State Key Laboratory of Urban Water Resource and Environment, School of Chemistry and Chemical Engineering , Harbin Institute of Technology , 92 West Da-Zhi Street , Harbin 150001 , China.
ACS Nano. 2019 Mar 26;13(3):3573-3579. doi: 10.1021/acsnano.9b00086. Epub 2019 Mar 13.
Topological defects are crucial to the shaping of the crystalline membrane systems such as lipid bilayers, virus capsids, and graphene as well as the arrangement of cells in tissues. In a typical case, the introduction of disclination defects elastically buckles the crystalline membranes into conical shapes. However, how planar membranes transform to cones triggered by disclinations is still rarely observed in the experiments. Herein, we experimentally observe the transformation from phospholipid bicelles to cones in response to disclinations. During the transformation process, the wall thickness increases, while the conical generatrix length remains the same with respect to the radius of bicelles. The cones with apex angles of 112.8°, 83.6°, 60°, 39°, and 19.2° are observed when 1, 2, 3, 4, and 5 pentagon defects are introduced, respectively. Monodispersed microcones are obtained by adjusting aging temperature and time. These microcones are then used as templates to form platinum conical micromotors with open tips or closed tips, which display different heading directions in HO solution. Our work provides a shape evolution pathway of planar membranes in response to disclinations. The homogeneous microcones can find wide applications in micromotors fabrication, the study of curvature-dependent processes, and the formation of advanced materials.
拓扑缺陷对于晶体膜系统的形成至关重要，如脂质双层、病毒衣壳和石墨烯，以及组织中细胞的排列。在典型情况下，引入螺旋缺陷会使晶体膜弹性弯曲成锥形。然而，由螺旋缺陷引发的平面膜如何转化为锥形，在实验中仍很少观察到。在此，我们通过实验观察到磷脂双体囊泡响应螺旋缺陷转化为锥形的过程。在转化过程中，壁厚度增加，而锥形母线长度相对于双体囊泡的半径保持不变。当引入 1、2、3、4 和 5 个五边形缺陷时，观察到顶角分别为 112.8°、83.6°、60°、39°和 19.2°的锥形。通过调节老化温度和时间，可以得到单分散的微锥形。然后将这些微锥形用作模板，在 HO 溶液中形成具有开口或封闭尖端的铂锥形微马达，它们显示出不同的指向。我们的工作提供了平面膜响应螺旋缺陷的形状演化途径。均匀的微锥形在微马达制造、曲率相关过程的研究和先进材料的形成方面有广泛的应用。
