Structure induced changes of the optical properties of metallo-supramolecular polyelectrolytes incorporated into a polymer matrix

在这个项目中，将从结构-性能关系的角度来探索一类新的力学响应性聚合物复合材料。复合材料的组成包括金属超分子聚电解质(MEPEs)和聚合物。MEPE充当机械响应功能单元，而聚合物则定义复合材料的粘弹性性质。这些复合材料的力学响应效应假设是基于这样的假设，即机械力会引起MEPE配位环境的变化，从而导致颜色的变化。该项目的第一个目标是合成在机械变形时显示颜色变化的特定复合材料。第二个目标是详细研究颜色变化的机制，并验证上述假说。中心金属离子的配位环境将通过拉曼光谱、X射线荧光和X射线吸收光谱等光谱方法来表征，作为组成和机械变形的函数。荧光基团的整合使得即使在低浓度下也可以通过荧光光谱分析MEPE中的微小变化。通过明智地选择配体、金属离子和反离子，MEPEs很容易被修饰，以便调整与聚合物基质的相互作用以及由此产生的机械变色响应。

In this project a new class of mechano-responsive polymer composites shall be explored in terms of their structure-property relationships. The components of the composites are based on metallo-supramolecular polelectrolytes (MEPEs) and on polymers. The MEPE acts as the mechano-responsive functional unit, while the polymer defines the viscoelastic properties of the composite. The hypothesis of the mechano-responsive effect in these composites is based on the assumption that a mechanical force will induce a change in the coordination environment of the MEPE thus resulting in a color-change. The first goal of the project is to synthesize defined composites that show a color change upon mechanical deformation. The second goal is to study the mechanism of the color change in detail and to verify the above-mentioned hypothesis. The coordination environment of the central metal ions will be characterized by spectroscopic methods such Raman-, X-ray fluorescence, and X-ray absorption-spectroscopy as function of composition and mechanical deformation. Integration of fluorescent groups allows analysis of small changes in the MEPE even at low concentrations by fluorescence spectroscopy. By the judicious choice of the ligands, metal ions and counter ions the MEPEs are readily modified in order to tune the interaction with the polymer matrix as well as the resulting mechano-chromic response.