“Loading of some Radionuclides on Nano-sorbents for Nuclear Applications”

Abstract

This thesis is consists of three chapters, namely introduction, experimental and results & discussion, which will be summarized more in the following sections. Chapter (I): Introduction This chapter includes the introduction, which covers a brief interpretation of the production, separation, and applications of radioactive isotopes. It also represents a brief concept concerning the use of radioisotopes in nuclear application, particularly in the use and production of sealed radioactive sources. This chapter provides a brief account of a literature survey on various manufactured sealed radioactive sources either in the research field for the calibration of γ-detectors or in the medical field for use in the production of brachytherapy seeds for the treatment of ocular and prostate cancer. It is a good explanation of the sealed radioactive sources being categorized according to their geometry, radioactivity level, capsule materials, and sealing techniques. This chapter also deals with the basis of nanotechnology, nanomaterials, and different techniques applied to nanoparticles synthesis. Chapter (II): Experimental This chapter contains a full description of chemicals, reagents and instrumentations used in this work. It offers a thorough description of the nano-sorbent materials preparation methods and the radioisotopes used. This chapter provides a summary of the different techniques used in characterizing of the nano-sorbents being prepared. It includes a detailed description of the experimental steps performed under various experimental conditions in the sorption process of the radionuclides studied onto the prepared nano-sorbents. This chapter also contains the experimental procedures used in the preparation of sealed radioactive sources 134Cs(I) and 60Co(II), and offers a brief description on the necessary quality control tests. Chapter (III): Results and discussion This chapter comprises three sections, the preparation and characterization of nano-sorbent materials, sorption studies of 134Cs(I) and 60Co(II) on prepared nano-sorbent materials and their use in the preparation of sealed radioactive sources, in addition to sorption studies of 131I on both prepared silver metal NPF and silver oxide NPs. It includes the experimental results, their interpretation and comparison to other published data. The detailed and systematic studied include various techniques for the preparation of silver nano-structures. Sol-gel auto-combustion technique was used in silver metal NPF whereas wet chemical precipitation technique was used in silver oxide NPs preparation. Physical and chemical properties of both prepared silver metal NPF and silver oxide NPs were investigated and characterized using FT-IR spectroscopy, thermal analysis, X-ray diffraction (XRD), High resolution transmission electron microscope (HRTEM), and Energy dispersive x-ray spectroscopy (EDX). The prepared nano-sorbents were found to be chemically stable in water, salt solutions of Na+ and NH4+ chloride in the investigated concentration range . While silver metal NPF exhibits a slight dissolution at room temperature (25±1 °C) in 10 M of hydrochloric and nitric acids and 6 M of sodium hydroxide solutions. Whereas silver oxide NPs are slightly dissolved in 10 M hydrochloric and nitric acids and 9 M sodium hydroxide solutions at room temperature (25±1 °C). Noticeable dissolution was achieved in hot concentrated acid solutions. The FTIR spectrum confirmed the formation of sorbent materials made from silver metal and silver oxide. The X-ray diffraction pattern showed that both nano-sorbent materials prepared were crystalline in nature. The high resolution transmission electron microscope (HRTEM) images of both prepared nano-sorbent materials with different magnification powers confirmed the nano-scale size of both prepared silver nano-structures with an average particle size ≤ 20 nm for silver metal NPF and primary particle size of ≤ 2nm with some degree of agglomerated particles of average size 12 nm for silver oxide NPs. The EDX spectrum of silver metal NPF demonstrated the presence of carbon due to the combustion reaction involved in the preparation of silver metal NPF, thus confirming the purity of prepared silver oxide NPs.