Study of Synthesis of Nanoparticulate Zinc Oxide Aiming at the Confection of Appropriated Targets for the Production of Radioisotopes

2016 ◽  
Vol 881 ◽  
pp. 485-490
Author(s):  
Nelcy D.S. Mohallem ◽  
Juliana B. da Silva ◽  
Cristiana P. Rezende
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Gamma Spectroscopy ◽  
Low Cost ◽  
Average Particle Size ◽  
Average Particle ◽  
Radioisotope Production ◽  
Target Preparation ◽  
Multifunctional Material ◽  
Freeze Dried

Zinc Oxide (ZnO) is a multifunctional material, which produces radionuclides of gallium by irradiation, widely used in diagnosis and nuclear medicine. In this work, two precursors were tested as well as two routes of synthesis, with the objective of obtaining nanoparticles appropriate to the production of pellets with grain size and porosity suitable for target preparation used in the radioisotope production by irradiation. The sintered pellets obtained from zinc acetate and NH4OH, and freeze-dried presented density of 90% of the theoretical density, average particle size of 1 μm and macropore size of 500 nm. These targets generated radionuclide of gallium (67Ga and 66Ga) inside the pores, without rupture of the pellets, confirmed by gamma spectroscopy, at low cost of production.

scholarly journals Thermal, Structural, and Physical Properties of Freeze Dried Tropical Fruit Powder

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
K. A. Athmaselvi ◽  
C. Kumar ◽  
M. Balasubramanian ◽  
Ishita Roy
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Average Particle Size ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Tropical Fruit ◽  
X Ray ◽  
Freeze Dried ◽  
Fruit Powder ◽  
Lcr Meter

This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya) fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.

scholarly journals Investigation of Organic Field-Effect Transistor (OFET) based NO2 Sensing Response using Low-Cost Green Synthesized Zinc Oxide Nanoparticles

2020 ◽  
Vol 33 (1) ◽  
pp. 31-36
Author(s):  
G. Balanagireddy ◽  
Ashwath Narayana ◽  
M. Roopa
Keyword(s):  
Zinc Oxide ◽  
Field Effect ◽  
Room Temperature ◽  
Field Effect Transistor ◽  
Low Cost ◽  
Average Particle Size ◽  
Microwave Assisted Synthesis ◽  
Average Particle ◽  
Nanostructured Particles ◽  
Effect Transistor

A low-cost and green-synthesized zinc oxide nanostructured particles are extensively studied owing to their remarkable and ample characteristics with less toxicity and eco-friendly approach. The present work comprehends the green synthesis of ZnO nanostructured particles using bougainvillea leaf extract-arbitrated microwave-assisted synthesis and their use in field effect transistor for nitrogen dioxide sensing at room temperature. The as-synthesized nanoparticles were characterized using analytical techniques; XRD determined the pure crystallite structure with no impurities, SEM confirmed the spherical shape of nanoparticles with ~20 nm (average particle size) and the atomic weight percentage were analyzed using EDAX, notable photophysical properties were revealed from absorption and emission spectra performed using UV-visible spectroscopy. Poly(3-hexylthiophene) and ZnO nanoparticles were employed in the field effect transistor (p-type) for NO2 sensing at room temperature with the mobility (field-effect) of ~10-4 cm2 V-1 s-1. The sensitivity of the fabricated OFET device was extracted from the transistor characteristics (at Vgs = -30 V and Vds = -40 V) found to be ~4.8 × 10-3 nA/ppm. The device exhibited engrossing characteristics such as excellent recoverability (> 95%), with ultrafast response time (< 30 s) and greater sensitivity with high stability as can be assessed from the electrical characteristics.

