Microwave Assisted Preparation of YAG and Yb:YAG Transparent Ceramic Nanopowders for Laser Crystal

2016 ◽  
Vol 697 ◽  
pp. 76-79 ◽  
Author(s):  
Wei Si ◽  
Cang Xiong ◽  
Yi Wen Jiang ◽  
Zhi Feng Xing ◽  
Wei Pan
Keyword(s):  
Microwave Radiation ◽  
Laser Crystal ◽  
Radiation Power ◽  
Average Particle Size ◽  
Thermo Gravimetric Analysis ◽  
Transparent Ceramic ◽  
Precipitation Method ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
Microwave Assisted

YAG and Yb:YAG transparent ceramic nanopowders for laser crystal were synthesized by microwave-assisted alkoxide hydrolysis precipitation method. The YAG and Yb:YAG nanopowders were characterized by differential thermal analysis and thermo gravimetric analysis (DTA-TG), infrared spectrum (IR), X-ray diffraction (XRD), field emission scanning electron microscope (FESEM) and photoluminescence (PL) spectrum. The results show that the crystallizing temperature of the precursor of YAG and Yb:YAG is about 930 °C. The pure phase YAG and Yb:YAG nanopowders can be obtained at microwave radiation power of 385 W, microwave radiation time of 30 min and sintering temperature of 1100 °C. The average particle size of YAG is about 120 nm. Yb:YAG is uniform sphere and the average sizes is about 100 nm. The intensity of luminescence of Yb:YAG nanopowders decreased with the increasing of microware time. The maximum luminous intensity of the Yb:YAG nanopowders can be obtained when the microwave radiation is 30 min.

Biosynthesis and Characterization of Copper Nanoparticles Using a Bioflocculant Extracted from Alcaligenis faecalis HCB2

2019 ◽  
Vol 11 (11) ◽  
pp. 1064-1070 ◽  
Author(s):  
Nkosinathi G. Dlamini ◽  
Albertus K. Basson ◽  
V. S. R. Rajasekhar Pullabhotla
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Copper Nanoparticles ◽  
Average Particle Size ◽  
Thermo Gravimetric Analysis ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
X Ray ◽  
Transmission Electron ◽  
Ft Ir

Bioflocculant from Alcaligenis faecalis HCB2 was used in the eco-friendly synthesis of the copper nanoparticles. Nanoparticles were characterized using a scanning electron microscope (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy, thermo gravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FT-IR). The transmission electron microscopy images showed close to spherical shapes with an average particle size of ∼53 nm. Energy-dispersive X-ray spectroscopy analysis confirmed the presence of the Cu nanopartilces and also the other elements such as O, C, P, Ca, Cl, Na, K, Mg, and S originated from the bioflocculant. FT-IR results showed the presence of the –OH and –NH2 groups, aliphatic bonds, amide and Cu–O bonds. Powder X-ray diffraction peaks confirmed the presence of (111) and (220) planes of fcc structure at 2 of 33° and 47° respectively with no other impurity peaks.

scholarly journals Synthesis of Cu2ZnSnS4 (CZTS) Ink by an Easy Hydrothermal Method

2021 ◽  
Author(s):  
Mahnaz Karbassi ◽  
Saeid Baghshahi ◽  
Nastaran Riahi-Noori ◽  
Roozbeh Siavash Moakhar
Keyword(s):  
Copper Acetate ◽  
Average Particle Size ◽  
Thermo Gravimetric Analysis ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
Tin Chloride ◽  
Vis Spectroscopy ◽  
Czts Nanoparticles

Abstract The quadrilateral p-type semiconductor Cu2ZnSnS4 (CZTS) with a direct bandgap of 1.4 to 1.5 eV and a high absorption coefficient in the visible light range, is considered an excellent absorbent layer in the production of solar cells. The application of Cu2ZnSnS4 film absorbent materials is promising in the field of low-cost solar cell production. In this paper, a simple, efficient, controllable, and inexpensive solvothermal method is used to make the CZTS nanoparticles from zinc acetate, copper acetate, tin chloride, thiourea, and hexadecyl amine solvent. The ink was prepared from the CZTS powder and applied by the doctor Blade technique on soda-lime glass. The X-ray diffraction (XRD) and Raman spectroscopy analysis showed that the CZTS synthesis nanoparticles had a pure Kesterite structure. The thermo-gravimetric analysis showed about 12% of the loss weight of CZTS nanoparticles using field emission scanning electron microscopy, energy dispersive spectroscopy, dynamic light scattering, and zeta potential indicated that the synthesized nanoparticles had a strong absorption in the range of 125–477 nm with an average particle size of 300 nm and plate shape. The energy bandgap of CZTS nanoparticles was measured to be 1.49 eV using UV-Vis spectroscopy.

