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Direct Observation of Polymer Chains in Solutions

直接观察溶液中的聚合物链

基本信息

批准号：
08455454
负责人：
ISODA Seiji
金额：
$ 4.29万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08455454/
关键词：
Low Temperature Quick Freezing Polymer Solution High-Resolution 高分子鎖

项目摘要

We have investigated polymerization and chemical reactions in thin solid films and many new findings on the reactions have been obtained. However, chemical spices are reacted usually in solutions, so that it is desirable to observe chemical reactions in solutions by molecularly resolved imaging. In order to observe directly the chemical reactions in solutions, this project was aimed to provide a new technique to observe organic molecules like polymer molecules in solutions. Since polymers are long in shape, it is expected to be easy and convenient to observe their images by electron microscopy.Though present transmission electron microscope has ability to resolve molecules or even atoms in materials, the specimen should be kept in vacuum. Then, molecules in solution could not be observed as they are in solution by conventional electron microscope. In this study, the specimen was frozen and observed with a cryo-electron microscope. The solution was quickly frozen by plunging it into liquid propane at 100K and observed with a cryo-transmission electron microscope with a specially designed cryotransfer system. The frozen specimen was observed at about 4K so as not to change the structure in solution during the microscopic observation.The chemical polymerization of pyrrole with a ionic polymer was investigated as an application of the technique. The polymerization process to form spherical polypyrrole particles was observed from micelle formation of ionic polymer to the final spherical product in water solution. The other example is the fine metal particles with some surfactants in water solution. As a result, the metal particles were found to be formed arbitrary places, but they are encapsulated with the surfactants. Accordingly they are dispersed as fine nano-particles in solution. The metal formation process was imaged step-by-step by freezing the solution.

我们对固体薄膜中的聚合反应和化学反应进行了研究，得到了许多新的发现。然而，化学香料通常在溶液中反应，因此希望通过分子分辨成像来观察溶液中的化学反应。为了直接观察溶液中的化学反应，该项目旨在提供一种新的技术来观察溶液中的有机分子，如聚合物分子。由于聚合物的形状较长，人们期望用电子显微镜观察其图像时能方便快捷，虽然目前的透射电子显微镜已能分辨材料中的分子甚至原子，但样品必须保持在真空中。然后，溶液中的分子不能像在溶液中那样通过常规电子显微镜观察到。在这项研究中，标本冷冻和冷冻电镜观察。通过将溶液在100K下浸入液体丙烷中快速冷冻，并用具有专门设计的冷冻转移系统的冷冻透射电子显微镜观察。为了在显微镜下观察时不改变溶液中的结构，在4K左右对冷冻样品进行了观察。作为该技术的应用，研究了吡咯与离子聚合物的化学聚合。观察了在水溶液中从离子聚合物形成胶束到最终形成球形产物的聚合过程。另一个例子是金属微粒与某些表面活性剂的水溶液。结果，发现金属颗粒在任意位置形成，但它们被表面活性剂包封。因此，它们在溶液中分散为细小的纳米颗粒。通过冷冻溶液，逐步成像金属形成过程。