Computer simulation study of the structure and dynamics of ring polymers
Computer simulation study of the structure and dynamics of ring polymers
复制标题
DOI：
10.1063/1.477247
复制
发表时间：
1998-10-08
影响因子：
4.4
通讯作者：
Szamel, G
中科院分区：
文献类型：
--
作者：
Brown, S;Szamel, G
我们研究的平衡结构和动力学的非级联，非打结的聚合物环在熔体中。与早期的研究一致，我们发现，在熔体中的环比线性链更紧凑。此外，我们表明，“关联洞”的平衡相关函数是更深，更广泛的环比线性链。这表明与线性链的熔体相比，在环的熔体中存在较少的互穿。我们还发现，环扩散速度比线性链。对于较小的环，这个结果与Muller、Wittmer和Gales的早期工作一致[Phys. Rev. E 53，5063（1996）]。这项研究的主要结果是，更快的环扩散持续到环的大小至少比线性链的纠缠交叉大十倍。此外，我们证明了这一点。对于所研究的所有环尺寸，单链弛豫时间对环尺寸的依赖性弱于线性链。最后，我们发现，更快的扩散和更快的弛豫可以合理化的较小尺寸的环：自扩散系数和弛豫时间的依赖环和线性链的回转半径是非常相似的。(C)1998年美国物理学会。
We study the equilibrium structure and dynamics of unconcatenated, unknotted polymer rings in the melt. In agreement with earlier studies we find that rings in the melt are more compact than linear chains. In addition, we show that the "correlation hole" in the equilibrium correlation functions is deeper and wider for rings than for linear chains. This suggests that there is less interpenetration in the melt of rings compared to the melt of linear chains. We also find that rings diffuse faster than linear chains. For smaller rings this result agrees with the earlier work of Muller, Wittmer, and Gales [Phys. Rev. E 53, 5063 (1996)]. The main result of this study is that faster ring diffusion persists up to ring size at least ten times greater than the entanglement crossover of Linear chains. Furthermore, we show that. for all ring sizes studied, the dependence of the single-chain relaxation time on ring size is weaker than for linear chains. Finally, we find that both faster diffusion and faster relaxation can be rationalized by the smaller size of rings: The dependence of self-diffusion coefficient and relaxation time on radius of gyration of rings and linear chains is remarkably similar. (C) 1998 American Institute of Physics.