Synthesis of Lanthanum Nickelate and Praseodymium Substituted Compounds by Molten Salt Technique

2011 ◽  
Vol 699 ◽  
pp. 67-78 ◽  
Author(s):  
S. Ignatius Arockiam ◽  
L. John Berchmans ◽  
S. Angappan ◽  
A. Visuvasam ◽  
V. Mani
Keyword(s):  
Molten Salt ◽  
Parent Compound ◽  
Average Particle Size ◽  
Thermo Gravimetric Analysis ◽  
Lone Pair ◽  
Rhombohedral Structure ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
Absorption Bands ◽  
Lanthanum Nickelate

Lanthanum Nickelate (LaNiO3) and Praseodymium (Pr) substituted compounds were prepared by molten flux method using chloride precursors. The investigation presents the characterization of the synthesized materials using TGA/DTA, XRD, FTIR, CHNS, EDAX, UV-visible, EPR spectral and SEM studies. The thermo gravimetric analysis reveals the decomposition and thermal reactions of the precursors at different temperature regions. The XRD analysis shows that the synthesized crystals have the rhombohedral structure. FTIR spectra exhibit the absorption bands for the O-H stretching vibration and Ni-O bands at different wave lengths. A shift in band position has been observed on the substitution of Pr3+ions in the parent compound. The CHNS analysis presents the impurities level in the synthesized compounds. The EDAX analysis shows the concentration of La, Ni, Pr and O in the synthesized compounds. The band gap of the material has been determined from UV spectra and it is found to be 4.96 eV for the parent compound. The lone pair of electron state is identified from the EPR spectra. The SEM micrographs have shown the presence of fine crystallites with irregular morphology. The average particle size of the powders is ranging between 25-35 μm. From the above studies, it has been concluded that pure crystals of LaNiO3and Praseodymium substituted compounds can be conveniently synthesized by molten salt technique.

Effect of Polyvinylpyrrolidone Ratio on Synthesis of High Concentration Nano-Silver Colloid

2012 ◽  
Vol 466-467 ◽  
pp. 381-385
Author(s):  
Wei Wei Li ◽  
Lu Hai Li ◽  
Li Xin Mo ◽  
Ji Lan Fu
Keyword(s):  
Particle Size ◽  
Silver Nitrate ◽  
Average Particle Size ◽  
Thermo Gravimetric Analysis ◽  
Molar Ratio ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
Silver Colloid ◽  
High Concentration ◽  
Nano Silver

Conductive ink, especially the nano-silver ink is becoming more and more popular in printable electronic field. In order to synthesize high concentration, stable nano-silver colloid, liquid chemical reduction is used and different ratios of PVP to silver nitrate are studied. After precise adjustments of the parameters, colloid with silver content of wt7.8% is obtained. Particle size distribution, UV-Vis spectra, thermo gravimetric analysis and SEM images are conducted to characterize the silver particles. The results show that when molar ratio of PVP to silver nitrate is 0.6, the average particle size is 170nm and some deposit can be seen, while the ratio increases to 1.5, the size decreases to 68nm, and the residue quality of the silver colloid showed in the TG analysis is 7.88%. After aging for 1 month, the colloid is still stable and the color keeps to the original dark green. When the ratio continues increasing to 2.5, particle size becomes 112nm and some larger particles beyond 3μm can be observed.

scholarly journals Developing of buffer-precipitation method for lead metaborate (Pb(BO2)2 H2O) nanostructures

2020 ◽  
Vol 38 (1) ◽  
pp. 138-142
Author(s):  
Berna Bulbul ◽  
Seda Beyaz
Keyword(s):  
Inductively Coupled Plasma ◽  
Average Particle Size ◽  
Particle Surface ◽  
Synthesis Method ◽  
Cost Effective ◽  
Precipitation Method ◽  
Average Particle ◽  
Gravimetric Analysis ◽  
Reflectance Measurement ◽  
Vis Spectroscopy

