Two types of ionic liquid (IL) based surfactants bearing a terminal pyrrole moiety were synthesized, and used as both structure-directing agents and monomers to prepare mesostructured silica with densely packed pyrrole units within channels via a hydrothermal synthesis procedure. A systematic study was carried out to address the influence of the relative concentration of the IL and the type of head group and counter ions on the mesostructure. As a main result, it was found that both the prepared imidazolium- and pyridium-based surfactants displayed a significantly strong tendency towards formation of a highly ordered two-dimensional (2D) hexagonal mesostructure in a broad range of conditions with excellent reproducibility. In situpolymerization of the pyrrole groups closely packed in the central region of the formed silica pore channels led to the desired mesostructured silica with well-distinct aligned polypyrrole (PPy) molecular wires in channels, which are clearly visible under TEM after the removal of silica framework. It is found that, due to the spatial confinement of the silica framework, the encapsulated PPys are elongated and straight, leading to longer conjugation length.
合成了两种以结构为基础的
离子液体(IL)表面活性剂,这些表面活性剂具有末端
吡咯基团,并被用作结构导向剂和单体,通过
水热合成程序制备了具有密集
吡咯单位的介孔
硅。进行了系统研究,以探讨IL的相对浓度以及头基和对离子类型对介观结构的影响。主要结果显示,所制备的
咪唑铵和
吡啶基表面活性剂在广泛条件下均表现出较强的趋向于形成高度有序的二维(2D)六角形介观结构,并具有极好的可重复性。在形成的
硅孔道中央区域,紧密堆积的
吡咯基团的原位聚合导致了所需的介孔
硅,
硅骨架移除后,通道内明显可见有序的聚
吡咯(PPy)分子导线。研究发现,由于
硅骨架的空间限制,封装的PPy呈现出延长和直线的形态,从而导致更长的共轭长度。