メタル・オーガニック・フレームワーク Cu3BTC2の負の熱膨張行動の調整
Christian Schneider1, David Bodesheim1, Michael G Ehrenreich1
1Department of Chemistry , Technical University of Munich , Lichtenbergstrasse 4 , Garching D-85748 , Germany.
Journal of the American Chemical Society
|June 12, 2019
まとめ
研究者はネガティブな熱膨張 (NTE) を調整するために改造した金属有機フレームワーク (MOF) を使用しました. Cu3BTC2フレームワークにTCNQを導入することで,NTEの動作が変化し,MOFプロパティの制御のための新しい方法が示されました.
科学分野:
- 材料科学
- 化学について
- 固体物理学
背景:
- メタル・オーガニック・フレームワーク (MOF) は,構造と性質の関係の研究のためのモジュラー・プラットフォームを提供します.
- 負の熱膨張 (NTE) は,しばしば低エネルギー集団運動に関連した,MOFにおける顕著な現象である.
- NTEの制御は,高度な材料のアプリケーションに不可欠です.
研究 の 目的:
- MOFの格子ダイナミクスとNTEの振る舞いに対する追加リンクの導入 (改装) の影響を調査する.
- MOFでNTEを実験的にチューニングする方法を実証する.
- オープンな金属サイトを持つMOFへの改修の一般的適用性を調査する.
主な方法:
- 試作MOF Cu3BTC2 (HKUST-1) をTCNQ (7,7,8,8-テトラシアノキノディメタン) で改造する.
- 異なる TCNQ 負荷による NTE 行動の実験的特徴付け.
- コンピューターモデリングと 遠赤外線スペクトロスコーピーは フレームの硬化を確認します
主要な成果:
- 容量の熱膨張係数 (αV) を -15.3 × 10−6 K−1 (Cu3BTC2) から -8.4 × 10−6 K−1 (1.0TCNQ@Cu3BTC2) に調整する.
- TCNQの負荷とフレームの硬化との間には相関関係があることが証明された.
- ネットワーク接続により格子ダイナミクスの変更を確認します.
結論:
- レトロフィーティングは,MOFの格子ダイナミクスを実験的にアクセスして修正するための効果的な戦略です.
- このアプローチにより,MOFにおけるNTEの動作を微調整できます.
- 改修方法は,オープンな金属サイトを持つMOFに広く適用され,設計の可能性を拡大します.
関連する概念動画
01:22Thermal Expansion
5.6K
The expansion of alcohol in a thermometer is one of many commonly encountered examples of thermal expansion, which is the change in size or volume of a given system as its temperature changes. The most visible example is the expansion of hot air. When air is heated, it expands and becomes less dense than the surrounding air, which then exerts an upward force on the hot air to, for example, make steam and smoke rise, and hot air balloons float. The same behavior happens in all liquids and gases,...
5.6K
01:27Thermal expansion and Thermal stress: Problem Solving
2.1K
San Francisco's Golden Gate Bridge is exposed to temperatures ranging from -15 °C to 40 °C. At its coldest, the main span of the bridge is 1275 m long. Assuming that the bridge is made entirely of steel, what is the change in its length between these temperatures?
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in temperature (ΔT) is 55...
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in temperature (ΔT) is 55...
2.1K
02:32Bonding in Metals
52.1K
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.
52.1K
03:06Alkali Metals
24.2K
Group 1 elements are soft and shiny metallic solids. They are malleable, ductile, and good conductors of heat and electricity. The melting points of the alkali metals are unusually low for metals and decrease going down the group, while the density increases going down the group with the exception of potassium (Table 1).
Table 1: Properties of the alkali metals
Table 1: Properties of the alkali metals
24.2K
02:37Metallic Solids
20.5K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
20.5K
00:54What is Behavior?
10.2K
Behaviors are actions that an organism engages in—they can be related to finding food, reproducing, defending against threats, and many other possible actions. Behaviors include activities related to the environment around the animal—such as migration—as well as social interactions within a species or population. Many behaviors involve motor output—that is, muscle movements—while others involve less visible actions, such as learning.
10.2K