Presidential Young Investigator Award

这项研究的目的是了解分子的作用， 和微观结构动力学来决定宏观的 聚合物的材料特性。 在聚合物的情况下， 液体，他们结合实验和理论 方法，以提高我们预测他们的能力， 流变性能 由于这些问题的复杂性， 液体，并为了获得适当的信息进行测试 理论，有必要观察个人的动态 多组分系统中的组分，并遵循特定模式 对宏观变形的反应。 访问 这种程度的信息，这项研究将发展 结合光谱和流变学方法来研究 嵌段共聚物的有序-无序转变， 混溶聚合物熔体中的刚性杆的取向顺序 流动下的聚合物液晶。 分子运动在固体聚合物中起着重要作用， 一方面是流动性的开始， 对于可混溶聚合物的宽玻璃化转变特性， 共混体系 因此，将固态氘原子核 磁共振来观察分子运动的速率， 共混物的每种组分单独地作为以下的函数 温度通过玻璃化转变。 这些观察结果 将为我们提供新的视角， 玻璃化转变的温度和宽度。

The goal of this research is to understand the role of molecular and microstructural dynamics in determing the macroscopic material properties of polymers. In the case of polymeric liquids, they are combining experimental and theoretical approaches in order to advance our ability to predict their rheological properties. Due to the complex nature of these fluids, and in order to obtain appropriate information to test theory, it is necessary to observe the dynamics of individual components in multicomponent systems and to follow specific modes of relaxation in response to macroscopic deformation. To access this level of information, this research will be developing combined spectroscopic and rheometric methods to study the order-disorder transition in block copolymers, the rheology of miscible polymer melts, and the orientational order of rigid-rod polymer liquid crystals under flow. Molecular motions play an important role in solid polymers as well, and one aspect is the onset of mobility that is responsible for the broad glass transition characteristic of miscible polymer blends. Therefore, will be used solid-state deuterium nuclear magnetic resonance to observe the rate of molecular motion in each component of the blend individually as a function of temperature through the glass transition. These observations will give new insight into the factors that determine the temperature and breadth of the glass transition.