scholarly journals Synthesis and Characterization of YAG Nanoparticles by Ultrasound-Assisted and Ultrasound-Microwave-Assisted Alkoxide Hydrolysis Precipitation Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Si ◽  
Chao Ding ◽  
Siqi Ding
Keyword(s):  
Calcination Temperature ◽  
Yttrium Aluminum Garnet ◽  
Ph Value ◽  
Atomic Diffusion ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Intermediate Phases ◽  
Transmission Electron ◽  
Ft Ir ◽  
Ultrasound Assisted

Yttrium aluminum garnet (YAG, Y3Al5O12) nanoparticles were synthesized by ultrasound-assisted and ultrasound-microwave-assisted alkoxide hydrolysis precipitation methods. The effect of reaction parameters including pH value, ultrasonic radiation time, and calcination temperature on the composition of the products was investigated. The YAG nanoparticles and their precursor were characterized by X-ray powder diffraction (XRD), differential thermal analysis (DTA), Fourier-transform infrared spectroscopy (FT-IR), and high-resolution transmission electron microscopy (HRTEM). The results show that the single ultrasound-assisted method to synthesize YAG phase often contains intermediate phases of YAM (Y4Al2O9) and YAP (YAlO3); pure YAG phase can form only at special conditions and as single crystal. The pure phase YAG powders can be obtained at each experimental condition when using ultrasound-microwave-assisted synthesis and the grain is polycrystalline. This is due to the microwave radiation which promotes atomic diffusion and forms a lot of crystal nuclei of YAG in the precursor. The YAG nanoparticles with a grain size of 18 nm can be obtained at a calcination temperature of 900°C when using ultrasound-microwave-assisted method.

scholarly journals Microwave-assisted synthesis, characterization and photoluminescence of shuttle-like BaMoO4 microstructure

2015 ◽  
Vol 33 (3) ◽  
pp. 537-540 ◽  
Author(s):  
Anukorn Phuruangrat ◽  
Budsabong Kuntalue ◽  
Titipun Thongtem ◽  
Somchai Thongtem
Keyword(s):  
Electron Microscopy ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Ft Ir ◽  
Xrd Patterns ◽  
Scanning Electron ◽  
Ft Ir Spectroscopy

Abstract Shuttle-like BaMoO4 microstructure has been successfully synthesized from Ba(N03)2·4H20 and Na2MoO4·2H2O as starting materials in ethylene glycol solvent containing 20 mL 5 M NaOH by microwave radiation at 180 W for 30 min. The as- synthesized BaMoO4 product was characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Raman spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photolumines­cence (PL) spectroscopy. XRD patterns revealed that the products was tetragonal BaMoO4 phase. SEM and TEM characteriza­tion showed that the product had a shuttle-like BaMoO4 microstructure. PL of the shuttle-like BaMoO4 microstructure showed a maximum emission at 466 nm excited by 280 nm wavelength.

scholarly journals Fast Microwave-Assisted Synthesis and Photoluminescence of CaWO4Nanocrystals

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Quanguo Li ◽  
Yanhua Shen ◽  
Taohai Li
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Microwave Assisted Synthesis ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Ft Ir ◽  
Microwave Assisted Method

In this work, CaWO4nanoparticles have been synthesized by microwave-assisted method at a low temperature of 120°C. The as-prepared powders were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). It is found that the reaction time played an important role in the morphology controlling and crystallinity level of CaWO4crystals. The effects of photoluminescent properties have a great relationship with crystallinity.

Silicotungstic Acid Catalyzed Microwave Assisted Synthesis of Fused 4H-Pyrimido[2,1-b]thiazoles and 4H-Pyrimido[2,1-b]benzothiazoles under Solvent-Free Conditions

2020 ◽  
Vol 5 (1) ◽  
pp. 62-67
Author(s):  
Ankita S. Rahate ◽  
Neha A. Shah ◽  
Prashant S. Jadhav ◽  
Sagar T. Sankpal ◽  
Hemant V. Chavan
Keyword(s):  
Microwave Assisted Synthesis ◽  
Silicotungstic Acid ◽  
One Pot ◽  
Mass Spectral ◽  
Benzothiazole Derivatives ◽  
Microwave Assisted ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
Acid Catalyzed ◽  
Work Up

