Chemistry of Nanostructured Porous Si

该奖项由加州大学圣地亚哥分校材料研究部固态化学项目颁发，旨在研究表面化学对多孔硅（Si）光子晶体稳定性的影响。获得该奖项的Michael Sailor教授将探索多孔硅表面的化学修饰对其空气和水稳定性的影响，使用旨在通过Si-碳键连接功能物质的反应。还将研究两种相关的附着化学：烷基卤化物的电化学还原；末端烯烃的硅氢化反应。与Si- h或Si- o表面相比，这些化学物质赋予多孔Si表面显著的稳定性。要回答的基本问题是：化学稳定性提高的原因是什么？系统地研究了孔径、有机改性剂的链长、表面覆盖率和取代基的性质对空气和水介质稳定性的影响。该项目将导致对纳米晶硅表面反应性的新认识，在许多领域有潜在的应用。近年来，人们对开发低功耗微型传感器越来越感兴趣，这些传感器可用于检测环境中的有毒物质、污染物或化学和生物战剂。人们对可用于诊断疾病的便携式传感器也有类似的高度兴趣。该领域最大的挑战之一是将实验室规模仪器的灵敏度和特异性放入手掌或更小的包装中。这项研究的目标是发展纳米材料的化学性质，使其能够实现这类应用。这个项目将从晶体硅晶片开始，也就是计算机行业用来制造微芯片的材料，它将制造出纳米级的结构，可以作为化学或生物化合物的传感器。该项目将使人们更好地了解硅纳米材料的化学性质，从而在医疗诊断和治疗、污染监测和国土安全应用的遥感器、信息显示和光电子学等领域取得进展。这项工作的主要成果将是为研究生和本科生提供高度跨学科的材料化学和纳米科学教育。学生将准备在工业、政府和学术界的高科技和生物技术部门担任各种具有挑战性的研究职位。

This award from the Solid State Chemistry program in the Division of Materials Research to University of California San Diego is to develop an understanding of the effect of surface chemistry on the stability of porous silicon (Si) photonic crystals. With this award Professor Michael Sailor will probe the effects of chemical modification of the porous Si surface on its air and water stability using reactions designed to attach functional species via Si-Carbon bonds. Two related attachment chemistries would also be studied: electrochemical reduction of alkyl halides; and hydrosilylation of terminal alkenes. These chemistries have been found to impart remarkable stability to the porous Si surface relative to Si-H or Si-O surfaces. The fundamental question to be answered is: what is the reason for this improved chemical stability? A systematic study on the effect of pore dimensions, chain length of the organic modifier, surface coverage, and nature of the substituents on stability in air and aqueous media will be performed. The project should lead to new understanding of the reactivity of nanocrystalline silicon surfaces for potential applications in number fields. In recent years there has been increased interest in developing low-power, miniature sensors that can be used to detect toxics, pollutants, or chemical and biological warfare agents in the environment. There is similar high interest in portable sensors that can be used to diagnose illness. One of the biggest challenges in this area is to place the sensitivity and specificity of a laboratory-scale instrument into a palm-top or smaller package. The goal of this research is to develop the chemistry of nanomaterials that can enable such applications, among others. Starting with crystalline silicon wafers, the same material used by the computer industry to build microchips, the project will build nanoscale structures that can act as sensors for chemical or biological compounds. The project should lead to a better understanding of the chemistry of silicon nanomaterials that will enable advances in the areas of medical diagnostics and therapeutics, remote sensors for pollution monitoring and homeland security applications, information display and optoelectronics. The primary product of this work will be to provide graduate and undergraduate students with a highly interdisciplinary education in materials chemistry and nanoscience. The students will be prepared for a variety of challenging research positions in the high-tech and biotech sectors of industry, government, and academia.