Ge Ting, Kalathi Jagannathan T, Halverson Jonathan D, Grest Gary S, Rubinstein Michael
Department of Chemistry, University of North Carolina , Chapel Hill, North Carolina 27599, United States.
Department of Chemical Engineering, National Institute of Technology Karnataka , Surathkal, Mangalore 575025, India.
Macromolecules. 2017 Feb 28;50(4):1749-1754. doi: 10.1021/acs.macromol.6b02632. Epub 2017 Feb 13.
The motion of nanoparticles (NPs) in entangled melts of linear polymers and nonconcatenated ring polymers are compared by large-scale molecular dynamics simulations. The comparison provides a paradigm for the effects of polymer architecture on the dynamical coupling between NPs and polymers in nanocomposites. Strongly suppressed motion of NPs with diameter larger than the entanglement spacing is observed in a melt of linear polymers before the onset of Fickian NP diffusion. This strong suppression of NP motion occurs progressively as exceeds and is related to the hopping diffusion of NPs in the entanglement network. In contrast to the NP motion in linear polymers, the motion of NPs with > in ring polymers is not as strongly suppressed prior to Fickian diffusion. The diffusion coefficient decreases with increasing much slower in entangled rings than in entangled linear chains. NP motion in entangled nonconcatenated ring polymers is understood through a scaling analysis of the coupling between NP motion and the self-similar entangled dynamics of ring polymers.
通过大规模分子动力学模拟，比较了纳米颗粒（NPs）在线性聚合物缠结熔体和非连环环状聚合物中的运动。该比较为聚合物结构对纳米复合材料中NPs与聚合物之间动态耦合的影响提供了一个范例。在菲克NP扩散开始之前，在线性聚合物熔体中观察到直径大于缠结间距的NPs的运动受到强烈抑制。随着超过，NP运动的这种强烈抑制逐渐发生，并且与NP在缠结网络中的跳跃扩散有关。与线性聚合物中的NP运动相反，在菲克扩散之前，环状聚合物中>的NPs的运动没有受到同样强烈的抑制。在缠结的环中，扩散系数随的增加而降低的速度比在缠结的线性链中慢得多。通过对NP运动与环状聚合物的自相似缠结动力学之间的耦合进行标度分析，可以理解缠结的非连环环状聚合物中的NP运动。
