Polyamorphism and molecular dynamics of molecular liquids

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K14679
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 13040:Biophysics, chemical physics and soft matter physics-related
• Research Institution: Tokai University (2020-2022); National Institute for Materials Science (2019)
• Principal Investigator: Sasaki Kaito 東海大学, 理学部, 助教 (60806173)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: ポリアモルフィズム / マンニトール / ガラス転移 / Johari-Goldstein β緩和 / α緩和

Outline of Final Research Achievements

Silicon, phosphorus, silica (SiO2), and some molecular liquids have two amorphous states with single components but completely different thermodynamic properties. This has been called polyamorphism, a polymorph of the amorphous state. This study aims to characterize the molecular motion of hydrogen-bonded molecular liquids exhibiting polyamorphism before and after the polyamorphic transition. We used mannitol, one of sugar alcohols, as the main sample to investigate the characteristics of α-relaxation and Johari-Goldstein β-relaxation, which are widely observed in glass-forming materials, and their relationship to the polyamorphic transition.

Free Research Field

化学物理、ソフトマターの物理

Academic Significance and Societal Importance of the Research Achievements

実験的に到達が困難な圧力、温度領域を含めれば、ほとんどすべての液体がポリアモルフィズムを示すという意見がある。これはつまり、液体の基本的な性質を理解する上で、ポリアモルフィズムが重要な考え方の一つであることを意味している。よって、水素結合性の分子性液体のポリアモルフィズムと分子運動の関係を議論した本研究は、広く液体の物性を議論するために必要な情報となりうる。