Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 8, 64287 Darmstadt, Germany.
Department of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, 992-8510 Yamagata-ken, Japan.
J Chem Theory Comput. 2021 Jan 12;17(1):474-487. doi: 10.1021/acs.jctc.0c00954. Epub 2020 Dec 4.
A quantitative prediction of polymer-entangled dynamics based on molecular simulation is a grand challenge in contemporary computational material science. The drastic increase of relaxation time and viscosity in high-molecular-weight polymeric fluids essentially limits the usage of classic molecular dynamics simulation. Here, we demonstrate a systematic coarse-graining approach for modeling entangled polymers under the slip-spring particle-field scheme. Specifically, a frequency-controlled slip-spring model, a hybrid particle-field model, and a coarse-grained model of polystyrene melts are combined into a hybrid simulation technique. Via a rigorous parameterization strategy to determine the parameters in slip-springs from existing experimental or simulation data, we show that the reptation behavior is clearly observed in multiple characteristics of polymer dynamics, mean-square displacements, diffusion coefficients, reorientational relaxation, and Rouse mode analysis, consistent with the predictions of the tube theory. All dynamical properties of the slip-spring particle-field models are in good agreement with classic molecular dynamics models. Our work provides an efficient and practical approach to establish chemical-specific coarse-grained models for predicting polymer-entangled dynamics.
基于分子模拟对聚合物缠结动力学进行定量预测是当代计算材料科学的一大挑战。在高分子量聚合物流体中，弛豫时间和粘度的急剧增加从本质上限制了经典分子动力学模拟的应用。在这里，我们展示了一种基于滑移弹簧粒子场方案的用于模拟缠结聚合物的系统粗粒化方法。具体来说，将频率控制的滑移弹簧模型、混合粒子-场模型和聚苯乙烯熔体的粗粒化模型结合到一种混合模拟技术中。通过严格的参数化策略，从现有的实验或模拟数据中确定滑移弹簧中的参数，我们表明，在聚合物动力学的多个特征中，如均方位移、扩散系数、重取向松弛和罗瑟模式分析中，都可以清楚地观察到蠕动行为，这与管理论的预测一致。滑移弹簧粒子场模型的所有动力学性质都与经典分子动力学模型很好地吻合。我们的工作为建立用于预测聚合物缠结动力学的化学特异性粗粒化模型提供了一种有效且实用的方法。
