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دسترسی آزاد مقاله
1 - Comparison of the vanadyl-selective electrodes prepared by sol–gel and PVC membrane techniques
Masoud Giahi Mohammad Ali Bagherinia Azin AzariSol-gel and polymeric membrane electrodes, based on thiacalix[4]arene as a neutral carrier, weresuccessfully developed for the detection of VO2+ in aqueous solutions. The sol-gel and PVCmembrane electrodes exhibited linear response with Nernstian slopes of 29.3 and 28.4 چکیده کاملSol-gel and polymeric membrane electrodes, based on thiacalix[4]arene as a neutral carrier, weresuccessfully developed for the detection of VO2+ in aqueous solutions. The sol-gel and PVCmembrane electrodes exhibited linear response with Nernstian slopes of 29.3 and 28.4 mV perdecade, respectively, within the vanadyl ion concentration ranges from 1.0 × 10-6 to 1.0 × 10-1mol dm-3 and from 1.0 × 10-5 to 1.0 × 10-1 mol dm-3 for sol-gel and PVC membrane sensors.The PVC-based and sol-gel electrodes show detection limits of 3.1 × 10-6 and 4.9 × 10-7 mol dm-3, respectively, and also response time of about 15 s to achieve a 95% steady potential for VO2+concentration. By testing the stability lifetimes of the electrodes over a six-month period, nosignificant change was observed in the performance of the sol-gel electrode, however, the PVCbasedvanadyl-selective electrode exhibited a gradual decrease in the slope after two months.Investigating the influence of membrane composition, the pH of the test solution, and theinterfering ions on the electrodes performance revealed good selectivity of electrodes for a numberof alkali, alkaline earth, transition and heavy metal ions. The determined isothermal temperaturecoefficients of these electrodes showed a better thermal stability of sol-gel electrode rather thanthat of the PVC-based vanadyl-selective electrode, however, the electrodes performance isdeteriorated by temperatures higher than 50 °C. پرونده مقاله -
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2 - The comparison synthesis of CuNiO2 nanoparticles prepared by sol-gel auto-combu on, microwave and co-precipitation techniques
S. A. Khorrami N. Naderfa M. G. G MojadadThe CuNiCA nanopanicles have been synthesized by sol-gel auto-combusson. microwave and co-precipitationtechniques. Then, the results of the three techniques were compared. In the vol-ael auto-combustion synthesiswas used glycine as a fuel. At first, sol was prepared. Th چکیده کاملThe CuNiCA nanopanicles have been synthesized by sol-gel auto-combusson. microwave and co-precipitationtechniques. Then, the results of the three techniques were compared. In the vol-ael auto-combustion synthesiswas used glycine as a fuel. At first, sol was prepared. Then, gel was achieved from drying so'. The prepared gelwas burnt at 350°C. In the noicrowavc technique, gel was prepared. Then, the final nanoparticles were producedon influence of microwave irradiation. The CuNiO2 nanoparticles 'ere prepared by co-pAcipitation methodinvolved metal sulfates The temperature of calcmations was 620T. These minoparticles were investigated byX-ray diffraction (XRD) and Scanning Plectmn Microscopy (SEM) techniques. The XRD results show that thenangeryssil eon tat iis various phases. stnictures and the average size of MilliThIMCIIMA CuNi0: cry stallities wascalculated by Scherer equation. Scanning Electron Microscopy was also used to characterize the microstnic tareand morphology. پرونده مقاله -
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3 - Morphology investigation of alumina nano-powders prepared by a sol-gel combustion method
S. A. Khorrami R. Lotfi M. A. Baghchesara S. MoradiHighly sinterable alumina nano-powders have been synthesized by a sol-gel combustion method with glycine asfuel. The preparation involved the thermal decomposition of a chelating agent (fuel)-nitrate gel and theformation of amorphous precursors. The nanopowders calcined چکیده کاملHighly sinterable alumina nano-powders have been synthesized by a sol-gel combustion method with glycine asfuel. The preparation involved the thermal decomposition of a chelating agent (fuel)-nitrate gel and theformation of amorphous precursors. The nanopowders calcined at 1100°C were characterized by X-ray powderdiffraction (XRD) and Scanning Electron Microscopy (SEM). It was found that the chelating agent and fuelused had a significant influence on the average grain size of a-A1203 nanopowder. The rate of combustionreaction between chelating agent (fuel) and nitrate was responsible for the growth of the grain. پرونده مقاله -
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4 - Synthesis and Characterization of Doped TiO2 Nanoparticles by the Sol-Gel Method and Investigation of Photocatalytic Activity
S. Ghasemi R. Fazaeli M. YousefiCu2+,Ce3+-doped nanostructure TiO2 -coated Nd3+ (TiO2 /Nd3+) were prepared by sol-gel method. TiO2 were synthesized by the sol-gel method using tetra n-butyl orthotitanat (TBT) as a precursor. The prepared nanoparticles characterized by FT-IR, XRD, SEM- EDS and TEM. The چکیده کاملCu2+,Ce3+-doped nanostructure TiO2 -coated Nd3+ (TiO2 /Nd3+) were prepared by sol-gel method. TiO2 were synthesized by the sol-gel method using tetra n-butyl orthotitanat (TBT) as a precursor. The prepared nanoparticles characterized by FT-IR, XRD, SEM- EDS and TEM. The XRD showed that the major phase of nanocomposite is anatase. The morphology of the TiO2/Nd3+/Cu2+and TiO2 /Nd3+/Ce3+ microsphere was investigated using SEM. The TEM shows that the size of TiO2 /Nd3+/Cu2+and TiO2 / Nd3+/Ce3+were 8-10 nm. Moreover, particle shapes were spherical. IR spectrum indicated that Ti-O bond-formed in the chitosan-TiO2nano composite. Acid red 151(AR 151) removed photo-chemically by adding doped TiO2 nanoparticle and H2 O2 in the presence of the UV radiation. The results showed that the photo-degradation percentage decreased as oxidant concentration increases. The maximum degradation percentage (H2 O2 0.2M) was about 96% TiO2 / Nd3+catalyst. The result also showed that the kinetics model reaction in presence of both catalysts followed the fromof pseudo-second order equation presented by Blanchard. پرونده مقاله -
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5 - Eco-friendly Synthesis of Magnesium Oxide Nanoparticles using Arabic Gum
Saeid Taghavi Fardood Ali Ramazani Sang Woo JooMagnesium oxide nanoparticles were synthesized using Arabic gum as a biotemplate andmagnesium nitrate as the magnesium source by the sol-gel method. This method has manyadvantages such as nontoxic, economic viability, ease to scale up, less time consuming andenvironment چکیده کاملMagnesium oxide nanoparticles were synthesized using Arabic gum as a biotemplate andmagnesium nitrate as the magnesium source by the sol-gel method. This method has manyadvantages such as nontoxic, economic viability, ease to scale up, less time consuming andenvironmental friendly approach for the synthesis of MgO nanoparticles without using anyorganic chemicals. Nanoparticles were characterized by Fourier transform infrared (FT-IR)spectroscopy, UV-visible spectroscopy and powder X-ray diffraction (XRD). The averagecrystallite size of MgO nanoparticles was calculated using Scherrer formula and WilliamsonHall equation. The powder X-ray diffraction (XRD) analysis revealed the formation of cubicphase MgO with average particle size of 14 (Scherrer formula) and 5.3 (Williamson Hallequation) nm. پرونده مقاله -
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6 - Sol-gel Synthesis and Characterization of Zinc Oxide Nanoparticles Using Black Tea Extract
Saeid Taghavi Fardood Ali Ramazani Sang Woo JooThe use of plant extract is generating the interest of researchers toward cost effective,nontoxic, economic viability and eco-friendly green synthesis of nanoparticles. In the presentwork, zinc oxide (ZnO) nanoparticles were synthesized using black tea extract and zinc چکیده کاملThe use of plant extract is generating the interest of researchers toward cost effective,nontoxic, economic viability and eco-friendly green synthesis of nanoparticles. In the presentwork, zinc oxide (ZnO) nanoparticles were synthesized using black tea extract and zinc nitrateas the zinc source by the sol-gel method. The synthesized ZnO nanoparticles werecharacterized by powder X-ray diffraction (XRD), UV-visible spectroscopy and FourierTransform Infrared Spectroscopy (FTIR). The average crystallite size of ZnO nanoparticleswas calculated using Scherrer formula. The X-ray powder diffraction (XRD) analysisrevealed the formation of wurtzite hexagonal phase ZnO with average particle size of 32 nm. پرونده مقاله -
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7 - Photocatalytic Mineralization of Methylene BlueAqueous Solutions by Ag/TiO2 Nano Composite
Leila Torkian Ehsan AmerehNanocomposite of Ag/TiO2 and nanocrystalline TiO2 were prepared by using TiCl4 as a precursor in a simple sol-gel process. The prepared photo-catalysts were characterized by X-ray diffraction (XRD), scanning electron micrographs (SEM), energy dispersive X-ray microanaly چکیده کاملNanocomposite of Ag/TiO2 and nanocrystalline TiO2 were prepared by using TiCl4 as a precursor in a simple sol-gel process. The prepared photo-catalysts were characterized by X-ray diffraction (XRD), scanning electron micrographs (SEM), energy dispersive X-ray microanalysis (EDX), transmission electron microscopy (TEM) and diffuse reflectance spectroscopy (DRS). A complete and effective photocatalytic degradation of a cationic aromatic dye, Methylene blue, in aqueous solutions has been carried out using nanocomposite of Ag/TiO2 and nanocrystalline TiO2 under UV-C light irradiation. Experiments were conducted to compare the photocatalytic activities of nanocomposite Ag/TiO2 with nanocrystalline TiO2 . The photoreactions were followed by monitoring the degradation of the dye as a function of irradiation time, in the presence of the nanophoto-catalysts, by the visible/ultraviolet absorption spectroscopy. It has been found that the presence of silver in TiO2 nanoparticles reduces the duration of complete photocatalytic degradation of Methylene blue by 20% due to the enhancement of electron-hole separation by the electron trapping of silver particles. پرونده مقاله -
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8 - Green Synthesis of α-Fe2O (hematite) Nanoparticles using Tragacanth Gel
Saeid Taghavi Fardood Ali Ramazani Zahra Golfar Sang Woo Jooα-Fe2O3 (hematite) nanoparticles were synthesized using tragacanth gel as biotemplate andiron chloride as the iron source by the sol-gel method. This method has many advantages suchas nontoxic, economic viability, ease to scale up, less time consuming and environm چکیده کاملα-Fe2O3 (hematite) nanoparticles were synthesized using tragacanth gel as biotemplate andiron chloride as the iron source by the sol-gel method. This method has many advantages suchas nontoxic, economic viability, ease to scale up, less time consuming and environmentalfriendly approach for the synthesis of α-Fe2O3 nanoparticles without using any organicchemicals. Nanoparticles were characterized by Fourier transform infrared (FT-IR)spectroscopy, UV-visible spectroscopy and X-ray diffraction (XRD). The powder X-raydiffraction (XRD) analysis revealed the formation of Rhombohedral phase α-Fe2O3 withaverage particle size of 21 nm. پرونده مقاله -
