Modeling the Fabrication of Functional Polymeric Materials by Spinodal Decomposition

该拟议的研究计划是申请人正在进行的研究的一部分，该研究通过数学建模和计算机模拟在聚合物溶液和共混物中进行相分离（旋节分解）。 相分离的聚合物溶液和共混物的应用发现于：（1）用于分离过程的聚合物膜，（2）用于电光器件和智能窗的聚合物分散液晶膜，（3）用于需要上级机械性能的目的的工程聚合物复合材料，和（4）聚合物微电子电路和抗蚀剂。 这个拟议的研究计划的总体目标是发展的形态演变的聚合物溶液和共混物进行相分离（spinodal分解），以制造功能性聚合物材料的基本理解。 本研究提案的具体目标是：（1）模拟、模拟和表征在温度和浓度梯度存在下经历表面诱导相分离的聚合物溶液和共混物的形态，（2）模拟、模拟和表征经历顺序淬火进入相图的亚稳和不稳定区域的聚合物溶液和共混物的形态，以及（3）对在温度和浓度梯度存在下经历压力诱导相分离的聚合物溶液和共混物的形态进行建模、模拟和表征。 温度和浓度梯度通常发生在聚合物溶液和共混物加工过程中，以制造功能性聚合物材料。该模型将包括相分离的Cahn-Hilliard理论和聚合物热力学的Flory-Huggins-de Gennes理论。 该模型将使用有限差分法和伽辽金有限元法求解。 数值结果将使用科学可视化软件进行处理，以便模型和数值结果可以与已发表的实验结果进行验证。 将通过计算结构因子并结合数字图像分析使用科学可视化来表征形态学。

This proposed research program is part of the ongoing research that the applicant is pursuing on phase separation (spinodal decomposition) in polymer solutions and blends through mathematical modeling and computer simulation. Applications of phase separated polymer solutions and blends are found in: (1) polymeric membranes for separation processes, (2) polymer dispersed liquid crystal films for electro-optical devices and smart windows, (3) engineering polymer composite materials for purposes that require superior mechanical properties, and (4) polymeric microelectronic circuits and resists. The overall objective of this proposed research program is to develop a fundamental understanding of the morphological evolution of polymer solutions and blends undergoing phase separation (spinodal decomposition) to fabricate functional polymeric materials. The specific objectives are of this research proposal: (1) to model, simulate and characterize the morphology of polymer solutions and blends undergoing surface-induced phase separation in the presence of temperature and concentration gradients, (2) to model, simulate and characterize the morphology of polymer solutions and blends undergoing sequential quenching into the metastable and unstable regions of the phase diagram, and (3) to model, simulate and characterize the morphology of polymer solutions and blends undergoing pressure-induced phase separation in the presence of temperature and concentration gradients. Temperature and concentration gradients typically occur during polymer solutions and blends processing to fabricate functional polymeric materials.******The model will consist of the Cahn-Hilliard theory for phase separation and Flory-Huggins-de Gennes theory for polymer thermodynamics. The model will be solved using the finite difference and Galerkin finite element methods. The numerical results will be processed using scientific visualization software so that the models and numerical results can be validated with published experimental results. The morphology will be characterized by computing the structure factor and using scientific visualization in conjunction with digital image analysis.