Frozen Topology: Entanglements Control Nucleation and Crystallization in Polymers
Frozen Topology: Entanglements Control Nucleation and Crystallization in Polymers
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DOI：
10.1103/physrevlett.112.195702
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发表时间：
2014-05-16
影响因子：
8.6
通讯作者：
Sommer, Jens-Uwe
中科院分区：
文献类型：
--
作者：
Luo, Chuanfu;Sommer, Jens-Uwe
聚合物链在结晶过程中形成层状结构，显示出热历史记忆。利用分子动力学模拟和原始路径分析，我们显示了一个直接依赖于本地纠缠长度的密度和晶体茎长度。纠缠态在外界条件改变后的缓慢弛豫可以直接解释热历史对聚合物结晶的作用，特别是记忆效应。对局域纠缠态的分析可以用来预测核化事件的发生。我们的研究结果提出了一个新的见解的非平衡性质的聚合物晶体，这可能被确定为“冻结拓扑结构”的聚合物熔体。
Polymer chains form lamellar structures during crystallization which display a memory of thermal history. Using molecular dynamics simulations and primitive path analysis, we show a direct dependence of both density and crystalline stem length on the local entanglement length. The slow relaxation of the entanglement state after a change of external conditions can directly explain the role of thermal history for polymer crystallization, in particular memory effects. The analysis of the local entanglement state can be used to predict the occurrence of nucleation events. Our results present a fresh insight of the nonequilibrium properties of polymer crystals which might be identified as "frozen topology" of polymer melts.