Institute for Nano- and Microfluidics, Technische Universität Darmstadt, 64287 Darmstadt, Germany.
Institut für Computerphysik, Universität Stuttgart, 70569 Stuttgart, Germany.
Phys Rev E. 2017 Sep;96(3-1):032503. doi: 10.1103/PhysRevE.96.032503. Epub 2017 Sep 27.
We study the stretching of a surface-tethered polyelectrolyte confined between parallel surfaces under the application of a dc electric field. We explore the influence of the electric-field strength, the length of the polyelectrolyte, and the degree of confinement on the conformation of the polyelectrolyte by single-molecule experiments and coarse-grained coupled lattice-Boltzmann molecular-dynamics simulations. The fractional extension of the polyelectrolyte is found to be a universal function of the product of the applied electric field and the molecular contour length, which is explained by simple scaling arguments. The degree of confinement does not have any significant influence on the stretching. We also confirm that an electrohydrodynamic equivalence principle relating the stretching in an electric field to that in a flow field is applicable.
我们研究了在直流电场作用下，受约束于平行表面之间的表面束缚聚合物的拉伸。我们通过单分子实验和粗粒化耦合格子玻尔兹曼分子动力学模拟，研究了电场强度、聚合物长度和约束程度对聚合物构象的影响。发现聚合物的分数延伸是施加电场与分子轮廓长度乘积的通用函数，这可以用简单的标度分析来解释。约束程度对拉伸没有显著影响。我们还证实了一个电动力学等效原理，该原理将电场中的拉伸与流场中的拉伸联系起来是适用的。
