James Franck Institute and the Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA.
J Chem Phys. 2013 Apr 28;138(16):164902. doi: 10.1063/1.4800082.
The theory of equilibrium solvation of polymers B by a relatively low molar mass solvent A, developed in the simplest form in Paper I, is used to explore some essential trends in basic thermodynamic properties of solvated polymer solutions, such as the equilibrium concentrations of solvated polymers AiB and free solvent molecules A, the mass distribution φ(AiB)(i) of solvated clusters, the extent of solvation of the polymer Φ(solv), the solvation transition lines T(solv)(φB(o)), the specific heat C(V), the osmotic second virial coefficient B2, phase stability boundaries, and the critical temperatures associated with closed loop phase diagrams. We discuss the differences between the basic thermodynamic properties of solvated polymers and those derived previously for hierarchical mutual association processes involving the association of two different species A and B into AB complexes and the subsequent polymerization of these AB complexes into linear polymeric structures. The properties of solvated polymer solutions are also compared to those for solutions of polymers in a self-associating solvent. Closed loop phase diagrams for solvated polymer solutions arise in the theory from the competition between the associative and van der Waals interactions, a behavior also typical for dispersed molecular and nanoparticle species that strongly associate with the host fluid. Our analysis of the temperature dependence of the second osmotic virial coefficient reveals that the theory must be generalized to describe the association of multiple solvent molecules with each chain monomer, and this complex extension of the present model will be developed in subsequent papers aimed at a quantitative rather than qualitative treatment of solvated polymer solutions.
聚合物 B 被相对低摩尔质量溶剂 A 平衡溶解的理论，在论文 I 中以最简单的形式发展起来，用于探索溶剂化聚合物溶液基本热力学性质的一些基本趋势，如平衡浓度溶剂化聚合物 AiB 和游离溶剂分子 A、溶剂化聚集体的质量分布 φ(AiB)(i)、聚合物的溶胀程度 Φ(solv)、溶胀转变线 T(solv)(φB(o))、比热 C(V)、渗透压第二维里系数 B2、相稳定性边界和与封闭环相图相关的临界温度。我们讨论了溶剂化聚合物的基本热力学性质与以前涉及两种不同物种 A 和 B 形成 AB 配合物的相互关联过程以及随后这些 AB 配合物聚合为线性聚合物结构的分层相互关联过程的基本热力学性质之间的差异。溶剂化聚合物溶液的性质也与自缔合溶剂中聚合物溶液的性质进行了比较。封闭环相图在理论上来自于缔合和范德华相互作用之间的竞争，这种行为也典型于与主体流体强烈缔合的分散分子和纳米颗粒物质。我们对第二渗透压第二维里系数的温度依赖性的分析表明，该理论必须推广到描述每个链单体与多个溶剂分子的缔合，本模型的这个复杂扩展将在后续论文中开发，旨在对溶剂化聚合物溶液进行定量而不是定性处理。
