论文标题
稳态延伸流中的关联聚合物的幂律拉伸
Power-Law Stretching of Associating Polymers in Steady-State Extensional Flow
论文作者
论文摘要
我们提出了一个用于延伸流动中关联聚合物的布朗动力学的试管模型。在线性响应中，该模型证实了Leibler-Rubinstein-Colby理论对粘性扩散率的分析预测。尽管单模式DEMG近似准确地描述了在“粘性” Weissenberg数字上方的聚合物的短暂拉伸（应变速率与粘性仪时间的产物），但预留的模型未能捕获出稳态扩展流动中的伸展运动的显着发展：虽然平均伸展流量是有限的，但延伸的平均延伸是有限的。我们提出了一个分析模型，该模型显示了强大的随机强迫如何驱动分布的长尾巴，这会导致罕见的事件达到阈值伸展，并构成一个框架，在该框架中，流动诱导的结晶的成核速率可以在流动下的聚合物系统中理解。该模型还举例说明了具有强大和缩放，波动的广泛驱动系统。
We present a tube model for the Brownian dynamics of associating polymers in extensional flow. In linear response, the model confirms the analytical predictions for the sticky diffusivity by Leibler- Rubinstein-Colby theory. Although a single-mode DEMG approximation accurately describes the transient stretching of the polymers above a 'sticky' Weissenberg number (product of the strain rate with the sticky-Rouse time), the pre-averaged model fails to capture a remarkable development of a power-law distribution of stretch in steady-state extensional flow: while the mean stretch is finite, the fluctuations in stretch may diverge. We present an analytical model that shows how strong stochastic forcing drive the long tail of the distribution, gives rise to rare events of reaching a threshold stretch and constitutes a framework within which nucleation rates of flow-induced crystallization may understood in systems of associating polymers under flow. The model also exemplifies a wide class of driven systems possessing strong, and scaling, fluctuations.