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9 - Synthesis and Characterizations of Silica Nanoparticles by a New Sol-Gel Method
B. Gorji M.R. Allahgholi Ghasri R. Fazaeli N. NiksiratSilica nanoparticles were synthesized by chemical methods from tetraethylorthosilicate (TEOS), polyethylene glycol 5% and hydrochloric acid 0.001 N. The sol-gel process was applied for the preparation of nano silica gel. This method is hydrolysis and condensation reacti چکیده کاملSilica nanoparticles were synthesized by chemical methods from tetraethylorthosilicate (TEOS), polyethylene glycol 5% and hydrochloric acid 0.001 N. The sol-gel process was applied for the preparation of nano silica gel. This method is hydrolysis and condensation reactions of TEOS as precursor of silica. The optimal synthesis conditions for the preparation of silica nanoparticles were obtained and the produced silica nanoparticles were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results indicated that the silica nanoparticles were successfully formed. The prepared samples change from amorphous to α-crystallite phase. The XRD analysis indicated the amorphous structure of the synthesized silica nanoparticles while the SEM and TEM images exhibited monodispersedNano sized silica particles with a size about 34 nm. In this study, the soft process of sol-gel reaction is favourable from a view point of energy conservation. Additionally, the advantages of this technique were the purity of products and ability to control nanometer sized internal structure. پرونده مقاله -
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10 - LaCo0.5Fe0.5O3 Nanoparticles as a Highly Efficient Adsorbent for Rapid Removal of Trypan Blue Dye From Aqueous Media
Mojtaba Ershadi Haman Tavakkoli Arezoo Ghaemi Afruz AzarkishNanoparticles of perovskite-type LaCo0.5Fe0.5O3 (LCFO) were fabricated by sol–gel method.Thermal decomposition process of the complex precursor was examined by means of differentialthermal analysis–thermal gravimetric analysis (DTA/TGA). X-ray diffraction (X چکیده کاملNanoparticles of perovskite-type LaCo0.5Fe0.5O3 (LCFO) were fabricated by sol–gel method.Thermal decomposition process of the complex precursor was examined by means of differentialthermal analysis–thermal gravimetric analysis (DTA/TGA). X-ray diffraction (XRD) resultsshowed that single perovskite phase has been completely formed after calcination at 750 °C. Inaddition, the surface morphology and composition of these nanopowders were also investigatedusing SEM and EDX. These nanoparticles showed the excellent adsorption efficiency towardsTrypan Blue (TB) as a reactive dye in aqueous solution. The adsorption studies were carried outat different pH values, dye concentrations, various adsorbent dosages and contact time in a batchexperiments. LCFO exhibited good dye removal efficiency at acidic pH specially pH 2.Experimental results indicated that the adsorption kinetic data follow a pseudo-second-order ratefor tested dye. The isotherm evaluations revealed that the Freundlich model better fits to theexperimental equilibrium data than Langmuir the model. پرونده مقاله -
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11 - Synthesis of Cu-TiO2Nanocomposite and Investigation of the Effectiveness of PEG, Pectin, and CMCas Additives
B. Khodadadi M. Sabeti S. Moradi P. Aberomand Azar S. Raeis FarshidRecently, TiO2 has been widely used as a photocatalyst for degradation of environmental pollutants. In the present study, the advantage of metal doping onto TiO2 for enhanced photocatalitic activity has been investigated. Copper-Titanium dioxide nanocomposites were prep چکیده کاملRecently, TiO2 has been widely used as a photocatalyst for degradation of environmental pollutants. In the present study, the advantage of metal doping onto TiO2 for enhanced photocatalitic activity has been investigated. Copper-Titanium dioxide nanocomposites were prepared by the sol-gel method in the presence of Carboxy Methyl Cellulose (CMC), Pectin, and Poly Ethylene Glycol (PEG) as additives. The structures and properties of prepared samples were identified by IR spectra, Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD) methods. Furthermore, the photocatalytic activity under UV-irradiation to remove organic pollutant was investigated. The results have revealed that the photocatalytic activity of the nanocomposite in presence of additives increased. SEM pictures have shown that the particle size of Cu-TiO2 powder with additives was smaller than other samples without any additive. پرونده مقاله -
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12 - Preparation, Characterization and Photocatalytic Activity of Ag-Cd-ZnO and Ag-Cu-ZnO Nanostructures
Bahar Khodadadi Maryam Bordbar Maryam SajediIn this study, ZnO nanopowders and ZnO doped with metals (Cu , Ag- doped ZnO) and (Cd, Ag- doped ZnO) were synthesized by the sol-gel method in order to investigation on the codoping effect on the band gap and photocatalytic activity of ZnO. The synthesized samples are چکیده کاملIn this study, ZnO nanopowders and ZnO doped with metals (Cu , Ag- doped ZnO) and (Cd, Ag- doped ZnO) were synthesized by the sol-gel method in order to investigation on the codoping effect on the band gap and photocatalytic activity of ZnO. The synthesized samples are characterized by IR spectroscopy technique. Moreover, the absorption coefficients of the ZnO, Ag-Cd-ZnO and Ag-Cu-ZnO were analyzed by Tauc’s approach and the direct band gap is calculated. According to these results, compared with pure ZnO, the band gap of the Ag-Cd-ZnO and Ag-Cu-ZnO decreases and it is dependent on the content of dopands. Furthermore, photocatalytic activity for all samples was investigated under UV irradiation in an aqueous medium. The results have been revealed that Ag-Cd-ZnO and Ag-Cu-ZnO shown more photocatalytic actitivity in comparison with pure ZnO. پرونده مقاله -
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13 - Preparation, Characterization, and Investigation of Photocatalytic Activity of TiO2/SiO2/Co Nanocomposite Using Additives
Shahram Moradi Parviz Aberomand Azar Bahar Khodadadi Saied Abedini Khorami Mohammad Hadi GivianradTitanium dioxide has been widely used for photo-catalytic and self-cleaning activities. In this study, TiO2 /SiO2 /Co nanocomposite was prepared by sol-gel method in the presence of Polyvinyl Pyrrolidone (PVP), and Hydroxyl Propyl Cellulose (HPC) as additives, and chara چکیده کاملTitanium dioxide has been widely used for photo-catalytic and self-cleaning activities. In this study, TiO2 /SiO2 /Co nanocomposite was prepared by sol-gel method in the presence of Polyvinyl Pyrrolidone (PVP), and Hydroxyl Propyl Cellulose (HPC) as additives, and characterized by IR spectra, Scanning Electron Microscopy (SEM), Energy Dispersive Analytical X-Ray (EDAX), and X-Ray Diffraction (XRD) methods. The influence of metal doping and additives effect onto TiO2 /SiO2 on the structure and photo-catalytic behavior was evaluated. Moreover, Photo-catalytic activity was investigated in different conditions. The results revealed that the photo-catalytic activity of TiO2 /SiO2 doped with appropriate content of Cobalt in the presence of additives exceeded, and TiO2 /SiO2 /Co nanocomposite with HPC had the best photo-catalytic activity. پرونده مقاله -
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14 - Novel Solvothermal Route for the Synthesis of Pure Ultrafine Anatase Nanoparticles
Aliakbar Tarlani Fatemeh DarkhoshTitanium oxide nanoparticles were synthesized via a solvothermal treatment of titanium isopropoxide in the presence of L-lysine (lysine). The prepared nanostructures characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), thermogravimetric analysis (T چکیده کاملTitanium oxide nanoparticles were synthesized via a solvothermal treatment of titanium isopropoxide in the presence of L-lysine (lysine). The prepared nanostructures characterized by atomic force microscopy (AFM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), diffraction scanning calorimetry (DSC), scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. Results exhibited that peptization in the absence of the additive led to the non-uniform (from nano to micro size) anatase particles, while well-dispersed anatase nanoparticles were obtained in the small range from titania-lysine precursor. Well-organizing the growth of anatase particles during the calcinations can be attributed to initial amorphous phase of the as-synthesized lysine sample. پرونده مقاله -
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15 - Preparation, Structural and Magnetic Behavior of Sr(AlCr)xFe(12-2x) O19 Hexagonal Ferrites
Mahboobeh Alimoradi Mohammad Yousefi Babak Sadeghi Mostafa M.Amini Alireza AbbasiIn this investigation, strontium hexaferrite nanocomposites co-doped with aluminum and chromium were prepared Sr(AlCr)xFe(12-2x)O19 with x different amounts (x= 0, 0.2, 0.4, 0.6 and 0.8), were synthesized. The magnetic nanocomposites have been prepared by simple sol-gel چکیده کاملIn this investigation, strontium hexaferrite nanocomposites co-doped with aluminum and chromium were prepared Sr(AlCr)xFe(12-2x)O19 with x different amounts (x= 0, 0.2, 0.4, 0.6 and 0.8), were synthesized. The magnetic nanocomposites have been prepared by simple sol-gel auto-combustion method. The morphology and structure of nano-samples were determined by FTIR, XRD and FESEM . The results of the XRD pattern confirmed P63/mmc space group and the single phase of the synthesized samples. The crystal size of the prepared samples decreases with increasing Al and Cr.The magnetic properties of these compounds are determined by the VSM. Magnetic properties (Mr, Ms and Hc) were measured. The result showed that Mr and Ms decrease with the increase of Al and Cr. پرونده مقاله -
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16 - Gel-Citrate Method for Fabrication of Nano La0.7 Sr0.3 MnO3 Perovskite Type Oxide and its Application in Removal of RB4 Dye
Haman Tavakkoli Farideh SarafionIn this work La0.7Sr0.3MnO3 , one group of nanosized perovskite-type oxides were prepared by sol-gel method. The perovskite structure has been characterized by X-ray diffraction (XRD) , scanning electron microscopy (SEM) , energy dispersive X-ray spectrometer (EDX) and چکیده کاملIn this work La0.7Sr0.3MnO3 , one group of nanosized perovskite-type oxides were prepared by sol-gel method. The perovskite structure has been characterized by X-ray diffraction (XRD) , scanning electron microscopy (SEM) , energy dispersive X-ray spectrometer (EDX) and Fourier transform infrared (FTIR) . The nanoparticles showed the excellent adsorption properties towards reactive blue 4 (RB4) as a reactive dye. The adsorption studies are carried out at different pH values, different adsorbate concentrations, various adsorbent dosages, different temperature, and contact time in a batch experiments to find the optimum conditions. پرونده مقاله -
