Hydrodynamic interactions can dramatically influence the dynamics of fully flexible, ring-shaped polymers in ways unknown for any other polymer architecture or topology. Tumbling under shear is a common dynamic pattern of motion for all polymer architectures. Here we show the existence of a shear-induced inflation phase exclusive to ring polymers, the onset of which depends on the ring’s contour length. This is accompanied by a strong suppression of tumbling, which resumes at even higher shear rates. The ring swells in the vorticity direction, and the horseshoe regions on the stretched and swollen ring are effectively locked in place relative to its center-of-mass. Furthermore, knots tied onto such rings can serve as additional ‘stabilisation anchors'. Under strong shear, the knotted section remains well-localised while tank-treading from one horseshoe region to the other in sudden bursts. We find knotted polymers of high contour length behave very similarly to unknotted rings of the same contour length.

流体动力学相互作用可以以任何其他聚合物结构或拓扑结构都未知的方式显着影响完全柔性的环状聚合物的动力学。在剪切作用下滚动是所有聚合物结构的常见运动动态模式。在这里，我们显示了仅存在于环状聚合物中的剪切诱导的膨胀相的存在，其开始取决于环的轮廓长度。这伴随着翻滚的强烈抑制，这种翻滚以更高的剪切速率恢复。环在涡度方向上膨胀，并且拉伸和膨胀环上的马蹄形区域相对于其质量中心有效地锁定在适当的位置。此外，打结在这样的环上的结可以用作额外的“稳定锚”。在高剪切力下 在从一个马蹄形区域突然踩到另一个马蹄形区域时，打结的部分仍保持良好的定位。我们发现，轮廓长度较高的打结聚合物与轮廓长度相同的未打结环非常相似。