Hydrodynamic Interactions and Entanglements of Polymer Solutions in Many-Body Dissipative Particle Dynamics
Hydrodynamic Interactions and Entanglements of Polymer Solutions in Many-Body Dissipative Particle Dynamics
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DOI：
10.3390/polym8120426
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发表时间：
2016-12
期刊：
影响因子：
5
通讯作者：
Xin Yong
中科院分区：
文献类型：
--
作者：
Xin Yong
使用多体耗散粒子动力学（MDPD），聚合物溶液的浓度跨越稀和半稀制度建模。通过映射到平均场Flory-Huggins理论，建立了液-气共存系统的MDPD相互作用的参数化。聚合物链的静态和动态特性的表征主要集中在水动力相互作用和缠结的影响上。通过改变溶剂质量和测量旋转半径和端到端距离，探讨了聚合物链在稀溶液中的卷球过渡。聚合物链在不良、θ和良好溶剂中的静态和动态结垢关系都很好地符合考虑了水动力相互作用的Zimm理论。聚合物体积分数高达0.7的半稀溶液表现出排除体积相互作用的筛选和随后的聚合物线圈收缩。此外，纠缠在半稀溶液中占主导地位，这抑制了链的扩散和弛豫。拓扑破坏的定量分析证实了在MDPD模拟中纠缠是正确捕获的。
Using many-body dissipative particle dynamics (MDPD), polymer solutions with concentrations spanning dilute and semidilute regimes are modeled. The parameterization of MDPD interactions for systems with liquid–vapor coexistence is established by mapping to the mean-field Flory–Huggins theory. The characterization of static and dynamic properties of polymer chains is focused on the effects of hydrodynamic interactions and entanglements. The coil–globule transition of polymer chains in dilute solutions is probed by varying solvent quality and measuring the radius of gyration and end-to-end distance. Both static and dynamic scaling relations for polymer chains in poor, theta, and good solvents are in good agreement with the Zimm theory with hydrodynamic interactions considered. Semidilute solutions with polymer volume fractions up to 0.7 exhibit the screening of excluded volume interactions and subsequent shrinking of polymer coils. Furthermore, entanglements become dominant in the semidilute solutions, which inhibit diffusion and relaxation of chains. Quantitative analysis of topology violation confirms that entanglements are correctly captured in the MDPD simulations.