Chemistry Weekly Seminar - Mehrnaz Mikhchian, PhD Student
Mehrnaz Mikhchian, PhD student in the Department of Chemistry, University of Saskatchewan, will present a seminar at 1:30 pm in Thorvaldson 159.
Title
An investigation of the long-term aqueous corrosion behaviour of glass, crystalline ceramics, and glass-ceramic composite materials
Abstract
Deep geological repositories are being considered internationally as a future plan for the permanent disposal of high-level radioactive waste (i.e., used nuclear fuel). A common challenge associated with geological disposal is groundwater corrosion and leaching of the radionuclides incorporated in a wasteform into the environment. Glass-ceramic composite materials are being considered as potential nuclear wasteform candidates due to having high waste loading and expected enhanced chemical durability compared to borosilicate glass on its own. However, the long-term aqueous corrosion resistance (i.e., over years) of these glass-ceramic composite materials and how the structure of these materials change after being exposed to an aqueous environment are not fully understood.
This presentation is focused on our recent studies of the long-term aqueous corrosion behaviour of the Fe-Al-BG-CaZrTi2O7 and Fe-Al-BG-Ce0.94Ti2O6–δ composite materials and how their corrosion mechanisms compare to the individual Fe-Al-BG, CaZrTi2O7, and Ce0.94Ti2O6–δ phases. A combination of surface and bulk techniques has been used in this research to provide detailed information on the corrosion that occurs at the surface or bulk regions of these materials after being exposed to water for a period of one year. The results of this study have shown that the corrosion of the Fe-Al-BG-CaZrTi2O7 and Fe-Al-BG-Ce0.94Ti2O6–δ composite materials leads to the formation of an amorphous surface layer during the early stages of exposure to water (i.e., between 15 and 60 days) which could restrict the further release of ions into the water.
Date: Friday, October 20
Time: 1:30 pm
Place: Thorvaldson 159