Berezney John P, Marciel Amanda B, Schroeder Charles M, Saleh Omar A
Materials Department, University of California, Santa Barbara, California 93106, USA.
Institute for Molecular Engineering, The University of Chicago, Chicago, Illinois 60637, USA.
Phys Rev Lett. 2017 Sep 22;119(12):127801. doi: 10.1103/PhysRevLett.119.127801. Epub 2017 Sep 21.
Bottle-brush polymers exhibit closely grafted side chains that interact by steric repulsion, thereby causing stiffening of the main polymer chain. We use single-molecule elasticity measurements of model brush polymers to quantify this effect. We find that stiffening is only significant on long length scales, with the main chain retaining flexibility on short scales. From the elasticity data, we extract an estimate of the internal tension generated by side-chain repulsion; this estimate is consistent with the predictions of blob-based scaling theories.
瓶刷聚合物呈现出紧密接枝的侧链，这些侧链通过空间排斥相互作用，从而导致主聚合物链变硬。我们使用模型刷聚合物的单分子弹性测量来量化这种效应。我们发现，变硬仅在长长度尺度上显著，主链在短尺度上保持柔韧性。从弹性数据中，我们提取了由侧链排斥产生的内部张力的估计值；该估计值与基于液滴的标度理论的预测一致。
