Max Planck Institute for Polymer Research, Mainz, Germany.
Langmuir. 2011 Feb 15;27(4):1524-9. doi: 10.1021/la1044255. Epub 2010 Dec 16.
A discotic polycyclic aromatic hydrocarbon, hexa-peri-hexabenzocoronene, was oriented by slow cooling from the isotropic phase on a water surface as a film. For melt processing at low temperatures, an HBC derivative with long swallow-tailed alkyl side chains was chosen. The supramolecular organization in the resulting thin layer was investigated by electron microscopy. In high-resolution mode, the structural study showed large domains in which the columnar structures were oriented uniaxially with an edge-on arrangement of the hydrophobic molecules. The length of the stacks exceeded several hundred nanometers without obvious defects. The small-area analysis by TEM allowed the direct visualization of individual packed molecules. Electron diffraction revealed a high in-plane order of the columnar superstructures in which the discs were tilted by ca. 40° with respect to the stacking direction. This is the first example of a discotic system melt processed on the water surface yielding a pronounced order.
一种盘状多环芳烃，六并苯并[def] coronene，通过在水面上从各向同性相缓慢冷却作为薄膜被取向。为了在低温下进行熔融加工，选择了具有长燕尾烷基侧链的 HBC 衍生物。通过电子显微镜研究了所得薄膜中的超分子组织。在高分辨率模式下，结构研究表明存在大的畴，其中柱状结构沿单轴取向，疏水分子呈边缘排列。堆叠的长度超过数百纳米，没有明显的缺陷。通过 TEM 进行的小面积分析允许直接观察单个堆积分子。电子衍射揭示了柱状超结构的高面内有序性，其中盘绕相对于堆叠方向倾斜约 40°。这是在水面上熔融加工得到明显有序的盘状体系的第一个例子。
