関連する実験動画
Updated: Jul 15, 2026

16:24
Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
液体の水中の最初の調整殻の構造
Ph Wernet1, D Nordlund, U Bergmann
1Stanford Synchrotron Radiation Laboratory, Post Office Box 20450, Stanford, CA 94309, USA.
まとめ
液体の水分子は主に2つの水素結合構成で存在し,氷の四面体構造ではありません. 液体の水を加熱すると,これらの二重結合構造にわずかなシフトが生じます.
科学分野:
- 物理化学 物理化学
- マテリアルサイエンス 材料科学
- 凝縮物質物理学 凝縮物質物理学
背景:
- 液体の水の局所的な分子構造を理解することは,多くの科学分野にとって極めて重要です.
- 以前の研究では,間接的な方法やシミュレーションに頼り,結果が異なることが多かった.
研究 の 目的:
- 液体の水の最初の協調殻の局所的な分子配置を調査する.
- 六角形の氷 (Ih) と液体の水の構造を比較し,モデルをシミュレートする.
主な方法:
- X線吸収光譜法 (XAS) とX線ラーマン分散法 (XRS) を利用した.
- 大量と表面の六角氷 (Ih) との実験データを比較し,理論的な計算を行った.
主要な成果:
- 液体の水分子は主に2つの水素結合構成を採用し,氷の四面体構造と異なる.
- 分子のわずかな部分 (5-10%) は,25°Cから90°Cまで加熱すると,四面体から二重結合の構成に変化する.
- 現在の分子ダイナミクスシミュレーションによって予測された構造との有意な不一致が観察されました.
結論:
- 液体の水の局所構造は,特定の水素結合装置によって特徴付けられています.
- 実験的発見は,液体の水の構造のモデルに厳格な制約を与える.
- 現在の分子ダイナミクスシミュレーションは,液体の水の局所構造を正確に表現するために精細化が必要になる可能性があります.
関連する概念動画
States of Water
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Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
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Cohesion
Cohesion is the attraction between molecules of the same type, such as water molecules. Water molecules have an overall neutral charge but are polar molecule. An oxygen atom in one water molecule has a partial negative charge that can bind to a hydrogen atom with a partial positive charge in a second water molecule, forming a hydrogen bond. Each water molecule can form up to four hydrogen bonds with other water molecules. Hydrogen bonds are responsible for water's cohesive nature.
On a surface,...
On a surface,...
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Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen bonds, and dispersion...
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Micelle formation is an intricate process that hinges on the properties of amphiphilic or amphipathic molecules and the conditions of the system in which they are found. Amphiphilic molecules, which have both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts, play a critical role in this process.In aqueous environments, these molecules arrange themselves such that their hydrophilic heads are turned towards the water phase, while their hydrophobic tails are oriented away...

