Spectroscopic Studies on Photophysical and Photochemical Processes in Associated Water-soluble Polymers

相关水溶性聚合物中光物理和光化学过程的光谱研究

基本信息

批准号：
04640474
负责人：
NAKASHIMA Kenichi
金额：
$ 1.22万
依托单位：
Saga University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1993
项目状态：
已结题

项目摘要

Block copolymers has been known to form micelles (polymer micelles) in a solvent selective for one of the blocks. Many investigations have been performed on the micelles because they have a variety of properties different from conventional detergent micelles. This study has been undertaken to reveal the characteristics of polymer micelles as a reaction field for photophysical and photochemical processes such as energy transfer. The block copolymers employed are Pluronic F68 (EO_<78>PO_<30>EO_<78>) and Pluronic L64 (EO_<13>PO_<30>EO_<13>). The results obtained are as follows :1.Electronic energy transfer from rhodamine B (donor) to malachite green (acceptor) are examined. The energy transfer is drastically suppressed as the micelles are formed. The decrease of energy transfer is ascribed to that the increase of microviscosity upon micellization dominates other factors such as concentration effect.2.The structures of Pluronic micelles are investigated by the use of rhodamine B and octadecylrhodamine B as fluorescent probes. It is revealed that the micelles undergo a large conformational change from a swollen to a shrunken structure as temperature is increased and that the critical micelle concentrations (CMC's) of the Pluronics are strongly depend on temperature in contrast to those of conventional detergents. Microviscosities of the Pluronic micelles are estimated from the degree of polarization and the fluorescence lifetimes. The CMC's of the Pluronics are also determined.

已知块共聚物在其中一个块中的溶剂选择性中形成胶束（聚合物胶束）。已经对胶束进行了许多研究，因为它们具有与常规洗涤剂胶束不同的多种特性。这项研究已进行了揭示聚合物胶束作为光学和光化学过程（例如能量转移）的反应场的特征。所使用的块共聚物是Pluronic F68（EO_ <78> PO_ <30> eo_ <78>）和Pluronic L64（EO_ <13> po_ po_ <30> eo_ <13>）。获得的结果如下：1。检查从若丹明B（供体）到孔雀石绿（受体）的电子能量转移。当形成胶束时，能量转移会大大抑制。能量转移的降低归因于胶束化时微度粘度的增加占主导地位，例如浓度效应。2。通过使用Rhodamine b和Octadecylrhodamine B作为荧光探针，研究了pluronic胶束的结构。据显示，随着温度升高，胶束从肿胀到缩小的结构发生了巨大的构象变化，而多元学的临界胶束浓度（CMC）与常规洗涤剂相比，强烈取决于温度。从极化程度和荧光寿命估算出型胶束的微度疗法。还确定了pluronics的CMC。