Tubiana Luca, Kobayashi Hideki, Potestio Raffaello, Dünweg Burkhard, Kremer Kurt, Virnau Peter, Daoulas Kostas
Physics Department, University of Trento, via Sommarive, 14 I-38123 Trento, Italy.
INFN-TIFPA, Trento Institute for Fundamental Physics and Applications, I-38123 Trento, Italy.
J Phys Condens Matter. 2021 Apr 29;33(20). doi: 10.1088/1361-648X/abf20c.
Recent theoretical studies have demonstrated that the behaviour of molecular knots is a sensitive indicator of polymer structure. Here, we use knots to verify the ability of two state-of-the-art algorithms-configuration assembly and hierarchical backmapping-to equilibrate high-molecular-weight (MW) polymer melts. Specifically, we consider melts with MWs equivalent to several tens of entanglement lengths and various chain flexibilities, generated with both strategies. We compare their unknotting probability, unknotting length, knot spectra, and knot length distributions. The excellent agreement between the two independent methods with respect to knotting properties provides an additional strong validation of their ability to equilibrate dense high-MW polymeric liquids. By demonstrating this consistency of knotting behaviour, our study opens the way for studying topological properties of polymer melts beyond time and length scales accessible to brute-force molecular dynamics simulations.
最近的理论研究表明，分子结的行为是聚合物结构的一个敏感指标。在此，我们使用结来验证两种最先进的算法——构型组装和分层逆映射——使高分子量（MW）聚合物熔体达到平衡的能力。具体而言，我们考虑了通过这两种策略生成的、分子量相当于几十倍缠结长度且具有各种链柔性的熔体。我们比较了它们的解结概率、解结长度、结谱和结长度分布。这两种独立方法在结特性方面的出色一致性，为它们使致密的高分子量聚合液体达到平衡的能力提供了又一有力验证。通过证明这种结行为的一致性，我们的研究为研究聚合物熔体的拓扑性质开辟了道路，这些性质超出了蛮力分子动力学模拟所能达到的时间和长度尺度。
