Immobilization of Hydrogen-Bonded Capsules on Silicon Wafer

在这个项目中，我们的目标是将氢键胶囊固定在硅片上，并探索这些分子结构的物理、有机和材料性质，目的是开发药物输送系统和超分子尼龙搭扣。我们将用烯烃分子合成空穴，这种空穴可以自组装成由各种客体分子模板形成的胶囊结构。末端烯烃非常适合于通过硅氢化反应在氢端硅上光化学或热沉积空穴。为了表征和研究修饰后的表面和胶囊的自组装，我们将使用多种表面分析方法以及客体4，4-二甲基苯的包裹使能荧光开启特性。这里使用的胶囊结构通过非常强的氢键结合在一起，甚至可以在水中存活。因此，该系统可能非常适合于将合适形状的药物分子装入胶囊的腔内的药物输送系统。同时，超分子尼龙搭扣可以由界面胶囊自组装而成，该体系可以在真空、空气和各种溶剂中存活，因此得到了广泛的应用。此外，胶囊的形成强烈依赖于嘉宾的模板效应。因此，这种超分子尼龙搭扣的强度可以通过使用不同的客体分子来很好地调节。例如，可光切换的客体，如4，4-二甲基偶氮苯，甚至可能赋予超分子尼龙搭扣以光开关能力。因此，我们相信本项目的研究将为超分子结构修饰表面的应用开辟新的前沿。

In this project, we are aiming at the immobilization of hydrogen-bonded capsules on silicon wafers and explore the physical organic and material properties of these molecular architectures with purpose to develop drug-delivery systems and supramolecular Velcro. We will synthesize cavitands with alkene feets which can self-assemble into capsular structures templated by a variety of guest molecules. The terminal alkenes are well suited for a photochemical or thermal deposition of the cavitands on hydrogen-terminated silicon through hydrosilylation. For the characterization and study of the modified surface and capsule self-assembly we will use multiple surface analysis methods as well as the encapsulation-enabled fluorescence turn-on properties of guest 4,4-dimethylbenzil. The capsular structures used here are held together by very strong hydrogen bonds and can even survive in water. Therefore, this system may be well suited to a drug-delivery system for appropriate shaped drug molecules which fit into the capsule`s cavity. Meanwhile, a supramolecular Velcro can be constructed from an inter-surface capsule self-assembly and this system may survive in vacuum, air and a variety of solvents and thus finds broad applications. In addition, the capsule formation is strongly dependent on the template effect of guests. Therefore, the strength of this supramolecular Velcro may be well tuned by using different guest molecules. For example, a photo-switchable guest, such as 4,4-dimethylazobenzene, may even endow the supramolecular Velcro with photoswitchability. Therefore, we believe the research in this project will open new frontiers for applications of surfaces modified by supramolecular architectures.