Wu Jiaxin, Guo Fuchen, Li Ke, Zhang Linxi
Department of Physics, Zhejiang University, Hangzhou 310027, China.
Polymers (Basel). 2021 Dec 26;14(1):79. doi: 10.3390/polym14010079.
The sliding dynamics along two asymmetric/symmetric axial chains of ring chains linked by a linear chainis investigated using molecular dynamics (MD) simulations. A novel sub-diffusion behavior is observed for ring chains sliding along eithera fixed rod-like chain or fluctuating axial chain on asymmetric/symmetric axial chainsat the intermediate time range due to their strongly interplay between two ring chains. However, two ring chains slide in the normal diffusion at along time range because their sliding dynamics can be regarded as an overall motion of two ring chains. For ring chains sliding on two symmetric/asymmetricaxial chains, the diffusion coefficient D of ring chains relies on the bending energy of axial chains (K) as well as the distance of two axial chains (d). There exists a maximum diffusion coefficient D at d = d* in which ring chains slide at the fastest velocity due to the maximum conformational entropy for the linking chain between two ring chainsat d = d*. Ring chain slide on fixed rod-like axial chainsfaster in the symmetric axial chain case than that in the asymmetric axial chain case. However, ring chains slide on fluctuatingaxial chainsslower in the symmetric axial chain case than that in the asymmetric axial chain case. This investigation can provide insights into the effects of the linked chain conformation on the sliding dynamics of ring chains in a slide-ring gel.
利用分子动力学(MD)模拟研究了由线性链连接的环状链的两条不对称/对称轴向链上的滑动动力学。由于两条环状链之间的强烈相互作用,在中间时间范围内,观察到环状链沿着不对称/对称轴向链上的固定棒状链或波动轴向链滑动时出现了一种新的亚扩散行为。然而,在长时间范围内,两条环状链以正常扩散方式滑动,因为它们的滑动动力学可被视为两条环状链的整体运动。对于在两条对称/不对称轴向链上滑动的环状链,环状链的扩散系数D依赖于轴向链的弯曲能(K)以及两条轴向链之间的距离(d)。在d = d时存在最大扩散系数D,此时环状链以最快速度滑动,这是因为在d = d时两条环状链之间的连接链具有最大构象熵。在对称轴向链情况下,环状链在固定棒状轴向链上的滑动速度比在不对称轴向链情况下更快。然而,在对称轴向链情况下,环状链在波动轴向链上的滑动速度比在不对称轴向链情况下更慢。这项研究能够为连接链构象对滑环凝胶中环状链滑动动力学的影响提供见解。