Conformation and Dynamics of Individual Star in Shear Flow and Comparison with Linear and Ring Polymers
Conformation and Dynamics of Individual Star in Shear Flow and Comparison with Linear and Ring Polymers
复制标题
剪切流中单个星体的构象和动力学以及与线性和环状聚合物的比较
DOI：
10.1021/acs.macromol.6b02636
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发表时间：
2017-02-14
期刊：
影响因子：
5.5
通讯作者：
An, Lijia
中科院分区：
文献类型：
--
作者：
Chen, Wenduo;Zhang, Kexin;An, Lijia
具有不同结构的聚合物如何响应剪切应力是发展对其动力学行为的基本理解的关键问题。我们利用多粒子碰撞动力学与分子动力学模拟相结合的方法研究了单个星形聚合物在简单剪切流中的构象、取向、动力学和流变性。我们的研究表明，随着臂数的增加，星形聚合物呈现出从翻滚到类似坦克踩踏的线性转变。在转变区域，流动引起的变形、取向、运动频率和流变特性与减少的Weissenberg数呈普遍的标度关系，与臂的数量和长度无关。此外，我们对线性聚合物、环状聚合物和星形聚合物之间的流动诱导行为进行了全面的比较。结果表明，与线性聚合物不同，星形聚合物和环状聚合物的变形、取向变化和剪切变薄都较弱。
How polymers with different architectures respond to shear stress is a key issue to develop a fundamental understanding of their dynamical behaviors. We investigate the conformation, orientation, dynamics, and rheology of individual star polymers in a simple shear flow by multiparticle collision dynamics integrated with molecular dynamics simulations. Our studies reveal that star polymers present a linear transformation from tumbling to tank-treading-like motions as the number of arms increases. In the transformation region, the flow-induced deformation, orientation, frequency of motions, and rheological properties show universal scaling relationships against the reduced Weissenberg number, independent of the number and the length of arms. Further, we make a comprehensive comparison on the flow-induced behaviors between linear, ring, and star polymers. The results indicate that distinct from linear polymers, star and ring polymers present weaker deformation, orientation change, and shear thinning, either ...