Entropy Elasticity - Entropy Dynamics

According to statistical mechanics, entropy in an equilibrium state is proportional to the number of microscopic forms that can be taken in that state. Therefore, when an external force is applied to an object, resulting in a state with a small number of microscopic forms (or levels), a force acts to return it to its original state. This is called entropy elasticity. This is the force that acts when a gas is compressed or rubber is stretched. However, care must be taken because even in systems with entropy elasticity, energy elasticity (lattice distortion, etc.) may also be at work at the same time. [See alternative terminology] Rubber elasticity

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

統計力学によれば，平衡状態におけるエントロピーは，その状態でとりうる微視的な形態の数に比例する．したがって，物体に外力を加えて微視的な形態(あるいは準位)の数の少ない状態をもたらすと，もとの状態に戻ろうとする力がはたらく．これをエントロピー弾性という．気体の圧縮，ゴムの伸長などに際してはたらく力がこれである．ただし，エントロピー弾性のある系でも，エネルギー弾性(格子のひずみ，その他)も同時にはたらいている場合もあるので注意を要する．[別用語参照]ゴム弾性

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