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Investigations on the dynamics of polyelectrolyte multilayers by spinlabeling and EPR spectroscopy

自旋标记和 EPR 光谱研究聚电解质多层膜的动力学

基本信息

批准号：
347223722
负责人：
Dr. Uwe Lappan
金额：
--
依托单位：
Leibniz-Institut für Polymerforschung Dresden (IPF)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/347223722?language=en
关键词：
Investigations dynamics polyelectrolyte multilayers spinlabeling

项目摘要

Subject of the project are polyelectrolyte multilayers that can be prepared by alternating adsorption of polyanions and polycations using the Layer-by-layer technique on various substrates. It is a general and broadly applicable technique that enables manufacturing numerous different tailored structures. Polyelectrolyte multilayers find increasing attention in the targeted modification of surfaces and membranes. Various aspects, such as the growth mechanism, the internal structure of the layers as well as the dynamics are of fundamental interest for practical applications. While many details of the structures are known, there is much less knowledge for no less important dynamics of polymers in the multilayers. The aim of the project is to gain new insights into the mobility of chain segments of polyelectrolytes in multilayers and to show correlations between the internal structure and dynamics in these multilayers and resulting properties. In order to achieve this goal polyelectrolyte molecules are equipped with spin labels and incorporated in a defined manner in the PEM. The EPR spectroscopy offer the potential to study the rotational diffusion of the spin label linked to the macromolecule and to gain quantitative information about the mobility of polymer segments, which are complemented by NMR data,which are sensitive to longer time scales. The experimental investigations aim at the relationships between the chemical structure of the polyelectrolytes used, the conditions at the preparation of the PEM and the parameters of the surrounding medium (ionic strength, pH) and the mobility of polymer segments in different zones of the multilayer. The internal dynamics of the polyelectrolytes in the multilayers has an influence on the transport in the multilayer and through the multilayer when it is used as a membrane. The correlation of the temperature dependence of the polymer dynamics and the diffusion of small guest molecules results in insights in the mechanism of transport.

该项目的主题是可通过在各种基底上使用逐层技术交替吸附聚阴离子和聚阳离子来制备的多层膜。它是一种通用且广泛适用的技术，能够制造许多不同的定制结构。聚电解质多层膜在表面和膜的有针对性的改性中越来越受到关注。各个方面，如生长机制，层的内部结构以及动力学是实际应用的基本兴趣。虽然结构的许多细节是已知的，但对于多层膜中聚合物的重要动力学的知识要少得多。该项目的目的是获得新的见解的多层膜中的聚电解质的链段的流动性，并显示在这些多层膜的内部结构和动力学之间的相关性和由此产生的性能。为了实现这一目标，将自旋标记物配备到分子中，并以确定的方式将其掺入PEM中。EPR光谱提供了研究与大分子连接的自旋标记的旋转扩散的潜力，并获得有关聚合物链段的流动性的定量信息，这些信息由NMR数据补充，NMR数据对较长的时间尺度敏感。实验研究的目的是在所使用的聚电解质的化学结构之间的关系，在制备的PEM和周围介质的参数（离子强度，pH值）和聚合物链段在多层的不同区域的流动性的条件。当用作膜时，多层膜中聚电解质的内部动力学对多层膜中的传输和通过多层膜的传输有影响。聚合物动力学的温度依赖性和小客体分子的扩散的相关性导致在运输机制的见解。