Control of crystallization of sodium octosilicate ilerite in the hydrothermal synthesis

摘要

Octosilicate, called ilerite, is a layered polysilicate and is anticipated to be useful as a host compound of various functional materials. However, there are some problems in its industrial uses because a long time (more than 10 days) is required to synthesize it and to control the crystal growth is difficult. In this study, in order to solve these problems, polyethylene glycol (PEG) 200 was added as a template for aiding the crystallization to the starting solution in the hydrothermal synthesis. The crystallization rate and crystallinity of products increased with an increase in the additional amount of PEG 200. The product size decreased and the size distribution was narrowed at larger additional amounts of PEG 200. The result shows that the crystal growth can be controlled in the presence of PEG 200.