关于胶体体系动力学捕获态边界问题的探讨

项目名称： 关于胶体体系动力学捕获态边界问题的探讨

项目编号： No.21474121

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 袁光萃

作者单位： 中国科学院化学研究所

项目金额： 88万元

中文摘要： 本项目从实验角度研究胶体粒子体系动力学捕获态（凝胶、玻璃）转变的基本问题。我们选用吸附性聚合物来调控粒子间的短程吸引作用。取决于所加入的聚合物的量是否足以完全覆盖粒子表面，粒子间的短程吸引作用可以是明确的桥联键或统计的排空吸引作用。我们把聚合物和粒子的体积分数比作为一个重要参数来调控粒子的稳定、聚集、凝胶和玻璃化，从而构建胶体-吸附性聚合物混合体系的状态图。给定粒子的体积分数，提高聚合物的浓度，实现桥联凝胶-液体-排空凝胶、桥联吸引玻璃-液体（或排斥玻璃）-排空吸引玻璃的转变；给定粒子与聚合物的比例，提高粒子的体积分数，实现桥联凝胶-桥联吸引玻璃、液体-排斥玻璃、排空凝胶-排空吸引玻璃的转变。我们从热力学和动力学角度去描述这些状态转变的特征和精确确定状态分界线的位置，希望能深入理解胶体捕获态转变的本质。

中文关键词： 胶体；吸附；短程吸引；动力学捕获；临界点

英文摘要： In this project, we plan to investigate the fundamental problems about dynamical states (including gel and glass) in colloidal systems. Adsorbing polymer will be used to induce short range attraction between particles. The short range attraction may come from the well-defined bridging bonding or from the statistical depletion induced by extra free polymers, depending on whether the amount of polymer is smaller or larger than the saturated adsorption concentration for given volume fraction of particles. Therefore, a state diagram in mixed suspension of colloid and adsorbing polymer will be constructed by taking the volume ratio of polymer and particle as an important factor to trigger the stabilization, aggregation, gelation and glass transition of the mixtures. For mixtures with given volume fraction of particles, increasing concentration of the polymer, transition of bridging gel-liquid-depletion gel, and transition of bridging attractive glass-liquid (or repulsive glass)-depletion attractive glass are expected. For given mixing ratio of two components, increasing concentration of the whole system, transition of bridging gel-bridging attractive glass, transition of liquid- repulsive glass, and transition of depletion gel-depletion attractive glass are expected. By describing the characters of these transitions and precisely determining the position of the state boundaries from static and dynamic point of views, we hope to have a deep understanding on the nature of trnsitions between dynamical arrested states of colloidal system.

英文关键词： colloid;adsorption;short range attraction;dynamical arrest;critical point