Elucidating Grain Boundary Complexion Transitions and their Role on Grain Growth in Granular Block Copolymer Microstructures

非技术性SUMMARY嵌段共聚物是能够自组织成功能纳米结构的材料，在从净水膜到下一代锂离子电池再到高性能聚合物光伏等应用中具有技术相关性。嵌段共聚聚合物纳米结构中的缺陷阻碍了这些技术的实现，这些缺陷在自组织过程中形成，降低了材料的性能。该项目的目标是建立一种变革性的新工艺来控制和减少嵌段共聚物纳米结构中的缺陷数量。这将促进可扩展和经济的材料制造工艺的发展，使材料的性能得到改善。该计划将支持一门新的聚合物材料实验室课程的教学，并为一名研究生和几名本科生研究人员提供培训。将利用与少数群体服务机构的教育工作者正在进行的合作来支持少数群体学生的参与。最后，基于触觉人机交互的新型教育技术作为一种吸引和吸引初中生学习科学和工程的手段的潜力将被确立。技术总结降低缺陷密度的大颗粒微结构的制造是嵌段共聚物(BCP)材料在广泛的创新材料技术中应用的先决条件。因此，了解退火过程中的晶粒生长机制和缺陷结构的演变是一个对BCP基材料的科学和工程都具有重要意义的课题。该项目的目的是阐明BCP/均聚物共混物中填料-基质相互作用对颗粒粗化的作用，并检验晶界络合转变--即分离到晶界界面的填料相内的转变--增加了颗粒生长的驱动压力，从而增加了颗粒粗化的速度。在第一部分中，该计划将集中于建立BCP/均聚物共混体系中的相容范围和(平衡)微区形成，在该体系中，均聚物与主体共聚物域形成LCST共混物。在第二部分，该项目将专注于建立填料/基质相互作用对静止有序薄膜中晶界界面能量的影响。如果成功，该项目将为开发低缺陷密度BCP材料的新加工策略提供基础，这种材料利用设计的填料添加剂对颗粒粗化的“催化”作用，有效地将BCP组织成所需的大颗粒微结构。该计划将加强“软材料微结构与性能”新课程的教学，并在聚合物和纳米材料的关键领域为一名研究生和几名本科生研究人员提供培训。最后，对动觉实验在高分子与材料科学教学中的效益进行了评价。

NON-TECHNICAL SUMMARYBlock copolymers are materials that are capable of self-organizing into functional nanostructures that are of technological relevance in applications ranging from membranes for water purification to next-generation lithium ion batteries to high-performance polymer photovoltaics. The realization of these technologies is hindered by defects in block copolymer nanostructures that form during the self-organization process and that reduce the properties of materials. The goal of this project is to establish a transformative new process to control and reduce the number of defects in block copolymer nanostructures. This will promote the development of scalable and economic fabrication processes for materials with improved properties. The program will support the teaching of a new laboratory course on polymer materials and provide training for one graduate student and several undergraduate student researchers. Ongoing collaborations with educators at minority serving institutions will be leveraged to support the participation of minority students. Finally, the potential of novel educational technologies based on 'haptic human-computer interactions' as a means to engage and attract middle and high school students to the study of science and engineering will be established. TECHNICAL SUMMARYThe fabrication of large-grained microstructures with reduced defect densities presents a prerequisite to the application of block copolymer (BCP) materials across a wide range of innovative material technologies. Understanding of the mechanism of grain growth and the evolution of defect structures during the annealing process is therefore a subject that is of fundamental relevance to both the science and engineering of BCP-based materials. The objective of this project is to elucidate the role of filler-matrix interactions on grain coarsening in miscible BCP/homopolymer blends and to test the hypothesis that grain boundary complexion transitions -- i.e. transitions within the phase of filler that is segregated to grain boundary interfaces -- increase the driving pressure for grain growth and hence the rate of grain coarsening. In a first part, the program will be focused on establishing the miscibility range and (equilibrium) microdomain formation in BCP/homopolymer blends systems in which the homopolymer forms a LCST blend with the host copolymer domain. In a second part, the project will focus on establishing the effect of filler/matrix interactions on the energy of grain boundary interfaces in quiescent organized films. If successful, this project will provide a basis for the development of novel processing strategies towards low defect-density BCP materials that harness the 'catalytic' effect of designed filler additives on grain coarsening to efficiently organize BCPs into desired large-grained microstructures. The program will enhance the teaching of a new class on "Soft Material Microstructure and Properties" and provide training for one graduate and several undergraduate researchers in the critical area of polymer and nanoscale materials. Finally, the benefits of kinesthetic experiments to the teaching of polymer and material science will be evaluated.