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reduced-graphene-oxides
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Synthesis and cyto-genotoxicity evaluation of graphene on mice spermatogonial stem cells
, Article Colloids and Surfaces B: Biointerfaces ; Volume 146 , 2016 , Pages 770-776 ; 09277765 (ISSN) ; Akhavan, O ; Shamsara, M ; Daliri, M ; Dashtizad, M ; Farmany, A ; Sharif University of Technology
Elsevier
2016
Abstract
The present study analyzed the dose-dependent cyto- and genotoxicity of graphene oxide and reduced graphene oxide on spermatogonial stem cells (SSCs) for the first time. The results showed that graphene oxide significantly increased oxidative stress at concentrations of 100 and 400 μg/ml, while low concentrations did not have a significant effect. In addition, according to the MTT assay, the cell number decreased in high-concentration (100 and 400 μg/ml) graphene oxide-treated samples compared to untreated cells. However, a reduced graphene-treated sample demonstrated a significant increase in cell number. Moreover, microscopic analysis found high concentrations of graphene nanosheets in...
Fabrication of new magnetite-graphene nanocomposite and comparison of its laser-hyperthermia properties with conventionally prepared magnetite-graphene hybrid
, Article Materials Science and Engineering C ; Volume 75 , 2017 , Pages 572-581 ; 09284931 (ISSN) ; Moradi, S ; Azizi, F ; Outokesh, M ; Shadanfar, K ; Mousavi, S. S ; Sharif University of Technology
Abstract
A single step supercritical method was introduced for synthesis of “magnetite - reduced graphene oxide (M-rGO)” composite in supercritical methanol. Modified surface, smaller size, lesser cytotoxicity, and homogenous dispersion of Fe3O4 nanoparticles on the graphene surface were advantages of this new M-rGO composite in comparison to the materials synthesized by conventional wet chemical method (M-GO). Nanocomposites were injected in tissue equivalent phantoms of agarose gel in 10 mg/g dosage, and were irradiated by a 1600 mW laser beam at wavelength of 800–810 nm. The M-rGO and M-GO were found to be the most and the least efficient samples for increasing the temperature of the phantom. As...
Heat transfer and entropy generation analysis of hybrid graphene/Fe3O4 ferro-nanofluid flow under the influence of a magnetic field
, Article Powder Technology ; Volume 308 , 2017 , Pages 149-157 ; 00325910 (ISSN) ; Sadeghinezhad, E ; Akhiani, A. R ; Tahan Latibari, S ; Metselaar, H. S. C ; Kherbeet, A. S ; Mehrali, M ; Sharif University of Technology
Elsevier B.V
2017
Abstract
The heat transfer characteristics and entropy generation rate of hybrid graphene-magnetite nanofluids under forced laminar flow that subjected to the permanent magnetic fields were investigated. For this purpose, a nanoscale reduced graphene oxide-Fe3O4 hybrid was synthesized by using graphene oxide, iron salts and tannic acid as the reductant and stabilizer. The thermophysical and magnetic properties of the hybrid nanofluid have been widely characterized and thermal conductivity has shown an enhancement of 11%. The experimental results indicated that the heat transfer enhancement of hybrid magnetite nanofluid compared to the case of distilled was negligible when no magnetic field was...
Nanocomposite with promoted electrocatalytic behavior based on bimetallic pd-ni nanoparticles, manganese dioxide, and reduced graphene oxide for efficient electrooxidation of ethanol
, Article Journal of Physical Chemistry C ; Volume 122, Issue 18 , 2018 , Pages 9783-9794 ; 19327447 (ISSN) ; Shahrokhian, S ; Amini, M. K ; Sharif University of Technology
American Chemical Society
2018
Abstract
In this work, a nanocomposite containing manganese dioxide (MnO2) modified reduced graphene oxide (rGO) supported bimetallic palladium-nickel (Pd-Ni) catalyst is prepared by electrodeposition method. The nanocomposite modifier film is prepared by forming a thin layer of graphene oxide (GO) via drop-casting of GO nanosheet dispersion on glassy carbon electrode (GCE), followed by electrochemical reduction of the film to provide rGO/GCE. Then, a two-step potential procedure is applied to deposit MnO2 nanoparticles on rGO/GCE. At the optimum deposition conditions, MnO2 nanoparticles with a thickness of 30-50 nm homogeneously covered the rGO surface (MnO2/rGO/GCE). Finally, the bimetallic Pd-Ni...
Synthesis and properties of Ce-doped TiO2-reduced graphene oxide nanocomposite
, Article Journal of Alloys and Compounds ; Volume 742 , 2018 , Pages 986-995 ; 09258388 (ISSN) ; Nemati, A ; Bagherzadeh, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
A nanocomposite of Ce-doped TiO2-reduced graphene oxide (CedT/RGO) was synthesized to evaluate the synergistic effects of constituents on electrical and photoelectric properties. The nanoparticles of titania and CedT were synthesized via the sol-gel method. Then, RGO was prepared using a new version derived from the Hammer's method and hydrothermal methods. Finally, CedT/RGO nanocomposite was synthesized applying hydrothermal method. The nanoparticles and nanocomposite were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy and elemental mapping. Then, diffuse reflectance and...
