LAUSR

The static and dynamic behaviors of linear and ring polymers under shear flow over a wide range of shear rates are studied using a hybrid simulation method that couples multiple-particle collision dynamics with molecular dynamics. The results reveal that the polymer size increases monotonically with increasing shear rate when hydrodynamic interactions are ignored, in agreement with classic theoretical predictions. However, for the cases with hydrodynamic interactions, due to the transition from a linear to a nonlinear velocity profile, the size of both linear and ring chains exhibits a nonmonotonic dependence on the shear rate, and this counterintuitive behavior could be divided into three main regimes. At specific shear rates, linear polymers exhibit a relatively stable stretched state and a rapidly rotating collapsed state, which correspond to the maximum and minimum sizes, respectively. Although the rings behave similarly to the linear polymers, there exist two different relatively stable stretched sta...