Patterned Hierarchies of Functional Materials

功能材料的图案化层次结构

• 批准号: RGPIN-2018-05912
• 负责人: Andrews, Mark
• 金额: $ 1.75万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=643968
• 关键词: Patterned; Hierarchies; Functional; Materials

Life, consciousness, replication, magnetism, liquid crystallinity and biological morphogenesis are what we call "emergent" properties. These can be said to evolve from hierarchies of patterns. A hierarchy can be understood as a kind of branched tree that shows how its different parts are connected. The “tree” functions as a tree only by virtue of how all the parts interact. The tree, like consciousness or biological morphogenesis, is really not reducible to atoms and molecules. Emergence refers to the way that parts come together (assemble) to yield some sort of pattern that is connected to a functional property, like the ability to conduct light or magnetism. It is from the patterning of the parts that such properties emerge. In Nature, micro-organisms like diatoms (phytoplankton) take up silicic acid from water. Silicic acid is a tetrahedral 4-atom molecule that is used by the diatom to build a very ornate “glass house” - a protective shell called the frustule. The frustule has a complex periodic pattern, though the glass itself is disordered at the molecular scale. Diatoms are responsible for the oxygen in every 4th breath one takes, so it is useful to understand the role that the frustule might play in harvesting light for photosynthesis. We suspect that diatoms use the frustule as a complex optical device to collect sunlight and channel it to its chloroplasts to fix carbon dioxide and make oxygen. In our research, we use theoretical models and conduct experiments to show how diatoms are photonic (optical) on a very small scale – they are nanophotonic. We show how pattern formation leads to nanophotonic behavior. Magnetism too is the result of patterning of electrons in an ordered way (ferromagnetism is an example). There are unusual fluids – ferrofluids – that consist of magnetic nanoparticles like magnetite, Fe3O4. When a flat pool of such a fluid is exposed to a magnetic field, a pattern suddenly forms. This breaks the rotational symmetry of the pool, and we call this a phase transition. Symmetry-breaking leads to patterns. We are interested not only in how these patterns form, but how to make permanent records of them. We have discovered a way to do so, and we describe it in this research proposal. Permanent patterns of magnetic material will allow us to create new kinds of magnetism for things like tiny actuators that can be mobilized in magnetic fields to imitate the cilia of micro-organisms or in the human lung. Such a study can impact health research. In the end, the study of patterned structures will tell us something new about how to create new functions of matter that emerge from patterns. It is for these reasons that we entitle our research program, Patterned Hierarchies of Functional Materials.

生命、意识、复制、磁性、液晶性和生物形态发生都是我们所说的“紧急”性质。这些可以说是从模式的层次结构演变而来的。层次结构可以理解为一种分枝树，它显示了不同部分是如何连接的。“树”只有通过所有部分如何相互作用才能起到树的作用。树，就像意识或生物形态发生一样，真的不能还原为原子和分子。浮现指的是部件聚集在一起(组装)以产生某种图案的方式，这种图案与功能特性有关，比如传导光或磁的能力。正是从零件的图案中，才能产生这样的特性。在自然界，硅藻(浮游植物)等微生物从水中吸收硅酸。硅酸是一种四面体的四原子分子，硅藻用它来建造一个非常华丽的“玻璃房子”--一种被称为锥体的保护壳。尽管玻璃本身在分子尺度上是无序的，但玻璃锥体具有复杂的周期图案。硅藻负责每四次呼吸中的氧气，因此了解锥体在收集光合作用的光中可能起到的作用是有用的。我们怀疑，硅藻将锥体作为一种复杂的光学装置来收集阳光，并将其引导到其叶绿体，以固定二氧化碳和制造氧气。在我们的研究中，我们使用理论模型和进行实验来展示硅藻是如何在非常小的尺度上是光子(光学)的--它们是纳米光子。我们展示了图案的形成如何导致纳米光子行为。磁性也是电子有序图案化的结果(铁磁性就是一个例子)。有一种不同寻常的流体--磁流体--由磁性纳米粒子组成，如磁铁矿、Fe3O4。当这种液体的扁平水池暴露在磁场中时，突然形成了一种图案。这打破了水池的旋转对称性，我们称之为相变。打破对称性会导致模式。我们感兴趣的不仅是这些图案是如何形成的，而且是如何对它们进行永久记录的。我们已经发现了一种这样做的方法，我们在这项研究提案中对其进行了描述。磁性材料的永久图案将允许我们为微小的致动器等东西创造新的磁性，这些致动器可以在磁场中动员起来，模仿微生物或人类肺部的纤毛。这样的研究可能会影响健康研究。最后，对图案化结构的研究将告诉我们一些新的东西，关于如何创造从模式中出现的物质的新功能。正是出于这些原因，我们将我们的研究项目命名为功能材料的图案化层次结构。