The elemental soup found in these materials is the culprit. The glass is made of oxides of silicon, aluminum, calcium, and other elements, while the ceramic is an oxide of barium, chromium, and aluminum. And stainless steel has mainly iron with some nickel and chromium. Synergistic chemical interactions between these elements causes the corrosion, Guo says. The researchers observed these reactions when they pressed a piece of nuclear waste glass or ceramic—minus radioactive elements—to a stainless steel plate and immersed them in a sodium chloride solution for 30 days. At the end of the experiment, the steel was pitted along the edge where it touched the glass or ceramic.
by Prachi Patel, special to C&EN |
January 30, 2020