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17 - The Influence of Ag Doping on Structural, Optical Properties and Photocatalytic Activity of TiO2/SiO2 Nanocomposite
Bahar KhodadadiIn the present study, TiO 2 /SiO 2 and TiO 2 /SiO 2 /Ag nanocomposite powders were synthesized by sol-gel technique. Moreover, for investigation of the Ag doping effect different concentrations of dopant were added. Structures were characterized by IR spectros چکیده کاملIn the present study, TiO 2 /SiO 2 and TiO 2 /SiO 2 /Ag nanocomposite powders were synthesized by sol-gel technique. Moreover, for investigation of the Ag doping effect different concentrations of dopant were added. Structures were characterized by IR spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive Analytical X-Ray (EDAX), and X-Ray Diffraction (XRD) methods. Furthermore, the absorption coefficients of the samples were analyzed by Tauc’s model and the direct band gaps were calculated. Photocatalytic activity of all samples was investigated under UV irradiation in an aqueous medium. The results were shown that photocatalytic activity improves in the presence of appropriate amount of Ag as dopant. پرونده مقاله -
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18 - Synthesis of Hydroxyapatite-Bioglass Nanocomposite Using Modified Sol-Gel Method
M. TaherianThe aim of this study is comparing preparation methods of hydroxyapatite-bioglass composite nanopowders which can be prepared in different routes based on sol-gel method for orthopaedic/dental applications. Nanostructure materials present a unique and incomparable chara چکیده کاملThe aim of this study is comparing preparation methods of hydroxyapatite-bioglass composite nanopowders which can be prepared in different routes based on sol-gel method for orthopaedic/dental applications. Nanostructure materials present a unique and incomparable character for orthopedic and dental implant. Hydroxyapatite-bioglass composite nanopowders with the same contents of bioglass (20%) as reinforcement have been prepared by using a sol-gel method in four routes: mixing sols before aging time, mixing bioglass sol with hydroxyapatite gel after gelation, mixing calcinated bioglass nanopowder with hydroxyapatite sol, and mixing two calcinated powders by mechanical alloying. Bioactive glass of the type CaO-P2O5-SiO2 was obtained by the source of tetraethylorthosilicate, triethylphosphate and calcium nitrate tetrahydrate. On the other hand, phosphoric pentoxide and also calcium nitrate tetrahydrate were applied as the source of hydroxyapatite. Calcination temperature was 600°C for both compositions. XRD, SEM, and EDS techniques were used to investigate the microstructure and morphology of the nanopowders. Results indicated that because of different mixing time of hydroxyapatite with bioglass in either sol form, gel form or calcinated powder, the morphology, crystallinity, crystallite size and composition of products were varied. bioglass remained amorphous in all routes of synthesis. Because of presence of amorphous bioglass, In situ synthesis of hydroxyapatite-bioglass composite nanopowders resulted in decreasing the crystallinity and the crystallite size of hydroxyapatite. Furthermore, by mixing two nanopowders after calcination, hydroxyapatite crystallinity was maximum and also by using this route proportion of two parts can be easily controlled. پرونده مقاله -
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19 - Experimentally Designed of PVC/NiAl2O3/AlF3 Nanocomposite by Sol-Gel Method
Elinaz Ahmadian Maryam Kargar Razi Babak Sadeghi Mahbobeh NakhaeiIn this study, we have synthesized nano Aluminum Fluoride (nAF) nanoparticles by the sol-gel method and studied the nano-sized morphology of crystals. In the other section, the PVC/NiAl2O3/AlF3 (nPNA) nanocomposite was successfully prepared and characterized by FT-IR, a چکیده کاملIn this study, we have synthesized nano Aluminum Fluoride (nAF) nanoparticles by the sol-gel method and studied the nano-sized morphology of crystals. In the other section, the PVC/NiAl2O3/AlF3 (nPNA) nanocomposite was successfully prepared and characterized by FT-IR, and HRTEM techniques. FTIR peaks of the PVC and nPNA have been shown spherical shape of PVC and also spherical shapes nanoparticles of nPNA loaded on PVC. A solvothermal method has been successfully introduced and applied for catalyst efficiency. This nanocomposite was used for the removal of Congo red dye. For this purpose, the morphology and the structure of crystals have been changed by modification on precursor gel. Meanwhile, precursor gel preparation and the interaction on the nano-sized area have been studied. This study exhibited that PVC/NiAl2O3/AlF3 (nPNA) nanocomposite is an effective catalyst for the synthesis of some organic derivatives. The results show that the as-prepared nanocomposite is an efficient catalyst and that PVC/NiAl2O4/AlF3 nanocomposite can be used in the next-generation of some organic reactions and faster production of various materials. پرونده مقاله -
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20 - Preparation and Characterization of ZrO2/ZnO Nanocomposite under Ultrasonic Irradiation via Sol-gel Route
Sh. Aghabeygi M. Zare-Dehnavi A. Farhadyar N. FarhadyarNanocomposite of ZrO2/ZnO was prepared under ultrasonic irradiation by sol gel process from directly mixing Zirconium and Zinc gels, and the mixture was placed under ultrasonic irradiation for 2 hours then aging time the filtrated composite gel was calcinated at 500° چکیده کاملNanocomposite of ZrO2/ZnO was prepared under ultrasonic irradiation by sol gel process from directly mixing Zirconium and Zinc gels, and the mixture was placed under ultrasonic irradiation for 2 hours then aging time the filtrated composite gel was calcinated at 500°C for 3h in furnace. The precursor sol of zirconium was prepared from an aqueous solution of ZrCl4 and zinc acetate dihydrated was dissolved in de-ionized water. The FT-IR analysis and the XRD study were exhibited that the crystal structure and purity of the ZrO2/ZnO nanocomposite FESEM images was indicated the morphology and the average size of the NPs. The average size of the ZrO2/ZnO nanocomposite was determined 37 nm. پرونده مقاله -
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21 - Self-assembly of ZnO nanoparticles on Low Density Polyethylene Film with sol gel and its Application for Milk Active Packaging
Mohammad Ali Shayegh sayedehmona Alavinassab Somayeh Shahedi Saeid JafariThis study reports the antibacterial capability a low density polyethylene (LDPE) modified with ZnO nanoparticles using Sol Gel technique. Antibacterial activity of prepared films against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was examined. The چکیده کاملThis study reports the antibacterial capability a low density polyethylene (LDPE) modified with ZnO nanoparticles using Sol Gel technique. Antibacterial activity of prepared films against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was examined. The operational conditions such as pH, time, amount of ZnO nanoparticles and silanol concentration was optimized using respond surface methodology (RSM). The proposed film under optimum condition was applied for packaging of milk sample. The highest antibacterial activity of ZnO/LPDE were pH (6.0), time (103 min), amount of ZnO nanoparticles (0.68 % w/v) and silanol agent concentration (4.81 % v/v). The antibacterial properties of ZnO/LDPE films were assessed based on the diameter of inhibition zone in a disk diffusion test against E. coli and S. aureus. These films have significantly reduced the growth of mentioned bacteria. Overall, antimicrobial packaging shows promise as an effective method for the inhibition of certain bacteria include E. coli and S. aureus in milk. The resulting ZnO/LDPE package films containing Milk sample exhibit superior and prolonged antibacterial activity against E. coli and S. aureus during 7 and 14 days. پرونده مقاله -
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22 - Application of Taguchi design for optimization of corrosion behavior of amorphous silica thin film deposited through sol-gel dipping technique
Hamideh Aghasi Sanaz NaghibiAmorphous silica thin films were applied on the 316L stainless steel substrates by sol-gel dipping technique. The starting chemicals (TEOS, ethanol, HCl, PEG, and NaOH) were used to prepare a gel and then deposited on a substrate. The microstructure, topography, corrosi چکیده کاملAmorphous silica thin films were applied on the 316L stainless steel substrates by sol-gel dipping technique. The starting chemicals (TEOS, ethanol, HCl, PEG, and NaOH) were used to prepare a gel and then deposited on a substrate. The microstructure, topography, corrosion behavior, and surface hardness were investigated using SEM, AFM, electrochemical method, and micro-hardness measurements. The fabrication parameters utilized to enhance the anticorrosion and mechanical properties including calcinations temperature, pH value, and mole ratio of alkoxide to alcohol were studied. Taguchi approach was used as a statistical experimental design technique to set the optimal parameters. Roughness and current corrosion density were evaluated as the response parameter. pH is the parameter of most major effect on the roughness; pH less than or equal to 4 increases the roughness but more pH value decreases the roughness. The ratio of alkoxide to alcohol is the most influential variable on current corrosion density. The increase of alkoxide amount improves the corrosion behavior, which might be related to the increase of the coating density. Consequently, the optimized conditions obtained through Taguchi method target at reaching the highest anticorrosion efficiency involving calcination at 300 °C, pH=6, and the mole ratio of alkoxide to alcohol as 0.167. پرونده مقاله -
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23 - Characterization of SiO2-TiO2 Coatings on 316l Stainless Steel Substrates
Manuel Gutierrez Martinez Lizangela Guerra Barbara Bermudez Reyes Roberto Cabriales Luis ReyesThis paper reports nano-structured SiO2-TiO2 coatings using the sol-gel technique on 316L steel substrates. Nanoindentation, surface analysis and corrosion resistance tests were performed on different samples. The nanomechanical tests allowed to compare uncoated steel s چکیده کاملThis paper reports nano-structured SiO2-TiO2 coatings using the sol-gel technique on 316L steel substrates. Nanoindentation, surface analysis and corrosion resistance tests were performed on different samples. The nanomechanical tests allowed to compare uncoated steel samples (Eavg = 193.24 GPa and mean hardness of 2.63 GPa and coated steel samples (Eavg = 287.38 GPa and mean hardness of 5.74 GPa), resulting into an improvement of the resistance and modulus of elasticity on the coated steel substrates. From a surface analysis an average thickness of 1.12 μm was obtained in the coated samples, presenting a dense and consolidated coating. Polarization resistance (PR) and electrochemical impedance spectroscopy (EIS) tests were performed. The PR tests showed a resistance of 2.11 105 (Ω cm2) for the uncoated steel, while the coated steel showed a resistance of 3.46 105 (Ω cm2), observing an increase in resistance compared to bare steel. The EIS tests showed greater resistance by the coated steel (5.8 105 (Ω cm2)) compared to the bare steel (2.8 105 (Ω cm2)). The effects of the electrolyte in both conditions were observed by SEM after immersion for 24 hours, showing pitting by the bare steel and good protection by the coated steel. پرونده مقاله -
