BIOMIMETIC SYNTHESIS OF CRYSTALLINE MATERIALS WITH COMPOSITE STRUCTURES

技术的进步要求对材料结构、性能和功能的控制程度不断提高。即便如此，从单片材料中获得的性能范围仍然相对有限。相比之下，复合材料的创造，其中两种不同的材料结合在一起，打开了大门，制造具有许多潜在应用的新材料。该提案将研究和开发一种简单的仿生方法，通过简单的一锅法在宿主晶体基质中形成复合材料/封装第二相颗粒，其中颗粒被用作生长添加剂。Meldrum的初步工作已经证明，当乳胶具有适当的表面化学性质时，即当它们被带负电的聚合物（即聚酸链）的电晕装饰时，相对高密度的乳胶颗粒可以掺入碳酸钙（方解石）单晶中。这项拨款提案旨在详细研究这种合成方法，提供对颗粒如何在晶体中结合的基本理解，然后解决由此产生的复合材料的可能应用。我们将研究单晶和多晶材料中的颗粒封装，解决有机乳胶，无机溶胶和金属纳米颗粒的掺入问题。(1)设计和合成具有明确表面化学性质的模型颗粒，研究颗粒尺寸、表面化学性质和晶体生长机制对颗粒包封的具体影响。(2)作为一种替代策略，我们还将在诱导结晶之前将颗粒封闭在无定形前驱相中。这是一种潜在的通用方法，可以应用于许多陶瓷。(3)我们将探索嵌段共聚物胶束和囊泡包封的途径，这将有利于水不溶性和水溶性活性的包封。(4)在对单晶和多晶碳酸钙中颗粒包裹的要求有了基本的了解之后，我们将通过研究大范围对比晶体中的颗粒包裹来检验该模型的普遍性。(5)最后，我们将应用我们的新方法来形成一系列功能复合材料。碳酸钙和磷酸钙将用作颜料、磨料、抗菌剂、维生素和调味料等添加剂的主体材料。我们还将应用这种仿生策略来形成功能陶瓷复合材料，包括陶瓷/金属微复合材料（金属陶瓷）和铁电复合材料。

Advances in technology demand an ever-increasing degree of control over material structure, properties and function. Even so, the range of properties that can be obtained from monolithic materials remains relatively limited. In contrast, the creation of composite materials, in which two dissimilar materials are combined, opens the door to the fabrication of new materials with many potential applications. This proposal will investigate and exploit a simple biomimetic approach to forming composite materials / encapsulating particles of a second phase within a host crystalline matrix by a simple one-pot method, in which the particles are used as growth additives.Meldrum's preliminary work has demonstrated that a relatively high density of latex particles can be incorporated within calcium carbonate (calcite) single crystals when the latex has appropriate surface chemistry - that is when they are decorated with a corona of negatively-charged polymer (i.e. polyacid) chains. This grant proposal seeks to investigate this synthetic approach in detail, providing a fundamental understanding of how particles can be incorporated within crystals, and then addressing possible applications of the resulting composite materials. We will investigate particle encapsulation within both single crystal and polycrystalline materials, addressing the incorporation of organic latexes, inorganic sols and metal nanoparticles. (1) Model particles with well-defined surface chemistries will be designed and synthesised, and the specific effects of particle size, surface chemistry and crystal growth mechanism in particle encapsulation will be studied. (2) As an alternative strategy we will also occlude particles within an amorphous precursor phase before inducing crystallisation. This is a potentially generic method that could be applied to many ceramics. (3) We will explore routes to encapsulating block copolymer micelles and vesicles, which will facilitate the encapsulation of both water-insoluble and water-soluble actives. (4) After gaining a fundamental understanding of the requirements for particle inclusion within single crystal and polycrystalline calcium carbonate, we will test the generality of this model by investigating particle incorporation in a wide range of contrasting crystals. (5) Finally, we will apply our new approach to form a range of functional composite materials. Calcium carbonate and calcium phosphate will be used as host materials for additives such as pigments, abrasives, antimicrobial agents, vitamins and flavourings. We will also apply this biomimetic strategy to the formation of functional ceramic composites, including ceramic/metal microcomposites (cermets) and ferroelectric composite materials.