The research group of Professor Hajime Tanaka of the University of Tokyo and Research Fellow Rui Shi conducted research on the similarities and differences between water and silica, which are the most abundant liquids and solids on the earth, and their physical qualities. Succeeded in elucidating the origin.
The research group regards the structuring in liquids as the arrangement of surrounding particles when viewed from the central particle, and pays particular attention to the order of distance from the center and the order of orientation.The local structural order formed in the liquids of both substances was clarified.
In the case of water molecules, the inside of the molecule is covalently bonded, the intermolecular is stabilized by hydrogen bonds and bonds with different energy scales, and the degree of freedom of the structure of the water molecule itself is small, so it is suitable not only for oxygen but also for hydrogen. There is order.On the other hand, in the case of silica, since all the bonds are stabilized by covalent / ionic bonds, the degree of freedom in the arrangement of oxygen is large and the directional order is low.
As a result, there is a similarity in the order of distance between water and silica, but there is a big difference in the order of orientation, which are similar to the crystal structure, density anomaly, viscosity anomaly, etc. of both substances and glass formation. It turned out to be the physical origin of the great difference in ability.
This achievement has an applied impact in the sense that it elucidates the basic properties of the most familiar liquids, water and silica, and also opens new avenues for understanding tetrahydral liquids and intentionally controlling glass-forming ability. Is also expected to be large.
