Effect of solute nature on the polyamorphic behavior of glassy dilute aqueous solution

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K03888
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13040:Biophysics, chemical physics and soft matter physics-related
• Research Institution: National Institute for Materials Science
• Principal Investigator: SUZUKI Yoshiharu 国立研究開発法人物質・材料研究機構, 先端材料解析研究拠点, 主幹研究員 (90236026)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 水 / ポリアモルフィズム / ポリオール水溶液 / トレハロース水溶液 / 液体―液体転移 / ポリアモルフィック転移 / 高圧液体冷却ガラス化法

Outline of Final Research Achievements

In this study, the low-concentration aqueous solution in which solutes are homogeneously dispersed is prepared. The transformations of low-concentration aqueous solution, such as the amorphous-amorphous transition, glass to liquid transition and crystal growth process, are examined at low temperatures and high pressures, and then the effects of solute on the states of glassy water and crystal ice were elucidated. The main result is the first experimental observation of a reversible liquid-liquid transition of trehalose aqueous solution with pressure change. This shows the validity of the liquid-liquid critical point hypothesis of water. In addition, it is shown that the solute inhibited the crystal growth of cubic ice.

Free Research Field

水と水溶液のポリアモルフィズム

Academic Significance and Societal Importance of the Research Achievements

水溶液を用いたポリアモルフィック転移と液液転移に関する本研究は、その存在が疑問視されていた「２つの水の存在（水のポリアモルフィズム）」が水溶液の物性や構造に深く関係していること示している。本成果は、溶液化学や生化学などの水に関係する全ての研究分野に「水のポリアモルフィズム」という新しい研究指針を与えている点で、学術的な意義が大きい。