AbstractAmorphous lead metaborate (Pb(BO2)2 H2O) nanostructures were synthesized by a simpl and cost-effective synthesis method which is based on precipitation of lead ions using boric acid/sodium hydroxide buffer (pH 9.2) in the presence of polyethylene glycol (PEG). Scanning electron microscopy images showed that the average particle size is 30±9 nm and the particle shape is mostly spherical. The chemical formulation of Pb(BO2)2 H2O was confirmed by infrared spectroscopy, inductively coupled plasma and thermal gravimetric analysis (TGA). The percentage of PEG molecules on the particle surface equal to 2.5 % was determined by TGA. Optical reflectance measurement was performed by UV-Vis spectroscopy. Based on the Kubelka-Munk function, it was calculated that the Pb(BO2)2 H2O nanostructures have a direct band gap of 4.6 eV.

scholarly journals Parametric Study on Microwave-Assisted Pyrolysis Combined KOH Activation of Oil Palm Male Flowers Derived Nanoporous Carbons

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2876
Author(s):  
Napat Kaewtrakulchai ◽  
Kajornsak Faungnawakij ◽  
Apiluck Eiad-Ua
Keyword(s):  
Microwave Radiation ◽  
Oil Palm ◽  
Radiation Power ◽  
Operating Time ◽  
Bet Surface Area ◽  
Koh Activation ◽  
Nanoporous Carbons ◽  
Microwave Assisted ◽  
Activating Agent ◽  
Male Flowers

Oil palm male flowers (PMFs), an abundant agricultural waste from oil palm plantation in Thailand, have been utilized as an alternative precursor to develop nanoporous carbons (NPCs) via microwave-assisted pyrolysis combined potassium hydroxide (KOH) activation. The influences of relevant processing variables, such as activating agent ratio, microwave power, and activation time on the specific pore characteristics, surface morphology, and surface chemistry of PMFs derived nanoporous carbons (PMFCs) have been investigated to explore the optimum preparation condition. The optimum condition under a microwave radiation power of 700 W, activation holding time of 6 min, and activating agent ratio of 2:1 obtained the PMFC with the highest Brunauer–Emmett–Teller (BET) surface area and total pore volume approximately of 991 m2/g and 0.49 cm3/g, composed of a carbon content of 74.56%. Meanwhile, PMFCs have a highly microporous structure of about 71.12%. Moreover, activating agent ratio and microwave radiation power indicated a significant influence on the surface characteristics of PMFCs. This study revealed the potential of oil palm male flowers for the NPCs’ production via microwave-assisted KOH activation with a short operating-time condition.

scholarly journals Enhanced Photocatalytic Activity of Cu2O Cabbage/RGO Nanocomposites under Visible Light Irradiation

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1712
Author(s):  
Appusamy Muthukrishnaraj ◽  
Salma Ahmed Al-Zahrani ◽  
Ahmed Al Otaibi ◽  
Semmedu Selvaraj Kalaivani ◽  
Ayyar Manikandan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermo Gravimetric Analysis ◽  
Visible Region ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dye Pollutants ◽  
Transmission Electron

Towards the utilization of Cu2O nanomaterial for the degradation of industrial dye pollutants such as methylene blue and methyl orange, the graphene-incorporated Cu2O nanocomposites (GCC) were developed via a precipitation method. Using Hummers method, the grapheme oxide (GO) was initially synthesized. The varying weight percentages (1–4 wt %) of GO was incorporated along with the precipitation of Cu2O catalyst. Various characterization techniques such as Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), UV–visible diffused reflectance (UV-DRS), Raman spectroscopy, thermo gravimetric analysis (TGA), energy-dispersive X-ray analysis (EDX), and electro chemical impedance (EIS) were followed for characterization. The cabbage-like morphology of the developed Cu2O and its composites were ascertained from field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HR-TEM). In addition, the growth mechanism was also proposed. The results infer that 2 wt % GO-incorporated Cu2O composites shows the highest value of degradation efficiency (97.9% and 96.1%) for MB and MO at 160 and 220 min, respectively. Further, its catalytic performance over visible region (red shift) was also enhanced to an appreciable extent, when compared with that of other samples.

