Computational and Chemical Biology, Fondazione Istituto Italiano di Tecnologia, Genova 16163, Italy.
School of Physics, University College, Dublin 4, Ireland.
J Phys Chem B. 2020 Oct 15;124(41):9267-9274. doi: 10.1021/acs.jpcb.0c07575. Epub 2020 Oct 4.
Entropy-driven demixing transitions play an important role in a variety of phenomena in solution chemistry, in mixtures of ionic liquids, in polymers, and in biosystems. A simple coarse-grained model of a binary (A and B) fluid mixture of Lennard-Jones particles carrying classical harmonic oscillators whose frequency decreases with increasing homo-coordination separates into two nearly pure phases with increasing , as the entropy gain in lowering the oscillators' frequency overcomes the potential energy and ideal entropy advantage of the homogeneous phase. We characterize features of the demixing transition and outline physical questions that can be addressed by this simple and inexpensive model. Besides and beyond these conceptual points, we provide examples of how the model could be adapted to real systems, aiming at their quantitative description by a coarse-grained model made of particles carrying momentum, energy, and entropy.
熵驱动的分相转变在溶液化学、离子液体混合物、聚合物和生物系统中的各种现象中起着重要作用。一个携带经典谐振子的二元（A 和 B）Lennard-Jones 粒子流体混合物的简单粗粒化模型，其频率随同配位数的增加而降低，当降低谐振子频率的熵增益克服了同相的位能和理想熵优势时，混合物会分离成两个近乎纯的相。我们描述了分相转变的特征，并概述了可以通过这个简单且廉价的模型来解决的物理问题。除了这些概念性的观点之外，我们还提供了如何将模型应用于实际系统的示例，旨在通过由携带动量、能量和熵的粒子组成的粗粒化模型对其进行定量描述。
