50 V. Mg–C nanoparticles were characterized by various techniques. Dynamic light scattering result indicated that size of magnesium nanoparticles is about 35 nm. X-ray diffraction showed that the produced sample consisted of hexagonal magnesium and amorphous carbon and...
Synthesis and characterization of carbon-stabilized magnesium nanoparticles
, Article Journal of Cluster Science ; Volume 28, Issue 3 , 2017 , Pages 881-889 ; 10407278 (ISSN) ; Asgari, F ; Arzi, M ; Hojaji, A ; Sadrnezhaad, S. K ; Sharif University of Technology
Springer New York LLC
2017
Abstract
Magnesium nanopowder has attracted many interests in the recent years, which has a very difficult and costly synthesis process because of its high activity. In this work, magnesium nanoparticles stabilized with amorphous carbon (Mg–C nanoparticles) were synthesized by submerged arc discharge technique in kerosene. The arc discharge was generated between two electrodes of magnesium at the arc current of 1 A and arc voltage of 50 V. Mg–C nanoparticles were characterized by various techniques. Dynamic light scattering result indicated that size of magnesium nanoparticles is about 35 nm. X-ray diffraction showed that the produced sample consisted of hexagonal magnesium and amorphous carbon and...
Physical properties of sputtered amorphous carbon coating
, Article Journal of Alloys and Compounds ; Volume 513 , 2012 , Pages 135-138 ; 09258388 (ISSN) ; Larijani, M. M ; Afshar, A ; Eshghabadi, M ; Shokouhy, A ; Sharif University of Technology
Abstract
In this study the effect of deposition temperature and thickness on the physical properties of carbon films deposited by magnetron sputtering PVD was investigated. The results of Raman spectra and grazing incidence XRD (GIXRD) patterns show that the graphitization increases by increasing the deposition temperature. There is a change in deposition mechanism at 400 °C from amorphous carbon deposition to nano-structured graphite deposition. Also by increasing substrate temperature the electrical resistance of carbon films reduces significantly up to 300 °C and then remains largely constant. High intrinsic compressive stress in low temperature deposited carbon films causes cracks and...
A comparison of carbon coated and uncoated 316L stainless steel for using as bipolar plates in PEMFCs
, Article Journal of Alloys and Compounds ; Volume 509, Issue 27 , July , 2011 , Pages 7400-7404 ; 09258388 (ISSN) ; Yari, M ; Afshar, A ; Jafarian, M ; Eshghabadi, M ; Sharif University of Technology
2011
Abstract
Two kinds of carbon coated and uncoated 316L stainless steel are studied to use as bipolar plates in fuel cells. The results show that the conductive amorphous carbon film has a low corrosion rate in simulated PEMFC environment. Rather long term potentiostatic tests and SEM investigations indicate that carbon thin films can be a good candidate to use as bipolar plate
Morphology, optical and electrical properties of Cu-Ni nanoparticles in a-C:H prepared by co-deposition of RF-sputtering and RF-PECVD
, Article Applied Surface Science ; Volume 258, Issue 2 , 2011 , Pages 727-731 ; 01694332 (ISSN) ; Vesaghi, M. A ; Gelali, A ; Zahrabi, H ; Solaymani, S ; Sharif University of Technology
Abstract
We report optical and electrical properties of Cu-Ni nanoparticles in hydrogenated amorphous carbon (Cu-Ni NPs @ a-C:H) with different surface morphology. Ni NPs with layer thicknesses of 5, 10 and 15 nm over Cu NPs @ a-C:H were prepared by co-deposition of RF-sputtering and RF-Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) from acetylene gas and Cu and Ni targets. A nonmetal-metal transition was observed as the thickness of Ni over layer increases. The surface morphology of the sample was described by a two dimensional (2D) Gaussian self-affine fractal, except the sample with 10 nm thickness of Ni over layer, which is in the nonmetal-metal transition region. X-ray diffraction profile...
