Department of Physics, Erciyes University, 38039 Kayseri, Turkey.
J Chem Phys. 2012 Jun 14;136(22):224901. doi: 10.1063/1.4726405.
This paper is a contribution of our systematic investigation of the global phase behaviors of the chain molecules mixtures, i.e., polymer mixture solutions. The phase behavior of fluid mixtures is understood by the critical lines in fluid-gas diagrams. The critical lines of binary fluid system may, under circumstances, exhibit closed loops in the critical lines. A distinction is made between free critical loops, as described by type VI in the Scott and van Konynenburg classification, and "rooted" critical loops, as found in the shield region. We define rooted loops as closed critical lines that are attached to the critical line structure by means of unstable critical line. We obtain the rooted loops in the global phase diagrams of the polymer mixture solutions within the framework of a model that combines the lattice gas model of Schouten, ten Seldam and Trappeniers with the Flory-Huggins theory, and we present the influence of the chain length of long molecules on the rooted critical loops. We present the results in the density-density and the temperature (T)-pressure (P) planes in detail.
这篇论文是我们对链状分子混合物（即聚合物混合溶液）的整体相行为进行系统研究的贡献。通过流体-气体图中的临界线来理解流体混合物的相行为。在某些情况下，二元流体系统的临界线可能会在临界线中呈现闭合环。我们将自由临界环（Scott 和 van Konynenburg 分类中的类型 VI 所描述的）与屏蔽区域中发现的“有根”临界环区分开来。我们将有根环定义为通过不稳定的临界线连接到临界线结构的闭合临界线。我们在 Schouten、ten Seldam 和 Trappeniers 的格子气体模型与 Flory-Huggins 理论相结合的模型框架内获得了聚合物混合溶液整体相图中的有根临界环，并展示了长链分子的链长对有根临界环的影响。我们详细地在密度-密度和温度（T）-压力（P）平面上呈现了结果。
