The Martin Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02454, USA.
Soft Matter. 2014 Jul 14;10(26):4700-10. doi: 10.1039/c4sm00803k.
Monodisperse suspensions of rod like chiral fd viruses are condensed into a rod-length thick colloidal monolayers of aligned rods by depletion forces. Twist deformations of the molecules are expelled to the monolayer edge as in a chiral smectic A liquid crystal, and a cholesteric band forms at the edge. Coalescence of two such isolated membranes results in a twist wall sandwiched between two regions of aligned rods, dubbed π-walls. By modeling the membrane as a binary fluid of coexisting cholesteric and chiral smectic A liquid-crystalline regions, we develop a unified theory of the π-walls and the monolayer edge. The mean-field analysis of our model yields the molecular tilt profiles, the local thickness change, and the crossover from smectic to cholesteric behavior at the monolayer edge and across the π-wall. Furthermore, we calculate the line tension associated with the formation of these interfaces. Our model offers insights regarding the stability and the detailed structure of the π-wall and the monolayer edge.
单分散棒状手性 fd 病毒悬浮液通过耗尽力被凝聚成棒长厚度的取向棒胶体单层。分子的扭曲变形被排斥到单层边缘，就像手性近晶 A 液晶一样，在边缘形成胆甾相带。两个这样的孤立膜的合并导致在两个取向棒区域之间夹有一个扭曲壁，称为π壁。通过将膜建模为共存的胆甾相与手性近晶 A 液晶区域的二元流体，我们开发了π壁和单层边缘的统一理论。我们模型的平均场分析得出了分子倾斜轮廓、局部厚度变化以及在单层边缘和穿过π壁处从近晶到胆甾相行为的转变。此外，我们计算了与这些界面形成相关的线张力。我们的模型提供了关于π壁和单层边缘的稳定性和详细结构的见解。
