MRI-R2: Acquisition of Equipment for Rare Earth Spectroscopic Studies of Sol-Gel Glass Structure

技术摘要：该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。含有荧光稀土（RE）离子的溶胶-凝胶衍生玻璃在激光器、光学传感器、光纤和光子器件等应用中具有潜在的用途。然而，re掺杂的溶胶-凝胶玻璃的光学行为尚未完全了解。这里提出的工作将使用光谱学来回答关于溶胶-凝胶玻璃结构影响RE荧光产率的基本问题。已经确定了两种主要的非辐射衰变机制：通过邻近羟基配合物和二氧化硅基质的振动激发失活，以及孔隙表面聚集的RE离子之间的能量转移。本项目将探索新的合成技术，包括在起始溶液中使用干燥控制化学剂，以减少荧光猝灭。RE离子将被用作结构参数（如孔隙连通性）的光谱探针，以帮助确定最小化RE-羟基相互作用的最有效方法。此外，研究RE离子之间的能量传递将用于探索RE离子在多孔溶胶-凝胶基质中的分布如何与合成方案相关。通过在玻璃中实现更均匀的RE离子分布，这些测量对于优化这些材料的光学性能至关重要。我们的目标是更深入地了解RE离子的荧光行为，从而为上面列出的应用开发出一类新的更高效的荧光材料。我们在材料科学方面的创新研究项目涉及戴维森学院、汉密尔顿学院和惠特曼学院三所本科文理学院的教师和学生之间的合作。这笔拨款提供的新设备将扩大每个实验室进行基于时间和连续波光谱的独特能力。本科生将参与这个跨学科项目的各个方面，并将受益于在不同参与学院使用最先进设备进行研究的更多机会。概要：本奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。溶胶-凝胶材料在令人惊讶的广泛领域有着有趣的用途——从飞机涂层到生物活性酶的宿主。溶胶-凝胶玻璃工艺使用现成的起始材料和相对较低的温度来生产具有与传统熔融工艺制造的玻璃相当的光学性能的玻璃。创造在诸如荧光粉照明、激光、光学传感器、光纤和光子器件等应用中潜在有用的新型光学材料是我们努力的重点。我们在材料科学方面的创新研究项目涉及戴维森学院、汉密尔顿学院和惠特曼学院三所本科文理学院的教师和学生之间的合作。通过利用我们各自实验室的优势，我们将继续在理解玻璃中荧光稀土离子吸收、转移和释放能量的方式方面取得重大进展。本科生参与这项研究过程的所有阶段，从拨款写作到实验设计和实施，再到在评审期刊上发表论文和在专业会议上发表演讲。事实上，我们最近的两名学生的研究获得了国家认可。这笔拨款提供的新设备将极大地扩展每个实验室的独特能力，以检查这些材料中稀土离子发出的光的时间演变和能量分布。在现有合作的基础上，越来越多的学生将获得更多不同的机会，在使用最先进的设备的同时探索最前沿的科学思想。我们的科学目标是更深入地了解RE离子之间的相互作用，以及RE离子与其玻璃宿主之间的相互作用，从而开发出可用于光学应用的新型更高效的荧光材料。

0959552BoyeDavidson CollegeTechnical Summary: This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Sol-gel derived glass containing fluorescing rare earth (RE) ions are potentially useful in applications such as lasers, optical sensors, and fiber optic and photonic devices. However, the optical behavior of RE-doped sol-gel glasses is not yet fully understood. The work proposed here will use optical spectroscopy to answer fundamental questions about the ways that sol-gel glass structure influences RE fluorescence yield. Two primary non-radiative decay mechanisms have been identified: deactivation through vibrational excitation of neighboring hydroxyl complexes and the silica matrix, and energy transfer among clustered RE ions on pore surfaces. This project will explore new synthesis techniques, including the use of drying control chemical agents in the starting solutions, to reduce fluorescence quenching. RE ions will be used as spectroscopic probes of structural parameters such as pore connectivity to aid in identifying the most effective methods for minimizing the RE-hydroxyl interactions. In addition, studies of energy transfer among RE ions will be used to explore how RE ion distribution in the porous sol-gel matrix correlates with synthesis protocols. These measurements will be crucial in optimizing the optical performance of these materials by achieving a more uniform distribution of RE ions in the glass. The goal is to obtain a deeper understanding of the fluorescence behavior of the RE ions, leading to a new class of more efficient fluorescent materials for the applications listed above. Our innovative research program in materials science involves collaboration between faculty and students at three undergraduate liberal arts colleges - Davidson, Hamilton, and Whitman Colleges. The new equipment provided by this grant will expand each laboratory's unique ability to perform time-based and cw spectroscopies. Undergraduate students will be involved in every aspect of this cross-disciplinary project and will benefit from increased opportunities to perform research with state-of-the-art equipment at the different participating colleges.Layman Summary: This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Sol-gel materials have interesting uses in a surprisingly broad range of disciplines - from coatings on aircraft to hosts for biologically active enzymes. The sol-gel glass process uses readily available starting materials and relatively low temperatures to produce glasses with optical behavior comparable to glasses made by the traditional melt process. Creating new optical materials that are potentially useful in applications such as phosphor lighting, lasers, optical sensors, and fiber optic and photonic devices is the focus of our efforts. Our innovative research program in materials science involves collaboration between faculty and students at three undergraduate liberal arts colleges - Davidson, Hamilton, and Whitman Colleges. By leveraging the strengths of our individual laboratories, we will continue to make significant progress in understanding the ways that energy is absorbed, transferred and released by fluorescing Rare Earth (RE) ions in the glass. Undergraduate students are involved at all stages of this research process from grant writing to experimental design and implementation and on to publication in refereed journals and presentations at professional meetings. In fact, two of our recent students have received national recognition for their research. The new equipment provided by this grant will greatly expand each laboratory's unique ability to examine the time evolution and energy distribution of light emitted by RE ions in these materials. Building on the existing synergy of our collaboration, an increased number of students will be provided with more varied opportunities to explore cutting edge scientific ideas while working with state-of-the-art equipment. Our scientific goals are to obtain a deeper understanding of the interaction among RE ions, and between RE ions and their glass host, leading to a new class of more efficient fluorescent materials available for optical applications.