The topological glass in ring polymers
The topological glass in ring polymers
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DOI：
10.1209/0295-5075/102/58005
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发表时间：
2013-06-01
期刊：
影响因子：
1.8
通讯作者：
Turner, Matthew S.
中科院分区：
文献类型：
--
作者：
Lo, Wei-Chang;Turner, Matthew S.
我们研究的动力学集中，长，半柔性，unknotted和unlinked环聚合物嵌入在凝胶中的粗粒度模型的Monte Carlo模拟。这涉及到环紧密化成双链结构，在那里它们可以被建模为线性聚合物。经典的聚合物玻璃化转变涉及随着温度向Tg降低，聚合物分子内微观自由度的快速丧失。在这里，我们感兴趣的温度远高于Tg的聚合物保持高的微观流动性。我们分析了减缓应力松弛起源于环间渗透（螺纹）。对于长的聚合物，准拓扑贯穿的扩展网络形式。最长的弛豫时间似乎指数地取决于环聚合物轮廓长度，这让人想起通常的指数减慢（例如，温度）在经典玻璃中。最后，我们讨论了这是如何代表一个普遍性类玻璃动力学。版权所有（C）2013 EPLA
We study the dynamics of concentrated, long, semi-flexible, unknotted and unlinked ring polymers embedded in a gel by Monte Carlo simulation of a coarse-grained model. This involves the ansatz that the rings compactify into a duplex structure where they can be modelled as linear polymers. The classical polymer glass transition involves a rapid loss of microscopic freedom within the polymer molecule as the temperature is reduced toward T-g. Here we are interested in temperatures well above T-g where the polymers retain high microscopic mobility. We analyse the slowing of stress relaxation originating from inter-ring penetrations (threadings). For long polymers an extended network of quasi-topological penetrations forms. The longest relaxation time appears to depend exponentially on the ring polymer contour length, reminiscent of the usual exponential slowing (e.g., with temperature) in classical glasses. Finally, we discuss how this represents a universality class for glassy dynamics. Copyright (C) EPLA, 2013