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24 - Design and investigation of TiO2 –SiO2 thin films on AISI 316L stainless steel for tribological properties and corrosion protection
Behrooz ShayeghThe TiO2–SiO2 thin films were deposited on AISI 316L stainless steel via sol-gel method. Then, the effect of the added amount of SiO2 on the structure, morphology and mechanical properties of the films and corrosion behavior of AISI 316L stainless steel substrate چکیده کاملThe TiO2–SiO2 thin films were deposited on AISI 316L stainless steel via sol-gel method. Then, the effect of the added amount of SiO2 on the structure, morphology and mechanical properties of the films and corrosion behavior of AISI 316L stainless steel substrate were investigated. So, X-ray diffraction, field-emission scanning electron microscopy, atomic force microscopy, depth-sensing indentation technique supporting micro-scratch mode and potentiodynamic polarization test were used. It was observed that the appropriate amount SiO2 addition into TiO2 film not only decreased the particle size of TiO2–SiO2 crystal but also could help to improve the surface quality. The mechanical and tribological properties of the films were found to be improved in the range of 10–15%mol SiO2 addition compared with the pure TiO2. The minimum root mean square value was obtained from the film with a silica content of 10%mol. In addition, the corrosion behavior of AISI 316L stainless steel was improved by adding 15%mol SiO2. Under UV illumination conditions, photo-generated electrons accumulated in this film could perfectly protect the substrate photocathodically. پرونده مقاله -
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25 - Fabrication and charge modification of ceramic membranes using copper Nanoparticles for desalination
Mohamad Mahdi Zerafat Majid Shokri Doodeji Omid NejadianCeramic membranes are considered as alternatives for their polymeric counterparts due to high mechanical strength and thermal resistance; thus long lifetime. Usually, asymmetric ceramic membranes are synthesized including several layers with different pore size distribu چکیده کاملCeramic membranes are considered as alternatives for their polymeric counterparts due to high mechanical strength and thermal resistance; thus long lifetime. Usually, asymmetric ceramic membranes are synthesized including several layers with different pore size distributions with the top-layer playing the main separation role. Titania has several properties such as photocatalytic activity and chemical stability making it sutitable as an option for the top-layer. This study is devoted to the preparation and characterization of a ceramic membrane, dip-coating of mesoporous interlayers and preparation of a microporous anatase top-layer via sol–gel technique. Moreover, the performance of the membrane modified by nano-copperis investigated for salt rejection enhancement. Membranes were characterized by FE-SEM and X-ray diffraction. The sol particle size was determined using DLS. Cross-flow filtration setup was used for membrane permeability and salt retention experiments. Membrane top-layer showed crystal structures including rutile and anatase phases. By increasing salt concentration, chloride rejection is decreased and retention is increased by increasing the pressure. In case of modified membranes using nano-copper, higher retentions are observed, with 35% rejection for NaCl and 73% for Na2SO4. پرونده مقاله -
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26 - Synthesis of Unsymmetrical Ethers Catalysed by Polyvinyl sulfuric acid & PVSA / Nano RH SiO2 as a Novel Solid Acid Nanocomposite
roya moeinzadeh Ali Kiasat Hadi AsarehThe methodology involves preparing polyvinyl sulfuric acid as a solid acid by simple mixing of polyvinyl alcohol with chlorosulfonic acid in CH2Cl2 at room temperature. The catalytic ability of the solid acid was investigated for the facile conversion of benzylic چکیده کاملThe methodology involves preparing polyvinyl sulfuric acid as a solid acid by simple mixing of polyvinyl alcohol with chlorosulfonic acid in CH2Cl2 at room temperature. The catalytic ability of the solid acid was investigated for the facile conversion of benzylic alcohols to the unsymmetrical ethers with aliphatic alcohols in the presence of the solid acid. Results show that the solid acid is an appropriate catalytic agent for these condensation reactions. The silica was also extracted from low-cost rice husk and the amorphous silicagel nanoparticles was prepared with solgel method. The polyvinyl sulfuric acid was supported on nano rice husk silica. Then the catalytic effect of this system was investigated for synthesis of unsymmetrical ethers which consisted of a combination of high acidic power for this solid acid and high- surface area of nanoparticles. Results show that totally catalytic effect of polyvinyl sulfuric acid supported on nano silica is more suitable than polyvinyl sulfuric acid. The reason for this is in its ability to produce the end products in shorter reaction times while having high isolated yields. پرونده مقاله -
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27 - The effect of adding different amount of spinning additives on preparation of nano Alumina fibers using a combined method of sol gel and electrospining
Fateme Mirjalili fyrozeh danafarAlumina nanofibers were produced using a combined method of sol-gel and electros pinning method. In this method, the sol was prepared by mixing of tri-isoproxide aluminum in aqueous solution onitric acid. Spinning aid such as: ethylene glycol-acid lactic and poly vinyl چکیده کاملAlumina nanofibers were produced using a combined method of sol-gel and electros pinning method. In this method, the sol was prepared by mixing of tri-isoproxide aluminum in aqueous solution onitric acid. Spinning aid such as: ethylene glycol-acid lactic and poly vinyl alcohol was added to the solution .The sol was then heated at 80 °C to obtain gel. Then, the resulting gel was converted into aluminum oxide nanofibers by electrospinning method. The nanofibers were dried at 60 °C for 24 h and finally sintered for 2 h at 1200 ° C. The results of XRD and FTIR showed that in all samples the dominant phase was the corundum phase. Finally, to decrease the sintering temperature, magnesium nitrate hexahydrate (MgN2O6 * 6H2O) and sodium ethoxylate (SiC8 H2o O4) were added to the sol containing 10% Polyvinyl alcohol. The results of XRD and FTIR indicated the presence of corundum phase when the sintering temperature of 1000°C was used. Accordingly, the energy consumption was reduced as the sintering temperature decreased about 200°C by adding the additives,. The results of SEM and TEM showed formation of non-agglomerated nano fibers with 41nm diameters at 1000°C when 10% polyvinyl alcohol and 2% sodium ethoxylate (SiC8 H20 O4) was added to the sol. پرونده مقاله -
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28 - ZnO/WO3 nanocomposites: Pechini sol-gel synthesis, characterization, and photocatalytic performance for desulfurization of thiophene
Mehdi Mousavi-Kamazani Nahid Kalhori Mohammad GhodratiIn recent decades, considerable research about the destruction of hazardous pollutants sulfur from petroleum products was conducted. However, reforms in this area have not been satisfactory and efforts are ongoing. The aim of this study was to investigate and overcome t چکیده کاملIn recent decades, considerable research about the destruction of hazardous pollutants sulfur from petroleum products was conducted. However, reforms in this area have not been satisfactory and efforts are ongoing. The aim of this study was to investigate and overcome thiophene sulfur contaminants using high purity synthesized ZnO/WO3 nanocomposite and homogeneous composition by Pechini sol-gel method at low temperature. Zinc oxide is one of the most dynamic elements known in this field, its presence together with tungsten oxide prevents the crystallization of tungsten nanoparticles. Fuzzy structure, percentage of elements, surface morphology, penetration reflection spectrum, and photocatalytic degradation of thiophene were determined by XRD, EDS, SEM, and DRS analyzes, respectively. DRS results indicate high light absorption, reduced bandgap due to the presence of WO3 after combination with ZnO, and increased efficiency. Finally, the nanocomposite with more than 84% efficiency resulted in the degradation of oxidative desulfurization of thiophene after 150 min under visible light. پرونده مقاله -
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29 - A novel investigation on characterization of bioactive glass cement and chitosan-gelatin membrane for jawbone tissue engineering
Farhad Ghomi َAzadeh Asefnejad Morteza Daliri Vahabeddin Godarzi Mehran HematiThe aim of this work was to investigate the characterization of a bioactive glass (BG) ceramic prepared by sol–gel technique and chitosan-gelatin membranes prepared by lyophilization technique containing 0, 1 and 2 vol.% ethanol. Early-absorbing and late-absorbing چکیده کاملThe aim of this work was to investigate the characterization of a bioactive glass (BG) ceramic prepared by sol–gel technique and chitosan-gelatin membranes prepared by lyophilization technique containing 0, 1 and 2 vol.% ethanol. Early-absorbing and late-absorbing bone substitutes in practice constitute the main volume of bone substitutes used by dentist and orthopedic surgeons. When the graft is to be gradually replaced by normal bone, the important issue is the duration and rate of graft absorption. The prepared samples were characterized using fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. The presence of Ag nanoparticles into bioactive glass was evaluated. Porous membranes were examined under scanning electron microscopy (SEM) to estimate the size of the pores and analysis the morphological behavior. The pore diameter could be controlled within the range 10–30 µm by adjusting the percent of ethanol. The formation of needle-like hydroxyapatite (HA) crystals on the surface of the membrane after 7 days immersion in the ringer's solution was also assessed using SEM images. The SEM images results illustrated the porous structures in the membranes. The average pore size for chitosan-gelatin membrane with 2% ethanol were 30±6.3 μm. Finally, these obtained results suggested that the developed membrane with 2% ethanol possess the prerequisites for tissue engineering and can be used for jawbone tissue engineering applications. پرونده مقاله -
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30 - Fabrication of Bi14W2O27/Bi2WO6 photocatalyst for improved desulfurization of thiophene under simulated sunlight irradiation
