Collaborative Research: Structure-Mechanics Relationships for Ultra-thin Block Copolymer Films

第1部分：非技术性总结这个合作项目汇集了马萨诸塞大学阿默斯特大学和宾夕法尼亚大学的科学家，以获得新的理解，即当聚合物材料制成厚度接近单个分子大小的薄膜时，机械性能，如硬度和强度是如何变化的。超薄膜，如本项目中研究的薄膜，希望有助于降低过滤等过程中的能源消耗，以及半导体制造中的能耗。然而，目前的材料不能在这些应用中提供足够的强度。新的实验方法将与分子模拟相结合，以了解聚合物薄膜中的结构如何在这些高度受限的状态下影响其性能。除了与开发新的基础科学和材料设计指南相关的广泛影响外，该项目将通过包括实验和模拟在内的丰富、协作的研究经验为博士生、本科生和高中生的教育提供新的机会。第2部分：技术总结本合作项目将提供关于嵌段共聚物域结构在控制超薄聚合物薄膜的全部机械响应中的作用的新的基础数据和知识，其中薄膜厚度相当于或小于域结构尺寸。该方法结合了先进的模拟和新颖的实验方法的优点，基于受限材料中的位置对链段迁移率和链间纠缠的作用以及由此对力学性能的影响来测试新的假设。在实验上，一种最新的力学测量方法，称为超薄薄膜单轴拉伸测试仪(TUTTUT)，将被用于量化超薄嵌段共聚物膜的力学性能。实验将与使用粗粒模型来预测聚合物膜的分子响应的模拟相结合，并且模拟将提供作为远离嵌段共聚物膜中界面的位置的函数的纠缠网络和局部动力学的局部图像。通过这些努力，联合PIS将支持下一代材料科学家和工程师的教育、培训和灵感，重点是增加女性和传统上代表性不足的少数民族的参与。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

PART 1: NON-TECHNICAL SUMMARYThis collaborative project brings together scientists at the University of Massachusetts Amherst and the University of Pennsylvania to gain new understanding of how mechanical properties, like stiffness and strength, change when a polymeric material is made into a film with thickness near the size of an individual molecule. Ultra-thin films, such as the ones studied in this project, are desired to help decrease energy consumption in processes like filtration, as well as in semiconductor manufacturing. However, current materials are unable to provide sufficient strength in these applications. New experimental methods will be combined with molecular simulations to understand how structures in the polymer thin films affect their properties in these highly confined states. Beyond the broad impact related to the development of new fundamental science and materials-design guidelines that will decrease materials waste and increase energy efficiency, this project will provide new opportunities for educating Ph.D. students, undergraduate students, and high-school students through rich, collaborative research experiences involving both experiments and simulations.PART 2: TECHNICAL SUMMARYThis collaborative project will provide new fundamental data and knowledge on the role of block copolymer domain structure in controlling the full mechanical response of ultra-thin polymer films, where film thickness is comparable to or smaller than the domain structure size scale. The proposed approach unites the strengths of advanced simulations and novel experimental methods to test new hypotheses based on the role of position within a confined material on segmental mobility and inter-chain entanglements, and the consequential impact on mechanical properties. Experimentally, a recent mechanical measurement method, called The Uniaxial Tensile Tester for Ultra-Thin films (TUTTUT), will be used to quantify the mechanics of ultra-thin block copolymer films. The experiments will integrate with simulations that use coarse-grained models to predict the molecular response of polymer films, and the simulations will provide a local picture of the changes in the entanglement network and local dynamics as a function of position away from the interfaces in the block copolymer films. Through these efforts, the co-PIs will support the education, training, and inspiration of the next generation of materials scientists and engineers, with a focus toward increased participation of women and traditionally under-represented minorities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.