良溶剂中环形高分子单链的结构与动力学性质的模拟研究
摘要
The conformational and dynamical properties of individual linear and ring polymers in good solution were studied by mesoscale simulations which combining multi-particle collision dynamics and molecular dynamics simulations. The excluded volume interactions play a more significant role for ring polymers than for linear polymers because of the smaller average distance among monomers of rings without ends. The ratio of mean-square radius of gyration between the linear and ring polymer with a same molecular weight in the presence of excluded volume interactions is 1.77, which is slightly smaller than the theoretical estimation (2) in theta solvents, indicating that ring polymers swell more in good solvents than their linear counterparts. Correspondingly, the ratio of diffusion coefficients between the ring and linear polymer was estimated as 1.10. The diffusion properties are dominated by the interplay between excluded volume interactions and hydrodynamic interactions. Furthermore, in order to elucidate the role of hydrodynamic interactions, we also compared these results with those without hydrodynamic interactions. The results showed that the diffusion coefficients with hydrodynamic interactions are larger than those without hydrodynamic interactions.