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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Ultrafine Grained and Nanostructured Materials
- نوع مقاله: Journal Article
- کلمات کلیدی: corrosion,Nanocomposite,aluminum,Electrolyte,Plasma Electrolytic Oxidation,nickel sulfate
- چکیده:
- چکیده انگلیسی: Plasma electrolytic oxidation (PEO) was performed on a 1010 Aluminum alloy. To achieve the
nanocomposite structure, Si3N4 nanoparticles were added into the electrolyte. In an alkaline aqueous
suspension (silicate-based), the effect of adding NiSO4 on the applied voltage, microstructure,
composition, wear, and corrosion resistance of PEO coatings was investigated using Scanning
Electron Microscopy (SEM), elemental analysis with Energy Dispersive Spectroscopy (EDS), X-Ray
Diffraction (XRD), cyclic polarization test, and pin-on-disk wear test. The results showed that adding
nickel sulfate (NiSO4) and infiltration of its constituents into coatings lead to a more favored corrosion
behavior. Moreover, in the case of best sample, anodic current at the highest applied potential
condition during the cyclic polarization test indicated a drop within two decades. Moreover,
coefficient of friction decreased almost by half.- انتشار مقاله: 10-05-1394
- نویسندگان: Ali Abolhasani,Mahmood Aliofkhazraei,Seyed Saeed Farhadi,Alireza Sabour Rouhaghdam,Masoud Asgari
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Nano Dimension
- نوع مقاله: Journal Article
- کلمات کلیدی: Antibacterial activity,silver nanoparticles,hydroxyapatite,Nitro reduction,Graphene oxide nanosheets,Ternary nanocomposite
- چکیده:
- چکیده انگلیسی: In this paper, a novel ternary nanocomposite namely reduced graphene oxide/hydroxyapatite/silver (rGO/HAP/Ag) was prepared by a simple hydrothermal method using graphene oxide nanosheets, Ca(NO3)2, (NH4)2HPO4, and AgNO3 as starting materials. The as-prepared nanocomposite was characterized by using various photophysical techniques including Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). Additionally, the antibacterial and catalytic activities of the nanocomposite were evaluated. The results showed that the rGO/HAP/Ag nanocomposite exhibited high performance in the reduction of toxic nitro compounds (4-nitrophenol, 2-nitrophenol, 4-nitroaniline, and 2-nitroaniline) into the less toxic corresponding amines using NaBH4 within 21-42 min with a rate constant equal to 0.1646, 0.0898, 0.1071 and 0.2 min-1, respectively. Moreover, the rGO/HAP/Ag nanocomposite could be separated from the reaction mixture due to its heterogeneous nature and reused without any change in structure. In addition, the antibacterial activity of the rGO/HAP/Ag nanocomposite by disk diffusion method was evaluated against Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Klebsiella pneumonia). The results showed that this novel ternary nanocomposite has good antibacterial activity against Gram-positive bacteria.
- انتشار مقاله: 22-03-1397
- نویسندگان: Maryam Beiranvand,Saeed Farhadi,Abdelnassar Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Nano Dimension
- نوع مقاله: Journal Article
- کلمات کلیدی: Photocatalytic degradation,Microwave Irradiation,Transition metal oxides,Co3O4 nanorods,Methylene blue dye
- چکیده:
- چکیده انگلیسی: In this work, Co3O4 nanorods were successfully prepared by microwave-assisted solid state decomposition of rod-like CoC2O4.2H2O precursor within a very short reaction time (6 min) without the use of a solvent/surfactant and complicated equipment. The as-obtained Co3O4 nanorods were fully characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet–visible spectroscopy (UV–Vis), energy-dispersive X-ray spectroscopy (EDX), and magnetic measurements. TEM and SEM images showed that the Co3O4 nanorods have a length of 1-3 µm and diameter of 40-80 nm. FT-IR, XRD, EDX and selected-area electron diffraction demonstrated that the nanorods are composed of pure cubic phase Co3O4. Magnetic measurements at room temperature suggested the existence of a weak ferromagnetic behavior. The optical spectrum indicated two direct band gaps at 2.20 and 3.60 eV with a blue shift compared with the bulk sample. The photocatalytic activity of Co3O4 nanorods was investigated for the degradation of methylene blue (MB) as a model of dye pollutants in the presence of H2O2 as a green oxidant. The Co3O4 nanorods showed high efficiency for the degradation of MB dye by using H2O2 under visible light irradiation. Trapping experiments indicated that hydroxyl (•OH) radicals were the main reactive species for dye degradation in the present photocatalytic system. In addition, the possible photodegradation mechanism was also proposed based on the trapping experiment results.