Mohammad Ebadi Majid Asri Farshad BeshkarIn this work, novel Bi14W2O27/Bi2WO6 nanocomposite was prepared by a modified Pechini sol-gel approach. The effect of the gelling agent, chelating agent and mole ratio of chelating agent to total metals was controlled to produce ultrafine Bi14W2O27/Bi2WO6 nanoparticles. چکیده کاملIn this work, novel Bi14W2O27/Bi2WO6 nanocomposite was prepared by a modified Pechini sol-gel approach. The effect of the gelling agent, chelating agent and mole ratio of chelating agent to total metals was controlled to produce ultrafine Bi14W2O27/Bi2WO6 nanoparticles. The as-prepared Bi14W2O27/Bi2WO6 nanocomposite was characterized by XRD, FESEM, FT-IR, EDS and UV–Vis analysis. The Bi14W2O27/Bi2WO6 nanostructures exhibited excellent photocatalytic desulfurization of thiophene (~90%) after 120 min of simulated sunlight irradiation. The high-efficiency photocatalytic desulfurization of the as-prepared Bi14W2O27/Bi2WO6 can be attributed to the improved visible-light absorption, ultrafine nanoparticles, and high separation and low recombination rates of charge carriers. In addition, a reliable photocatalytic desulfurization mechanism was explained using radical trapping experiment, which indicated that the photogenerated •O2− and •OH species had a significant contribution in the photocatalytic desulfurization reactions of Bi14W2O27/Bi2WO6 nanocomposite. The excellent photocatalytic desulfurization efficiency, good recyclability, solar-driven, and simple synthesis of Bi14W2O27/Bi2WO6 nanocomposite are promising for photocatalytic applications. پرونده مقاله -
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31 - The effect of Mn doping on structural, magnetic and optical properties of TiO2 nanoparticles
alireza razeghizadeh elham elahi vahdat rafeeThe aim of this paper is to study the effect of Mn concentration on the structural, magnetic and optical properties of TiO2 nanoparticles. TiO2 nano powders with Mn concentration of 0%, 0.2%, 1% and 5% were synthesized by the sol-gel method. The structural, surface morp چکیده کاملThe aim of this paper is to study the effect of Mn concentration on the structural, magnetic and optical properties of TiO2 nanoparticles. TiO2 nano powders with Mn concentration of 0%, 0.2%, 1% and 5% were synthesized by the sol-gel method. The structural, surface morphology and average crystal grain size, optical, magnetic properties and chemical compounds of the samples are studied using XRD, FE-SEM, Uv-Vis, VSM and EDX analysis respectively. The results indicate that the samples are crystallized at anatase phase. Also, the average size of the nanoparticles is decreased by increasing Mn doping percent. The study of the optical properties shows that the absorption maximum dislocates toward higher wavelengths by adding Mn to the sample. This shift may be ascribed to the enhanced trapped electron absorption caused by the Mn-doped ions. The optical energy band gap of the doping samples shows significant reduction rather the pure state. The samples show significant paramagnetic behavior when the Mn concentration is 5%. پرونده مقاله -
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32 - Pechini Sol-Gel Synthesis and Characterization of NiWO4/W5O14/WO3 Nanocomposite for Photocatalytic Desulfurization of Thiophene
Mehdi Mousavi-Kamazani Mahvash Siahmansouri Mohammad GhodratiOne of the most important problems in the oil industry is the presence of sulfur and sulfur compounds in crude oil. Sulfur compounds in crude oil can have detrimental effects on the environment, equipment, catalysts, and end products. One of the most important goals of چکیده کاملOne of the most important problems in the oil industry is the presence of sulfur and sulfur compounds in crude oil. Sulfur compounds in crude oil can have detrimental effects on the environment, equipment, catalysts, and end products. One of the most important goals of researchers in recent years is to sweeten petroleum products from these compounds. This study aims to use NiWO4/W5O14/WO3 composite nanostructure to solve this problem using the photocatalytic oxidative desulfurization method. This composite nanostructure has been synthesized by Pechini sol-gel method with high purity at low temperature and examined by XRD, EDS, FESEM, and FT-IR analysis. Due to the presence of WO3 in the composition, the bandgap was greatly reduced and the efficiency was increased. As a result, the nanostructure could degrade more than 73% of the sulfur in thiophene in 180 min under visible light. By optimizing the amount of photocatalyst and irradiation time, the efficiency can be improved. پرونده مقاله -
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33 - Separation and Quantification of Hydrocarbons of LPG Using Novel MWCNT-Silica Gel Nanocomposite as Packed Column Adsorbent of Gas Chromatography
Seyed Mojtaba Mostafavi Masoumeh Piryaei Ahmad Rouhollahi Ali MohajeriIn this study, a new silica gel based adsorbent was fabricated and its ability in separation and quantification of alkanes mixture was investigated. Silica gel (SiO2) is a polar absorbent which is mainly used to separate polar compounds. Also, the carbon materials such چکیده کاملIn this study, a new silica gel based adsorbent was fabricated and its ability in separation and quantification of alkanes mixture was investigated. Silica gel (SiO2) is a polar absorbent which is mainly used to separate polar compounds. Also, the carbon materials such as activated carbon and recently carbon nanotube (CNTs), have been widely used for separation of nonpolar materials. Carbon nanotubes are nanosized carbon-based sorbents that have a high surface area and a large aspect ratio and are known to be stable at high temperatures. It is, therefore, conceivable to use of their unique properties in gas chromatography. In this work, a MWCNT-Silica gel nanocomposite was prepared by Sol-Gel process and it was used as stationary phase in gas chromatography for separation of alkanes mixture. In first part, ability of silica gel adsorbent was studied and then results were compared with new MWCNT-Silica gel nanocomposite. Finally, a quantitative investigation was done on a LPG sample and propane, 2-methylpropane, n-butane, 2,2-dimethylpropane, 2-methylbutane and n-pentane were measured by standard addition. پرونده مقاله -
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34 - Preparation of Symmetrical Tetraphenyl Porphyrin Metal Complexes and Their Spectroscopic Studies
S. Khaliq M. Danish M. Yasin R. AsimPorphyrins molecules are gaining importance in the present era. Porphyrins are important part of biological molecules like hemoglobin and chlorophyll .Photo system 1 and photo system 2 is important sunlight trap in chloroplast. Electron transport chain is a series of ch چکیده کاملPorphyrins molecules are gaining importance in the present era. Porphyrins are important part of biological molecules like hemoglobin and chlorophyll .Photo system 1 and photo system 2 is important sunlight trap in chloroplast. Electron transport chain is a series of chemical reaction in which energy is formed in the form of ATP (Adenosine triphosphate).The members of electron transport chains are cytochrome 450 which are Porphyrins like molecules. Porphyrins are important part of solar cells, apart from above mentioned application; Porphyrins have special importance in the photodynamic therapy. This therapy has special role in the treatment of acne; psoriasis .Photodynamic therapy has successfully treated various kinds of malignant cells and has special role to treat cancers. The present thesis addresses the formation of tetra phenyl porph1yrins through Adler and Ruthmend synthesis .This is the common chemical reaction which can be obtained in the university laboratories. The tetra phenylporphyrin, developed from above mentioned method were converted into metal complexes. Four metals iron, cobalt, copper and nickel have chosen in the form of their chlorides and acetates. Porphyrin synthesis is a challenging approach as it contains various forms of impurities and it is very difficult to analysis the complex formation. The present paper contains different Porphyrins metal complexes which have been developed and the formations of complexes were confirmed through IHNMR (nuclear magnetic resonance spectroscopy) analysis which is the strongest tool in the modern chemistry. The formation of complexes can be further confirmed by infra-red spectroscopy and ultraviolet spectroscopy. Atomic force microscopy was also conducted and all the analysis confirmed the formation of tetra phenylporphyrin and its metal complexes. پرونده مقاله -
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35 - Separation of Aromatic and Alcoholic Mixtures using Novel MWCNT-Silica Gel Nanocomposite as an Adsorbent in Gas Chromatography
Seyed Mojtaba Mostafavi Ahmad Rouhollahi Ali Mohajeri Masoumeh PiryaeiThe separations of alcohols with hydrophilic and hydrophobic parts, and the separation of aromatic mixtures, are extremely important processes in gas and petroleum industries. Choosing an adsorbent for performing this separation is the most important part of the process چکیده کاملThe separations of alcohols with hydrophilic and hydrophobic parts, and the separation of aromatic mixtures, are extremely important processes in gas and petroleum industries. Choosing an adsorbent for performing this separation is the most important part of the process. Silica gel is used as an adsorbent is various techniques such as pressure swing adsorption (PSA) and gas and liquid chromatography. Due to the polarity of silica gel, it is used for the separation of polar molecules. Carbon materials such as activated carbon and recently carbon nanotube (CNTs) are widely used for the separation of nonpolar materials. In the course of this study, a new composite was fabricated using sol-gel methods. Multiwall carbon nanotubes (non-polar carbon-based adsorbents with high surface areas) were mixed with a silica gel base (a strong polar adsorbent). The composite was then used in the separation of mixtures of both aromatic hydrocarbons and alcohols. پرونده مقاله -
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36 - Quantitative Determination of LPG Hydrocarbons by Modified Packed Column Adsorbent of Gas Chromatography Via Full Factorial Design
