US-Austria Cooperative Research: Impedance Studies of Sol-Gel Materials

该奖项支持加州大学洛杉矶分校的Bruce S. Dunn与维也纳技术大学技术电化学研究所的Manfred W. Breiter教授的合作研究。他们研究的目的是更多地了解凝胶在溶液、凝胶化和老化阶段的介电特性。他们将应用阻抗谱来提供有关凝胶发育和形态的信息，并更好地了解其输运性质。加州大学洛杉矶分校的研究小组将负责合成各种凝胶。合作的奥地利集团为复杂阻抗的光谱测量和分析模型的开发提供了不同寻常的专业知识和专业设施。这种安排为在同一样品上应用宏观和微观分析技术提供了独特的机会。过去对溶胶-凝胶材料电学性质的研究在很大程度上局限于对干燥和焙烧材料的研究。提出的工作将探索凝胶在溶液和凝胶的早期阶段的运输过程。正是在这些阶段，介电性能受到实质性的变化，因为移动离子受到阻碍，弛豫时间被结构刚性改变。更好地理解凝胶微观结构与输运特性之间的关系将有助于他们在凝胶化阶段之前开发具有高阻抗的凝胶。该结果将补充Dunn博士目前的nsf支持的研究，该研究使用发光光谱来监测局部化学和结构变化。这项研究旨在将有机分子结合到溶胶-凝胶宿主中，以“设计”出新的特性。

This award supports Bruce S. Dunn of UCLA for collaborative research with Professor Manfred W. Breiter of the Institute of Technical Electrochemistry of the Technical University of Vienna. The objective of their research is to learn more about the dielectric properties of gels during their solution, gelation and aging stages. They will apply impedance spectroscopy to provide information about gel development and morphology and to gain a better understanding of transport properties. The UCLA group will be responsible for synthesizing various gels. The collaborating Austrian group offers unusual expertise and specialized facilities for the spectroscopic measurement of complex impedance and the development of analytical models. This arrangement provides a unique opportunity to apply macroscopic and microscopic analytical techniques on the same samples. Past studies of the electrical properties of sol-gel materials have been largely restricted to investigations of dried and fired materials. The proposed work will explore the transport processes of gels during the earlier stages of solution and gelation. It is during these stages that dielectric properties are subject to substantial change as mobile ions become impeded and relaxation times are altered by structural rigidity. A better understanding of the relationship between transport properties and gel micro- structure will help them to develop gels that possess high impedance prior to their gelation stage. The results will complement Dr. Dunn's current NSF-supported research which uses luminescent spectroscopy to monitor local chemical and structural changes. That research is aimed at the incorporation of organic molecules into sol-gel hosts, in order to "engineer" new properties.