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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.研究了被排斥壁限制在狭缝中的高分子单链的弛豫速率和弛豫模式。它们在平行于壁面方向上的行为可以理解为一个大小与狭缝宽度相当的二维不相容体积链。垂直方向的行为可以通过假设相邻斑点的位移的垂直分量之间的排斥相互作用来理解。研究了一种星星聚合物的弛豫速率和弛豫模式。从弛豫模式和弛豫速率对臂数和每臂段数的依赖关系中，发现了对应于整体形状变形和两个相邻臂位置交换的两个弛豫过程，虽然前者已被理论预言，但后者还没有.在二维和三维空间中研究了被困在管状网络中的高分子链的弛豫速率和弛豫模式。在二维空间中 ...更多信息 ns时，由于排斥体积相互作用的存在，弛豫速率对链段数的幂律依赖指数大于无排斥体积相互作用时的理论值。最小弛豫率的行为与其他弛豫率的行为不同。在三维空间中，排除体积相互作用的影响很小.研究了熔体中高分子链的弛豫速率和弛豫方式。的幂律依赖性的最小松弛速率的倒数的片段的数量N的表观指数增加超过理论预测值，三，作为N的增加。根据N最大值的数据，表观指数估计为3.5，这与实验结果一致。第p个最小弛豫速率对p的幂律依赖指数小于理论值2。第一和第二慢弛豫模式的行为与理论预测一致.研究了考虑排斥体积相互作用和流体动力学相互作用的高分子单链的弛豫速率和弛豫模式。提出了一个描述弛豫速率谱随流体动力相互作用强度变化的理论公式，并通过模拟得到了证实。少