论文标题
流体多态性的通用最大价值模型
Generic Maximum-Valence Model for Fluid Polyamorphism
论文作者
论文摘要
最近，已经提出了最大价值模型，以模拟由硫的聚合诱导的液态液相变。在本文中，我们提出了一个简单的通用模型，该模型使用任何任意配位数的最大价值方法来描述单组分流体中的液态多态性。该模型包含三种类型的相互作用：i）原子在低压下产生液态气体过渡的范德华力相互吸引，ii）原子可能形成共价键，诱导关联，ii）原子之间具有最大价值和原子与任何价值的原子之间的其他排斥力。这种额外的排斥产生了液态液相分离和P-T相图上负热量膨胀系数（密度异常）的区域。我们显示了用于相应配位数Z = 1，2，..6的二聚化，聚合，凝胶和网络形成的液态液相变的存在，并讨论了这种产生流体多态性的通用模型的限制。
Recently, maximal valence model has been proposed to model liquid-liquid phase transition induced by polymerization in sulfur. In this paper we present a simple generic model to describe liquid polyamorphism in single-component fluids using a maximum-valence approach for any arbitrary coordination number. The model contains three types of interactions: i) atoms attract each other by van der Waals forces that generate a liquid-gas transition at low pressures, ii) atoms may form covalent bonds that induce association, and iii) additional repulsive forces between atoms with maximal valence and atoms with any valence. This additional repulsion generates liquid-liquid phase separation and the region of negative heat expansion coefficient (density anomaly) on a P-T phase diagram. We show the existence of liquid-liquid phase transitions for dimerization, polymerization, gelation and network formation for corresponding coordination numbers z = 1, 2, ..6 and discuss the limits of this generic model for producing fluid polyamorphism.
