Conformations and Dynamics of Polymers at Interfaces

小行星9316157 最近，几个研究小组已经证明，由于大的熵与限制长的聚合物分子在界面上，经典的润湿理论开发的简单的液体不适用。 为了更好地了解聚合物薄膜的润湿性能，我们采用了各种互补技术（西姆斯，反射率，TEM和AFM）进行三重计划。 1)液体聚合物薄膜的润湿特性：我们正在探索链尺寸对薄膜稳定性，表面扩散，玻璃化转变，粗糙表面润湿和总密度的作用。 目前正在发展对平均场理论的修正，以包括新的实验现象。 2)通过末端官能化聚合物的表面改性：末端接枝聚合物的构象正在稳态剪切下的熔体和溶液中进行研究。 电刷的面内结构正在研究中，并与理论模拟进行比较。 3)三嵌段共聚物的表面诱导有序化：三嵌段共聚物具有形成表面诱导胶束凝胶膜的独特能力。 我们正在研究的渗透和润湿的均聚物膜在这些凝胶表面上的两个组件的相对分子量和相互作用能与排序表面的函数。 已知非常薄的聚合物膜具有多种应用，例如润滑剂、用于光学和电子部件的涂层以及粘合剂。 为了使这些膜有效，它们必须润湿它们所铺展的表面或渗透通过界面以提供粘合强度。 ***

9316157 Rafailovich Recently, several research groups have demonstrated that due to the large entropy associated with confining long polymer molecules at interfaces, the classical wetting theories developed for simple liquids do not apply. I order to obtain a better understanding of the wetting properties of polymer films we are employing a variety of complementary techniques (SIMS, reflectivity, TEM, and AFM) to conduct an three-fold program. 1) Wetting properties of thin liquid polymer films: We are exploring the role of the chain dimensions on the film stability, surface diffusion, glass transition, wetting of rough surfaces, and total density. Modification of mean-field theories to include new experimental phenomena are being developed. 2) Surface modification via end- functionalized polymers: The conformations of end-grafted polymers are being studied both in melts and solutions under steady-state shear. The in-plane structure of brushes is being studied and compared with theoretical simulations. 3) Surface induced ordering of triblock copolymers: Triblock copolymers have the unique ability to form surface-induced micelle gel films. We are studying the penetration and wetting of homopolymer films on these gel surfaces as a function of the relative molecular weights of the two components and the interaction energies with the ordering surface. Very thin polymer films are known to have a large variety of applications such as lubricants, coatings for optical and electronic components, and adhesives. In order for these films to be effective, they must wet the surfaces upon which they are spread or penetrate through the interfaces to provide adhesive strength. ***