Collaborative Research: Chemical Synthesis with Periodic Mesostructures at High Pressure

合作研究：高压下周期性介观结构的化学合成

• 批准号: 1305839
• 负责人: Yingwei Fei
• 金额: $ 8.34万
• 依托单位: Carnegie Institution of Washington
• 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=1305839&HistoricalAwards=false
• 关键词: Collaborative; Research; Chemical; Synthesis; 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.

技术摘要拟议的研究由固态和材料化学计划资助，旨在利用表面活性剂模板软自组装产生的周期性介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，直到孔隙空间被填充。对如此渗透的碳进行热处理将产生周期性介观结构碳化硅/碳复合材料。随后，这些复合材料将在高压和高温下进行处理，将碳相转化为金刚石的周期性介观结构。合成将在多砧组件中进行，压力高达 27 GPa，温度高于 2000°C。所生产的介观结构碳化硅/金刚石复合材料将进行结构表征并测试其机械性能。通过从 SiC/金刚石复合材料中选择性去除碳化硅相，将产生介孔形式的金刚石。此外，我们将通过原位拉曼、SAXS和红外光谱实验探索高压下介观结构内相变的机制和动力学。原位实验将在金刚石砧室中进行。预计这些目标的实现将在高压科学和周期性细观结构的不同领域创造开创性的知识，并产生潜在有用的新材料。非技术概要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、微电子和药物输送）而属于最重要的材料类别。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，并研究细观结构内高压下的相变机制。因此，该项目将增进对周期性介观结构化学高压行为的理解，并对目前代表性不足的领域合成高压化学产生广泛影响。金刚石可以说是技术上最重要的高压相。金刚石介观结构复合材料是本研究的预期产品，可以作为超硬材料得到应用。金刚石被称为生物相容性材料，因此介孔形式的金刚石在药物输送方面具有潜力。该工作的商业相关成果将通过里哈伊纳米技术网络和里哈伊工业联络计划传达给工业界。金刚石材料生产的领先公司将参与材料测试，这将促进技术转让。该项目将由授予学位的大学（里海大学）和非授予学位的研究机构（华盛顿卡内基研究所）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（介观结构材料的合成、高压合成）和分析技术（电子显微镜、X射线衍射、气体吸附等）的不寻常组合。这项工作的成果将被纳入“高级无机化学”和“固态化学”课程。