Intermolecular Structure and Dynamics in Multicomponent Glasses

结合光谱学、理论和聚合物科学，在玻璃化转变温度以下研究了聚合物基玻璃的结构和动力学。这种方法在物理化学和材料科学的界面上运作，利用分子信息来解释观察到的体性质。核磁共振，这项研究中使用的工具，探测化学基团水平上的结构和运动，然后与多组分玻璃的宏观或大块材料性质有关。这些非晶材料的局部分子间结构是通过碳-13自旋扩散实验确定的，而分子的取向是通过自旋弛豫和线形实验监测的。核磁共振实验和仪器的快速发展继续为固体研究提供新的途径，这将提供几年前无法达到的洞察力水平。开发了定量解释模型，将光谱数据与机械和热响应以及与塑化和渗透率等技术相关的材料行为联系起来。特殊的多组分玻璃，聚碳酸酯及其混合物，由于其有趣和重要的材料特性而被选择进行研究。解释的努力也与理论的发展联系在一起。使用晶格模型来解释聚合物稀释剂的结构和动力学以及吸附气体的流动性就是一个很好的例子。模拟和建模用于协助开发物理上合理的解释模型。

Structure and dynamics of polymer-based glasses are studied below the glass-transition temperature with a combination of spectroscopy, theory, and polymer science. This approach operates at the interface of physical chemistry and material science to utilize molecular information to account for observed bulk properties. Nuclear magnetic resonance, the tool utilized in this investigation, probes structure and motion at the level of chemical groups which is then related to the macroscopic or bulk material properties of the multicomponent glasses. Local intermolecular structure in these amorphous materials is determined by carbon-13 spin diffusion experiments, while molecular reorientation is monitored with spin relaxation and line shape experiments. Rapid development of NMR experiments and instrumentation continues to offer new avenues for the study of solids which will provide a level of insight not attainable a few years ago. Quantitative interpretational models are developed which link the spectroscopic data to mechanical and thermal response as well as such technologically relevant materials behaviour as plasticization and permeability. The particular multicomponent glasses, polycarbonates and their mixtures, are selected for study as the result of their interesting and important materials properties. The interpretational efforts are also tied to the development of theory. The use of lattice models to interpret polymer-diluent structure and dynamics as well as mobilityof sorbed gas is a case in point. Simulation and modeling are used to assist in the development of physically sensible interpretational models.