Determination of Tube Theory Parameters Using a Simple Grid Model as an Example
Determination of Tube Theory Parameters Using a Simple Grid Model as an Example
复制标题
以简单网格模型为例确定管理论参数
DOI：
10.1021/ma302103p
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发表时间：
2013
期刊：
影响因子：
5.5
通讯作者：
Likhtman A
中科院分区：
文献类型：
--
作者：
Likhtman A
虽然管理论在定性描述缠结聚合物方面是成功的，但更定量的描述需要精确和一致的参数定义。在这里，我们调查最简单的模型纠缠聚合物，即一个单一的劳斯链在立方晶格的线障碍，并说明了典型的问题和不确定性的管理论。特别是，我们表明，在一般情况下，需要三个纠缠相关的参数，但只有两个组合，它们是相关的长时间动态。相反，平台模量不能从这两个参数确定，需要一个更详细的纠缠模型与明确的纠缠力，如滑动弹簧模型。结果表明，在网格模型的Rouse时间内管大于自由链的Rouse时间，在对比标准管理论假设。
Although the tube theory is successful in describing entangled polymers qualitatively, a more quantitative description requires precise and consistent definitions of its parameters. Here we investigate the simplest model of entangled polymers, namely a single Rouse chain in a cubic lattice of line obstacles, and illustrate the typical problems and uncertainties of the tube theory. In particular we show that in general one needs three entanglement related parameters, but only two combinations of them are relevant for the long-time dynamics. Conversely, the plateau modulus can not be determined from these two parameters and requires a more detailed model of entanglements with explicit entanglement forces, such as the slip-springs model. It is shown that for the grid model the Rouse time within the tube is larger than the Rouse time of the free chain, in contrast to what the standard tube theory assumes.