Nanocrystalline BaTiO3 from freeze-dried nitrate solutions

1996 ◽  
Vol 11 (5) ◽  
pp. 1199-1209 ◽  
Author(s):  
J. M. McHale ◽  
P. C. McIntyre ◽  
K. E. Sickafus ◽  
N. V. Coppa
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
High Surface ◽  
Nitrate Solution ◽  
Average Particle Size ◽  
Volume Ratio ◽  
Product Formation ◽  
Cubic Phase ◽  
Average Particle ◽  
Freeze Dried

An aqueous, all nitrate, solution-based preparation of BaTiO3 is reported here. Rapid freezing of a barium and titanyl nitrate solution, followed by low temperature sublimitation of the solvent, yielded a freeze-dried nitrate precursor which was thermally processed to produce BaTiO3. XRD revealed that 10 min at temperatures ≧600 °C resulted in the formation of phase pure nanocrystalline BaTiO3. TEM revealed that the material was uniform and nanocrystalline (10–15 nm). The high surface to volume ratio inherent in these small particles stabilized the cubic phase of BaTiO3 at room temperature. It was also found that the average particle size of the BaTiO3 produced was highly dependent upon calcination temperature and only slightly dependent upon annealing time. This result suggests a means of selection of particle size of the product through judicious choice of calcination temperature. The experimental details of the freeze-dried precursor preparation, thermal processing of the precursor, product formation, and product morphology are discussed.

scholarly journals Improved biodiesel production from waste cooking oil with mixed methanol–ethanol using enhanced eggshell-derived CaO nano-catalyst

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yeshimebet Simeon Erchamo ◽  
Tadios Tesfaye Mamo ◽  
Getachew Adam Workneh ◽  
Yedilfana Setarge Mekonnen
Keyword(s):  
Particle Size ◽  
Low Cost ◽  
Average Particle Size ◽  
Waste Cooking Oil ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Average Particle ◽  
Cooking Oil ◽  
Nano Catalyst

AbstractIn this report, the utilization of mixed methanol–ethanol system for the production of biodiesel from waste cooking oil (WCO) using enhanced eggshell-derived calcium oxide (CaO) nano-catalyst was investigated. CaO nano-catalyst was produced by calcination of eggshell powder at 900 °C and followed by hydration-dehydration treatment to improve its catalytic activity. The particle size, morphology, and elemental composition of a catalyst were characterized by using XRD, SEM, and EDX techniques, respectively. After hydration-dehydration the shape of a catalyst was changed from a rod-like to honeycomb-like porous microstructure. Likewise, average particle size was reduced from 21.30 to 13.53 nm, as a result, its surface area increases. The main factors affecting the biodiesel yield were investigated, accordingly, an optimal biodiesel yield of 94% was obtained at 1:12 oil to methanol molar ratio, 2.5 wt% catalyst loading, 60 °C, and 120-min reaction time. A biodiesel yield of 88% was obtained using 6:6 equimolar ratio of methanol to ethanol, the yield even increased to 91% by increasing the catalyst loading to 3.5 wt%. Moreover, by slightly increasing the share of methanol in the mixture, at 8:4 ratio, the maximum biodiesel yield could reach 92%. Therefore, we suggest the utilization of methanol–ethanol mixture as a reactant and eggshell-derived CaO as a catalyst for enhanced conversion of WCO into biodiesel. It is a very promising approach for the development of low-cost and environmentally friendly technology. Properties of the biodiesel were also found in good agreement with the American (ASTM D6571) fuel standards.

“Colloidal” Zinc Oxide

1937 ◽  
Vol 10 (2) ◽  
pp. 309-311
Author(s):  
H. A. Curran ◽  
T. R. Dawson
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Manufacturing Industry ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Average Particle ◽  
Average Particle Diameter ◽  
Zinc Oxides ◽  
Two Samples ◽  
Good Grade

Abstract Some ten years ago, when so-called “colloidal” zinc oxides were being introduced to the rubber manufacturing industry, two samples were investigated to determine their behavior in rubber compared with ordinary good quality zinc oxide used in rubber. According to accounts published at the time, “colloidal” zinc oxide possesses an average particle size just within the limit of resolution of high-power microscopes, and an average particle diameter of 0.15 micron. In rubber it has been claimed to impart superior reinforcement, higher tensile strength, greater resistance to abrasion, and enhanced activation of organic accelerators. In the following report, samples A and B represent two samples of the same grade of “colloidal” zinc oxide, and C a good grade of regular zinc oxide.

