Kocherginsky Nikolai, Gruebele Martin
Biomime, Inc., Urbana, IL 61801;
Department of Chemistry, University of Illinois, Urbana, IL 61801; Department of Physics, University of Illinois, Urbana, IL 61801
Proc Natl Acad Sci U S A. 2016 Oct 4;113(40):11116-11121. doi: 10.1073/pnas.1600866113. Epub 2016 Sep 19.
Nonequilibrium thermodynamics describes the rates of transport phenomena with the aid of various thermodynamic forces, but often the phenomenological transport coefficients are not known, and the description is not easily connected with equilibrium relations. We present a simple and intuitive model to address these issues. Our model is based on Lagrangian dynamics for chemical systems with dissipation, so one may think of the model as physicochemical mechanics. Using one main equation, the model allows a systematic derivation of all transport and equilibrium equations, subject to the limitation that heat generated or absorbed in the system must be small for the model to be valid. A table with all major examples of transport and equilibrium processes described using physicochemical mechanics is given. In equilibrium, physicochemical mechanics reduces to standard thermodynamics and the Gibbs-Duhem relation, and we show that the First and Second Laws of thermodynamics are satisfied for our system plus bath model. Out of equilibrium, our model provides relationships between transport coefficients and describes system evolution in the presence of several simultaneous external fields. The model also leads to an extension of the Onsager-Casimir reciprocal relations for properties simultaneously transported by many components.
非平衡态热力学借助各种热力学力来描述输运现象的速率，但现象学输运系数往往未知，且这种描述不易与平衡关系相联系。我们提出一个简单直观的模型来解决这些问题。我们的模型基于具有耗散的化学系统的拉格朗日动力学，因此可以将该模型视为物理化学力学。使用一个主要方程，该模型允许系统地推导所有输运和平衡方程，但存在一个限制，即系统中产生或吸收的热量必须很小，模型才有效。给出了一个使用物理化学力学描述的所有主要输运和平衡过程示例的表格。在平衡态下，物理化学力学简化为标准热力学和吉布斯 - 杜亥姆关系，并且我们表明对于我们的系统加浴模型，热力学第一和第二定律是满足的。在非平衡态下，我们的模型提供了输运系数之间的关系，并描述了在几个同时存在的外场情况下系统的演化。该模型还导致了昂萨格 - 卡西米尔互易关系对于由多个组分同时输运的性质的扩展。
