Acquisition of Fluorescence Lifetime and Transient Fluores- cense Equipment

这笔研究设备赠款用于购买荧光寿命和瞬时荧光设备，主要供托克尔森和刘易斯两位合作PI以及西北大学的其他研究人员使用。Torkelson的研究是将荧光和磷光技术应用于研究与聚合物科学和工程有关的基本问题：聚合物溶液中的扩散限制相互作用，聚合物共混物和嵌段共聚体系中溶液和体态的相分离，聚合物玻璃中局部自由体积的分布及其对物理老化的敏感性，以及均聚和嵌段共聚体系中的聚合物-聚合物互穿、互扩散和相关性。刘易斯的研究重点是研究通过电子执行的络合物发生的反应，这些络合物被用来确定激基络合物和自由基离子对在环加成和质子转移等对有机光化学至关重要的反应中的作用。该仪器计划近期的用途包括：研究聚合物溶液中的扩散限制相互作用，这可能有助于更好地理解自由基聚合中的凝胶效应；研究嵌段共聚物溶液中的相分离现象和增容现象，与均聚物共混，以及在本体状态下；均聚物、嵌段共聚物和聚合物共混物中的分子间关联；获得无定形聚合物体系中的局部自由体积分布；确定聚合物焊接现象中的扩散模式(聚合物-聚合物界面上的互扩散)；聚合物体系的基本光物理表征；准分子和激基络合物动力学研究；以及Lewis酸络合物激发态的研究。

This research equipment grant is for the purchase of fluorescence lifetime and transient fluorescence equipment to be used primarily by the two co-PIs Torkelson and Lewis as well as other researchers at Northwestern. Torkelson's research is the application of fluorescence and phosphorescence techniques in the study of basic issues elated to polymer science and engineering: diffusion-limited interaction in polymer solutions, phase separation in polymer blends and in block copolymer systems in solution and the bulk state, the distribution of local free volume and its sensitivity to physical aging in polymer glasses, and polymer-polymer interpenetration, interdiffusion, and correlations in homopolymer and block copolymer systems. The focus of Lewis' research is the investigation of reactions which occur via electronically executed complexes which are used to establish the role of exciplexes and radical ion pairs in reactions of fundamental importance to organic photochemistry such as cycloaddition and proton transfer. Near term uses planned for the instrumentation include: the study of diffusion-limited interactions in polymer solutions which may lead to a better understanding of the gel effect in free radical polymerization; investigation of phase separation phenomena and compatibilization in block copolymers solutions, blend with homopolymers, and in the bulk state; intermolecular correlations in homopolymers, block copolymers and polymer blends; obtaining local free volume distribution in amorphous polymer systems; determination of the mode of diffusion in polymer welding phenomena (interdiffusion across a polymer-polymer interface); characterization of the basic photophysics of polymer systems; excimer and exciplex kinetics studies; and investigations of excited state of Lewis acid complexes.