Enhanced oral bioavailability of nisoldipine-piperine-loaded poly-lactic-co-glycolic acid nanoparticles

2017 ◽  
Vol 6 (6) ◽  
pp. 517-526 ◽  
Author(s):  
Permender Rathee ◽  
Anjoo Kamboj ◽  
Shabir Sidhu
Keyword(s):  
Oral Bioavailability ◽  
Drug Loading ◽  
Average Particle Size ◽  
Entrapment Efficiency ◽  
Pharmacokinetic Interaction ◽  
Precipitation Method ◽  
Pharmacokinetic Studies ◽  
Average Particle

AbstractBackground:Piperine helps in the improvement of bioavailability through pharmacokinetic interaction by modulating metabolism when administered with other drugs. Nisoldipine is a substrate for cytochrome P4503A4 enzymes. The study was undertaken to assess the influence of piperine on the pharmacokinetics and pharmacodynamics of nisoldipine nanoparticles in rats.Methods:Optimization studies of nanoparticles were performed using Taguchi L9 orthogonal array, and the nanoparticles were formulated by the precipitation method. The influence of piperine and nanoparticles was evaluated by means of in vivo kinetic and dynamic studies by oral administration in rats.Results:The entrapment efficiency, drug loading, ζ potential, and average particle size of optimized nisoldipine-piperine nanoparticles was 89.77±1.06%, 13.6±0.56%, −26.5 mV, and 132±7.21 nm, respectively. The in vitro release in 0.1 n HCl and 6.8 pH phosphate buffer was 96.9±0.48% and 98.3±0.26%, respectively. Pharmacokinetic studies showed a 4.9-fold increase in oral bioavailability and a >28.376±1.32% reduction in systemic blood pressure by using nanoparticles as compared to control (nisoldipine suspension) in Wistar rats.Conclusion:The results revealed that piperine being an inhibitor of cytochrome P4503A4 enzymes enhanced the bioavailability of nisoldipine by 4.9-fold in nanoparticles.

scholarly journals Preparation and characterization of domperidone nanoparticles for dissolution improvement

2018 ◽  
Vol 27 (1) ◽  
pp. 39-52
Author(s):  
Mohammed Sabar Al-lami ◽  
Malath H. Oudah ◽  
Firas A. Rahi
Keyword(s):  
Particle Size ◽  
Average Particle Size ◽  
In Vitro Release ◽  
Methyl Cellulose ◽  
Precipitation Method ◽  
Average Particle ◽  
Antisolvent Precipitation ◽  
Stirring Time

This study was carried out to prepare and characterize domperidone nanoparticles to enhance solubility and the release rate. Domperidone is practically insoluble in water and has low and an erratic bioavailability range from 13%-17%. The domperidone nanoparticles were prepared by solvent/antisolvent precipitation method at different polymer:drug ratios of 1:1 and 2:1 using different polymers and grades of poly vinyl pyrolidone, hydroxy propyl methyl cellulose and sodium carboxymethyl cellulose as stabilizers. The effect of polymer type, ratio of polymer:drug, solvent:antisolvent ratio, stirring rate and stirring time on the particle size, were investigated and found to have a significant (p? 0.05) effect on particle size. The best formula was obtained with lowest average particle size of 84.05. This formula was studied for compatibility by FTIR and DSC, surface morphology by FESEM and crystalline state by XRPD. Then domperidone nanoparticles were formulated into a simple capsule dosage form in order to study of the in vitro release of drug from nanoparticles in comparison raw drug and mixture of polymer:drug ratios of 2:1. The release of domperidone from best formula was highly improved with a significant (p? 0.05) increase.

Investigations on Cu2+-substituted Ni–Zn ferrite nanoparticles

2016 ◽  
Vol 30 (32n33) ◽  
pp. 1650347
Author(s):  
Amarjeet ◽  
Vinod Kumar
Keyword(s):  
Spinel Phase ◽  
Thermo Gravimetric Analysis ◽  
Peak Position ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Zn Ferrite

[Formula: see text] ([Formula: see text] = 0.1, 0.3 and 0.5) nanoparticles were prepared by chemical co-precipitation method. The developed nanoparticles were characterized for structural properties by powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. Peak position in the X-ray diffraction pattern confirmed the single spinel phase of the developed particles. Infrared (IR) spectroscopy in mid-IR range showed the presence of characteristic absorption bands corresponding to octahedral and tetrahedral bonds in the spinel structure of prepared samples. Thermo-gravimetric analysis (TGA) measurements showed a considerable weight loss in the developed samples above 700[Formula: see text]C. Frequency dependence of the electrical properties of the developed material pellets was studied in the frequency range of 1 kHz–5 MHz. Temperature dependence of the dielectric constant of [Formula: see text] was studied at different temperatures, i.e. at 425, 450 and 475 K, in the frequency range of 1 kHz–5 MHz. It was found that the electrical conductivity decreases with increasing Cu[Formula: see text] ion content while it increases with the increase in temperature.

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