College of Science, Nanjing University of Science and Technology, Nanjing 210094, China.
J Phys Chem B. 2010 Mar 18;114(10):3488-93. doi: 10.1021/jp911193r.
We studied athermal relaxation of bulk extended chains by means of dynamic Monte Carlo simulations, and we got intermediately relaxed melts with a memory of chain orientations but no more crystalline order. The orientational memory in the melts dominated the crystal orientation and nucleation types. The difference in crystallization behaviors induced by orientational relaxation suggested the mechanism of hierarchical crystallization. Thus, we studied the isothermal crystallization of a binary blend of different relaxed chains. We observed the prior crystallization of less relaxed chains could act as a shish to induce epitaxial crystallization of more relaxed chains to form kebabs. This mechanism had demonstrated the structure of precursors and gave insight into the formation of shish-kebab crystals in polymer melts. The results suggested that in flow-induced polymer crystallization the hierarchical orientational relaxation of chains decided the formation of shish-kebabs.
我们通过动态蒙特卡罗模拟研究了大块扩展链的非热松弛。我们得到了具有链取向记忆但没有更多晶体有序性的中间松弛熔体。熔体中的取向记忆主导了晶体取向和成核类型。取向松弛引起的结晶行为差异表明了分级结晶的机制。因此，我们研究了不同松弛链的二元共混物的等温结晶。我们观察到较不松弛链的优先结晶可以作为 shish 诱导更多松弛链的外延结晶，形成 kebab。这种机制展示了前体的结构，并深入了解了聚合物熔体中 shish-kebab 晶体的形成。结果表明，在流动诱导的聚合物结晶中，链的分级取向松弛决定了 shish-kebabs 的形成。
