A research group led by Professor Tomoyuki Mochida of the Graduate School of Science, Kobe University announced that he developed the world's first such liquid substance that "it becomes solid when exposed to light and returns to liquid when heated", and was published in the English chemical magazine "Chemical Communications". Published in the.This is a research result that can be expected to expand into the industrial world in the future.
Technology for controlling the properties of substances by external stimuli such as light and heat is very important in the field of electronic materials.For example, in the production of printed circuit boards and the like, photosensitive resins having the property of hardening when irradiated with light are used, but there is a problem that once they are used, they are difficult to reuse.
Meanwhile, in recent years, a substance called a "coordination polymer" in which a metal ion and an organic ligand are linked has been attracting attention as a "functional solid" capable of having various functions.The research group thought, "If the bond between metal ions and organic molecules can be controlled by light or heat, a material whose properties can be significantly changed by external stimuli can be created." development.By light and heat, we succeeded in realizing mutual conversion between substances with completely different bonding states and chemical properties of ionic liquids and coordination polymer solids.
This liquid is colorless and transparent, non-volatile, and does not freeze even at -50 ° C, but changes to a coordination polymer solid when exposed to ultraviolet light for several hours, and returns to an ionic liquid when heated at 130 ° C for 1 minute.Much research has been done on coordination polymers and synthesis methods have been developed, but the "method of irradiating a liquid with light to produce coordination polymers" developed by the same research group is the first in the world. Become.
With the successful development of a reusable photocurable liquid, it is expected that it will be applied to printed circuit boards, stereolithography, and adhesives in the future. "We would like to further advance the molecular design and take on the challenge of research to impart functions such as gas absorption and desorption to the produced coordination polymers," says Professor Mochida.
