Controlling the Microstructure of Materials Using Processing Flows

CTS-9421015 Julia Kornfield将对流体动力作用下的聚合物材料的结构进行实验研究，并将其应用于具有工程宏观性能的材料的设计和加工。第二，选择了具有本征各向异性结构的模型聚合物材料、嵌段共聚物和侧基液晶。分子和微观结构的流动诱导的排列将作为宏观应力和应变的函数在不同的长度尺度上进行测量。P.I.开发的一系列机械、光学和核磁共振技术将用于监测聚合物熔体在连续和振荡剪切运动过程中的结构演变。预计研究结果将指导聚合物的选择和相应的加工步骤，以实现所需的微观结构取向和宏观性能。该项目结合了与工业相关的聚合物材料和设备的基础实验和新想法。在聚合物中使用流动诱导微结构，以及利用应力在两种状态之间切换聚合物的结构和相关性质方面提出了创新的想法。***

ABSTRACT CTS-9421015 Julia Kornfield The structure of polymeric materials under the effect of hydrodynamical forces will be experimentally investigated, with application to designing and processing materials with engineered macroscopic properties. Two, model polymeric materials with intrinsically anisotropic structures have been selected as model materials, block copolymers and side-group liquid crystals. Molecular and microstructural flow-induced alignments will be measured as a function of macroscopic stress and strain during floe, at different length scales. A series of mechanical, optical and Nuclear magnetic Resonance (NMR) techniques developed by the P.I. will be used to monitor the structural evolution of polymer melts during continuous and oscillatory shear motion. It is expected that the results of the research will guide the polymer selection and the corresponding processing steps require to achieved a desired microstructural alignment and macroscopic properties. The project combines fundamental experiments and new ideas for industrially relevant polymeric materials and devices. Innovative ideas are proposed concerning the use of flow induced microstructures in polymers, and use of stress to switch the structure and related properties of a polymer between two states. ***