Babu S B, Stark H
Institut für Theoretische Physik, Technische Universität Berlin, Germany.
Eur Phys J E Soft Matter. 2011 Dec;34(12):1-7. doi: 10.1140/epje/i2011-11136-2. Epub 2011 Dec 28.
The dynamics of a semi-flexible sheet or tethered membrane in a solvent is studied using the method of stochastic rotation dynamics. Hydrodynamic interactions between different parts of the sheet are naturally included in this method. We confirm the scaling law for the radius of gyration versus sheet size predicted for a self-avoiding tethered membrane. The mean-square displacement shows both sub-diffusive and diffusive behavior similar to linear polymers. In the intermediate scattering function the sub-diffusive behavior appears as stretched exponential which we reproduce in our simulations. Thereby, we confirm an early prediction between the roughness and the sub-diffusion exponent derived from Zimm dynamics (E. Frey, D.R. Nelson, J. Phys. I 1, 1715 (1991)). Finally, we show that the diffusion coefficient of the square sheet is inversely proportional to the edge length of the sheet again in good agreement with theoretical predictions.
利用随机旋转动力学方法研究了半柔性薄片或束缚膜在溶剂中的动力学。该方法自然地包含了薄片不同部分之间的流体动力学相互作用。我们证实了自回避束缚膜所预测的回转半径与薄片尺寸的标度律。均方位移表现出与线性聚合物类似的亚扩散和扩散行为。在中间散射函数中，亚扩散行为表现为拉伸指数形式，我们在模拟中重现了这一形式。由此，我们证实了早期从齐姆动力学得出的粗糙度与亚扩散指数之间的预测关系（E. 弗雷，D.R. 纳尔逊，《法国物理杂志I》1, 1715 (1991)）。最后，我们表明方形薄片的扩散系数与薄片的边长成反比，这再次与理论预测相符。
