Serafin Francesco, Bowick Mark J, Nagel Sidney R
Physics Department and Syracuse Soft and Living Matter Program, Syracuse University, 13244, Syracuse, NY, USA.
Kavli Institute for Theoretical Physics, University of California, 93106, Santa Barbara, CA, USA.
Eur Phys J E Soft Matter. 2018 Dec 11;41(12):143. doi: 10.1140/epje/i2018-11755-y.
Chemical design of block copolymers makes it possible to create polymer vesicles with tunable microscopic structure. Here we focus on a model of a vesicle made of smectic liquid-crystalline block copolymers at zero temperature. The vesicle assumes a faceted tetrahedral shape and the smectic layers arrange in a stack of parallel straight lines with topological defects localized at the vertices. We counted the number of allowed states at [Formula: see text]. For any fixed shape, we found a two-dimensional countable degeneracy in the smectic pattern depending on the tilt angle between the smectic layers and the edge of the tetrahedral shell. For most values of the tilt angle, the smectic layers contain spiral topological defects. The system can spontaneously break chiral symmetry when the layers organize into spiral patterns, composed of a bound pair of +1/2 disclinations. Finally, we suggest possible applications of tetrahedral smectic vesicles in the context of functionalizing defects and the possible consequences of the spiral structures for the rigidity of the vesicle.
嵌段共聚物的化学设计使得创建具有可调节微观结构的聚合物囊泡成为可能。在此，我们关注零温度下由近晶型液晶嵌段共聚物制成的囊泡模型。该囊泡呈现多面四面体形状，且近晶层排列成平行直线的堆叠，拓扑缺陷位于顶点处。我们计算了在[公式：见正文]时的允许状态数。对于任何固定形状，我们发现在近晶图案中存在二维可数简并，这取决于近晶层与四面体壳边缘之间的倾斜角。对于大多数倾斜角值，近晶层包含螺旋拓扑缺陷。当层组织成由一对 +1/2 位错束缚而成的螺旋图案时，该系统可自发打破手性对称性。最后，我们提出了四面体近晶囊泡在缺陷功能化方面的可能应用，以及螺旋结构对囊泡刚性的可能影响。
