充電されたマクロモレキュルの溶液における通常の異常変異に対する塩の作用
Di Jia1, Murugappan Muthukumar1
1Department of Polymer Science and Engineering , University of Massachusetts , Amherst , Massachusetts 01003 , United States.
Journal of the American Chemical Society
|March 22, 2019
まとめ
高い塩分濃度では,電荷を帯びたマクロ分子溶液の新たな動態が明らかになる. ポリマーの分子の重さはこれらの移行に大きく影響し,通常の異常行動に関する既存の理論に挑戦します.
科学分野:
- 物理化学
- ポリマー科学
- 柔らかい物質の物理
背景:
- 溶液中の電荷のあるマクロモレクルは,塩の濃度によって影響される複雑なダイナミクスを示します.
- "普通から異常"の移行は,塩とポリマーの濃度が異なるマクロ分子行動の変化を記述します.
- 以前のモデルは,ポリマーと塩分濃度の比 (Cp/Cs) に焦点を当てて移行を予測した.
研究 の 目的:
- 充電されたマクロ分子溶液における"普通-異常"の移行における高塩濃度の役割を調査する.
- ポリマー分子量 (Mw) がポリエレクトロライト溶液の集合動力学に及ぼす影響を調査する.
- 塩のポリエレクトロライト系における観察された動態を説明する理論的枠組みを開発する.
主な方法:
- 拡散係数を測定するダイナミック光散射 (DLS) 技術.
- ポリマー濃度 (Cp),塩濃度 (Cs),およびポリマー分子量 (Mw) の体系的な変化
- 水性ナトリウムポリ (ステルネスルフォナート) と塩化ナトリウム溶液の実験調査
主要な成果:
- 以前から知られている"速い"と"遅い"モードに加えて,高いCp,Cs,Mwで新しい"速い"リラックスモードの観察.
- ポリエレクトロライト溶液のダイナミクスにおいてMwが重要な要素であり,Cp/Cs比だけではないことを示す.
- Mwが減少するにつれて,リラクゼーションモード3から2に1のダイナミックトランジションを特定する.
結論:
- 新しい高速モードの出現と観測されたダイナミックトランジションは"普通-異常"のトランジション理論を確立しました.
- 鎖,カウンターイオン,コイオンの結合解約を考慮する新しい理論モデルは,実験結果を質的に説明する.
- この研究は,生物学と技術に関連する塩溶液における電荷マクロ分子ダイナミクスを正確に特徴付けるための基礎を提供します.
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