الفهرس 
Synthesis and fabrication of nanostructures and nanomaterialsOnly 14 pages are availabe for public view
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Abstract
The peaceful usage of nuclear activities, the different applications and usage’s of radioactive isotopes in Nuclear power plants (NPPs), research laboratories, hospitals, industry and in the other different fields are in continuous increasing, so a great attention must be paid to radioactive waste produced from these activities to protect the humane and the environment from the radiation hazardous. Nanotechnology has become an active field of research which offers a variety of applications in different fields. Metal oxide nanoparticles are used widely because of their small size; they possess a large surface area to volume ratio, which improves their adsorption capacity. Moreover, these particles show unique characteristics, such as catalytic potential and high reactivity. Because of their high surface area, nanoparticles have a greater number of active sites for interaction with different chemical species. Nano-sized Al2O3 and mixed metal oxides such as MgFe2O4, NiFe2O4 and CoFe2O4 were prepared by a hybrid sol-gel auto combustion method using three different fuels urea, oxalic acid and citric acid. In addition to synthesis of magnesium hexacyanoferrate / MgFe2O4 (MgHCFC) composite, nickel hexacyanoferrate / NiFe2O4 (NiHCFC) composite and cobalt hexacyanoferrate / CoFe2O4 (CoHCFC) composite has been done. The prepared products were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and field emission scanning electron microscope (FE-SEM). The effect of the used fuels (urea, oxalic acid and citric acid) on the morphology and the crystallite size of the obtained nano products were studied. Citric acid fuel produced γ-Al2O3 with finest crystallite size about 3.95 nm and produced pure phase of MgFe2O4 and NiFe2O4 with average crystallite size 13.53 nm and 36.1 nm respectively. But urea fuel obtained a single phase of CoFe2O4 with average crystallite size about 38.41 nm. The three pure ferrite samples were used to prepare magnesium hexacyanoferrate /MgFe2O4 (MgHCFC), nickel hexacyanoferrate/NiFe2O4 (NiHCFC), cobalt
hexacyanoferrate/CoFe2O4 (CoHCFC) nanocomposite. γ-Al2O3 was used for removal of chromium Cr(VI) from aqueous media with maximum removal efficiency about 94.37 % , within 75 min, and the adsorption process fitted to Langmuir isotherm model and Pseudo-second-order model. MgFe2O4 , NiFe2O4 and CoFe2O4 were tested for removal of chromium Cr(VI) and 99TcO4-. These nanoadsorbents showed high removal efficiency for the two pollutants. The adsorption of chromium on MgFe2O4 was fitted to Freundlich isotherm model, while it was fitted to Langmuir isotherm model with NiFe2O4 and CoFe2O4 adsorbents. Moreover the adsorption process of 99TcO4- on MgFe2O4, NiFe2O4 and CoFe2O4 was fitted to Freundlich isotherm model. The rate of adsorption for both Cr(VI) and 99TcO4- on the three adsorbents was fitted to Pseudo-second-order model. On the other hand, (MgHCFC), (NiHCFC) and (CoHCFC) nano composite were used for removal of cesium from aqueous pollutants, and (NiHCFC) showed higher removal percent than the other two composited it was (% R=98.8%) at pH 6. As well as the adsorption process of cesium on (MgHCFC), (NiHCFC) and (CoHCFC) was fitted to Freundlich isotherm model and Pseudo-second-order model. So the prepared nano products can be used as promising adsorbents for treating the large amounts of liquid radioactive wastes that in contentious increase due to the wide spread of the various usages of radionuclides in different fields in life.