Abstract

The dynamic heterogeneity of polymer chains is characterized by the lower correlation times of its end Kuhn segments with respect to those of the middle segments. In this study, the heterogeneity was investigated using molecular dynamics simulation of freely jointed chains of various lengths in the melt. Our characterization of the segmental dynamics along the chain additionally revealed the heterogeneity of rotational anisotropy, which was also lower for chain-end segments compared to those for chain-middle ones. This heterogeneity can be quantitatively characterized by intra-segmental residual dipolar coupling, which influences the transverse magnetic relaxation rate of the various chain segments and, ultimately, defines the free induction decay shape for chains of any length. Further, in the second part of this report, the origin of this relationship is discussed in detail.

中文翻译：

---

模拟聚合物熔体中的链异质性：链段取向自相关函数

摘要

聚合物链的动态异质性的特征在于其末端库恩链段相对于中间链段的相关时间较低。在这项研究中，使用分子动力学模拟了熔体中各种长度的自由连接链的异质性。我们对链段动力学的表征还揭示了旋转各向异性的异质性，与链中段相比，链端段的异质性也较低。这种异质性可以通过段内残留偶极耦合来定量地表征，这会影响各个链段的横向磁弛豫速率，并最终定义任意长度链的自由感应衰减形状。此外，在本报告的第二部分，