Influence of Polymer-Solid Contacts on Chain Order and Dynamics Probed by Advanced NMR Spectroscopy

先进的固体核磁共振提供了关于聚合物在整体、固体界面和纳米复合材料界面中的构象、链序和动力学的独特信息。最近的发展，如1H-1H-或1H-13C-双量子核磁共振，以及对13C化学位移各向异性、2H四极耦合或核Overhauser效应（NOE）的研究，为研究高选择性系统中的延伸链构象及其动力学提供了充分的机会，这也在优先计划的其他项目中进行了研究。用核磁共振自旋扩散法探测改变后聚合物行为的空间扩展。重点将放在聚（丁二烯）聚（n-烷基甲基丙烯酸酯）、聚（n-烷基丙烯酸酯）和聚（苯乙烯）上，它们最近被证明具有不同的倾向，可以形成扩展链构象和纳米结构。在与亚微米颗粒的无机氧化物如SiO2或TiO2的混合物中，我们将研究局部结构和动力学如何受到表面存在的影响，以及这如何改变复合材料的性能。为了使界面最大化，固体将以纳米颗粒的形式引入，有或没有聚合物本身的短链修饰。核磁共振研究将在优先计划的合作下进行，通过x射线散射、光谱学、介电和机械松弛以及最后但并非最不重要的计算机模拟来研究相同的系统。

Advanced solid state NMR provides unique information about the conformation, chain order and dynamics of polymers in bulk, at the interface to solids and in the interphase in nanocomposites. Recent developments such as 1H-1H- or 1H-13C- double quantum NMR together with studies of 13C chemical shift anisotropy, 2H quadrupole coupling, or the Nuclear Overhauser Effect (NOE) offer ample opportunities to investigate extended chain conformations and their dynamics in systems with high selectivity, which are also studied in other projects of the Priority Programme. The spatial extension of the altered polymer behaviour will be probed by NMR spin diffusion. The focus will be on poly(butadiene) poly(n-alkylmethacrylates), poly(n-alkylacrylates), and poly(styrene), which have recently been shown to exhibit different tendencies to form extended chain conformations and nanostructures in bulk. In mixtures with sub-micron particles of inorganic oxides such as SiO2 or TiO2 we will study how the local structure and dynamics is influenced by the presence of the surface and how this changes the properties of the composites. In order to maximize the interface, the solids will be introduced as nanoparticles, with and without decoration by short chains of the polymers themselves. The NMR studies will performed in collaborations within the Priority Programme studying the same systems by X-ray scattering, optical spectroscopy, dielectric and mechanical relaxation and last, but not least computer simulation.