化学的均衡の力による再分配
Corissa K Lee1, Douglas A Davis, Scott R White
1Department of Materials Science and Engineering, Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States.
Journal of the American Chemical Society
|October 28, 2010
まとめ
ポリウレタン中のスピロピランメカニコフォアは,視覚的ストレス検出を提供します. この研究は,スマート素材アプリケーションの機械的ストレスの下での色変化運動と均衡のシフトを定量化しています.
科学分野:
- ポリマーサイエンスの科学
- マテリアルサイエンス 材料科学
- メカノ化学 メカノ化学
背景:
- スピロピラン (SP) メカノフォアは,ポリマーの視覚的ストレス検出を可能にします.
- これらのメカノフォアは,自己感知能力を持つスマートな材料を作成する可能性を秘めています.
- ステップ・グロース・ポリメリゼーションによるポリウレタンへの組み込みが達成されました.
研究 の 目的:
- 大量ポリウレタン中のSPメカノフォアのメカノ化学反応の運動学を調査する.
- カラーメロシアニン (MC) 形式へのストレス誘発のリング開きを定量化するために.
- 閉塞運動学と,SP/MCの均衡に及ぼす機械的ストレスの影響について研究する.
主な方法:
- ステップ・グロース・ポリメリゼーションにより,SPをポリウレタンに組み込む.
- SPからMCへの変換を定量化するために,一定のストレスのときの吸収量測定.
- メカノフォアの閉塞運動を研究するための光成像.
主要な成果:
- SPからMCへのストレス誘発のリング開きは,吸収量の変化によって定量化されました.
- メカノフォアの閉塞運動は,光画像を用いて研究された.
- SPとMCの形態のバランスに対する機械的ストレスの影響が報告されました.
結論:
- SPメカノフォアを持つポリウレタンは,視覚的ストレスを感知することを示しています.
- この研究は,バルクポリマーにおける機械化学反応の運動データを提供します.
- 発見は,自己感知型スマート素材の開発を支援しています.
関連する概念動画
02:27Le Chatelier's Principle: Changing Concentration
A system at equilibrium is in a state of dynamic balance, with forward and reverse reactions taking place at equal rates. If an equilibrium system is subjected to a change in conditions that affects these reaction rates differently (a stress), then the rates are no longer equal and the system is not at equilibrium. The system will subsequently experience a net reaction in the direction of a greater rate (a shift) that will re-establish the equilibrium. This phenomenon is summarized by Le...
02:20Dynamic Equilibrium
A reversible chemical reaction represents a chemical process that proceeds in both forward (left to right) and reverse (right to left) directions. When the rates of the forward and reverse reactions are equal, the concentrations of the reactant and product species remain constant over time and the system is at equilibrium. A special double arrow is used to emphasize the reversible nature of the reaction. The relative concentrations of reactants and products in equilibrium systems vary greatly;...
02:19Le Chatelier's Principle: Changing Temperature
Consistent with the law of mass action, an equilibrium stressed by a change in concentration will shift to re-establish equilibrium without any change in the value of the equilibrium constant, K. When an equilibrium shifts in response to a temperature change, however, it is re-established with a different relative composition that exhibits a different value for the equilibrium constant.
To understand this phenomenon, consider the elementary reaction:
To understand this phenomenon, consider the elementary reaction:
03:25Free Energy Changes for Nonstandard States
The free energy change for a process taking place with reactants and products present under nonstandard conditions (pressures other than 1 bar; concentrations other than 1 M) is related to the standard free energy change according to this equation:
01:30The Response of Equilibria to the Conditions
Named after the French chemist Henry Louis Le Chatelier, Le Chatelier's principle states that when a system at equilibrium is subjected to any change (like pressure, temperature, or concentration), the composition of the system adjusts in a way that counteracts the effect of this change, thereby attempting to restore the equilibrium.According to Le Chatelier's principle, for exothermic reactions, when the system's temperature is increased, the system will try to reduce the temperature. This...
01:23Introduction to Chemical Reactions
All chemical reactions begin with a reactant, the general term for one or more substances entering the reaction. Sodium and chloride ions, for example, are the reactants in the production of table salt. One or more substances produced by a chemical reaction are called the product. Chemical reactions follow the law of conservation of mass, which means that matter cannot be created nor destroyed in a chemical reaction. The components of the reactants—the number of atoms and the elements—are all...