Controlled Synthesis of Mesoporous Silicon Oxynitride Ceramics by Nitridization of Mesoporous Organosilicas

介孔有机硅氮化控制合成介孔氮氧化硅陶瓷

• 批准号: 0804846
• 负责人: Tewodros Asefa
• 金额: $ 21万
• 依托单位: Syracuse University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0804846&HistoricalAwards=false
• 关键词: Controlled; Synthesis; Mesoporous; Silicon; Oxynitride

NON-TECHNICAL DESCRIPTION. Silicon oxynitrides are ceramic materials that have high mechanical and thermal strength and chemical stability. The synthesis of silicon oxynitrides (SONs) with nanoscale and nanoporous structures, structures with one?thousandths of the diameter of a human hair, produces high surface area efficient catalysts, filtration membranes, sensors, nanoelectronics thin film devices and dielectric materials nanoelectronics applications. In this project, rational and facile synthetic methods involving controlled nitridization of pre-made mesoporous metal oxides such as organosilicas will be investigated and tunable mesoporous silicon oxynitride (SON) materials and thin films will be developed. By synthesizing SON with nanoscale and nanoporous structures and variable compositions and structures, it will be possible to improve their properties such as surface areas, dielectric constants, quantum confinement and luminescence. These enhancements will further improve their catalytic efficiency and properties for applications in gate dielectric devices, and photonic crystal waveguides. By understanding the kinetics and mechanisms of nitridization on various mesoporous organosilicas, low cost synthetic methods to SONs with tunable nanostructures and properties will ultimately result. The method can also further be adapted to other ceramic materials such as silicon carbides and silicon oxycarbide ceramics. The project will allow the training of undergraduate students, including minority students, and graduate students to be actively involved to learn solid-state ceramic nanomaterials synthesis and understand structure-property relationships. The students? results in this project are expected also to generate publications and be presented at national conferences. TECHNICAL DESCRIPTION. Ceramics are diverse materials with interesting mechanical, thermal, chemical, and optical properties and possessing a wide range of potential applications. Their high strength and thermal stability make them ideal for products subject to heavy use and wear and tear such as high speed ball bearings and cutting tool inserts. In recent years, research on silicon oxynitride (SON) ceramics has targeted novel applications including catalysis, where the solid SON ceramic participates in base-catalyzed chemical reactions. Attention has also turned to investigations of these materials in nanoscale applications, where the size of the material is 1/1000th of the width of a human hair. This project by Professor Asefa is exploring special type of ceramics, those made from nanoporous silicon oxynitrides, in applications such as catalysis, filtration membranes, sensors, and nanoelectronics thin film devices and dielectric materials for metal-oxide-semiconductor (MOS) integrated circuits. Current methods to synthesize nanostructured silicon oxynitrides are not optimum - they require harsh conditions and result in products whose structures are not as consistent and uniform as required. In this project, rational and facile synthetic methods involving controlled nitridization of pre-made mesoporous organosilca into tunable mesoporous silicon oxynitride materials and thin films will be developed. The approaches are expected to result in nanostructured and nanoporous ceramics having variable compositions and structures, and improved properties such as surface areas, dielectric constants, quantum confinement and luminescence. These enhancements will further improve their efficiency for solid-base catalysis, gate dielectric devices, and photonic crystal waveguides. Undergraduate students, including minority students, and graduate students will be actively involved in the proposed project and they will learn solid-state ceramic nanomaterials synthesis and understanding structure-property relationships nanoceramics. The students will present their research results at the department?s undergraduate seminars and at the American Chemical Society Regional Meetings.

非技术性描述。氮氧化硅是一种具有高机械强度、热强度和化学稳定性的陶瓷材料。具有纳米级和纳米孔结构的氮氧化硅(SON)的合成，具有人类头发直径的千分之一的结构，产生高比表面积的高效催化剂、滤膜、传感器、纳米电子薄膜器件和介电材料纳米电子应用。在这个项目中，我们将探索合理而简便的合成方法，包括对预制的介孔金属氧化物(如有机硅)进行控制氮化，并开发可调谐的介孔氮氧化硅(SON)材料和薄膜。通过合成具有纳米尺度和纳米孔道结构以及不同组成和结构的SON，将有可能改善其比表面积、介电常数、量子限制和发光等性能。这些改进将进一步提高它们的催化效率和在栅电介质器件和光子晶体波导中的应用性能。通过了解各种介孔有机硅上氮化反应的动力学和机理，最终将得到具有可调纳米结构和性能的低成本合成方法。该方法还可以进一步适用于其他陶瓷材料，如碳化硅和碳化硅陶瓷。该项目将使包括少数民族学生在内的本科生和研究生积极参与学习固态陶瓷纳米材料合成，并了解结构与性能的关系。学生们呢？预计该项目的成果还将出版出版物，并在国家会议上介绍。技术说明。陶瓷材料种类繁多，具有有趣的力学、热学、化学和光学性能，具有广泛的潜在应用前景。它们的高强度和热稳定性使其非常适合于需要大量使用和磨损的产品，如高速球轴承和刀具刀片。近年来，对氮氧化硅(SON)陶瓷的研究已经瞄准了包括催化在内的新的应用，其中固体SON陶瓷参与碱催化的化学反应。人们的注意力也转向了这些材料在纳米级应用中的研究，这种材料的大小是人类头发宽度的千分之一。Asefa教授的这个项目正在探索特殊类型的陶瓷，这些陶瓷由纳米多孔氮氧化硅制成，应用于催化、滤膜、传感器、纳米电子薄膜器件和金属氧化物半导体(MOS)集成电路的介质材料。目前合成纳米结构氮氧化硅的方法并不是最优的--它们要求苛刻的条件，导致产品的结构不像所要求的那样一致和均匀。在本项目中，将开发合理而简便的合成方法，将预制的介孔有机硅控制氮化成可调谐的介孔氮氧化硅材料和薄膜。这些方法有望导致纳米结构和纳米多孔陶瓷具有不同的组成和结构，并改善性能，如比表面积、介电常数、量子限制和发光。这些增强将进一步提高它们在固体基催化、栅电介质器件和光子晶体波导中的效率。包括少数民族学生在内的本科生和研究生将积极参与拟议的项目，他们将学习固态陶瓷纳米材料的合成和了解纳米陶瓷的结构-性能关系。学生们将在S系本科生研讨会和美国化学学会地区会议上展示他们的研究成果。