Zamponi M, Wischnewski A, Monkenbusch M, Willner L, Richter D, Likhtman A E, Kali G, Farago B
Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich, Germany.
Phys Rev Lett. 2006 Jun 16;96(23):238302. doi: 10.1103/PhysRevLett.96.238302. Epub 2006 Jun 13.
The dynamics of binary polymer blends of few labeled long chains in successively shorter matrix chains has been investigated by neutron spin echo (NSE) spectroscopy. For the first time the effect of constraint release on the chain relaxation has been directly observed on a microscopic scale. Decreasing the matrix chain length reduces the topological confinement until unconfined Rouse motion is observed, when the matrix chains are too short to confine the long chain in a tube. Whereas an analytical description of the effect is not yet available, a new simulation based on the slip-link model shows perfect agreement with the NSE data over the full range of matrix molecular weights.
通过中子自旋回波（NSE）光谱研究了少量标记长链在连续变短的基质链中的二元聚合物共混物的动力学。首次在微观尺度上直接观察到约束释放对链松弛的影响。当基质链太短而无法将长链限制在管中时，减小基质链长度会降低拓扑约束，直到观察到无约束的劳斯运动。虽然尚未获得对该效应的解析描述，但基于滑链模型的新模拟在基质分子量的整个范围内与NSE数据显示出完美的一致性。
