Zn4OベースのMOFの水の感受性は,構造と歴史に依存しています
Ping Guo1, Dhanadeep Dutta, Antek G Wong-Foy
1Department of Chemistry, University of Michigan , 930 N. University, Ann Arbor, Michigan 48109-1055, United States.
Journal of the American Chemical Society
|February 3, 2015
まとめ
メタル・オーガニック・フレームワーク (MOF) は水分に対する驚くべき安定性を示し,分解が起こる前に初期誘導期間があります. この研究は,水による構造的崩壊の際にMOFの毛孔サイズが進化したことを明らかにしています.
科学分野:
- マテリアルサイエンス 材料科学
- 化学 化学は化学です.
- ナノテクノロジー ナノテクノロジー
背景:
- 湿気は,金属有機フレームワーク (MOF) の不可逆的な構造崩壊を引き起こし,その内部表面積と孔の容量を減少させます.
- 湿度によるMOFの分解中の正確なメカニズムと毛穴の大きさの進化は,in situの多孔性探査の限界のためによく理解されていません.
研究 の 目的:
- 湿度曝露下でMOFのダイナミックな毛穴サイズ進化と分解メカニズムを調査する.
- MOFの安定性と分解運動に影響を与える要因を特定する.
主な方法:
- MOFの多孔性を動的にモニタリングするために,in situポジトロニウムアニヒレーションライフタイムスペクトロスコーピー (PALS) と組み合わせたフロースルーシステムを利用しました.
- 粉末のX線 difraktion (PXRD) と,さらなる検証のために,ex situガスの吸収測定を使用した.
主要な成果:
- いくつかのZn4OベースのMOFでは,水分解の予期せぬ誘導期が観察され,これは以前に想定されたよりも高い安定性を示しています.
- 非機能的なMOFのシグモイド性退廃傾向が特徴であり,一時毛穴のサイズ進化に関連しています.
- IRMOF-3は,MOF-5よりも低い分解相対湿度を示し,IRMOF-3では残留の多孔性が残っていた.
- 誘導期間の,水への先行暴露に対する,既往の依存性を実証した.
結論:
- この研究は,初期誘導期を特徴とする,水分に対する特定のMOFの以前に認識されていない安定性を明らかにしています.
- In situ PALSは,湿気誘発による劣化中のMOFの多孔性の時間的進化に関する重要な洞察を提供します.
- MOFの劣化メカニズムの理解は,ヒストリー依存性とシグモイド的行動を含む,湿気のある環境での応用にとって不可欠です.
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