Controlled Crumpling of Polymer Thin Films and Nanocomposites

聚合物薄膜的物理性质对于许多技术的发展至关重要，从替代能源到？聪明吗镀层. 在薄膜制度，个别分子的大小尺度是相称的膜？因此，定义材料性质的分子间和分子内机制受到表面性质的影响。 聚合物科学界最近的努力集中在限制对性能的影响，如玻璃化转变温度和弹性模量，但相对较少的是已知的几何限制对非线性变形相关的性能的影响。 拟议的研究将使用新的方法来折叠和起皱薄聚合物薄膜，同时量化这些非线性力学中涉及的能量聚焦和应变局部化过程。 具体的研究计划包括三个主要的努力：1）折叠和起皱的均匀，薄的聚合物膜; 2）折叠和起皱的纳米结构的聚合物膜;和3）表征起皱的表面特性。这些努力将区别于最近的研究与分子尺度的厚度，并结合褶皱力学与预图案化的基板的性能，以控制长程有序的褶皱片形态的研究薄膜的褶皱。此外，折叠的能量聚焦过程将用于组装纳米级组件，包括定制的无机纳米颗粒。通过这项研究获得的折叠和起皱的基本知识不仅将提供对分子长度尺度下材料特性的深入了解，而且还将导致控制聚合物薄膜形态和结构的先进概念，以用于先进的应用。非技术总结拟议的研究集中在开发新的方法来折叠和起皱超薄聚合物薄膜，这是只有几个分子厚。 这项研究的结果将产生广泛的影响，从提供分子组装如何在纳米长度尺度上响应机械应力的新知识，到在未来的应用中开发用于图案化表面的强大策略，例如替代能源技术。 除了该计划资助的研究外，研究团队还将推出一项创新计划，让来自不同背景的高中生参与科学研究的创造性方面。 该计划，材料挑战竞赛（MCC），将建立在现有的程序，是常见的本科工程学科（例如太阳能动力车的竞争），从西部马萨诸塞州地区的高中团队之间发起材料竞争。 该计划的实施将为马萨诸塞州西部的学生和公众提供机会，使他们认识到材料研究在应对当前技术挑战方面的重要性。

TECHNICAL SUMMARYThe physical properties of thin polymer films are critical for the development of numerous technologies, ranging from alternative energy sources to ?smart? coatings. In the thin film regime, the size scale of individual molecules is commensurate with the film?s thickness; therefore, the inter-molecular and intra-molecular mechanisms that define a material property are influenced by surface properties. Recent efforts in the polymer scientific community have focused on the impact of confinement on properties such as the glass transition temperature and elastic modulus, but relatively little is known on the impact of geometric confinement on properties related to non-linear deformation. The proposed research will use novel methods to fold and crumple thin polymer films, while quantifying the energy focusing and strain localizing processes involved in these non-linear mechanics. The specific research plan includes three primary efforts: 1) the folding and crumpling of homogenous, thin polymer films; 2) the folding and crumpling of nanostructured polymer films; and 3) the characterization of crumpled surface properties. These efforts will be distinguished from recent research on crumpling by studying films with molecular-scale thickness and combining crumpling mechanics with the properties of pre-patterned substrates to control long-range order in crumpled sheet morphologies. Additionally, the energy focusing processes of folding will be used to assemble nanoscale components, including tailored inorganic nanoparticles. The fundamental knowledge of folding and crumpling gained through this research not only will provide insight into materials properties at molecular length scales, but also will lead to advanced concepts for controlling the morphology and structure of thin polymer films for advanced applications. NON-TECHNICAL SUMMARYThe proposed research is focused on developing novel methods to fold and crumple ultra-thin polymer films, which are only a few molecules thick. The results of this research will have broad impact, from providing new knowledge of how molecular assemblies respond to mechanical stress at the nanometer length scale to developing robust strategies for patterning surfaces in future applications, such as alternative energy source technologies. In addition to the research funded by this program, the research team will introduce an innovative program to involve high school students from diverse backgrounds in the creative aspects of scientific research. This program, the Materials Challenges Competition (MCC), will build upon existing programs that are common in undergraduate engineering disciplines (e.g. the solar powered vehicle competition) to initiate a materials competition among high school teams from the Western Massachusetts region. The implementation of this program will provide opportunities for students and the general public in Western Massachusetts to realize the importance of materials research in answering current technological challenges.