Synthesis, Design and Function in New Materials Chemistry

材料化学的一个基本目标是了解材料是如何形成的，为什么它们具有各自的特性，并由此着手改进它们，并为给定的功能设计新材料。人们普遍认为，要做到这一点，必须首先获得材料结构的工作知识，从工程师的毫米尺度到原子水平（千万分之一毫米）。全面的材料化学家不仅必须能够制造具有特定性能的材料并使其在高压、高温和腐蚀性化学条件等恶劣操作条件下发挥作用，而且还必须能够确定其结构和化学反应性，以便为所研究的材料和化学过程设计一个工作结构-性能模型。我们的最终目标是通过理论与实验相结合的方法开发出这样的模型来指导材料化学家改进现有的技术材料或设计并创造出用于先进技术应用的全新化合物。为了实现这一目标，需要在新化合物及其性质的理论预测，其行为的合成和表征，以及在其合成和最终应用的实际操作条件下材料行为的原位研究之间的前沿科学。我们必须掌握将会遇到的各种极端化学和高温高压条件，这可能被称为材料化学家的烹饪锅：许多材料被要求在化学腐蚀性的高压和高温水或气体环境中表现出高标准的机械或耐化学性。例如用于密封深油井的水泥、用于废气催化转化器的先进陶瓷、用于高速钻井的超硬材料、用于催化和离子交换反应的微孔固体；甚至是在地球深处和其他行星的极高p、T条件下遇到的天然物质。对这些奇异物质的研究远非学术；它已经产生了新的超硬材料，如立方氮化硼和人造金刚石；新的半导体、超导体、插层化合物和高硬度材料预计将从这样的研究中产生。我们必须研究现有材料和新材料在形成过程中或在实际工作条件下发生的化学和结构变化。我们在实验室里使用光谱学，或者在同步加速器和中子源上，通过将强烈的x射线（或中子）射向材料及其内部，并快速收集和分析散射光，为我们提供有关其变化的结构、电子和键合特性的直接信息。从同步加速器源发出的x射线具有足够的强度和穿透力，可以穿过容器装置和所研究的材料，从而提供结构和化学信息，并绘制样品内部的图。我们设计和开发成像这类材料的新方法。我们还为实验室、同步加速器和中子源的原位材料研究设计了新的环境细胞，并结合了指导合成和原位实验发展的理论预测。理论与实验的互动为新材料的创造和理解提供了下一个循环

An essential goal of Materials Chemistry is to understand how materials are formed, why they have their individual properties, and from this how one can set about improving them and also designing new materials for a given function. It is universally held that to do this one must first obtain a working knowledge of how materials are structured, from the mm scale of the engineer down to the atomic level (1/10millionth mm). The complete materials chemist must be able not only to make materials with specific properties and set them into action, often under hostile operating conditions of high-pressure and temperature and corrosive chemical conditions, but must also be able to determine their structure and chemical reactivity in order to devise a working structure-properties model of the material and the chemical processes under study. Our ultimate aim is to use such models developed via a combined theoryexperimental approach to guide materials chemists in their quest to improve existing teachnological materials or design and create completely new compounds for advanced technology applications.To achieve this goal requires cutting edge science at the frontier between theoretical predictions of new compounds and their properties, synthesis and characterisation of their behaviour, and in situ studies of how the materials behaviour under realistic operating conditions of their synthesis and ultimate applications. We must master the wide range of extreme chemical and high temperature-high pressure conditions that will be encountered, in what might be termed the materials chemist's cooking pot : Many materials are required to perform to a high standard of mechanical or chemical resistance within chemically corrosive high pressure and temperature aqueous or gaseous environments. Examples are cements used to seal deep oilwells, advanced ceramics used in exhaust catalytic convertors, ultrahard materials used for high-speed drilling, microporous solids used in catalysis and ion exchange reactions; and even natural materials encountered under the extreme high-P,T conditions of the deep Earth and other planets. Study of such exotic materials is far from academic; it has already yielded new super-hard materials such as cubic boron nitride and synthetic diamond: new semiconductors, superconductors, intercalated compounds and high-hardness materials are predicted to result from such studies. We must study the chemical and structural changes occurring within existing and new materials as they are being formed or during their actual working conditions. We do this in the laboratory using spectroscopy, or at synchrotron and neutron sources by directing intense beams of X-rays (or neutrons) onto and inside the material, and rapidly collecting and analysing the scattered light to give us direct information on its changing structure and electronic and bonding properties. X-rays derived from a synchrotron source are sufficiently intense and penetrating that they pass through the container device and the material under study to give structural and chemical information and mapping of the inside of the sample. We devise and develop new methods for imaging such materials. We also design new environmental cells for in situ materials studies in the laboratory and at synchrotron and neutron sources, combined with theoretical predictions that guide the development of the synthesis and in situ experiments. The theory-experiment interaction feeds the next cycle of new materials creation and understanding