Coating of graphite flakes with MgO/carbon nanocomposite via gas state reaction
, Article Journal of Alloys and Compounds ; Volume 500, Issue 1 , June , 2010 , Pages 74-77 ; 09258388 (ISSN) ; Faghihi Sani, M. A ; Golestani Fard, F ; Saberi, A ; Soltani, A. K ; Sharif University of Technology
2010
Abstract
Coating of graphite flakes with MgO/carbon nanocomposite was carried out via gaseous state reaction between mixture of Mg metal, CO gas and graphite flakes at 1000 °C. XRD and FE-SEM analysis of coating showed that the coating was comprised of MgO nano particles and amorphous carbon distributed smoothly and covered the graphite surface evenly. Thermodynamic calculations were employed to predict the reaction sequences as well as phase stability. The effect of coating on water wettability and oxidation resistance of graphite was studied using contact angle measurement and TG analysis, respectively. It was demonstrated that the reaction between Mg and CO could result in MgO/C nanocomposite...
SnO2@a-Si core-shell nanowires on free-standing CNT paper as a thin and flexible Li-ion battery anode with high areal capacity
, Article Nanotechnology ; Volume 28, Issue 25 , 2017 ; 09574484 (ISSN) ; Sadati Faramarzi, M ; Abdollahi, A ; Ramzani, R ; Ghasemi, S ; Sanaee, Z ; Sharif University of Technology
Institute of Physics Publishing
2017
Abstract
Here, we report 3D hierarchical SnO2 nanowire (NW) core-amorphous silicon shell on free-standing carbon nanotube paper (SnO2@a-Si/CNT paper) as an effective anode for flexible lithium-ion battery (LIB) application. This binder-free electrode exhibits a high initial discharge capacity of 3020 mAh g-1 with a large reversible charge capacity of 1250 mAh g-1 at a current density of 250 mA g-1. Compared to other SnO2 NW or its core-shell nanostructured anodes, the fabricated SnO2@a-Si/CNT structure demonstrates an outstanding performance with high mass loading (∼5.9 mg cm-2), high areal capacity (∼5.2 mAh cm-2), and large volumetric capacity (∼1750 mAh cm-3) after 25 cycles. Due to the...
Fabrication and characterization of graphene-based carbon hollow spheres for encapsulation of organic corrosion inhibitors
, Article Chemical Engineering Journal ; Volume 352 , 2018 , Pages 909-922 ; 13858947 (ISSN) ; Ramazani, S. A. A ; Mahdavian, M ; Taheri, P ; Mol, J. M. C ; Sharif University of Technology
Elsevier B.V
2018
Abstract
In this work, we synthesized carbon hollow spheres (CHSs) using the silica templating method, encapsulated 2-mercaptobenzimidazole (MBI) inhibitor in the CHSs and evaluated their corrosion inhibition performance upon exposure of mild steel to a saline solution containing the released inhibitor. The effects of silica template surface modification on the CHS structure was evaluated, while the structure and morphology of the synthesized CHS was analyzed using field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), Raman spectroscopy and X-ray diffraction (XRD) spectroscopy. Furthermore, thermogravimetric analysis (TGA), energy-dispersive X-ray spectroscopy...
Nanostructural study of NiTi–TiO2–C core–shell nanoparticles generated by spark discharge method
, Article Applied Physics A: Materials Science and Processing ; Volume 124, Issue 9 , 2018 ; 09478396 (ISSN) ; Sabzehparvar, M ; Sadrnezhaad, S. K ; Amin, M. H ; Sharif University of Technology
Springer Verlag
2018
Abstract
Abstract: Nickel–titanium (NiTi) nanoparticles are ultrafine smart materials manifesting shape memory effect at very small scales. We have produced NiTi nanoparticles surrounded by an amorphous carbon shell using an innovative spark discharge system. The resulting nanoparticles were studied using various characterization methods to systematically study their size, morphology, size distribution, composition, structure, and thermal behavior. Field-emission scanning electron microscopy and dynamic light-scattering results indicated that the average size of the produced nanoparticles was about 13 nm. High-resolution transmission electron microscopy, energy-dispersive spectroscopy (EDS), and...