- انتشار مقاله: 26-03-1396
- نویسندگان: Sadigheh Bazgir,Saeed Farhadi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Nano Dimension
- نوع مقاله: Journal Article
- کلمات کلیدی: Antibacterial activity,Catalyst,silver nanoparticles,Phyto-synthesis,Grape fruit extract,Nitro reduction
- چکیده:
- چکیده انگلیسی: In this research, silver nanoparticles (Ag NPs) were prepared by a low-cost, rapid, simple and ecofriendly approach using Grape fruit extract as a novel natural reducing and stabilizing agent. The product was characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX) spectroscopy and transmission electron microscopy (TEM). The reaction conditions including time, content of reducing agent and silver nitrate, temperature and pH were investigated. The optimum yield of Ag NPs was obtained when 10 mM of silver nitrate was reacted with 9 mL of Grape fruit extract at pH = 9 and heated it to 55 oC within 25 minutes. The crystalline nature of Ag NPs was confirmed from XRD analysis. SEM and TEM images showed that the obtained Ag NPswere spherical in shape and their sizes were in the range of 25-85 nm. EDX analysis confirmed presence of the elemental silver. On the basis of FT-IR analysis, it can be stated that the hydroxyl, carbonyl and carboxyl functional groups present in bio-molecules of Grape fruit extract are responsible for the reduction of Ag+ ions and stabilization of the obtained Ag NPs. The biosynthesized Ag NPs showed good antimicrobial activity against Gram-positive (Bacillus cereus, Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative (Escherichia coli, Klebsiella pneumoniae)bacteria. In addition, the catalytic activity of the Ag NPs wasstudied for the reduction of nitro compounds by using NaBH4.
- انتشار مقاله: 14-06-1395
- نویسندگان: Saeed Farhadi,Bahram Ajerloo,Abdelnassar Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: International Journal of Nano Dimension
- نوع مقاله: Journal Article
- کلمات کلیدی: Co3O4 nanoparticles,Energetic complexes,Ferromagnetic order, Pentamminecobalt(III) complex,Thermolysis method,Transition metal oxides
- چکیده:
- چکیده انگلیسی: In this paper, an energetic coordination compound namely pentamminenitratocobalt(III) nitrate, [Co(NH3)5(NO3)](NO3)2, was used as a new precursor for the preparation of Co3O4 nanoparticles. The results showed that the complex is easily decomposed into the Co3O4 nanoparticles at low temperature (200 °C) without employing a surfactant or solvent and any complicated equipment. The product was characterized by differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX). Optical and magnetic properties of the product were studied by UV-visible (UV-vis) spectroscopy and a vibrating sample magnetometer (VSM), respectively. FT-IR, XRD and EDS analyses confirmed the formation of highly pure spinel-type Co3O4 phase with cubic structure. TEM images showed that the Co3O4 nanoparticles are approximately in the range of 10 to 24 nm with a mean size of around 17 nm. The optical spectrum of the Co3O4 nanoparticles revealed the presence of two band gaps at 3.45 and 2.20 eV which are blue-shifted relative to reported values for the bulk sample. The magnetic measurement of the product showed a weak ferromagnetic order at room temperature.
