Development of Computer System for Predicting Phase Diagrams of Associating Polymers

在本研究项目中，我们开发了一个预测缔合聚合物相行为的计算机系统。该系统由两部分组成：(1)基于我们最新的缔合聚合物理论，通过数值计算快速推导相图，并将其可视化。(2)采用非点阵珠簧模型链进行蒙特卡罗模拟，对上述导出的相图所指定的状态进行结构分析。在第一部分中，我们输入了必要的系统参数，如聚合物的化学种类、聚合程度、功能（官能团的数量、在链上的分布）、链的弯曲刚度、缔合常数和相互作用参数。相变的可能性，如宏观和微相分离，凝胶化，液体结晶，胶束化，水化等。我们在相空间中绘制了双轴、旋轴、溶胶/凝胶过渡线、微相分离过渡线、CMC、向列和近晶过渡线。在第二部分中，我们使用串珠-弹簧模型链对相位平面上指定的状态进行了蒙特卡罗模拟。聚合物链带有结合珠和非结合头。平衡后，对基本缔合类簇的分布、渗透性质、链种群等进行了评价。典型快照被可视化。到目前为止，已经安装到程序中的具体系统有：<Nongelling系统>二聚体形成，水化，侧链结合，氢键液晶< gelelling系统>简单凝胶化，多结凝胶化，2组分凝胶化，结合构象变化的凝胶化，氢键液晶网络

In this research project, we developed computer system for predicting phase behavior of associating polymers. Our system consists of two parts : (1) Fast derivation of phase diagrams by numerical calculation on the basis of our recent theory of associating polymers, and their visualization. (2) Monte Carlo simulation by using off-lattice bead-spring model chains for structural analysis of the state specified on the phase diagrams derived above.In the first part, we input necessary system parameters such as chemical species of polymers, their degree of polymerization, their functionality (number of functional groups, their distribution on a chain), bending rigidity of a chain, association constant, and interaction parameter. Possibility of phase transitions such as macro- and microphase separation, gelation, liquid-crystallization, micellization, hydration, etc. We draw binodals, spinodals, sol/gel transition lines, microphase separation transition lines, CMC, nematic and smectic transition lines in the phase space.In the second part, we carry out Monte Carlo simulation for the state specified on the phase plane by using bead-spring model chains. Polymer chains carry associative beads and non-associative b eads. After equilibriation, distribution of clusters, percolation properties, chain population of fundam ental association categories, etc. are evaluated. Typical snapshots are visualized. Specific systems which have been installed into the program so far are : <Nongelling Systems> Dimer Formation, Hydration, Side-Chain Association, Hydrogen-Bonded Liquid Crystals <Gelling Systems> Simple Gelation, Gelation with Multiple Junctions, 2-Component Gelation, Gelation coupled to Conformational Change, Hydrogen-Bonded Liquid Crystalline Networks