Simulational Analysis of Relaxation in Polymer Systems

聚合物体系松弛的模拟分析

基本信息

批准号：
11640380
负责人：
TAKANO Hiroshi
金额：
$ 1.34万
依托单位：
Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

1. Relaxation rates and modes of a single polymer chain confined in a slit by repulsive walls are studied. Their behaviors for the directions parallel to the walls can be understood as those of a two-dimensional excluded volume chain of blobs, of which size is comparable to the width of the slit. The behaviors for the perpendicular direction can be understood by assuming a repulsive interaction between the perpendicular components of the displacements of neighboring blobs.2. Relaxation rates and modes of a star polymer are studied. From the dependence of the relaxation modes and rates on the number of arms and the number of segments per arm, two relaxation processes corresponding to the deformation of the overall shape and the exchange of the positions of two neighboring arms are found. Although the former has been predicted by a theory, the latter has not.3. Relaxation rates and modes of a polymer chain trapped in a tube network are studied in two and three dimensions. In two dimensio … More ns, because of the excluded volume interaction, the exponent of the power law dependence of the relaxation rates on the number of segments is larger than the theoretical value for the case of no excluded volume interaction. The behavior of the smallest relaxation rate is different form that of the other relaxation rates. In three dimensions, the excluded volume interaction has little effect.4. Relaxation rates and modes of a polymer chain in a melt are studied. The apparent exponent of the power law dependence of the inverse of the smallest relaxation rate on the number N of segments increases beyond the theoretically predicted value, three, as N increases. From the data for the largest values of N, the apparent exponent is estimated as 3.5, which is consistent with the experimental results. The exponent of the power law dependence of the p-th smallest relaxation rate on p is smaller than the theoretical value, two. The behaviors of the first and second slowest relaxation modes are consistent with the theoretical prediction.5. Relaxation rates and modes of a single polymer chain are studied, where the excluded volume interaction and the hydrodynamic interaction are taken into account. A theoretical formula which describes how the relaxation rate spectrum changes as the strength of the hydrodynamic interaction changes is proposed and is confirmed by simulations. Less

1。被排斥壁限制在缝隙中的单个聚合物链的松弛率和模式是研究的。它们对平行于墙壁的方向的行为可以理解为二维排除体积的斑点链的行为，其大小与狭缝的宽度相当。垂直方向的行为可以通过假设相邻斑点的位移的垂直成分之间存在排斥性相互作用来理解。2。恒星聚合物的松弛率和模式是研究的。从弛豫模式和对臂数量的依赖性和每只手臂段数的数量，发现了两个弛豫过程，与整体形状的变形相对应，并发现了两个相邻臂的位置的交换。尽管前者是通过理论预测的，但后者却没有。3。在两个维度和三个维度上研究了被困在管网络中的聚合物链的松弛率和模式。在二维中……更多的ns，由于排除的体积相互作用，宽松率对段数量的功率定律依赖性的指数大于没有排除体积相互作用的情况的理论值。最小放松率的行为是其他放松率的不同形式。在三个维度中，排除的体积相互作用几乎没有效果。4。熔体中聚合物链的松弛率和模式是研究的。最小的放松率对段数n的逆逆依赖性的明显指数随着n的增加而增加，超出了理论预测值，三。从最大值的数据中，表观指数估计为3.5，这与实验结果一致。第pth最小放松率对P的幂定律依赖性的指数小于理论值两个。第一和第二慢的放松模式的行为与理论预测一致。5。单个聚合物链的松弛速率和模式是研究的，其中考虑了排除的体积相互作用和流体动力相互作用。一种理论公式，描述了随着流体动力相互作用的强度变化的强度，并通过模拟证实了弛豫率光谱如何变化。较少的