BIO-INSPIRED APPROACHES TO FUNCTIONAL NANOSTRUCTURED MATERIALS

本研究计划的重点是开发具有可控结构和先进性能的新材料的制造方法。我们的方法从生物矿物这一非凡的材料中获得灵感。虽然生物矿物质（包括骨骼、牙齿和贝壳等结构）是在温和的反应条件下产生的，但它们具有独特的形态和功能优化的特性。许多这些特性，如增强的抗断裂性，可以归因于生物矿物是复合材料的事实-其中硬无机矿物与软有机分子结合-它们的结构通常在许多不同的长度尺度上组织。值得注意的是，由单晶组成的生物矿物（如海胆刺）也是复合材料，其中蛋白质嵌入单晶宿主中。这是一个令人惊讶的观察结果，因为再结晶过程传统上被认为是净化结晶材料的有效方法。然而，大自然告诉我们，用这种方法制造复合材料是完全可能的。在提出的工作中，我们将开发将一系列有机和无机纳米颗粒纳入单晶宿主的方法。在此过程中，我们将通过结合功能主体晶体和功能客体粒子来创造新的功能材料。该项目总结为三个主要目标。首先，我们将确定控制单晶中粒子结合的基本设计规则。这将通过研究颗粒的大小、形状和表面功能化如何影响它们在包括碳酸钙和氧化锌在内的一系列晶体中的掺入来实现。这项工作将需要我们合成基于阴离子二嵌段共聚物的新型聚合物颗粒，并使用水溶性阴离子嵌段共聚物使无机纳米颗粒表面功能化。我们还将扩展工作，以研究囊泡和蠕虫样胶束的结合。在建立基本的设计规则后，我们将使用这些来制造新的微胶囊化系统。我们的新主客体系统的一个关键特征是纳米颗粒完全被包裹在单晶中，因此它们应该被保护免受氧化/反应，光或热降解或浸出。因此，它们非常适合微胶囊化应用。一系列的材料将被封闭在单晶CaCO3中，包括工业上相关的氧化敏感活性物质，如酶和维生素e。最后，我们将通过在无机单晶中加入无机纳米颗粒来生成无机/无机纳米复合材料。这为引入对比功能（例如光学、电气和磁性）提供了前所未有的机会，这是单一组件材料无法实现的。通过控制被遮挡的纳米颗粒的大小和分离，以及它们与主体晶体的界面等特征，有望获得具有可调物理性质的独特纳米复合材料。这种综合方法将为制备下一代纳米复合晶体提供一种通用的方法，这种晶体结合了功能和层次结构，并可能最终为生产重要的生物材料（如人造骨和坚韧的合成牙釉质）提供智力刺激和科学动力。

This research proposal focuses on developing methods for the fabrication of new materials with controlled structures and advanced properties. Our approach takes its inspiration from the remarkable materials that are biominerals. Although biominerals, which include structures such as bones, teeth and seashells, are produced under mild reaction conditions, they are characterised by unique morphologies and properties optimised for their function. Many of these properties, such as enhanced resistance to fracture, can be attributed to the fact that biominerals are composite materials - where the hard inorganic mineral is combined with soft organic molecules - and their structures are typically organised over many different length scales. Notably, biominerals comprising single crystals (such as sea urchin spines) are also composite materials, where proteins are embedded within the single crystal host. This is a surprising observation as the process of recrystallisation is traditionally considered as an effective method for purifying crystalline materials. Nature, however, shows us that it is entirely possible to create composite materials in this way.In the proposed work we will develop methods to incorporate a range of organic and inorganic nanoparticles within single crystal hosts. In doing so, we will create new functional materials by combining functional host crystals with functional guest particles. The project is summarised under three main goals. Firstly, we will determine the fundamental design rules governing the incorporation of particles within single crystals. This will be achieved by investigating how the size, shape and surface functionalisation of the particles affects their incorporation in a range of crystals including calcium carbonate and zinc oxide. This work will require us to synthesise novel polymer particles based on anionic diblock copolymers, and to functionalise the surfaces of inorganic nanoparticles with water-soluble anionic block copolymers. We will also extend the work to study the incorporation of vesicles and worm-like micelles. After establishing the fundamental design rules, we will use these to fabricate novel microencapsulation systems. A key feature of our new host-guest systems is that nanoparticles are completely entrapped within a single crystal, and hence they should be protected from oxidation/reaction, light or thermal degradation, or from leaching. They are therefore ideally suited to microencapsulation applications. A range of materials will be occluded within single crystal CaCO3, including industrially relevant oxidation-sensitive actives such as enzymes and Vitamin E. Finally, we will generate inorganic/inorganic nanocomposites by incorporating inorganic nanoparticles within inorganic single crystals. This provides an unprecedented opportunity to introduce contrasting functionalities (e.g. optical, electrical, and magnetic) - which cannot be achieved with a single component material. The ability to control features such as the size and separation of the occluded nanoparticles, and their interface with the host crystal is expected to lead to unique nancomposites with tunable physical properties. This integrated approach will provide a general methodology for preparing next-generation nanocomposite crystals that combine functionality with hierarchical structure, and may ultimately provide the intellectual stimulus and scientific impetus to produce vital biomaterials such as artificial bone and tough synthetic dental enamel.