Structure and Dynamics of Dilute Two-Dimensional Ring Polymer Solutions

Bulletin of the Korean chemical society

Chang Hyun Park¹  Younghoon Oh¹  Bong June Sung¹  Hyun Woo Cho¹  Jeongmin Kim¹ 

关键词: Ring polymer;    Molecular dynamics;    Two-dimensions;    Confinement;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Structure and Dynamics of dilute two-dimensional (2D) ring polymer solutions are investigated by using discontinuous molecular dynamics simulations. A ring polymer and solvent molecules are modeled as a tangent-hard disc chain and hard discs, respectively. Some of solvent molecules are confined inside the 2D ring polymer unlike in 2D linear polymer solutions or three-dimensional polymer solutions. The structure and the dynamics of the 2D ring polymers change significantly with the number (Nin) of such solvent molecules inside the 2D ring polymers. The mean-squared radius of gyration (R2) increases with Nin and scales as R ~ Nν with the scaling exponent ν that depends on Nin. When Nin is large enough, ν ≈ 1, which is consistent with experiments. Meanwhile, for a small Nin ≈ 0.66 and the 2D ring polymers show unexpected structure. The diffusion coefficient (D) and the rotational relaxation time (τrot) are also sensitive to Nin: D decreases and τ increases sharply with Nin. D of 2D ring polymers shows a strong size-dependency, i.e., D ~ ln(L), where L is the simulation cell dimension. But the rotational diffusion and its relaxation time (τrot) are not-size dependent. More interestingly, the scaling behavior of τrot also changes with Nin; for a large Nin τrot ~ N2.46 but for a small Nin τrot ~ N1.43.

【 授权许可】

Unknown