Shapes of fluid membranes with chiral edges
Shapes of fluid membranes with chiral edges
复制标题
具有手性边缘的流体膜的形状
DOI：
10.1103/physreve.102.032608
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发表时间：
2020
影响因子：
2.4
通讯作者：
Powers, Thomas R.
中科院分区：
文献类型：
--
作者：
Ding, Lijie;Pelcovits, Robert A.;Powers, Thomas R.
我们进行蒙特卡罗模拟的胶体流体膜的自由边缘和手性棒状病毒组成。该膜由通过键连接的珠的三角形网格建模，其中键和珠在每个蒙特卡罗步骤中自由移动。由于实验观察到的病毒成分扭曲，只有在膜边缘附近，我们使用的有效能量，有利于一个特定的符号的测地线扭曲的边缘。有效能量还包括膜弯曲刚度、边缘弯曲刚度和边缘张力。我们发现三类膜的形状导致的各种条款的自由能的竞争：分支形状，手性磁盘，和囊泡。增加边缘弯曲刚度使膜边缘平滑，从而导致沿边缘沿着不同点处的膜法线之间的相关性。边缘位移的归一化功率谱随着优选测地扭转的增加而显示出峰值。我们还考虑了在外力作用下膜的形状，通过固定膜两端之间的距离，并找到增加两端之间的距离值的形状。随着距离的增加，膜扭曲成一条带状，力最终达到一个平台。
We carry out Monte Carlo simulations of a colloidal fluid membrane with a free edge and composed of chiral rodlike viruses. The membrane is modeled by a triangular mesh of beads connected by bonds in which the bonds and beads are free to move at each Monte Carlo step. Since the constituent viruses are experimentally observed to twist only near the membrane edge, we use an effective energy that favors a particular sign of the geodesic torsion of the edge. The effective energy also includes the membrane bending stiffness, edge bending stiffness, and edge tension. We find three classes of membrane shapes resulting from the competition of the various terms in the free energy: branched shapes, chiral disks, and vesicles. Increasing the edge bending stiffness smooths the membrane edge, leading to correlations among the membrane normals at different points along the edge. The normalized power spectrum for edge displacements shows a peak with increasing preferred geodesic torsion. We also consider membrane shapes under an external force by fixing the distance between two ends of the membrane and finding the shape for increasing values of the distance between the two ends. As the distance increases, the membrane twists into a ribbon, with the force eventually reaching a plateau.