Asghar Pasban Seyed Mojtaba Mostafavi Hanieh Malekzadeh Benyamin Mohammad NazariIn this study, a new silica gel based adsorbent was fabricated and its ability in separation and quantification of alkanes mixture was investigated. Silica gel (SiO2) is a polar absorbent which is mainly used to separate polar compounds. Also, the carbon materials such چکیده کاملIn this study, a new silica gel based adsorbent was fabricated and its ability in separation and quantification of alkanes mixture was investigated. Silica gel (SiO2) is a polar absorbent which is mainly used to separate polar compounds. Also, the carbon materials such as activated carbon and recently carbon nanotube (CNTs), have been widely used for separation of nonpolar materials. Carbon nanotubes are nanosized carbon-based sorbents that have a high surface area and a large aspect ratio and are known to be stable at high temperatures. It is, therefore, conceivable to use of their unique properties in gas chromatography. Optimization of gas chromatography with modified and unmodified columns was investigated by full factorial design. According to the results of proposed design, the temperature, flow rate and carrier gas are known to be important factors affecting performance. In this work, a MWCNT-Silica gel nanocomposite was prepared by Sol-Gel process and it was used as stationary phase in gas chromatography for separation of alkanes mixture. In first part, ability of silica gel adsorbent was studied and then results were compared with new MWCNT-Silica gel nanocomposite. Finally, a quantitative investigation was done on a LPG sample and propane, 2-methylpropane, n-butane, 2,2-dimethylpropane, 2-methylbutane and n-pentane were measured by standard addition. Finally, the greatest difference between the response profiles in modified and unmodified column was determined. پرونده مقاله -
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37 - Sol-Gel Fabrication and Photocatalytic Properties of Indium Oxide-CNT Composite
Giang Li Lnfeng HuCarbon nanotube-In2O3 nanocomposites were synthesized by sol-gel method with the help of ultrasonic radiation. The samples were characterized by X-ray diffractometer, transmission electron microscopy and energy dispersive spectrometer. The UV absorbing properties were d چکیده کاملCarbon nanotube-In2O3 nanocomposites were synthesized by sol-gel method with the help of ultrasonic radiation. The samples were characterized by X-ray diffractometer, transmission electron microscopy and energy dispersive spectrometer. The UV absorbing properties were detected by the UV spectrophotometer. Photo degradation of methylene blue in aqueous solution was investigated by using CNT/In2O3 nanocomposite as photocatalyst. The results showed that nanocomposites were composed of carbon nanotubes coated evenly by In2O3, with diameter of 50-60 nm. UV-visible spectrum indicated that the as-prepared CNT/In2O3 nanocomposite had absorption of visible light as well as ultraviolet light. 40 % carbon nanotube (molar radio of carbon nanotube to InCl3·4H2O) nanocomposite had the highest degradation rate for methylene blue under the sunlight irradiation. پرونده مقاله -
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38 - The effect of Mn doping on structural, magnetic and optical properties of TiO2 nanoparticles
Alireza Razeghizadeh Elham Elahi Vahdat RafeeThe aim of this paper is to study the effect of Mn concentration on the structural, magneticand optical properties of TiO2 nanoparticles. TiO2 nanopowders with Mn concentration of 0%,0.2%, 1% and 5% were synthesized by the sol-gel method. The structural, surface morphol چکیده کاملThe aim of this paper is to study the effect of Mn concentration on the structural, magneticand optical properties of TiO2 nanoparticles. TiO2 nanopowders with Mn concentration of 0%,0.2%, 1% and 5% were synthesized by the sol-gel method. The structural, surface morphologyand average crystal grain size, optical, magnetic properties and chemical compounds of thesamples are studied using XRD, FE-SEM, Uv-Vis, VSM and EDX analysis respectively. The resultsindicate that the samples are crystallized at anatase phase. Also, the average size of thenanoparticles is decreased by increasing Mn doping percent. The study of the optical propertiesshows that the absorption maximum dislocates toward higher wavelengths by adding Mnto the sample. This shift may be ascribed to the enhanced trapped electron absorption causedby the Mn-doped ions. The optical energy band gap of the doping samples shows significantreduction rather the pure state. The samples show significant paramagnetic behavior whenthe Mn concentration is 5%. پرونده مقاله -
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39 - Comparative Study of Nanostructured Zr-Fe2O3 and CNT Modified Zr-Fe2O3 Thin Films for Photo Electrochemical Generation of Hydrogen
Vibhuti Yadav Sadhana Tyagi Devbrat Pundhir Saral Kumar GuptaNanostructured hematite thin films are doped with zirconium successfully and also modified by introducing CNT using sol-gel method for their implementation as photo-electrode in photo-electrochemical (PEC) cell for hydrogen generation. XRD, UV-visible spectroscopy and P چکیده کاملNanostructured hematite thin films are doped with zirconium successfully and also modified by introducing CNT using sol-gel method for their implementation as photo-electrode in photo-electrochemical (PEC) cell for hydrogen generation. XRD, UV-visible spectroscopy and PEC study techniques are used to characterize the thin films. The PEC responses of thin films are improved by introducing carbon nanotubes (CNT). پرونده مقاله -
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40 - Synthesis of Unsymmetrical Ethers Catalysed by Polyvinyl Sulfuric Acid & PVSA / Nano RH SiO2 as a Novel Solid Acid Nanocomposite
Roya Moeinzadeh Hadi Asareh Ali Reza KiasatThe methodology involves preparing polyvinyl sulfuric acid as a solid acid by simple mixing ofpolyvinyl alcohol with chlorosulfonic acid in CH2Cl2 at room temperature. The catalytic ability ofthe solid acid was investigated for the facile conversion of benzylic alcohols چکیده کاملThe methodology involves preparing polyvinyl sulfuric acid as a solid acid by simple mixing ofpolyvinyl alcohol with chlorosulfonic acid in CH2Cl2 at room temperature. The catalytic ability ofthe solid acid was investigated for the facile conversion of benzylic alcohols to the unsymmetricalethers with aliphatic alcohols in the presence of the solid acid. Results show that the solid acid isan appropriate catalytic agent for these condensation reactions. The silica was also extracted fromlow-cost rice husk and the amorphous silica gel nanoparticles were prepared with sol- gel method.The polyvinyl sulfuric acid was supported on nano rice husk silica. Then the catalytic effect of thissystem was investigated for synthesis of unsymmetrical ethers which consisted of a combination ofhigh acidic power for this solid acid and high- surface area of nanoparticles. Results show that totallycatalytic effect of polyvinyl sulfuric acid supported on nano silica is more suitable than polyvinylsulfuric acid. The reason for this is in its ability to produce the end products in shorter reaction timeswhile having high isolated yields. پرونده مقاله -
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41 - The effect of adding different amount of spinning additives on preparation of nano Alumina fibers using a combined method of sol gel and electrospining
F. Mirjalili F. Danafar A. Zarei MahmodabadiAlumina nano fibers were produced using a combined method of sol-gel andelectros pinning method. The sol was first prepared by mixing of tri-isoproxidealuminum in aqueous solution of nitric acid. In the next step, ethylene glycol,acid lactic and poly vinyl alcohol were چکیده کاملAlumina nano fibers were produced using a combined method of sol-gel andelectros pinning method. The sol was first prepared by mixing of tri-isoproxidealuminum in aqueous solution of nitric acid. In the next step, ethylene glycol,acid lactic and poly vinyl alcohol were added to the solution .Finally, the sol wasthen heated at 80 °C to obtain gel. The resulting gel was converted to nano fibersof aluminum oxide by electrospinning method. The nano fibers were dried at60 °C for 24 h and sintered at 1200 °C for 2 h. The results of XRD and FTIRshowed that, in all samples the dominant phase was the corundum phase. Todecrease the sintering temperature, magnesium nitrate hexahydrate (MgN2O6 *6H2O) and sodium ethoxylate (SiC8 H2o O4) were added to the sol containing10% Polyvinyl alcohol. The XRD and FTIR analysis of this sample indicated thepresence of corundum phase when the sintering temperature of 1000°C was used.Accordingly, the energy consumption was reduced as the sintering temperaturedecreased about 200°C by adding the additives. The SEM and TEM analysis alsoshowed formation of non-agglomerated nano fibers with diameters of 41nmwhen 10% polyvinyl alcohol and 2% sodium ethoxylate (SiC8 H20 O4) was addedto the sol. پرونده مقاله -
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42 - Fabrication and Charge Modification of Ceramic Membranes Using Copper Nanoparticles for Desalination
Majid Shokri Doodeji Mohamad Mahdi Zerafat Omid NejadianCeramic membranes are considered as alternatives for their polymeric counterparts due to highmechanical strength and thermal resistance; thus long lifetime. Usually, asymmetric ceramicmembranes are synthesized including several layers with different pore size distributi چکیده کاملCeramic membranes are considered as alternatives for their polymeric counterparts due to highmechanical strength and thermal resistance; thus long lifetime. Usually, asymmetric ceramicmembranes are synthesized including several layers with different pore size distributionswith the top-layer playing the main separation role. Titania has several properties such asphotocatalytic activity and chemical stability making it sutitable as an option for the top-layer.This study is devoted to the preparation and characterization of a ceramic membrane, dipcoatingof mesoporous interlayers and preparation of a microporous anatase top-layer viasol-gel technique. Moreover, the performance of the membrane modified by nano-copperisinvestigated for salt rejection enhancement. Membranes were characterized by FE-SEM andX-ray diffraction. The sol particle size was determined using DLS. Cross-flow filtration setupwas used for membrane permeability and salt retention experiments. Membrane top-layershowed crystal structures including rutile and anatase phases. By increasing salt concentration,chloride rejection is decreased and retention is increased by increasing the pressure. In case ofmodified membranes using nano-copper, higher retentions are observed, with 35% rejectionfor NaCl and 73% for Na2SO4. پرونده مقاله -
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43 - A novel investigation on the characterization of bioactive glass cement and chitosan-gelatin membrane for jawbone tissue engineering
Farhad Ghomi َAzadeh Asefnejad Morteza Daliri Vahabeddin Godarzi Mehran HematiThe aim of this work was to investigate the characterization of a bioactive glass(BG) ceramic prepared by sol-gel technique and chitosan-gelatin membranesprepared by lyophilization technique containing 0, 1, and 2 vol.% ethanol. Earlyabsorbingand late-absorbing bone sub چکیده کاملThe aim of this work was to investigate the characterization of a bioactive glass(BG) ceramic prepared by sol-gel technique and chitosan-gelatin membranesprepared by lyophilization technique containing 0, 1, and 2 vol.% ethanol. Earlyabsorbingand late-absorbing bone substitutes in practice constitute the mainvolume of bone substitutes used by dentists and orthopedic surgeons. Whenthe graft is to be gradually replaced by normal bone, the important issue is theduration and rate of graft absorption. The prepared samples were characterizedusing Fourier transformed infrared spectroscopy (FTIR) and X-ray diffraction (XRD)analysis. The presence of Ag nanoparticles in bioactive glass was evaluated.Porous membranes were examined under scanning electron microscopy (SEM)to estimate the size of the pores and analysis the morphological behavior. Thepore diameter could be controlled within the range of 10–30 μm by adjusting thepercentage of ethanol. The formation of needle-like hydroxyapatite (HA) crystals onthe surface of the membrane after 7 days of immersion in the ringer's solution wasalso assessed using SEM images. The SEM image results illustrated the porousstructures in the membranes. The average pore size for chitosan-gelatin membranewith 2% ethanol was 30±6.3 μm. Finally, these obtained results suggest thatthe developed membrane with 2% ethanol possesses the prerequisites for tissueengineering and can be used for jawbone tissue engineering applications. پرونده مقاله -
