Mechanical Control of Polymer Morphology and Properties: Theory and Simulation

9709101 Balazs这是一项理论研究资助，旨在研究作用力对聚合物薄膜和共混物的影响，以便制造定制的界面和高强度材料。为此，将开发理论模型和计算机模拟，以纳入外力；确定这些力如何影响形态；并将形态与宏观特性相关联。在聚合物薄膜的研究中，重点将放在固定在固体表面上的聚合物链上。这种聚合物涂层表面之间的相互作用负责稳定胶体溶液并减少界面之间的摩擦。为了模拟这一机械压缩、拉伸或变形受限聚合物层的问题，将使用二维自洽场计算和标度理论。这些结果将为制造光学器件提供指导，如双稳开关、在木材和纸制品生产中至关重要的絮凝剂，以及具有定制性能的层状复合材料。在聚合物共混物的研究中，重点将放在“现成”聚合物的混合上。作为一种以相对较低的成本创造新材料的手段，这一过程具有相当大的前景。然而，聚合物共混物的实际制造带来了巨大的挑战。大多数聚合物是不相容的，相分离成宏观区域。剪切和流动可以产生更细小的分散体，从而改善机械性能。这项研究拨款将使用理论模型和计算机模拟来研究各种力对聚合物性能的影响。特别是，研究将研究聚合物薄膜，如用于涂料的聚合物薄膜，以及聚合物共混物(混合聚合物)。这些研究处于聚合物科学和工程研究的前沿，除了具有重大的基础性意义和重大的理论挑战外，还有可能直接影响新材料的设计和生产。***

9709101 Balazs This is a theoretical research grant to study the effects of applied forces on polymer films and blends in order to fabricate tailored interfaces and high-strength materials. To do this, theoretical models and computer simulations will be developed to incorporate external forces; determine how these forces affect morphology; and, to correlate morphology to macroscopic properties. In the study of polymer films, the focus will be on polymer chains tethered to solid surfaces. The interactions between such polymer-coated surfaces are responsible for stabilizing colloidal solutions and reducing friction between interfaces. To model this problem of mechanically compressing, stretching or deforming confined polymer layers, two-dimensional self-consistent field calculations and scaling theory will be used. The results will provide guidelines for fabricating optical devices, such as bistable switches, flocculating agents, which are important in the production of wood and paper products, and layered composites with tailored properties. In the study of polymer blends, the focus will be on the mixing of "off-the-shelf" polymers. This process holds considerable promise as a means of creating new materials at relatively low cost. The actual fabrication of polymer blends, however, poses significant challenges. Most polymers are immiscible and phase separate into macroscopic domains. Shear and flow can produce finer dispersements which improve mechanical properties. %%% This research grant will use theoretical models and computer simulations to study the impact of various forces on the properties of polymers. In particular, the research will study polymer films, such as are used for coatings, and polymer blends (mixed polymers). These studies are at the forefront of research in polymer science and engineering, Besides being of great fundamental interest, and a significant theoretical challenge, the research has the potential to directly affect th e design and production of new materials. ***