硫酸ドデシルナトリウムミセルの溶液交換に対する塩の効果
Yahya Rharbi1, Mitchell A Winnik
1Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada M5S 3H6.
Journal of the American Chemical Society
|March 7, 2002
まとめ
塩化ナトリウムは,ミセルの断片化を促進することによって,SDSミセルの溶液交換を加速します. このプロセスは,イオン強度によって駆動され,水に溶けない溶液の移転に不可欠なサブミセルの形成と再構成が含まれています.
科学分野:
- 物理化学 物理化学
- コロイドと表面科学 コロイドと表面科学
- 超分子化学 超分子化学
背景:
- 硫酸二酸化ナトリウム (SDS) のミセルは,水に溶けない化合物の溶解に不可欠です.
- ミセル内の溶液交換ダイナミクスは,様々な化学的および生物学的プロセスに不可欠です.
- ミセラーの安定性と動態を理解することは,溶質の移転を制御するための鍵です.
研究 の 目的:
- 塩化ナトリウムがSDSミセルの溶液交換速度に与える影響を調査する.
- 水に溶けないピレンを含むトリグリセリドのための溶液交換のメカニズムを解明する.
- 溶解物交換率とイオン強度,ミセラ行動とを相関させるため.
主な方法:
- 水に溶けない溶液 (ピレンを含むトリグリセリド) でSDSミセラ溶液の調製.
- 光スペクトロスコーピーによる溶液交換のモニタリング,エクシマー (I(E)) とモノマー放射の測定.
- イオン強度を変えるために塩化ナトリウム濃度を体系的に変化させる.
主要な成果:
- 溶質の交換率 (k(obs)) は,イオン強度で大きく上昇し,パワー法依存 (k(obs) が類似した[Na(+) ](4)).
- エクシマーの排出量は塩を加えると指数関数的に減少し,溶質の再分配を示しています.
- この割合は,空のミセル濃度のみに依存するのではなく,ナトリウムイオン濃度に依存していた.
結論:
- 溶液交換は,ミセルの自発的な細分化によってサブミセラに発生し,その後再構成が行われます.
- ミセルの断片化は,大きな振幅の表面変動によって促進され,ヘッドグループ反発のカウンテリオンスクリーニングによって強化されます.
- 提案されたモデルは,SDSミセルの塩に依存した溶液交換メカニズムを説明しています.
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