Arnold Sommerfeld Center for Theoretical Physics and Center for NanoScience, Department of Physics, Ludwig-Maximilians-Universität München, Germany.
Chemphyschem. 2009 Nov 9;10(16):2891-9. doi: 10.1002/cphc.200900614.
The tube model is a central concept in polymer physics, and allows one to reduce the complex many-filament problem of an entangled polymer solution to a single-filament description. We investigate the probability distribution function of conformations of confinement tubes and single encaged filaments in entangled semiflexible polymer solutions. Computer simulations are developed that mimic the actual dynamics of confined polymers in disordered systems with topological constraints on time scales above local equilibration, but well below large-scale rearrangement of the network. We observe the statistical distribution of curvatures and compare our results to recent experimental findings. Unexpectedly, the observed distributions show distinctive differences from free polymers even in the absence of excluded volume. Extensive simulations permit to attribute these features to entropic trapping in network void spaces. The transient non-equilibrium distributions are shown to be a generic feature in quenched-disorder systems on intermediate time scales.
管模型是高分子物理中的一个核心概念，它可以将复杂的多纤维纠缠聚合物溶液问题简化为单纤维描述。我们研究了约束管和单根被束缚纤维在纠缠半柔性聚合物溶液中的构象的概率分布函数。我们开发了计算机模拟，这些模拟可以模拟在无序系统中受约束聚合物的实际动力学，在时间尺度上具有拓扑约束，超过局部平衡，但远低于网络的大规模重排。我们观察了曲率的统计分布，并将我们的结果与最近的实验发现进行了比较。出乎意料的是，即使在不存在排除体积的情况下，观察到的分布也与自由聚合物有明显的不同。广泛的模拟表明，这些特征归因于网络空隙空间中的熵捕获。瞬态非平衡分布被证明是中间时间尺度上淬火无序系统的一个普遍特征。
