水の流動性は,サブナノメートルのフィルムに限られている
Nature
|September 7, 2001
まとめ
ナノスケールフィルムの水の粘性は,有機溶剤とは異なり,散発レベルに近いままです. 閉じ込めは,分子翻訳ではなく,水素結合を破壊し,流動性を保ち,水に影響します.
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
- ナノテクノロジー ナノテクノロジー
背景:
- 閉じ込められた幾何学における水の分子移動性は,トライボロジーやタンパク質の折り畳みなど,様々な科学分野にとって極めて重要です.
- 以前の研究では,フィルム>2-3 nmの水の粘度が,非結合性有機液体を反映し,散発に似ていることが示されました.
研究 の 目的:
- ナノスケールフィルムに閉じ込められた水の有効粘度を調査する.
- 同様の閉じ込め条件下にある有機溶剤と水の行動を比較する.
主な方法:
- 閉じ込められた膜における液体の流れを直接測定する.
- ナノ孔やスライツ内の分子移動性の分析.
主要な成果:
- 水の有効粘度は,0.4nmの薄膜でも,その散発値の3分の1の範囲にとどまっていました.
- これは有機溶剤とは対照的に,粘度が <5〜8の分子層に限られた場合,著しく増加 (分散) します.
結論:
- 閉じ込められた水のユニークな行動は,異なる固化メカニズムに起因する.
- 閉じ込めは,主に水の水素結合ネットワークを混乱させ,変換の自由を抑制せず,それによって流動性を維持します.
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