Morphological Studies of Electrodeposited Cobalt Based Coatings: Effect of Alloying Elements

2014 ◽  
Vol 938 ◽  
pp. 52-57 ◽  
Author(s):  
Nor Azrina Resali ◽  
Koay Mei Hyie ◽  
Wan Normimi Roslini Abdullah ◽  
Nor Hayati Saad
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Low Cost ◽  
Average Particle Size ◽  
Void Formation ◽  
Dendritic Morphology ◽  
Average Particle ◽  
Morphological Studies ◽  
Cobalt Coating ◽  
Surface Morphologies

Electrodeposition is known as a simple and low-cost method to synthesize good-quality coating with excellent hardness. In this work, the morphology changes on Cobalt coating with the addition of iron and nickel elements were investigated. Co (Cobalt) and Co-based alloy coatings were prepared by electrodeposition technique using sulfate-based electrolytes. The process was conducted at 50°C temperature in an acidic environment (pH 3). The pure Co coating shows the tendency to form snowflake-like morphology structure. The dendritic morphology appeared in the Co-Fe coatings. However, the dendritic morphology was totally disappeared in the Co-Ni-Fe morphology and replaced by spherical morphology. The crystal structure of Co-Ni-Fe coating changed from bcc into mixed bcc+fcc structure with the addition of Ni element in Co-Fe composition. The Ni element which had been introduced in the Co-Fe composition improved the surface morphology and reduced the average particle size. The surface morphologies in the coatings affect the particles size and hardness property. This may due to the formation of full, compact coatings morphology and introduction of particles boundaries interphase. The Co-Ni-Fe coating with smaller particle size, less void formation and mixed crystal structure of bcc+fcc was roughly two times harder than pure Co.

A Study on Leaching of Zinc Oxide Ore in Ammonium Sulfate Solution

2014 ◽  
Vol 522-524 ◽  
pp. 1463-1466
Author(s):  
Dan Dan Wu ◽  
Shu Ming Wen ◽  
Jing Yang ◽  
Yi Jie Wang ◽  
Chao Lv
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Ammonium Sulfate ◽  
Average Particle Size ◽  
Sulfate Solution ◽  
Solution Temperature ◽  
Average Particle ◽  
Leaching Rate ◽  
Ammonium Sulfate Solution ◽  
Effects Of Temperature

In this paper, the leaching effect of zinc oxide ore was investigated using ammonium sulfate solution as leaching agent. The effects of temperature, concentration of ammonium sulfate, average particle size and stirring speed on the leaching of zinc oxide ore were studied. The leaching rate increased with increasing solution temperature, concentration, and stirring speed as well as with decreasing average particle size. Ammonium sulfate solution can therefore be used as an effective leaching agent for zinc extraction from zinc oxide ore.

Measurement of Average Particle Size of Fine Pigments

1932 ◽  
Vol 5 (2) ◽  
pp. 202-215 ◽  
Author(s):  
S. D. Gehman ◽  
T. C. Morris
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Carbon Black ◽  
Wave Length ◽  
Average Particle Size ◽  
Average Particle ◽  
Particle Sizes ◽  
Carbon Blacks ◽  
Count Method

Abstract A method of obtaining excellently dispersed suspensions of rubber pigments of accurate concentration is described in which the pigment is milled into rubber and the stock then dissolved in a solvent. The average particle sizes of carbon blacks measured by the Zsigmondy count method were found to range from 0.061μ for rubber gas black to 2.22μ for the coarsest one measured. The zinc oxide pigments had average particle sizes from 0.076μ to 0.57μ.. Measurements on several other pigments of interest are included. Because of the high visibility in the ultra-microscope, this method gives smaller values for average particle size than the photomicrographic methods. The results have been used to calibrate a microturbidimeter of the extinction type for use in measuring average particle size. Curves are included showing how the turbidities of suspensions of zinc oxide and carbon black vary with the average particle size, concentration, and wave length of light used.

