Conformation and Dynamics of Chain Molecules: Molecular Studies on Correlation between Structure and Properties in Condensed Systems

本研究项目涉及以下四个主要领域。在“孤立链与溶液中分子间相互作用”的第一个专题中，通过对一些刚性链系统的实验，提出了螺旋状蠕虫链的理论，并对其进行了检验。对rheta溶液中第三个病毒系数的精确测量提出了现有“双参数理论”无法解释的rheta条件的新概念。介绍了钙调蛋白和蛋白白蛋白构象的新情况。在“同质体系的动力学和构象行为”的第二个主题中，讨论了重复的“拓扑基础”、局部运动的“齿轮模型”、“DNA的脉冲凝胶电泳”和“棒状分子剪切溶液的稳定性”。给出了棒状聚合物、聚电解质溶液、聚合物/聚合物/溶剂体系、嵌段共聚物胶束扩散和微分粘弹性的实验结果。综述了中子散射和荧光退极化技术所揭示的聚合物局部节段运动，以及嵌段共聚物的密度泛函理论和剪切场下聚合物共混物的相行为。在“临界现象、相行为和界面现象”的第三个主题中，报告了各种体系中相转变的实验和理论结果，包括线圈-球转变、平行板间的链构象和界面上的聚合物链。最后，在第四类“理论分析与模拟”中，讨论了UCST行为理论、溶胶-凝胶过渡理论和生物进化的渗透理论。

This research project concerns with the following four major areas. In the first subject on "isolated chain and intermolecular interaction in solution," the theory of helical worm-like chain was developed and examined through experiments on some stiff chain systems. Precise measurements of the third viral coefficients in rheta solution suggested a new concept of the rheta condition that cannot be explained by the existing "two parameter theory." New pictures on the conformation of calmodulin and egg-white alubumin were presented. In the second subject on "dynamics and conformational behavior of homogeneous systems, "a topological foundation" of repetition, "a gear-model" on local motion, "pulse gel electrophoresis of DNA" and "stability of sheared solution of rodlike molecules" were discussed. Experimental results on rodlike polymers, polyelectrolyte solution, polymer/polymer/solvent systems, diffusion of block coplymer micelles and differential viscoelasticity were presented. Reviews were given on local segmental motions of polymers revealed by neutron scattering and fluoresence depolarization techniques, and also on a density functional theory of block copolymers and on phase behavior of polymer blends under shear field. In the third subject on "critical phenomena, phase behavior and interfacial phenomena" experimental and theoretical results on phase transition in various systems, coil-globule transition, chain conformation between parallel plates and polymer chain on the interface were reported. Finally, in the forth category on "theoretical analysis and simulation," theories on UCST behavior, sol-gel transition and percolation theory on biological evolution were discussed.