氷の意外な柔軟性を発見(A Chilling Discovery: The Surprising Flexibility of Ice)

2025-09-25 パシフィック・ノースウェスト国立研究所(PNNL)

米国パシフィック・ノースウェスト国立研究所(PNNL)の研究チームは、氷が予想外に柔軟で、外力に応じて分子構造を部分的に再配列できることを発見した。従来、氷は硬く脆い結晶として理解されてきたが、ナノスケール観察とシミュレーションにより、特定条件下で分子ネットワークが一時的に切断・再結合し、弾性的にしなやかに振る舞うことが確認された。この性質は氷河や極地環境での氷の流動性を説明するだけでなく、気候モデルの改良や、氷を利用した材料科学への応用につながる可能性がある。研究はまた、水素結合のダイナミクスが重要な役割を担うことを明らかにし、氷の物理化学的理解を更新した。

氷の意外な柔軟性を発見(A Chilling Discovery: The Surprising Flexibility of Ice)
Ice often traps air bubbles when it freezes. New research at the atomic nanoscale shows why. Ice is surprisingly flexible and adaptable to trapped air bubbles, which don’t cause strain that might cause cracks in the crystal structure.
(Photo by ArTDi101 | Shutterstock.com)

<関連情報>

極低温液体セルTEMによる液体水から結晶化した氷の分子分解能画像化 Molecular-resolution imaging of ice crystallized from liquid water by cryogenic liquid-cell TEM

Jingshan S. Du,Suvo Banik,Henry Chan,Birk Fritsch,Ying Xia,Ajay S. Karakoti,Andreas Hutzler,Subramanian K. R. S. Sankaranarayanan & James J. De Yoreo
Nature Communications  Published:25 September 2025
DOI:https://doi.org/10.1038/s41467-025-62451-0

Abstract

Despite the ubiquity of ice, a molecular-resolution image of nanoscopic defects or microstructures in ice crystallized from liquid water has never been obtained. This is mainly due to the difficulties in preparing and preserving crystalline ice samples that can survive under high-resolution imaging conditions. Here, we report the stabilization and Å-resolution electron imaging of ice Ih crystallized from liquid water by developing cryogenic liquid-cell transmission electron microscopy (CRYOLIC-TEM). We combine lattice mapping with molecular dynamics simulations to reveal that ice formation is highly tolerant to nanoscale defects such as misoriented subdomains and trapped gas bubbles, which are stabilized by molecular-scale structural motifs. Importantly, bubble surfaces adopt low-energy nanofacets and create negligible strain fields in the surrounding crystal. These bubbles can dynamically nucleate, grow, migrate, dissolve, and coalesce under electron irradiation and be monitored in situ near a steady state. This work improves our understanding of water crystallization behaviors at a molecular spatial resolution.

1701物理及び化学
ad
ad
Follow
ad
タイトルとURLをコピーしました