Bio-inspired Hierarchies of Functional Materials

我们描述的项目模块是从自然界中借鉴的。我们的计划是培养硅藻和颗石藻，并利用它们来制造新的材料和设备。硅藻是单一的细胞水生生物，负责地球上约20%的氧气供应。有趣的是，它们创造了自己的玻璃（二氧化硅）壳来容纳和保护它们的生物成分。这些玻璃壳被称为硅藻壳，它们呈现出华丽的图案，这对纳米科学很有意义。颗石藻也是单细胞海洋生物，但它们用碳酸钙制造出精致的外壳。正是这些华丽的图案和贝壳的制作材料给了我们灵感。在研究的一个模块中，我们计划溶解不同种类的硅藻的二氧化硅壳，以了解底层二氧化硅形态如何决定该过程的动力学。研究该反应的真实的原因是寻找有机硅化合物的新途径，目前有机硅化合物是通过将二氧化硅碳热还原为硅，然后将其转化为原料有机硅烷而制备的。我们计划使用解聚产物将有机硅重新组装成介孔固体。这些都是高度多孔的二氧化硅材料感兴趣的催化。在另一个模块中，我们将把硅藻和颗石藻的外壳转化为功能性有机聚合物和玻璃，方法是在外壳周围“模制”聚合物和玻璃。随后，我们溶解掉贝壳，得到“塑料”或玻璃状的复制品。但这些复制品可能被用作氧气传感器，例如。在第三个模块中，我们将壳转化为碳，并使用反向复制品来制作新的三维物体，这些物体可能是或可能不是硅基的。在第四个模块中，我们将研究光如何与壳的3D结构相互作用。这对于传感器、激光器和其他光学响应很重要，因为光可以被困在超微结构中，或者完全被排斥。

We describe project modules that take a page from nature. Our plan is to cultivate species of diatoms and coccolithophores and to use them to make new kinds of materials and devices. Diatoms are single cellaquatic organisms that are responsible for about 20% of the Earth's oxygen supply. Interestingly, they create their own glass (silica) shells to contain and protect their bio-components. The glass shells are called frustules and they exhibit ornate patterns that are of interest to nanoscience. Coccolithophores are also single cell marine organisms, but that create an elaborate shell from calcium carbonate. It is the ornate patterns and the materials from which the shells are made that inspire us. In one module of research we plane to dissolve the silica shell of different species of diatom to learn how the underlying silica morphology determines the kinetics of the process. The real reason for studying this reaction is to find new pathways to organosilicon compounds that currently are made by carbothermal reduction of silica to silicon, and its subsequent conversion to feedstock organosilanes. We plan to use the depolymerization products to reassemble the organosilicon into mesoporous solids. These are highly porous silica materials of interest to catalysis. In another module, we will convert the shells of diatoms and coccolithophores to functional organic polymers and glasses by "molding" polymers and glasses around the shells. Subsequently, we dissolve away the shells to give "plastic" or glassy replicas. But these replicas might be used as oxygen sensors, for example. In a third module, we convert the shells to carbon and use the inverse replicas to make new kinds of 3-dimensional objects that may or may not be silica-based. In the fourth Module we examine how light interacts with the 3D structure of the shell. This is important for sensors, lasers and other optical responses, since light can become trapped in the ultrastructure, or rejected altogether.