scholarly journals THE CALCINATION TEMPERATURE EFFECT ON THE ANTIOXIDANT AND RADIOPROTECTION PROPERTIES OF CeO2 NANOPARTICLES

REAKTOR ◽  
2018 ◽  
Vol 18 (1) ◽  
pp. 22 ◽  
Author(s):  
Iis Nurhasanah ◽  
Weni Safitri ◽  
Tri Windarti ◽  
Agus Subagio
Keyword(s):  
Escherichia Coli ◽  
Temperature Effect ◽  
Crystallite Size ◽  
Calcination Temperature ◽  
Enhancement Factor ◽  
Antioxidant Properties ◽  
Ceo2 Nanoparticles ◽  
Precipitation Method ◽  
Dose Enhancement ◽  
X Ray

The CeO2 nanoparticles are very interesting to be studied as biomedical materials due to its unique physical and chemical properties. The non-stoichiometric properties of CeO2 play a role in the redox/catalytic processes that scavenging free radicals. These properties make CeO2 nanoparticles as being potentially antioxidant and radioprotector materials. In this paper, we report the calcination temperature effect on the antioxidant properties and  radioprotective effect of CeO2 nanoparticles synthesized by precipitation method. The CeO2 nanoparticles were synthesized by precipitation method at various calcinations temperatures (300oC – 700oC). The formation of CeO2 nanoparticles and crystallite size was analyzed using X-ray diffractometers. The DPPH method was used to investigate antioxidant properties of CeO2.  Dose Enhancement Factor (DEF) of CeO2 nanoparticles were determined by measurement of the absorbed dose of X-ray radiation (Linac 6 MV 200 MU). X-ray diffraction pattern showed formation of cubic fluorite of CeO2 nanoparticles with crystallite size in the range 9 nm-18 nm.  Calcination temperature of 500oC resulted in CeO2 nanoparticles with the best antioxidant properties and lowest DEF value. The radioprotection effect of CeO2 nanoparticles was evaluated based on Escherichia coli survival toward X-ray radiation with a dose of 2 Gy. The CeO2 nanoparticles increased Escherichia coli survival of about 24.8% order.  These results suggested that CeO2 nanoparticles may potentially be as radioprotector of X-ray Linac 6 MV. Keywords: Antioxidant, CeO2 nanoparticles, Dose Enhancement Factor (DEF), radioprotector

Synthesis and Characterization of Cerium Oxide (CeO2) Nanoparticles

2009 ◽  
Vol 609 ◽  
pp. 189-194 ◽  
Author(s):  
C. Benmouhoub ◽  
A. Kadri ◽  
N. Benbrahim ◽  
S. Hadji
Keyword(s):  
Crystallite Size ◽  
Cerium Oxide ◽  
Ceo2 Nanoparticles ◽  
Precipitation Method ◽  
Synthesis And Characterization

Nanoparticles of cerium oxide (CeO2) are synthesized with cerium (III) nitrates (Ce(NO3)3, 6H2O) by precipitation method in ammonium hydroxyl solution (NH4OH). The influence of several parameters such as nature of the solvent, synthesizing temperature and the calcination on the crystallite size is studied by XRD, TEM and BET methods. The results show that both calcinations and synthesizing temperature affect the particles size. Also, the nature of solvent has a great effect on the morphology of CeO2 nanoparticles.

scholarly journals Different distributions of gold nanoparticles on the tumor and calculation of dose enhancement factor by Monte Carlo simulation

2019 ◽  
Vol 5 (4) ◽  
pp. 361-371 ◽  
Author(s):  
Sajad Keshavarz ◽  
Dariush Sardari
Keyword(s):  
Gold Nanoparticles ◽  
Uniform Distribution ◽  
Enhancement Factor ◽  
Radiation Energy ◽  
Distribution Model ◽  
Distribution Models ◽  
Dose Enhancement ◽  
X Ray ◽  
Nanoparticle Distribution ◽  
Nanoparticle Sizes

