High resolution shear profile measurements in entangled polymers.
High resolution shear profile measurements in entangled polymers.
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DOI：
10.1103/physrevlett.101.218301
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发表时间：
2008-11
影响因子：
8.6
通讯作者：
Keesha A. Hayes;Mark R. Buckley;I. Cohen;L. Archer
中科院分区：
文献类型：
--
作者：
Keesha A. Hayes;Mark R. Buckley;I. Cohen;L. Archer
我们使用共聚焦显微镜和粒子图像测速仪来可视化250-300 nm的运动。荧光示踪剂颗粒在缠结的聚合物中经受直线剪切流。我们的研究结果表明，在聚合物溶液中的线速度分布跨越了广泛的分子量和缠结数（8<或=Z<或=56），但揭示了施加和测量的剪切速率之间的巨大差异。这些研究结果不同意最近的报道，剪切带是一个特征的流动响应的缠结聚合物，而不是指向界面滑移的应变损失的一个重要来源。
We use confocal microscopy and particle image velocimetry to visualize motion of 250-300 nm. fluorescent tracer particles in entangled polymers subject to a rectilinear shear flow. Our results show linear velocity profiles in polymer solutions spanning a wide range of molecular weights and number of entanglements (8< or =Z< or =56), but reveal large differences between the imposed and measured shear rates. These findings disagree with recent reports that shear banding is a characteristic flow response of entangled polymers, and instead point to interfacial slip as an important source of strain loss.