Magnetic hyperthermia behaviour of Co and reduced GO nanocomposites
, Article Micro and Nano Letters ; Volume 15, Issue 4 , April , 2020 , Pages 239-244 ; Sadrnezhaad, S. K ; Sharif University of Technology
Institution of Engineering and Technology
2020
Abstract
Co-precipitation of CoCl2.6H2O with graphene oxide (GO) and heating at 400°C for 4 h under hydrogen resulted in the construction of cobalt/ reduced GO (Co/rGO) nanocomposite utilisable in magnetic thermal therapy. Field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometry, thermogravimetric analysis/derivative thermogravimetry, and X-ray diffraction methods characterised the samples. Time-temperature curves of the samples containing 30, 50, 70, and 100 µg ml−1 Co/rGO nanoparticles (NPs) suspended in phosphate-buffered saline were determined at different specific heating rates. Magnetic-field response of...
Nanofibrillated chitosan coated highly ordered titania nanotubes array/graphene nanocomposite with improved biological characters
, Article Carbohydrate Polymers ; Volume 254 , 2021 ; 01448617 (ISSN) ; Bagheri, R ; Heidarpour, H ; Vossoughi, M ; Golizadeh, M ; Samadikuchaksaraei, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Designing multifunctional surfaces is key to develop advanced materials for orthopedic applications. In this study, we design a double-layer coating, assembled onto the completely regular titania nanotubes (cRTNT) array. Benefiting from the biological and topological characteristics of chitosan nanofibers (CH) and reduced graphene oxide (RGO) through a unique assembly, the designed material features promoted osteoblast cell viability, prolonged antibiotic release profile, as well as inhibited bacterial biofilm formation. The synergistic effect of RGO and CH on the biological performance of the surface is investigatSed. The unique morphology of the nanofibers leads to the partial coverage of...
Vertically standing Cu2O nanosheets promoted flower-like PtPd nanostructures supported on reduced graphene oxide for methanol electro-oxidation
, Article Electrochimica Acta ; Volume 259 , 2018 , Pages 36-47 ; 00134686 (ISSN) ; Rezaee, S ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The present study reports a simple electrochemical approach to the fabrication of a new nanocomposite containing PtPd nanoflowers (NFs) promoted with two-dimensional (2D) nanosheets (NSs) structure cuprous oxide (Cu2O) supported on reduced graphene oxide (rGO) (PtPd-NFs/Cu2O-NSs/rGO). Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectra, Raman spectroscopy, and energy dispersive X-ray spectroscopy are used for characterization of the PtPd-NPs/Cu2O-NPs/rGO. SEM images showed that vertical-standing arrays of Cu2O with an edge length up to 1 μm and thickness of about 20 nm are electrodeposited on the surface of rGO film. Also, PtPd needle-like NFs with visible and...
Nickel molybdate nanorods supported on three-dimensional, porous nickel film coated on copper wire as an advanced binder-free electrode for flexible wire-type asymmetric micro-supercapacitors with enhanced electrochemical performances
, Article Journal of Colloid and Interface Science ; Volume 542 , 2019 , Pages 325-338 ; 00219797 (ISSN) ; Shahrokhian, S ; Sharif University of Technology
Academic Press Inc
2019
Abstract
Wire-shaped micro-supercapacitors attracted extensive attentions in next-generation portable and wearable electronics, due to advantages of miniature size, lightweight and flexibility. Herein, NiMoO 4 nanorods supported on Ni film coated Cu wire are successfully fabricated thorough direct deposition of Ni film onto Cu wire as the conductive substrate, followed by growth of the NiMoO 4 nanorods on Ni film coated Cu wire substrate by means a hydrothermal annealing process. The prepared 3D, porous electrode demonstrates extremely high areal specific capacitance of 12.03F cm −2 at the current density of 4 mA cm −2 and retained capacitance of 8.23 F cm −2 at a much higher current density of 80...
Electrospun Ag-decorated reduced GO-graft-chitosan composite nanofibers with visible light photocatalytic activity for antibacterial performance
, Article Chemosphere ; Volume 299 , 2022 ; 00456535 (ISSN) ; Mohammadi Ziarani, G ; Badiei, A ; Setayeshmehr, M ; Kiani, M ; Pourjavadi, A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The treatment of water contaminated by bacteria is becoming a necessity. The nanomaterials possessing both intrinsic antibacterial properties and photocatalytic activity are excellent candidates for water disinfection. The powdered form of nanomaterials can be aggregated while embedding the nanomaterials into the NFs can overcome the limitation and enhance the photocatalytic activity and transition from UV-light to visiblelight. Here, graphene oxide (GO) was synthesized, grafted to chitosan, and decorated with silver nanoparticles (Ag NPs) to produce Ag-decorated reduced GO-graft-Chitosan (AGC) NPs. The blends of polyacrylonitrile (PAN) and AGC NPs were prepared in various concentrations of...