Gold nanoparticles can be used to increase the dose of the tumor due to its high atomic number as well as being free from apparent toxicity. The aim of this study is to evaluate the effect of distribution of gold nanoparticles models, as well as changes in nanoparticle sizes and spectrum of radiation energy along with the effects of nanoparticle penetration into surrounding tissues in dose enhancement factor DEF. Three mathematical models were considered for distribution of gold nanoparticles in the tumor, such as 1-uniform, 2- non-uniform distribution with no penetration margin and 3- non-uniform distribution with penetration margin of 2.7 mm of gold nanoparticles. For this purpose, a cube-shaped water phantom of 50 cm size in each side and a cube with 1 cm side placed at depth of 2 cm below the upper surface of the cubic phantom as the tumor was defined, and then 3 models of nanoparticle distribution were modeled. MCNPX code was used to simulate 3 distribution models. DEF was evaluated for sizes of 20, 25, 30, 50, 70, 90 and 100 nm of gold nanoparticles, and 50, 95, 250 keV and 4 MeV photon energies. In uniform distribution model the maximum DEF was observed at 100 nm and 50 keV being equal to 2.90, in non-uniform distribution with no penetration margin, the maximum DEF was measured at 100 nm and 50 keV being 1.69, and in non-uniform distribution with penetration margin of 2.7 mm, the maximum DEF was measured at 100 nm and 50 keV as 1.38, and the results have been showed that the dose was increased by injecting nanoparticles into the tumor. It is concluded that the highest DEF could be achieved in low energy photons and larger sizes of nanoparticles. Non-uniform distribution of gold nanoparticles can increase the dose and also decrease the DEF in comparison with the uniform distribution. The non-uniform distribution of nanoparticles with penetration margin showed a lower DEF than the non-uniform distribution without any margin and uniform distribution. Meanwhile, utilization of the real X-ray spectrum brought about a smaller DEF in comparison to mono-energetic X-ray photons.

The Influence of Calcination Temperature on Quantitative Phase of Hematite from Iron Stone Tanah Laut

2015 ◽  
Vol 1112 ◽  
pp. 489-492
Author(s):  
Ali Mufid ◽  
M. Zainuri
Keyword(s):  
Particle Size ◽  
Calcination Temperature ◽  
Thermo Gravimetric Analysis ◽  
Precipitation Method ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Particle Size Analyzer ◽  
Co Precipitation

This research aims to form particles of hematite (α-Fe2O3) with a basis of mineral iron ore Fe3O4 from Tanah Laut. Magnetite Fe3O4 was synthesized using co-precipitation method. Further characterization using X-ray fluorescence (XRF) to obtain the percentage of the elements, obtained an iron content of 98.51%. Then characterized using thermo-gravimetric analysis and differential scanning calorimetry (TGA-DSC) to determine the calcination temperature, that at a temperature of 445 °C mass decreased by 0.369% due to increase in temperature. Further Characterization of X-ray diffraction (XRD) to determine the phases formed at the calcination temperature variation of 400 °C, 445 °C, 500 °C and 600 °C with a holding time of 5 hours to form a single phase α-Fe2O3 hematite. Testing with a particle size analyzer (PSA) to determine the particle size distribution, where test results indicate that the α-Fe2O3 phase of each having a particle size of 269.7 nm, 332.2 nm, 357.9 nm, 412.2 nm. The best quantity is shown at a temperature of 500 °C to form the hematite phase. This result is used as the calcination procedure to obtain a source of Fe ions in the manufacture of Lithium Ferro Phosphate.

scholarly journals PENGARUH WAKTU KALSINASI TERHADAP SIFAT FISIKA-KIMIA HIDROKSIAPATIT DARI CANGKANG GELOINA COAXANS

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Pepi Helza Yanti ◽  
Yendro Gandi
Keyword(s):  
Chemical Composition ◽  
Crystallite Size ◽  
Functional Groups ◽  
Ftir Spectrum ◽  
Precipitation Method ◽  
Absorption Bands ◽  
X Ray ◽  
Main Chemical Composition ◽  
Scherrer Equation

