Liu Feng, Chen Bin, Glettner Benjamin, Prehm Marko, Das Malay Kumar, Baumeister Ute, Zeng Xiangbing, Ungar Goran, Tschierske Carsten
Department of Engineering Materials, University of Sheffield, Mappin Street, Sheffield S1 3JD, Great Britain.
J Am Chem Soc. 2008 Jul 30;130(30):9666-7. doi: 10.1021/ja8038932. Epub 2008 Jul 3.
A new rectangular columnar liquid crystalline phase with p2gg lattice is reported, which represents a polygonal cylinder array composed of cylinders with trapezoidal cross section. In these polygonal cylinders, one of the sides has a different length and is composed of a different material than the others. This tiling pattern was obtained in two series of T-shaped facial amphiphilic triblock molecules in which a rigid rod-like p-terphenyl core is substituted laterally by a polar and flexible oligoethylene glycol chain, terminated either by a hydrogen-bonding COOH group or by a Li carboxylate group, and having identical or different alkyl groups in the terminal positions. The trapezoidal cylinder phase provides an improved packing for relatively long and rigid alkyl chains at lower temperature and more space inside the polygonal cylinders than triangular cylinders. This combination of conformational and space-filling effects leads to different phase sequences. The trapezoidal cylinder phases pave the way to a new level of complexity in LC engineering and show the huge potential of the general concept of polyphilic tectons for the design of new complex soft matter structures.
报道了一种具有p2gg晶格的新型矩形柱状液晶相，它代表了由具有梯形横截面的圆柱体组成的多边形圆柱体阵列。在这些多边形圆柱体中，其中一条边的长度不同，且由与其他边不同的材料组成。这种平铺图案是在两个系列的T形面两亲性三嵌段分子中获得的，其中刚性棒状对三联苯核心被极性且柔性的低聚乙二醇链横向取代，该链末端要么是氢键COOH基团，要么是羧酸锂基团，并且在末端位置具有相同或不同的烷基。梯形圆柱体相在较低温度下为相对长且刚性的烷基链提供了更好的堆积，并且在多边形圆柱体内比三角形圆柱体具有更多空间。这种构象和空间填充效应的结合导致了不同的相序列。梯形圆柱体相为液晶工程带来了新的复杂程度，并展示了多亲性构造单元的一般概念在设计新型复杂软物质结构方面的巨大潜力。
