Viscosity and structural alteration of a coarse-grained model of polystyrene under steady shear flow studied by reverse nonequilibrium molecular dynamics
Viscosity and structural alteration of a coarse-grained model of polystyrene under steady shear flow studied by reverse nonequilibrium molecular dynamics
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DOI：
10.1021/ma0707178
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发表时间：
2007-10-30
期刊：
影响因子：
5.5
通讯作者：
Muller-Plathe, Florian
中科院分区：
文献类型：
--
作者：
Chen, Xiaoyu;Carbone, Paola;Muller-Plathe, Florian
采用反向非平衡分子动力学（RNEMD）方法预测了该体系的热稳定性. e短链聚苯乙烯的粗粒模型的粘度。粗粒度模型已被推导出再现聚苯乙烯的结构。因此，它不是通用模型，而是聚合物专用模型。在这里，其性能的动态量进行了测试。零剪切粘度与实验数据进行了比较。这种显著的差异主要归因于粗粒度模型固有的动态特性。定性的结果相比，以前的结果通过传统的非平衡分子动力学（NEMD）和更通用的聚合物模型计算，协议是合理的。剪切下的结构变化进行了研究，通过表征分子的变形和双折射消光角。
The reverse nonequilibrium molecular dynamics (RNEMD) method is implemented to predict th. e viscosity of a coarse-grained model of short-chain polystyrene. The coarse-grained model has been derived to reproduce the structure of polystyrene. It is therefore not a generic model, but polymer-specific. Here, its performance for dynamical quantities is tested. The zero-shear viscosity is compared with experimental data. The pronounced difference can be mainly attributed to the inherent dynamic properties of the, coarse-grained model. The qualitative results are compared to previous results calculated via conventional nonequilibrium molecular dynamics (NEMD) and more generic polymer models, and the agreement is reasonable. The structural alterations under shear are investigated by characterizing the molecular deformation and birefringence extinction angle.