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44 - ZnO/WO3 nanocomposites: Pechini sol-gel synthesis, characterization, and photocatalytic performance for desulfurization of thiophene
Nahid Kalhor Mohammad Ghodrati Mehdi Mousavi-KamazaniThe aim of this study was to investigate and overcome thiophene sulfurcontaminants using high purity synthesized ZnO/WO3 nanocomposite andhomogeneous composition by Pechini sol-gel method at low temperature.Zinc oxide is one of the most dynamic elements known in this fi چکیده کاملThe aim of this study was to investigate and overcome thiophene sulfurcontaminants using high purity synthesized ZnO/WO3 nanocomposite andhomogeneous composition by Pechini sol-gel method at low temperature.Zinc oxide is one of the most dynamic elements known in this field, itspresence together with tungsten oxide prevents the crystallization of tungstennanoparticles. Fuzzy structure, percentage of elements, surface morphology,penetration reflection spectrum, and photocatalytic degradation of thiophenewere determined by XRD, EDS, SEM, and DRS analyses, respectively. DRS resultsindicate high light absorption, reduced bandgap due to the presence of WO3 aftercombination with ZnO, and increased efficiency. Finally, the nanocomposite withmore than 84% efficiency resulted in the degradation of oxidative desulfurizationof thiophene after 150 min under visible light. پرونده مقاله -
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45 - Effects of Ag, Nd codoping on structural, optical and photocatalytic properties of TiO2 nanocomposite synthesized via sol-gel method using starch as a green additive
Bahar KhodadadiIn this paper, undoped TiO2 and Ag-Nd-codoped TiO2 nanocomposites with different molar ratios of dopants were synthesized by the sol-gel method using starch as a natural additive. Structures were investigated by FT-IR and UV–Vis spectroscopy, SEM, and XRD methods. چکیده کاملIn this paper, undoped TiO2 and Ag-Nd-codoped TiO2 nanocomposites with different molar ratios of dopants were synthesized by the sol-gel method using starch as a natural additive. Structures were investigated by FT-IR and UV–Vis spectroscopy, SEM, and XRD methods. Moreover, the direct band gap was calculated by Tauc's approach. Furthermore, photocatalytic activity of all samples were investigated under UV irradiation in an aqueous medium. Compared with undoped TiO2, the band gap of the Ag-Nd -TiO2 samples decreases and depends on the content of dopants. In addition, photocatalytic activity improves in the presence of appropriate amount (1.5 mol%) of Ag and Nd as dopants. پرونده مقاله -
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46 - Photocatalytic self-cleaning properties of lanthanum and silver co-doped TiO2 nanocomposite on polymeric fibers
Hadi Fallah MoafiTitania, single-doped and lanthanum-silver co-doped titania nanocomposite were coated on cellulosic and polyacrylonitrile fibers via sol–gel method. The prepared samples were evaluated using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispe چکیده کاملTitania, single-doped and lanthanum-silver co-doped titania nanocomposite were coated on cellulosic and polyacrylonitrile fibers via sol–gel method. The prepared samples were evaluated using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), photoluminescence spectroscopy (PL) and BET surface area measurement. The photo self-cleaning activity of the nanocomposites coated-fibers were determined by degradation of methylene blue and eosin yellowish under UV-Vis light. Diffuse reflectance spectroscopy was used to monitor photodegradation of dyes. The results of EDX and XPS revealed that La and Ag was doped into TiO2 structure. The results of EDX, TEM and BET analyses indicated that the TiO2 and TiO2 nanocomposite coatings were composed of nanoparticles or aggregates with a size of less than 20 nm. All samples demonstrated photocatalytic self-cleaning properties when exposed to UV-Vis irradiation. The results showed that the La3+/Ag+ co-doping is more beneficial than single doping of TiO2 coating and the synergistic effect of La3+ and Ag+ is responsible for improving the photo-activity. This may be ascribed to the microstructure of TiO2 and the effect of the doping modes on the structural and electronic properties of the anatase phase. پرونده مقاله -
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47 - Magnetically separable MgFe2O4 nanoparticle for efficient catalytic ozonation of organic pollutants
Akbar Eslami Ali Oghazyan Mansour SarafrazMagnetically separable MgFe2O4 was synthesized and used in catalytical ozonation of 4-chlorophenol (4-CP). The prepared catalyst was characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electronic Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), چکیده کاملMagnetically separable MgFe2O4 was synthesized and used in catalytical ozonation of 4-chlorophenol (4-CP). The prepared catalyst was characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electronic Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Brunauer−Emmett−Teller (BET) and Vibrating-Sample Magnetometer (VSM). The optimum conditions for the highest efficacy of the catalytic ozonation process were found to be pH 7, catalyst dose 0.2 g/L, O3 concentration 1.67 mg/L.min, contact time of 30 min and 4-CP concentration 100 mg/L. At these optimal conditions, the efficiency of process was 93.5%. In addition, the results showed that the catalyst can significantly enhance the mineralization of 4-CP, and more than 70% 4-CP were mineralized in the presence of the catalyst, that is almost 2.5 times higher than ozonation alone. Moreover, the results revealed that the removal efficiency was not affected by solution pH and removal efficiency in the O3/MgFe2O4 process exceeded 90% over a wide pH range of 4–10. This study demonstrates that MgFe2O4 is a recyclable and efficient catalyst in the ozonation organic pollutants. پرونده مقاله -
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48 - Eco-friendly preparation and characterization of CuMn2O4 nanoparticles with the green capping agent and their photocatalytic and photovoltaic applications
Ali Sobhani-Nasab Mohammad Eghbali-Arani Seyed Mostafa Hosseinpour-Mashkani Farhad Ahmadi Mehdi Rahimi-Nasrabadi Vahid AmeriIn this study, copper manganese oxide (CuMn2O4) nanoparticles were successfully synthesized by a simple sol-gel technique in the presence of lactose as the green capping agent. The lactose concentration effect on the crystalline size and magnetic properties of final pro چکیده کاملIn this study, copper manganese oxide (CuMn2O4) nanoparticles were successfully synthesized by a simple sol-gel technique in the presence of lactose as the green capping agent. The lactose concentration effect on the crystalline size and magnetic properties of final products were systematically investigated. The structural, morphological, magnetic, and optical properties of as-obtained products were examined by techniques such as the Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscopy (FESEM), vibrating-sample magnetometer (VSM) and UV–Vis diffuse reflectance spectroscopy. SEM and VSM results show that lactose concentrations play an important role in the magnetic properties and morphology of CuMn2O4 nanoparticles. Degradation of type of dye (Rhodamine B = Rh B and Methyl orange = MO) under ultraviolet light was examined to assess the feasibility of using CuMn2O4 for photocatalytic activities. To demonstrate the possibility of developing an inexpensive solar cell, FTO/TiO2/CuMn2O4/Pt-FTO, the CuMn2O4 paste was put on the top of the TiO2 through the doctor blade technique. پرونده مقاله -
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49 - Properties of sol-gel synthesized multiphase TiO2 (AB)-ZnO (ZW) semiconductor nanostructure: An effective catalyst for methylene blue dye degradation
Manikandan Balakrishnan Rita JohnThe present study, describes the structural, electrical, and the photocatalytic activity of sol-gel synthesized TiO2- ZnO nanostructure. The synthesized mixed oxide nanostructure is characterized by XRD, FTIR, Raman, UV-Vis, FESEM, DLS and Impedance Spectroscopy analyse چکیده کاملThe present study, describes the structural, electrical, and the photocatalytic activity of sol-gel synthesized TiO2- ZnO nanostructure. The synthesized mixed oxide nanostructure is characterized by XRD, FTIR, Raman, UV-Vis, FESEM, DLS and Impedance Spectroscopy analyses. In addition, photocatalytic activity of multiphase TiO2 (TAB)-ZnO (ZW) nanostructure is analysed using Methylene Blue dye as the model dye under UV and Visible light illumination. The XRD analysis confirms the bi-phase TiO2 and mono-phase ZnO in the multiphase TiO2-ZnO nanostructures. The average crystallite size of 33 nm has been estimated using Scherrer formula. The crystallite size and mechanical properties such as strain, stress, and other parameters are analysed using Williamson-Hall model. The FTIR spectrum shows the characteristics absorption peaks of TiO2 and ZnO at 679.44 and 432.79 cm-1 respectively, and reveals the presence of TiO2 and ZnO in the synthesized multiphase nanostructure. The optical band gap is calculated using Tauc relation with the data obtained from UV-Vis spectrometer. The calculated band gap value is 3.1 eV. The FESEM study shows the spherical morphology and the DLS analysis confirms the particle size is 433 nm. The presence of Ti-O and Zn–O stretching modes are confirmed from Raman spectrum. The electrical properties such as dielectric constant, dielectric loss, and ac conductivity are analysed from impedance data. The prepared multiphase TiO2 (TAB)-ZnO (ZW) nanostructure shows better photocatalytic activity in both UV and visible light region. The rate constant has been calculated as 0.0083 and 0.0052 min-1 for UV and visible light irradiation. پرونده مقاله -
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50 - Optical, Morphological and Microstructural Investigation of TiO2 nanoparticles for Photocatalytic application
