Presidential Young Investigator Award

本研究的目的是了解分子和微观结构动力学在确定聚合物宏观材料特性中的作用。在聚合物液体的情况下，他们正在结合实验和理论方法，以提高我们预测其流变性能的能力。由于这些流体的复杂性，为了获得适当的信息来验证理论，有必要观察多组分系统中单个组分的动力学，并遵循宏观变形响应的特定松弛模式。为了获得这一水平的信息，本研究将开发结合光谱和流变学的方法来研究嵌段共聚物的有序-无序转变，混相聚合物熔体的流变学，以及刚性棒聚合物液晶在流动状态下的取向顺序。分子运动在固体聚合物中也起着重要的作用，其中一个方面是迁移率的开始，它负责可混溶聚合物共混物的广泛玻璃化转变特性。因此，将利用固态氘核磁共振来观察共混物中各组分分子运动速率单独作为温度通过玻璃化转变的函数。这些观察结果将对决定玻璃化转变温度和宽度的因素提供新的见解。

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.