Hidroksiapatit (HAp) merupakan salah satu senyawa biokeramik yang digunakan dalam berbagai aplikasi.  Pada penelitian ini telah dilakukan sintesis hidroksiapatit (HAp) dengan metode pengendapan menggunakan cangkang lokan (Geloina coaxans) dan H3PO4  sebagai prekursor. Analisis menggunakan X-Ray Flourocence (XRF) menunjukkan bahwa komposisi kimia utama pada cangkang lokan (Geloina coaxans) adalah CaO.  Produk terbaik diperoleh melalui waktu kalsinasi pada suhu 900 oC selama 180 menit yang ditunjukkan dengan puncak yang memiliki intensitas tertinggi pada 2θ = 31,7o dan puncak spesifik lainnya untuk hidroksiapatit pada 2θ = 32,89o, 32, 17o, 25,86o dan 49,46o. Difraktogram dibandingkan dengan JCPDS (No 09-0432). Berdasarkan perhitungan menggunakan persamaan Scherrer, didapatkan ukuran kristal dari hidroksiapatit (HAp) adalah 26,62 nm. Analisis menggunakan FTIR juga telah dilakukan untuk mengidentifikasi gugus fungsi pada hidroksiapatit yang diperoleh. Dari spektrum FTIR menunjukkan adanya pita serapan yang khas untuk gugus  OH‒, CO32- dan PO43-pada hidroksiapatit. Morfologi partikel berbentuk granular seperti bola dan gumpalan yang tidak seragam diperoleh melalui analisis menggunakan SEM.. ABSTRACT  Hydroxyapatite (HAp) is a bioceramic compound that is used in various applications. In this research, hydroxyapatite (HAp) synthesis has been carried out by precipitation method using Geloina coaxans shell and H3PO4 as precursors. Analysis using X-Ray Flourocence (XRF) showed that the main chemical composition of Geloina coaxans shell was CaO. The best product was obtained by calcination at 900 oC for 180 minutes indicated by a peak having the highest intensity at 2θ = 31.7o and other specific peaks for hydroxyapatite at 2θ = 32.89o, 32 ,17o, 25.86o and 49.46o. The difractogram was compared to JCPDS (No 09-0432). Based on calculations using the Scherrer equation, the crystallite size of hydroxyapatite was 26.62 nm. Analysis using FTIR has also been carried out to identify the functional groups of the hydroxyapatite obtained. The FTIR spectrum showed that there were unique absorption bands  for OH‒, CO32- and PO43- groups on hydroxyapatite. Analysis using SEM showed that the morphology was granular like balls and non-uniform aggregate

scholarly journals Synthesis of Zinc Oxide Nanoparticles for Oil Upgrading and Wax Deposition Control: Effect of Calcination Temperature

2020 ◽  
Vol 20 (4) ◽  
pp. 746
Author(s):  
Siti Nurliyana Che Mohamed Hussein ◽  
Fatin Syahirah Mohamed Fuad ◽  
Marina Ismail
Keyword(s):  
Crude Oil ◽  
Crystallite Size ◽  
Calcination Temperature ◽  
Zno Nanoparticles ◽  
Viscosity Reduction ◽  
Heavy Crude Oil ◽  
Wax Deposition ◽  
X Ray ◽  
Heavy Crude ◽  
Deposition Control

In this study, ZnO nanoparticles were synthesized using a sol-gel method for oil upgrading and wax deposition control. The synthesized ZnO nanoparticles were used to measure viscosity and wax deposition in the heavy crude oil and to investigate the effectiveness of the nanoparticles in the reduction of viscosity and wax deposition control of the heavy crude oil. This study investigated the effect of calcination temperature on ZnO nanoparticles during synthesis towards viscosity reduction and wax deposition control. ZnO nanoparticles were calcined at different temperatures ranging from 300 to 900 °C. The calcined ZnO nanoparticles were characterized using X-ray diffraction (XRD), Field Emission Scanning Electron microscope (FESEM), and Energy-dispersive X-ray spectroscopy (EDX) for its structure, size, shape, and morphology. The characterization results showed a hexagonal wurtzite structure of ZnO nanoparticles. The physical properties and rheology of heavy crude oil were characterized by using Electronic Rheometer and cold finger method to analyze the viscosity, shear rate, and wax deposition of the heavy crude oil for performance study. Decreased in crystallite size from 15.59 to 12.84 nm was observed with increasing calcination temperature from 300 to 400 °C, and a further increase of calcination temperature from 400 to 900 °C, the crystallite size increased from 12.84 to 41.58 nm. The degree viscosity reduction (DVR %) of heavy crude oil was observed to increase by 41.7%, with decreasing ZnO nanoparticles size from 30.11 nm to 12.84 nm. The optimum calcination temperature was 400 °C. Wax deposition decreases by 32.40% after the addition of ZnO nanoparticles into heavy crude oil.

