The research group of Professor Hajime Tanaka of the Institute of Industrial Science, University of Tokyo and others clarified for the first time in the world by observing the elementary process of crystal gel formation in real time with a three-dimensional confocal microscope.
When the particles dispersed in the liquid are attracted, a gel structure connected in a network is formed.This gelling phenomenon is a phenomenon that is seen around us on a daily basis like agar.A normal colloidal gel is a state in which colloidal particles aggregate and solidify with a random structure, but it has long been known that under "certain conditions", a gel state in which crystals are connected is formed. ..
This time, the group succeeded in direct observation of the dynamic process for the first time.In the process of crystal gel formation, it is first separated into a "liquid phase with a high concentration of colloidal particles" and a "gas phase with a low concentration".In the process, a network of liquid phases is formed, and crystal nuclei are formed in it.The crystal nuclei grow and reach the surface of the network structure, and when they come into direct contact with the gas phase, the colloidal particles of the gas phase condense on the crystal surface.As a result, it was clarified that a porous crystal with a smooth surface was formed.
This process is the same as the process of rapid ice crystal growth in clouds containing a mixture of supercooled water and ice (ice crystals), and this time the group is the first in the world to introduce the elementary process of cold rain formation. It can be said that it was observed at a microscopic level.
Paper information:[Nature Materials] Formation of porous crystals via viscoelastic phase separation