The silicotungstic acid catalyzed microwave assisted synthesis of substituted 4H-pyrimido[2,1- b]thiazole and 4H-pyrimido[2,1-b]benzothiazole derivatives was achieved by one-pot multi-component reaction of 2-aminothiazole or 2-aminobenzthiazole, aldehyde and ethyl acetoacetate under solventfree condition. A simple, rapid and environmental friendly protocol, good yields and easy work-up are some advantages of this protocol. The structures of the synthesized compounds were established by FT-IR, 1H NMR and mass spectral data.

scholarly journals Microwave-assisted synthesis and characterization of microstar shaped zinc oxide

Quimica Hoy ◽  
2012 ◽  
Vol 2 (3) ◽  
pp. 3
Author(s):  
Idalia Gómez ◽  
Miguel José Yucam´án ◽  
Flor Palomar
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Microwave Assisted Synthesis ◽  
Stoichiometric Ratio ◽  
Crystalline Materials ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Synthesis Procedure ◽  
Post Synthesis

A microwave-assisted solution-phase approach has been applied for the synthesis ofzinc oxide microstructures. Toe synthesis procedure was carried out by using the reagents: Zinc ni trate and Methenamine, at stoichiometric ratio. Analysis by means ofX-ray Diffraction (XRD) shows a crystalline phase in hexagonal wurtzite arrangement for ZnO. The presence ofmicrostar shaped zinc oxide (2-3μm) with nanorods,f50nm) arranged has been confirmed from High Resolution Scanning Electron Microscopy (HRSEM). The formation of nanorods was confirmed by Transmission Electron Microscopy. In Raman spectroscopy a red shift was detected in the microstructures compared with ZnO bulk. High crystalline materials without additional post-synthesis treatrnent were found.

scholarly journals Microwave Assisted Synthesis of MoS2/PANI/ZnO Nanocomposites as a Working Electrode for Energy Storage Applications

2021 ◽  
Vol 33 (7) ◽  
pp. 1585-1593
Author(s):  
J. Balavijayalakshmi ◽  
S. Krithika
Keyword(s):  
Energy Storage ◽  
Specific Capacitance ◽  
Transition Probabilities ◽  
Average Crystallite Size ◽  
Microwave Assisted Synthesis ◽  
Transition Metal Dichalcogenide ◽  
Active Electrode ◽  
Microwave Assisted ◽  
Ft Ir ◽  
Energy Storage Applications

Transition metal dichalcogenide and polyaniline doped zinc oxide nanocomposites influence the transition probabilities and electronic structure. In present study, the various concentrations of MoS2/PANI/ZnO nanocomposites are synthesized by microwave assisted method. These nanocomposites are characterized by using XRD, FESEM, HRTEM and FT-IR. The XRD results revealed an average crystallite size of synthesized nanocomposites, which was found to be 19-24 nm. The electrochemical properties of the nanocomposites are studied through the CV, EIS and GCD for the application of supercapacitor as an active electrode material. The MoS2/PANI/ZnO nanocomposites exhibited a specific capacitance of 577 F g-1 and also retained 90% of its initial specific capacitance even after 5000 cycles. Hence MoS2/PANI/ZnO nanocomposites have potential application for energy storage applications.

scholarly journals Synthesis and Characterization of 3-Substituted Indole Derivatives as Novel Mannich Bases

2021 ◽  
Vol 33 (4) ◽  
pp. 781-784
Author(s):  
E. Erdag
Keyword(s):  
Energy Efficiency ◽  
13C Nmr Spectroscopy ◽  
Mannich Bases ◽  
Synthesis And Characterization ◽  
Microwave Assisted Synthesis ◽  
Indole Derivatives ◽  
Heating Method ◽  
Microwave Assisted ◽  
Ft Ir

In this study, ten 3-substituted indole derivatives at the 3rd position of indole nucleus were synthesized via Mannich reaction with microwave assisted synthesis and the conventional reflux heating method. Microwave assisted synthesis is more preferrable than reflux method since the microwave irradiation lead to a higher product yields with better purity and improved energy efficiency with shortened reaction time. The structures of 3-substituted indole derivatives were characterized by FT-IR, elemental analysis, 1H NMR and 13C NMR spectroscopy

scholarly journals Aqueous extraction of anions from coal and fly ash followed by ion-chromatographic determination