- انتشار مقاله: 08-11-1394
- نویسندگان: Saeed Farhadi,Gholamali Nadri,Masoumeh Javanmard
- مشاهده
- جایگاه : پژوهشی
- مجله: Biofuel Research Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: Fuel cell,Proton Exchange Membrane,Organic-inorganic nanocomposite,Inorganic fillers
- چکیده:
- چکیده انگلیسی: Combination of inorganic fillers into organic polymer membranes (organic–inorganic hybrid membranes) has drawn a significant deal of attention over the last few decades. This is because of the incorporated influence of the organic and inorganic phases towards proton conductivity and membrane stability, in addition to cost decline, improved water retention property, and also suppressing fuel crossover by increasing the transport pathway tortuousness. The preparation methods of the composite membranes and the intrinsic characteristics of the used particles as filler, such as size, type, surface acidity, shape, and their interactions with the polymer matrix can significantly affect the properties of the resultant matrix. The membranes currently used in proton exchange membrane fuel cells (PEMFCs) are perfluorinated polymers containing sulfonic acid, such as Nafion®. Although these membranes possess superior properties, such as high proton conductivity and acceptable chemical, mechanical, and thermal stability, they suffer from several disadvantages such as water management, CO poisoning, and fuel crossover. Organic-inorganic nanocomposite PEMs offer excellent potentials for overcoming these shortcomings in order to achieve improved FC performance. Various inorganic fillers for the fabrication of composite membranes have been comprehensively reviewed in the present article. Moreover, the properties of polymer composites containing different nanoparticles have been thoroughly discussed.
- انتشار مقاله: 25-06-1395
- نویسندگان: Kolsoum Pourzare,Yaghoub Mansourpanah,Saeed Farhadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Biofuel Research Journal
- نوع مقاله: Journal Article
- کلمات کلیدی: Fuel cell,Proton Exchange Membrane,Organic-inorganic nanocomposite,Inorganic fillers
- چکیده:
- چکیده انگلیسی: Combination of inorganic fillers into organic polymer membranes (organic–inorganic hybrid membranes) has drawn a significant deal of attention over the last few decades. This is because of the incorporated influence of the organic and inorganic phases towards proton conductivity and membrane stability, in addition to cost decline, improved water retention property, and also suppressing fuel crossover by increasing the transport pathway tortuousness. The preparation methods of the composite membranes and the intrinsic characteristics of the used particles as filler, such as size, type, surface acidity, shape, and their interactions with the polymer matrix can significantly affect the properties of the resultant matrix. The membranes currently used in proton exchange membrane fuel cells (PEMFCs) are perfluorinated polymers containing sulfonic acid, such as Nafion®. Although these membranes possess superior properties, such as high proton conductivity and acceptable chemical, mechanical, and thermal stability, they suffer from several disadvantages such as water management, CO poisoning, and fuel crossover. Organic-inorganic nanocomposite PEMs offer excellent potentials for overcoming these shortcomings in order to achieve improved FC performance. Various inorganic fillers for the fabrication of composite membranes have been comprehensively reviewed in the present article. Moreover, the properties of polymer composites containing different nanoparticles have been thoroughly discussed.
- انتشار مقاله: 25-06-1395
- نویسندگان: Kolsoum Pourzare,Yaghoub Mansourpanah,Saeed Farhadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Advanced Journal of Chemistry-Section A
- نوع مقاله: Journal Article
- کلمات کلیدی: Semicarbazone,Schiff base ligand,crystal structure,Spectroscopy
- چکیده:
- چکیده انگلیسی: In this work, pyridine 4-carbaldehye semicarbazone Schiff base ligand (HL) was synthesized with condention of pyridine 4-carbaldehyde and semicarbazide hydrochloride in reflux method. The HL was characterized using the CHN elemental analysis, FT-IR, UV-Vis, and 1H NMR spectroscopy. The single crystals of HL prepared and used for the X-ray crystallography. Single-crystal X-ray diffraction revealed that, HL crystallized in a triclinic system with the space group P-1. The FT-IR spectra and X-ray crystallography results suggested that the HL ligand is in keto form.
- انتشار مقاله: 18-08-1398
- نویسندگان: Farzaneh Mahmoudi,Saeed Farhadi,Michal Dusek,Morgane Poupon
- مشاهده