中国物理B ›› 2017, Vol. 26 ›› Issue (3): 30506-030506.doi: 10.1088/1674-1056/26/3/030506

• GENERAL • 上一篇    下一篇

Moderate point: Balanced entropy and enthalpy contributions in soft matter

Baoji He(贺宝记), Yanting Wang(王延颋)   

  1. 1 CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
  • 收稿日期:2017-01-01 修回日期:2017-02-13 出版日期:2017-03-05 发布日期:2017-03-05
  • 通讯作者: Yanting Wang E-mail:wangyt@itp.ac.cn
  • 基金资助:

    Project supported by the National Basic Research Program of China (Grant No. 2013CB932804) and the National Natural Science Foundation of China (Grant Nos. 11274319 and 11421063).

Moderate point: Balanced entropy and enthalpy contributions in soft matter

Baoji He(贺宝记)1,2, Yanting Wang(王延颋)1,2   

  1. 1 CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China;
    2 School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2017-01-01 Revised:2017-02-13 Online:2017-03-05 Published:2017-03-05
  • Contact: Yanting Wang E-mail:wangyt@itp.ac.cn
  • Supported by:

    Project supported by the National Basic Research Program of China (Grant No. 2013CB932804) and the National Natural Science Foundation of China (Grant Nos. 11274319 and 11421063).

摘要:

Various soft materials share some common features, such as significant entropic effect, large fluctuations, sensitivity to thermodynamic conditions, and mesoscopic characteristic spatial and temporal scales. However, no quantitative definitions have yet been provided for soft matter, and the intrinsic mechanisms leading to their common features are unclear. In this work, from the viewpoint of statistical mechanics, we show that soft matter works in the vicinity of a specific thermodynamic state named moderate point, at which entropy and enthalpy contributions among substates along a certain order parameter are well balanced or have a minimal difference. Around the moderate point, the order parameter fluctuation, the associated response function, and the spatial correlation length maximize, which explains the large fluctuation, the sensitivity to thermodynamic conditions, and mesoscopic spatial and temporal scales of soft matter, respectively. Possible applications to switching chemical bonds or allosteric biomachines determining their best working temperatures are also briefly discussed.

关键词: moderate point, balanced entropy, enthalpy contribution

Abstract:

Various soft materials share some common features, such as significant entropic effect, large fluctuations, sensitivity to thermodynamic conditions, and mesoscopic characteristic spatial and temporal scales. However, no quantitative definitions have yet been provided for soft matter, and the intrinsic mechanisms leading to their common features are unclear. In this work, from the viewpoint of statistical mechanics, we show that soft matter works in the vicinity of a specific thermodynamic state named moderate point, at which entropy and enthalpy contributions among substates along a certain order parameter are well balanced or have a minimal difference. Around the moderate point, the order parameter fluctuation, the associated response function, and the spatial correlation length maximize, which explains the large fluctuation, the sensitivity to thermodynamic conditions, and mesoscopic spatial and temporal scales of soft matter, respectively. Possible applications to switching chemical bonds or allosteric biomachines determining their best working temperatures are also briefly discussed.

Key words: moderate point, balanced entropy, enthalpy contribution

中图分类号:  (Classical statistical mechanics)

  • 05.20.-y
65.40.gd (Entropy)