2016 ◽  
Vol 81 (12) ◽  
pp. 1441-1453
Author(s):  
Aleksandra Tasic ◽  
Ivana Sredovic-Ignjatovic ◽  
Ljubisa Ignjatovic ◽  
Danijel Djuranovic ◽  
Malisa Antic
Keyword(s):  
Fly Ash ◽  
Ph Value ◽  
Chromatographic Determination ◽  
Aqueous Extraction ◽  
Microwave Assisted Extraction ◽  
Ultrasound Assisted Extraction ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Coal Particles ◽  
Ultrasound Assisted

Three different techniques were applied for the aqueous extraction of anions from coal and fly ash: rotary mixer- and ultrasonic-assisted extraction with different duration time, and microwave-assisted extraction at different temperatures. Validation showed that the ion-chromatographic method was suitable for the analysis of anions in coal and fly ash extracts. The variations in the amounts of anions using different extraction times during rotary-assisted extraction were minimal for all investigated anions. The efficiency of ultrasound-assisted extraction of anions from coal depended on the sonication time and was highest at 30 min. The ultrasound-assisted extraction was less efficient for the extraction of anions from fly ash than rotary-assisted extraction. Increase of temperature in the microwave-assisted extraction had a positive effect on the amounts of all anions extracted from coal and sulphate from fly ash, while the amounts of fluoride and chloride in fly ash extracts decreased. The microwave-assisted extraction of coal at 150?C was compared with standard ASTM methods, and results were in good agreement only for chloride. Changes in the pH value and conductivity during ultrasound-assisted extraction were measured in order to explain changes on the surface of coal particles in contact with water and different processes that occur under environmental conditions.

Microwave-Assisted Synthesis of Unmodified Gold Nanoparticles for Colorimetric Detection of Dopamine

2017 ◽  
Vol 730 ◽  
pp. 167-171 ◽  
Author(s):  
Ekarat Detsri ◽  
Kanrayasiri Kamhom ◽  
Chatsuda Detsri
Keyword(s):  
Gold Nanoparticles ◽  
Sodium Citrate ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Chemical Reduction ◽  
Colorimetric Detection ◽  
Random Coil ◽  
Microwave Assisted Synthesis ◽  
Microwave Assisted ◽  
Transmission Electron

Unmodified gold nanoparticles (AuNPs) have been successfully synthesized by the chemical reduction of tetrachloride gold (III) ions ([AuCl4]-) in the presence of sodium citrate based on the rapid microwave−assisted approach. The diameter of the synthesized nanoparticles was found in the range of 16.50±2.75 nm. The AuNPs were characterized using UV−vis spectrophotometer, zeta potential analyzer and transmission electron microscope (TEM). The sodium citrate protected AuNPs were found to be selective and sensitive for the detection of dopamine. It was based on the aggregation change of the nanoparticles from random coil to hairpin structure upon the addition of dopamine concentration. The red shift of the plasmonic peak wavelength of AuNPs could be used for the detection of dopamine. The response to dopamine allows for a linear range from 10 to 125 mg⋅L-1 (R2 = 0.9804) with a limit of detection (LOD) at a signal to noise ratio of 3 of 12.85±1.38 mg⋅L-1. The colorimetric sensor was evaluated with 98.0−99.9% recovery of added dopamine in urine sample. The proposed sensor was successfully applied to the determination of dopamine in biological samples.

Study on Microwave-Assisted Synthesis of Ionic Liquids Based on Dialkylimidazolium

2011 ◽  
Vol 393-395 ◽  
pp. 1471-1474 ◽  
Author(s):  
Hu Zhu ◽  
You Ming Li ◽  
Xiao Fang Wan
Keyword(s):  
Ionic Liquids ◽  
Microwave Irradiation ◽  
13C Nmr ◽  
Reaction Rate ◽  
Synthesis Process ◽  
Microwave Assisted Synthesis ◽  
Interval Time ◽  
Microwave Assisted ◽  
Ft Ir

Controlled microwave irradiation has been employed in the improved process to prepare two main dialkylimidazolium-based ionic liquids: 1-butyl-3-methylimidazolium(BMIMCl) and 1-allyl-3-methylimidazolium chloride (AMIMCl). The synthesis process was studied by determining the production yields at certain interval time. Results shown the reaction was accelerated by 8 and 4 times respectively, and production yields were increased by 5.5% and 5.9%. Differences in synthesis between [AMIM]Cl and [BMIM]Cl indicated the improvement of the reaction rate of [BMIM]Cl was clearer because of the inerter reactant. FT-IR and 13C NMR were carried out and results shown the two ionic liquids were successfully synthesized.

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