Collaborative Research: Synthetic Chemistry with Periodic Mesostructures at High Pressure

合作研究：高压下周期性介观结构的合成化学

• 批准号: 1305845
• 负责人: Kai Landskron
• 金额: $ 45万
• 依托单位: Lehigh University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1305845&HistoricalAwards=false
• 关键词: Collaborative; Research; Synthetic; Chemistry; Periodic

TECHNICAL SUMMARYThe proposed research, funded by the Solid State and Materials Chemistry program, is aimed at synthesizing mesostructures of diamond at high pressure using periodic mesostructured carbons produced by soft self-assembly with surfactant templates. For the synthesis, the carbons will be infiltrated by polycarbosilanes until the pore space is filled. Heat-treatment of the so-infiltrated carbons will produce periodic mesostructured silicon carbide/carbon composite materials. Subsequently, these composites will be treated at high pressure and temperature to transform the carbon phase into periodic mesostructures of diamond. The synthesis will be performed in multi-anvil assemblies which allow for pressures of up to 27 GPa and temperatures above 2000°C. The produced mesostructured silicon carbide/diamond composites will be structurally characterized and tested for their mechanical properties. By selective removal of the silicon carbide phase from the SiC/diamond composites mesoporous forms of diamond will be produced. In addition, we will explore the mechanisms and kinetics of the phase transitions within mesostructures at high pressure by in-situ Raman, SAXS, and IR spectroscopic experiments. The in-situ experiments will be done in diamond anvil cells. It is expected that the realization of these aims will create seminal knowledge across the different fields of high-pressure science and periodic mesostructures, and produce potentially useful new materials. NON TECHNICAL SUMMARYMesoporous materials belong to the most important classes of materials due to their wide structural diversity and broad range of applications including catalysis, separation, microelectronics, and drug-delivery. Pressure and temperatures are the two major thermodynamic variables in synthesis. The emphasis of this work is to explore the role of high pressure in synthesis to produce mesostructures of diamond and investigate the mechanisms of phase transformations at high-pressure inside a mesostructure. Thereby, the project will advance the understanding of the chemical high-pressure behavior of periodic mesostructures and make a broad impact on synthetic high-pressure chemistry which is currently an underrepresented field. Diamond is the arguably the most technologically important high-pressure phase. Mesostructured composites of diamond, which are the expected products in this research, could find applications as ultrahard materials. Diamond is known as biocompatible material and thus mesoporous forms of diamond could have potential in drug-delivery. Commercially relevant outcomes of the work will be communicated to industry via the Lehigh Nanotechnology Network and Lehigh's Industrial Liaison Program. Leading companies for the production of diamond materials will be involved in materials testing, which will catalyze technology transfer. The project will be done in collaboration between a degree-granting University (Lehigh University) and a non-degree granting research institution (Carnegie Institution of Washington) thereby building a close tie between these institutions. The involved students and post-docs will learn an unusual combination of synthetic (synthesis of mesostructured materials, high pressure syntheses) and analytical techniques (electron microscopy, X-ray diffraction, gas sorption etc.). Results from the work will be integrated into "Advanced Inorganic Chemistry", and "Solid State Chemistry" courses.

技术总结这项拟议的研究由固态和材料化学计划资助，旨在通过使用表面活性剂模板进行软自组装产生的周期性中观结构碳，在高压下合成金刚石的介观结构。在合成过程中，碳将被聚碳硅烷渗透，直到孔隙被填满。对渗碳进行热处理，可得到周期性的中间结构碳化硅/碳复合材料。随后，这些复合材料将在高压和高温下处理，将碳相转变为周期性的金刚石细观结构。合成将在多个砧座组件中进行，允许压力高达27 Gpa，温度高于2000°C。所生产的中间结构碳化硅/金刚石复合材料将进行结构表征和机械性能测试。通过选择性地从碳化硅/金刚石复合材料中去除碳化硅相，将生成介孔形式的金刚石。此外，我们还将通过原位拉曼光谱、SAXS光谱和红外光谱实验，探索高压下介观结构相变的机理和动力学。现场实验将在钻石砧座单元中进行。预计这些目标的实现将在高压科学和周期性介观结构的不同领域创造出开创性的知识，并产生潜在有用的新材料。非技术综述介孔材料由于其广泛的结构多样性和广泛的应用，包括催化、分离、微电子学和药物输送，属于最重要的一类材料。压力和温度是合成中的两个主要热力学变量。这项工作的重点是探索高压在合成金刚石细观结构中的作用，并研究高压下细观结构中的相变机制。因此，该项目将促进对周期介观结构化学高压行为的理解，并对合成高压化学产生广泛的影响，目前合成高压化学是一个未被充分代表的领域。钻石可以说是技术上最重要的高压阶段。金刚石介观复合材料是本研究的预期产品，有望在超硬材料方面得到应用。钻石是已知的生物相容材料，因此介孔形式的钻石可能在药物输送方面具有潜力。这项工作的商业相关成果将通过利哈伊纳米技术网络和利哈伊的工业联络计划传达给业界。生产钻石材料的领先公司将参与材料测试，这将促进技术转让。该项目将在授予学位的大学(利哈伊大学)和非授予学位的研究机构(华盛顿卡内基研究所)之间合作完成，从而在这些机构之间建立密切的联系。参与的学生和博士后将学习合成技术(介观材料的合成、高压合成)和分析技术(电子显微镜、X射线衍射、气体吸附等)的不同寻常的结合。这项工作的成果将被纳入“高级无机化学”和“固体化学”课程。