Conformation and Dynamics of Individual Star in Shear Flow and Comparison with Linear and Ring Polymers
journal contributionposted on 03.02.2017, 14:51 by Wenduo Chen, Kexin Zhang, Lijun Liu, Jizhong Chen, Yunqi Li, Lijia An
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 contributed by a dense center or without ends.