フッ素化および水素化表面活性剤の混合ミセル
Lars Nordstierna1, István Furó, Peter Stilbs
1Division of Physical Chemistry and Industrial NMR Center, Department of Chemistry, Royal Institute of Technology, SE-10044 Stockholm, Sweden.
Journal of the American Chemical Society
|May 18, 2006
まとめ
この研究は,混合された表面活性剤システムが,完全な混合または脱混合ではなく,好ましい相互作用を示すことを明らかにしています. フッ素化および水素化表面活性剤は,異なるが共存するミセラ構造を形成する.
科学分野:
- 物理化学 物理化学
- コロイド科学 コロイド科学
- マテリアルサイエンス 材料科学
背景:
- 混合表面活性剤システムは,様々な用途において極めて重要です.
- 混合ミセルの分子相互作用を理解することは,それらの性質を制御する鍵です.
- 塩酸ナトリウムパーフルオオクタノアートと硫酸ナトリウムデシル混合物に関する以前の研究は,混合行動に関する矛盾した結果を示しました.
研究 の 目的:
- ナトリウムパーフルオオクタノアートとナトリウムデシル硫酸混合表面活性剤システムの混合振る舞いを再検討する.
- 分子およびミセラ混合または脱混合の程度を決定する.
- 表面活性物質の種類間の相互作用エネルギーを定量化するために.
主な方法:
- 核磁共振 (NMR) スペクトロスコーピー,特に (19) Fと (1) Hの化学シフト分析.
- 表面活性剤イオンの両方の自己拡散係数の測定.
- モノメア濃度とミセラ化学シフトを抽出するためのフレームワークを用いた分析.
- 正規解理論の第1近似の応用.
主要な成果:
- 実験データでは,完全な脱混合も完全な混合も示されていない.
- 単一のタイプのミセルが好まれ,優先的な調整が行われます:フッ素表面活性剤はフッ素表面活性剤と結合し,水素表面活性剤は水素表面活性剤と結合します.
- 混合エネルギー (オメガ) は0.98と決定され,表面活性物質の種類間の相互作用を定量化しました.
結論:
- 混合表面活性剤システムは,単一のミセラ型内の部分的な脱混合を示します.
- 偏好的な相互作用が,これらの混合ミセルの構造を支配する.
- この研究は,このおよび関連する表面活性剤の混合物における議論の余地のある混合行動の定量的な説明を提供します.
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