Structure formation in columnar mineral liquid crystals in confinement (D06)

在我们的研究之后，我们想研究限制对不等轴胶体液晶相的影响。由于这也需要使用光学技术，我们将重点从板状针铁矿转移到板状三水铝石颗粒。这些六边形可以使用晶种生长制备成具有光学可达直径，并且原则上可以制成荧光的。我们以前已经发现，原生的血小板形成一个α相和2种类型的柱状相：一个六方相与长程二维有序和hexaticlike相，这是有序的取向，但缺乏真正的长程位置顺序。由于这是内在相关的列的波动和缺陷的发生的可能性，我们的研究目标之一是研究如何六角形和六角序受到限制和锚定在不同的几何形状（间隙，楔）。我们还打算使用图案化的表面来研究楔中列的填充。研究这些受限系统的一个重要技术是微弧度x射线衍射，但新开发的同步加速器技术，如x射线显微镜可能是有趣的。这些测量将通过（偏振和/或共焦）光学显微镜进行补充，以解决局部（缺陷）结构。

Following up on our research, we want to study effects of confinement on liquid-crystal phases of anisometric colloids. Since this also requires the use of optical techniques, we shift our emphasis from boardlike Goethite to platelike Gibbsite particles. These hexagons can be prepared with optically accessible diameters using seeded growth and in principle can be made fluorescent. We have previously found that the native platelets form a nematic phase and 2 types of columnar phases: both a hexagonal phase with long-range 2D ordering and a hexaticlike phase which is ordered orientationally but lacks true long-range positional order. Since this is intrinsically related to the possibility of fluctuations of the columns and the occurrence of defects, one of our research goals is to study how the hexagonal and hexatic order is affected by confinement and anchoring in different geometries (gaps, wedges). We also intend to use patterned surfaces to study the packing of columns in wedges. An important technique to study these confined systems is microradian x-ray diffraction, but also newly developed synchrotron techniques like x-ray microscopy could be interesting. These measurements will be complemented by (polarization and/or confocal) light microscopy to address the local (defect) structure.