Bio-inspired Hierarchies of Functional Materials

我们描述了借鉴自然的项目模块。我们的计划是培养硅藻和球藻的种类，并利用它们制造新型材料和设备。硅藻是单细胞的 占地球氧气供应约20%的水生生物。有趣的是，它们创造了自己的玻璃(二氧化硅)外壳来容纳和保护它们的生物成分。玻璃外壳被称为锥体，它们展示了纳米科学感兴趣的华丽图案。球石生物体也是单细胞海洋生物，但它们用碳酸钙创造了一个精致的外壳。正是华丽的图案和制作贝壳的材料启发了我们。在一个研究模块中，我们计划溶解不同种类硅藻的硅壳，以了解潜在的二氧化硅形态如何决定这一过程的动力学。研究这一反应的真正原因是为了找到合成有机硅化合物的新途径，目前的合成方法是将二氧化硅碳热还原为硅，然后将其转化为原料有机硅烷。我们计划使用解聚产物将有机硅重新组装成介孔固体。这些都是对催化有兴趣的高度多孔的二氧化硅材料。在另一个模块中，我们将把硅藻和球藻基团的壳层转化为功能有机聚合物和玻璃，方法是在壳层周围“成型”聚合物和玻璃。随后，我们把贝壳溶解，制成“塑料”或玻璃状的复制品。但例如，这些复制品可能被用作氧气传感器。在第三个模块中，我们将贝壳转化为碳，并使用反向复制品来制造新型的三维物体，这些物体可能是也可能不是基于二氧化硅的。在第四个模块中，我们将研究光线如何与外壳的3D结构相互作用。这对传感器、激光和其他光学反应很重要，因为光可能会被困在超微结构中，或者完全被拒绝。

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 cell aquatic 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.