Steady State and Lifetime Fluorescence Spectrophotometer

麻省理工学院化学工程系拟购买一台SPEX fluorologic -t2荧光光谱仪，用于工程研究。该仪器将用于环境、生物和材料领域的若干研究项目，以探测系统中不同微域所提供的微环境，例如：(i)嵌段共聚物胶束和树状星形聚合物用作分离和反应的增溶介质；（ii）为色谱和传感器应用量身定制的自组装有机表面；（iii）用于药物合成反应的新型溶剂，包括超临界流体介质；（iv）用于光催化的胶体纳米晶体；(v)化学修饰的荧光；（六）作为细胞表面受体配体与聚合物结合的蛋白质。利用稳态和时间分辨荧光和去极化，可以获得微极性、微粘度、探针旋转和过渡运动的限制以及特异性和非特异性溶剂化效应的信息。探针在不同微域（如胶束、薄膜、蛋白质活性层、无机吸附剂）之间交换的动力学将被量化，微域（如胶束）的大小将被确定。这些结果将有助于设计微异构系统的应用范围考虑。

ABSTRACT T. Alan Hatton MIT CTS-9500227 The Department of Chemical Engineering at the Massachusetts Institute of Technology intends to purchase a SPEX Fluorolog-t2 Fluorescence Spectrometer which will be dedicated to support research in engineering. This instrument will be used for several research projects in the environmental, biological and materials areas to probe the microenvironments afforded by different microdomains in systems such as: (i) Block copolymer micelles and dendritic star polymers to be used as solubilization media for separations and reactions; (ii) tailored self-assembled organic surfaces for chromatographic and sensor applications; (iii) novel solvents for pharmaceutical synthesis reactions, including supercritical fluid media; (iv) colloidal nanocrystals for photocatalytic applications; (v) chemically-modified fluoresces; and (vi) proteins tethered to polymers as ligands for cell-surface receptors. Information on micropolarities, mocroviscosities, restrictions on rotational and transitional motion of probes, and specific and non-specific solvation effects can be obtained using steady state and time-resolved fluorescence and depolarization. Dynamics of exchange of probes between different microdomins (e.g., micelles, thin films, protein active sties, inorganic adsorbates) will be quantified, and the sizes of microdomains such as micelles determined. These results will be useful in the design of microheterogeneous systems for the range of application considered.