Polymer Dynamics on Surfaces and in Complex Media

9711226 Yu所提出的研究是针对水，聚合物覆盖的玻璃和硅晶片的表面上的链动力学，以调查限制的几何形状对链运动的影响。 此外，兴趣集中在高度相互作用的系统中的链扩散，其中扩散剂是已知的影响整个系统的流变学，即使当它们作为次要组分存在时。 通过光漂白后表面荧光恢复的界面动态技术、表面准电光散射、通过管道流的面内稳态剪切粘度，结合原子力显微镜、X射线光子光谱、中子反射率和光谱椭圆偏振仪的界面静态技术，PI将检查1）功能化玻璃表面上的扩散，2）在空气/水界面处的聚合物单层剪切粘度和扩张粘弹性，3）作为膜厚度的函数的聚合物扩散，和4）在由表面活性剂分子的极性头部组成的平坦表面上的微扩散。 拟议研究的目的是提出更好的材料设计方法，涵盖广泛的先进有机材料，用于许多不同的应用，如人工器官和植入物，所有溢出限制材料，药物输送设备和润滑剂。 这项研究是在分子水平上。 ***

9711226 Yu The proposed research is directed at the chain dynamics on surfaces of water, polymer covered glasses and silicon wafers in order to investigate the influence of confined geometries on the chain motions. In addition, interest is focused on the chain diffusion in highly interacting systems wherein the diffusants are known to impact on rheology of the entire system even when they are present as minor components. With the interfacial dynamic techniques of surface fluorescence recovery after photobleaching, surface quasielectric light scattering, in-plane steady shear viscosity by canal flow, in conjunction with the interfacial static techniques of atomic force microscopy, x-ray photon spectroscopy, neutron reflectivity and spectroscopic elllipsometry, the PI will examine 1) polyelectrolyte diffusion on functionalized glass surfaces, 2) polymer monolayer shear viscosity and dilational viscoelasticity at the air/water interface, 3) polymer diffusion as a function of film thickness, and 4) polyelectrolyte diffusion on planar surfaces consisting of polar heads of surfactant molecules. %%% The purposes of the proposed research are to come up with better materials design methods covering a wide range of advanced organic materials that are used in many different applications such as in artificial organs and implants, all spill confinement materials, drug delivery devices, and lubricants. This study is at the molecular level. ***