Phys.org January 13, 2020
Researchers at Iowa State University started with a liquid metal alloy of gallium, indium and tin synthesized into particles covered with a smooth oxide shell that has been chemically stabilized. As the particles are heated, the surface thickens and stiffens and begins to behave more like a solid. Eventually the surface breaks, allowing the liquid metal inside to come to the surface. The most reactive, gallium, breaks through first. More heat brings indium to the surface. And the highest heat—about 1,600 degrees Fahrenheit—brings out florets of tin. Time, temperature and oxygen levels are carefully controlled by the researchers. As this behavior applies to metals in general, other metals subject to the same treatment will behave the same way. The research could be used for designing ‘smart’ alloy systems for applications ranging from sensing to catalysis…read more. Open Access TECHNICAL ARTICLE
a) Schematic of oxide transformation mechanism for ternary core–shell liquid metal particle. b) SEM image of different oxidation steps correlating with the mechanisms displayed above. Credit: Angewandte Chemie International Edition (2019)Â