B. Manikandan K. R. Murali Rita JohnEnriched characteristics like porosity, stability and specific surface area assist TiO2 to find extensive applications in photocatalysis, dye sensitized solar cell, and sensors. TiO2 semiconductor was prepared using titanyl acetylacetonate and characterized by XRD, FTIR چکیده کاملEnriched characteristics like porosity, stability and specific surface area assist TiO2 to find extensive applications in photocatalysis, dye sensitized solar cell, and sensors. TiO2 semiconductor was prepared using titanyl acetylacetonate and characterized by XRD, FTIR, Raman, UV-Vis, FESEM, EDX, and DLS. XRD result confirmed the tetragonal structured anatase TiO2 semiconductor. Scherrer formula is used to calculate crystallite size and the obtained value is 6.81 nm. Microstrain, stress, energy density, and crystallite size are calculated using W-H model. The absorption peak of TiO2 is observed at 652.11 cm-1 from FTIR spectrum and authenticated the anatase TiO2 semiconductor. The UV absorption edge is identified at 365 nm and the bandgap is calculated from the Kubelka-Munk equation using Tauc plot. Raman spectrum show bands at 140,197, 395, 512, and 635 cm-1 and these peaks confirmed the presence of the anatase TiO2 stretching mode. FESEM micrographs exhibited agglomerated spherical morphology and the particle size was further analysed using DLS study. The elemental compositions were identified in the EDX analysis. The obtained spectrum showed 55.88 Wt% of O and 44.12 Wt% of Ti atoms. The prepared anatase TiO2 semiconductor indicated enhanced catalytic behaviour. The rate constants and half life time are related to crystallite size using mathematical relation. It is found that the degradation process varies with crystallite size. پرونده مقاله -
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51 - Synthesis, Characterization, and Antibacterial Properties of Surfactant Encapsulated Mn/Mg Co-doped Titania Nanoparticles
Sankara MiditanaThe current research work was mainly focused on the antibacterial performance of Mn/Mg co-doped TiO2 nanoparticles in presence of Gemini surfactant (GS). Mn, Mg co-doped TiO2 nanoparticles were synthesized by sol-gel method and calcined at 450 0C. The characterization r چکیده کاملThe current research work was mainly focused on the antibacterial performance of Mn/Mg co-doped TiO2 nanoparticles in presence of Gemini surfactant (GS). Mn, Mg co-doped TiO2 nanoparticles were synthesized by sol-gel method and calcined at 450 0C. The characterization results reveal that among all the co-doped TiO2 and surfactant encapsulated TiO2 nanoparticles, the MMT5-GS2 Nano catalyst exhibited the most favorable properties, featuring a small particle size, a large surface area, with respective values of 6.6 nm, 230.2 m2/g, and a bandgap of 2.66 eV. The efficiency of the synthesized catalysts was examined by the antibacterial activity of Escherichia coli (E. coli) and Klebsiella pneumonia pathogens. Among all the catalysts, MMT5-GS2 demonstrated the best performance. The zone of inhibition of bacterial growth for E. coli and Klebsiella pneumonia was measured to be (33.1±0.12 mm) and (26.1±0.12 mm) respectively, at a concentration of 400 µg/mL. These values are significantly higher than the standard value of (chloramphenicol-16.71±0.2) at 100 µg/mL, indicating the remarkable efficacy of the MMT5-GS2 nanocatalyst. The co-doped nano titania particles encapsulated with surfactant have great potential as antibacterial agents. پرونده مقاله -
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52 - Synthesis of a thin film of CuO/MgO/PVC nanocomposites for Photocatalytic applications
Rouabeh Nouhad Roshan Nazir Yassine Djaballah AbQayoom Mir Imene Ameur Ouidad BeldjebliThis study investigates the effect of a combination of copper and magnesium oxide nanoparticles embedded in a Polyvinyl chloride (PVC) matrix on photocatalytic activity. A thin film of CuO/MgO/PVC nanocomposites (NCs) was synthesized using the sol-gel route. Different w چکیده کاملThis study investigates the effect of a combination of copper and magnesium oxide nanoparticles embedded in a Polyvinyl chloride (PVC) matrix on photocatalytic activity. A thin film of CuO/MgO/PVC nanocomposites (NCs) was synthesized using the sol-gel route. Different weight percentages of CuO/MgO nanocomposites (5% and 15%) incorporated in the PVC matrix were deposited on glass strips using the spin coating method. The characterization of these thin films were carried out by a series of analytical and spectroscopic tools including PXRD, AFM, UV-Vis, and FTIR spectra analysis. The bandgap energy of MgO/PVC significantly reduced from 4.00 eV to 3.77 eV in 15% CuO/MgO/PVC NCs. This study also demonstrates the high ability of CuO/MgO/PVC thin films towards the photodegradation of methylene blue (MB) dye with a proposed reaction mechanism. A comparative analysis for the photodegradation of MB dye revealed superior photocatalysis by 15%with a rate constant of 5.20 × 10-3 min-1 showing about 44% efficiency. The credit goes to the decrease in the band gap, enhancement in charge separation, and increase in surface area of thin film CuO/MgO/PVC NCs. پرونده مقاله -
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53 - Synthesis of nanosized TiO2 powder by Sol-Gel method in acidic conditions
Parvain Gharbani Ali Mehrizad, Samad Motameni TabatabiiThe preparation of nano-sized TiO2 by titanium tetraisopropoxide (Ti(OiPr)4) via sol-gelmethod using acid as a catalyst is investigated and the optimized conditions concerning theproportional amount of acid, water, alcohol is established by XRD and SEM. The effect ofcal چکیده کاملThe preparation of nano-sized TiO2 by titanium tetraisopropoxide (Ti(OiPr)4) via sol-gelmethod using acid as a catalyst is investigated and the optimized conditions concerning theproportional amount of acid, water, alcohol is established by XRD and SEM. The effect ofcalcination temperature on phase transformation of TiO2 (rutile, anatase and brookite) wasdetermined by XRD. The smallest grain size of TiO2 powder we have obtained is 25 nm foranatase at 400 ºC by controlling the acidity and the mole ratio of starting materials. پرونده مقاله -
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54 - تاثیر حضور آب، بنزیل الکل و درصد CNT بر روی خواص نانوکامپوزیت TiO2-CNT تولید شده به روش سل-ژل درجا
علیرضا شافعی سعید شیبانیدر این پژوهش، نانوکامپوزیت TiO2-CNT به روش سل-ژل درجا تهیه شده است. نقش پارامترهای این فرآیند بر روی مورفولوژی پودر نهایی در سه بخش حضور بنزیل الکل، مرحله افزودن آب و درصد CNT بررسی شد. جهت مشخصه یابی از میکروسکوپ الکترونی روبشی نشر میدانی و دستگاه پراش اشعه ایکس استفاد چکیده کاملدر این پژوهش، نانوکامپوزیت TiO2-CNT به روش سل-ژل درجا تهیه شده است. نقش پارامترهای این فرآیند بر روی مورفولوژی پودر نهایی در سه بخش حضور بنزیل الکل، مرحله افزودن آب و درصد CNT بررسی شد. جهت مشخصه یابی از میکروسکوپ الکترونی روبشی نشر میدانی و دستگاه پراش اشعه ایکس استفاده شد. در مرحله اول تاثیر کلسیناسیون انجام شده بر روی ساختار پودر ارزیابی شد. نتایج حاصل از پراش اشعه ایکس نشان داد که پودرهای کامپوزیتی قبل از کلسیناسیون دارای ساختار آمورف است و بعد از آن به TiO2 با ساختار آناتاز تبدیل می شود. نتایج تصاویر مربوط به میکروسکوپ الکترونی روبشی نشر میدانی نشان می دهند که در صورت استفاده نکردن از بنزیل الکل، پودری با مورفولوژی غیریکنواخت و آگلومره شده بدست می آید. علاوه بر این، حضور آب از ابتدای فرآیند منجر به واکنش هیدرولیز با سرعت آرام تر شده و لذا پودر نانوکامپوزیتی با ساختار ریزتر و پوشش مطلوب تر TiO2 روی CNT به دست می آید. همچنین با کاهش درصد CNT از 10 به 1 درصد، پودر کامپوزیتی با اندازه ذرات درشت تر تشکیل می شود که به دلیل کاهش سطح CNT در دسترس برای تشکیل ذرات TiO2 است. پرونده مقاله -
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55 - مقایسه خواص برون تنی، فیزیکی-شیمیایی و ضدباکتریایی شیشههای زیست فعال 68S و 58S سنتز شده به روش سل-ژل
امیرحسین مغنیان محمد امین ظهورفاضلیهدف اصلی این پژوهش، مقایسه ترکیب شیمیایی شیشه های زیست فعال S58 و S68 و بررسی تاثیر میزان CaO بر تشکیل برون تنی هیدروکسی آپاتایت، سمیت و تکثیرسلولی سلولهای استخوانی MC3T3 همچنین خواص ضدباکتریایی سیستم سه جزئی SiO_2-CaO-P_2 O_5 سنتز شده به روش سل-ژل است. به این منظور اب چکیده کاملهدف اصلی این پژوهش، مقایسه ترکیب شیمیایی شیشه های زیست فعال S58 و S68 و بررسی تاثیر میزان CaO بر تشکیل برون تنی هیدروکسی آپاتایت، سمیت و تکثیرسلولی سلولهای استخوانی MC3T3 همچنین خواص ضدباکتریایی سیستم سه جزئی SiO_2-CaO-P_2 O_5 سنتز شده به روش سل-ژل است. به این منظور ابتدا، دو شیشه زیست فعال S58 ( mol%: 60%SiO2 – 36%CaO – 4%P2O5 ) و S68 (mol%:70%SiO_2-26% CaO-4% P_2 O_5) با مقدار ثابت P_2 O_5 به روش سل-ژل تهیه شدند. سپس، تاثیر میزان CaOدر ترکیباتشان بر زیست فعالی به صورت برون تنی با غوطهور کردن پودرهای S58 و S68 در محلول شبیهسازی شده بدن (SBF) برای دورههای زمانی تا 14 روز مورد بررسی قرارگرفت. بررسی ترکیب محلول SBF با آنالیز طیف سنجی پلاسمای جفت شده القایی (ICP-AES) اندازه گیری شد. همچنین، طیف سنجی تبدیل فوریه مادون قرمز (FTIR)، پراش الکترونX (XRD) و میکروسکوپ الکترونی روبشی (SEM) برای بررسی تشکیل هیدروکسیآپاتایت روی سطوح شیشههای زیستفعال انجام شد. از سوی دیگر، آزمون های رنگ آمیزی سلولی زنده/مرده، زولیم برماید(MTT) و آزمون الکالین فسفاتاژ(ALP) به ترتیب به منظور بررسی کیفیت و کمیت زیست پذیری سلولها، تکثیر سلول های MC3T3 در حضور شیشه های زیست فعال S58 ،S68 انجام شد. در نهایت، شیشه زیستفعال S58، با تکثیر سلولی و فعالیت (ALP) سلولهای MC3T3 افزایش یافته، زیست فعالی قابل قبول و ضد باکتریایی چشمگیر بالا در برابر باکتری (MRSA)، به عنوان یک ماده زیستی مناسبتر نسبت به شیشه زیست فعال S68 به منظور بهبود عملکرد ارائه یون-های درمانی و فاکتورهای رشد برای مهندسی بافت استخوانی معرفی میگردد. پرونده مقاله -
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56 - سنتز نانوذرات اکسید روی دوپ شده توسط نقره به روش سل-ژل پکینی و مشخصهیابی و بررسی خواص فوتوکاتالیستی انها
حمیدرضا یوسفی بابک هاشمیاکسید روی (ZnO)نیمه هادی اکسیدی است که خواص فوتوکاتالیستی داشته و قابلیت تجزیه مواد آلی و تصفیه پساب های صنعتی را دارا می باشد. در این تحقیق نانوذرات اکسیدروی دوپ شده با درصدهای متفاوت نقره (Ag) به روش سل-ژل پکینی برای بررسی خواص فوتوکاتالیستی سنتز گردید. نانو ذرات به د چکیده کاملاکسید روی (ZnO)نیمه هادی اکسیدی است که خواص فوتوکاتالیستی داشته و قابلیت تجزیه مواد آلی و تصفیه پساب های صنعتی را دارا می باشد. در این تحقیق نانوذرات اکسیدروی دوپ شده با درصدهای متفاوت نقره (Ag) به روش سل-ژل پکینی برای بررسی خواص فوتوکاتالیستی سنتز گردید. نانو ذرات به دلیل داشتن نسبت سطح به حجم بالا می توانند خواص فوتوکاتالیستی بهتری از خود نشان دهند. همچنین افزودن فلزات نجیب به نیمه هادی می تواند مانع از باز ترکیبی جفت الکترون –حفره گردد. نمونه های سنتز شده حاوی 0/6، 1/8، 3/1 و 6/2 درصد وزنی نقره بودند. نمونه های بدست امده توسط طیف سنج UV-Vis، پراش اشعه X (XRD)، میکروسکوپ الکترونی روبشی (SEM)، میکروسکوپ گسیل میدانی (FESEM)، و طیف سنجی فوتولومینسانس(PL) مشخصه یابی گردیدند. در نهایت از نمونه های سنتز شده نسبت به زمان تست فوتوکاتالیستی در برابر متیلن آبی به انجام شد. با توجه به نتایج مشاهده گردید با دوپ نمودن نقره اندازه ذرات اکسید روی کاهش می یابد همچنین با افزودن نقره به نانوذرات ZnO تا حدود 1/8 درصد وزنی کاهش محسوسی در شدت فوتولومینسانس نمونه ها در محدوده فرابنفش ایجاد شده که نشان دهنده کاهش نرخ بازترکیبی الکترون-حفره و به دنبال ان افزایش نرخ فوتوکاتالیستی نمونه ها می باشد. تکرارپذیر بودن خصلت رنگبری فوتوکاتالیست سنتز شده بوسیله تکرار سه سیکل فوتوکاتالیستی بر روی نمونه دوپ شده با 1/8 درصد وزنی نقره انجام شد، مشاهده گردید که راندمان کاتالیست سنتز شده کاهش چشمگیری نداشته و این نشان دهنده پایداری فوتو کاتالیست سنتز شده است. پرونده مقاله
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