Effect of molecular architecture on ring polymer dynamics in semidilute linear polymer solutions
Effect of molecular architecture on ring polymer dynamics in semidilute linear polymer solutions
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DOI：
10.1038/s41467-019-09627-7
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发表时间：
2019-04
影响因子：
16.6
通讯作者：
Yuecheng Zhou;K. Hsiao;Kathryn E. Regan;Dejie Kong;G. McKenna;R. Robertson-Anderson;Charles M. Schroeder
中科院分区：
文献类型：
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作者：
Yuecheng Zhou;K. Hsiao;Kathryn E. Regan;Dejie Kong;G. McKenna;R. Robertson-Anderson;Charles M. Schroeder
在软材料中，了解环聚合物的动力学是一个特别具有挑战性但又很有趣的问题。尽管最近取得了进展，但对环聚合物的非平衡行为还没有完全的了解。在这项工作中，我们使用单分子技术直接观察了DNA基环在半稀线性聚合物溶液中的流动动力学。我们的结果表明，在最初的瞬时拉伸过程结束很长时间后，伸展流动中环的构象波动非常大，即使在背景溶液中极低浓度的线性聚合物(0.025C*)下也能观察到这种情况。环状构象起伏的大小和特征时间尺度被确定为流动强度和聚合物浓度的函数。我们的结果表明，环的构象起伏是由于线性聚合物通过流动中伸展的开环链的瞬时穿线引起的。
Understanding the dynamics of ring polymers is a particularly challenging yet interesting problem in soft materials. Despite recent progress, a complete understanding of the nonequilibrium behavior of ring polymers has not yet been achieved. In this work, we directly observe the flow dynamics of DNA-based rings in semidilute linear polymer solutions using single molecule techniques. Our results reveal strikingly large conformational fluctuations of rings in extensional flow long after the initial transient stretching process has terminated, which is observed even at extremely low concentrations (0.025c*) of linear polymers in the background solution. The magnitudes and characteristic timescales of ring conformational fluctuations are determined as functions of flow strength and polymer concentration. Our results suggest that ring conformational fluctuations arise due to transient threading of linear polymers through open ring chains stretching in flow.