scholarly journals Smart Magnetically Responsive Hydrogel Nanoparticles Prepared by a Novel Aerosol-Assisted Method for Biomedical and Drug Delivery Applications

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Ibrahim M. El-Sherbiny ◽  
Hugh D. C. Smyth
Keyword(s):  
Drug Delivery ◽  
Particle Size ◽  
Low Cost ◽  
Average Particle Size ◽  
Average Particle ◽  
Partial Acid Hydrolysis ◽  
Hydrogel Nanoparticles ◽  
Air Jet ◽  
Magnetic Hydrogel ◽  
Drug Delivery Applications

We have developed a novel spray gelation-based method to synthesize a new series of magnetically responsive hydrogel nanoparticles for biomedical and drug delivery applications. The method is based on the production of hydrogel nanoparticles from sprayed polymeric microdroplets obtained by an air-jet nebulization process that is immediately followed by gelation in a crosslinking fluid. Oligoguluronate (G-blocks) was prepared through the partial acid hydrolysis of sodium alginate. PEG-grafted chitosan was also synthesized and characterized (FTIR, EA, and DSC). Then, magnetically responsive hydrogel nanoparticles based on alginate and alginate/G-blocks were synthesized via aerosolization followed by either ionotropic gelation or both ionotropic and polyelectrolyte complexation using CaCl2or PEG-g-chitosan/CaCl2as crosslinking agents, respectively. Particle size and dynamic swelling were determined using dynamic light scattering (DLS) and microscopy. Surface morphology of the nanoparticles was examined using SEM. The distribution of magnetic cores within the hydrogels nanoparticles was also examined using TEM. In addition, the iron and calcium contents of the particles were estimated using EDS. Spherical magnetic hydrogel nanoparticles with average particle size of 811 ± 162 to 941 ± 2 nm were obtained. This study showed that the developed method is promising for the manufacture of hydrogel nanoparticles, and it represents a relatively simple and potential low-cost system.

scholarly journals Comparative study on zinc oxide nanocrystals synthesized by two precipitation methods

Cerâmica ◽  
2018 ◽  
Vol 64 (369) ◽  
pp. 91-96 ◽  
Author(s):  
M. R. Bodke ◽  
Y. Purushotham ◽  
B. N. Dole
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Band Gap ◽  
Energy Band ◽  
Zinc Acetate Dihydrate ◽  
Average Particle Size ◽  
Chemical Compositions ◽  
Average Particle ◽  
Nitrate Hexahydrate ◽  
Energy Band Gap

Abstract Zinc oxide nanocrystals were synthesized by two precipitation methods successfully. The nanocrystals prepared via method I (zinc acetate dihydrate precipitation with KOH) were smaller in crystallite size (~20 nm) as compared to method II (zinc nitrate hexahydrate precipitation with N,N-dimethylformamide, ~33 nm). FTIR technique was used to study chemical bonding; SEM and EDS were used to study morphology and chemical compositions. Number of concentric rings corresponding to diffraction peaks was higher in SAED pattern for ZnO nanocrystals synthesized by method I than II. Variation in the energy band gap as a function of particle size was determined using absorption spectra from UV-vis-NIR spectrophotometer. Redshift was observed in the energy band gap of sample prepared via method II. Particle size and the structure of the nanocrystals were analysed by transmission electron microscope (TEM). From TEM study, it was found that the average particle size of method I nanocrystals was smaller compared to method II nanocrystals. Magnetic study was carried out using VSM. Ferromagnetism like contribution was observed for the sample prepared by method II.

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