Synthesis and Characterization of Stabilized Tetragonal Nano Zirconia by Precipitation Method

2019 ◽  
Vol 56 ◽  
pp. 142-151
Author(s):  
Hassan Shokry ◽  
Marwa Elkady ◽  
Hesham Hamad
Keyword(s):  
Phase Transformation ◽  
Crystallite Size ◽  
Calcination Temperature ◽  
Average Crystallite Size ◽  
Precipitation Method ◽  
Synthesis And Characterization ◽  
Calcination Temperatures ◽  
Ft Ir ◽  
20 Nm

Nano sized ZrO2 nanopowder was synthesized by precipitation method. Phase transformation was investigated as a function of calcination temperature by XRD, SEM , and FT-IR. It is indicated that the thermal anneling from 400 to 800 °C resulted in increasing the average crystallite size from 12 to 20 nm. As the calcination temperature increased, the crystallite size and the agglomeration were increased. The increase in the monoclinic content and grain growth are caused by the calcination temperatures even calcination at 800 °C.

Synthesis of High-Purity Fe2TiO5 Powders Utilizing a Local Ironstone

2019 ◽  
Vol 964 ◽  
pp. 50-54 ◽  
Author(s):  
Armayani Armayani ◽  
Irhamsyah Andi ◽  
Pratapa Suminar
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crystallite Size ◽  
Calcination Temperature ◽  
High Purity ◽  
Ball Mill ◽  
Weight Fraction ◽  
Commercial Product ◽  
X Ray Diffraction ◽  
X Ray

The synthesis of Fe2TiO5 powders has been successfully performed by making use of Fe2O3 and TiO2 powders. The Fe2O3 powder was obtained from local ironstone in Tanah Laut, South Kalimantan, while the TiO2 powder was a commercial product. The Fe2O3 powder was obtained from the local ironstone through coprecipitation method on pH 5, followed by calcination at 800 °C for 1 hour. The synthesis of Fe2TiO5 powder was done by mixing the raw powders using Planetary Ball Mill method for 5 hours. Thermogravimetric dan Differential Thermal Analysis (TG-DTA) was performed to estimate the calcination temperature. The milled mixtures were then calcined at temperatures of 700 – 1100 °C. X-Ray Diffraction (XRD) data showed that Fe2TiO5 formation started at 800 °C with a weight fraction of 3.60 wt%. The XRD data also showed that at 1100 °C the Fe2TiO5 formation has completed. The crystallite size of Fe2TiO5 powders was 50 and 66 nm after calcination at 900 and 1100 °C, respectively.

Characterization of the Theorectical Radiation Dose Enhancement from Nanoparticles

2007 ◽  
Vol 6 (5) ◽  
pp. 395-401 ◽  
Author(s):  
John C. Roeske ◽  
Luis Nuñez ◽  
Mark Hoggarth ◽  
Edwardine Labay ◽  
Ralph R. Weichselbaum
Keyword(s):  
Radiation Dose ◽  
Enhancement Factor ◽  
Low Energy ◽  
External Beam ◽  
X Rays ◽  
Nanoparticle Concentration ◽  
Dose Enhancement ◽  
X Ray ◽  
Delivered Dose

Recently, nanoparticles have been considered as a method of providing radiation dose enhancement in tumors. In order to quantify this affect, a dose enhancement factor (DEF) is defined that represents the ratio of the dose deposited in tumor with nanoparticles, divided by the dose deposited in the tumor without nanoparticles. Materials with atomic numbers (Z) ranging from 25 to 90 are considered in this analysis. In addition, the energy spectrum for a number of external beam x-ray sources and common radionuclides are evaluated. For a nanoparticle concentration of 5 mg/ml, the DEF is < 1.05 for Co-60, Ir-192, Au-198, Cs-137, 6, 18, and 25 MV x-rays for all materials considered. However, relatively large increases in the DEF are observed for 50, 80, 100, and 140 KVp x-rays as well as Pd-103 and I-125. The DEF increases for all sources as Z varies from 25–35. From Z = 40–60, the DEF plateaus or slightly decreases. For higher Z materials (Z>70), the DEF increases and is a maximum for the highest Z materials. High atomic number nanoparticles coupled with low energy external beam x-rays or brachytherapy sources offer the potential of significantly enhancing the delivered dose.

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