Colloidal membranes and assembly of heterogeneous 2D materials

非技术：两亲分子由亲水和亲油成分组成，它们彼此永久相连，因此阻碍了大块分离。当将这些分子加入水中时，它们会自组装成膜，这是一种具有非凡性能的柔韧薄板，在生物学、物理学和材料科学中起着至关重要的作用。人们普遍认为，两亲分子的拮抗性质是膜组装的基本要求。在这个提议中，PI将研究一种完全不同的方法来组装胶体基膜状材料。这种新型胶体膜的组装是在化学上均匀的丝状病毒和聚合物的简单混合物中进行的，丝状病毒具有台球的形状，而聚合物则类似于台球。除了对所有类膜材料的普遍特性提供基本见解外，研究结果还将描述一种新的、易于扩展的方法，将棒状纳米颗粒组装成新型纳米结构，这种纳米结构可以作为高效的光伏器件。PI的研究和教育计划通过他们共同强调可视化技术和跨学科的科学方法无缝地结合在一起。具体而言，PI将继续在现有的成功合作的基础上与探索博物馆在行动，以组织两年一次的博物馆参观，亲身演示光学显微镜和材料科学的各种概念。PI还将通过参加科学博览会、组织班级参观、接待学生到他的实验室等方式，扩大与当地中小学的联系。最后，PI将继续为本科生提供从事研究项目的机会，并将继续建立现有的地方和国家联系，以招收在STEM领域代表性不足的群体的学生。技术：胶体膜是由一棒状的厚的液体状单层排列棒组成的，通过包围聚合物溶液的渗透压将其结合在一起。本提案的目标是阐明支配胶体膜组装过程的基本规律，并将胶体膜作为新一代空间异质、形状变化功能材料工程的基础。PI将首先使用胶体膜作为一个强大的平台，用于组装定义良好的介观团簇和具有预定异质性的宏观二维材料。与此同时，PI将设计新的方法来测量胶体膜的机械性能，并利用这些知识来设计形状变化的3D材料。胶体膜本身就很有趣，因为它们为在微米尺度上组织复杂的二维材料提供了独特的机会。此外，尽管在分子尺度上不同，胶体单层和脂质双层的连续变形可以用相同的自由能表达式来描述。因此，它们提供了一个独特的机会来深入了解主要由系统的基本对称性决定的通用膜过程。

Non-technical: Amphiphilic molecules consist of water loving and oil loving components that are permanently linked to each other, thus frustrating bulk separation. When added to water these molecules self-assemble into membranes, thin flexible sheets with remarkable properties that play an essential role in biology, physics, and material science. It is commonly believed that the antagonistic nature of the amphiphilic molecules is an essential requirement for membrane assembly. In this proposal PI will study a fundamentally different method for assembly of colloidal based membrane-like materials. Assembly of the novel colloidal membranes takes place in a simple mixture of chemically homogeneous filamentous viruses, which have the shape of billiard cues, and polymers, which resemble billiard balls. Besides providing fundamental insight into universal aspects of all membrane-like materials, results will also describe a new and easily scalable process for assembly of rod-like nanoparticles into novel nanostructures that could act as efficient photovoltaic devices. The PI's research and education plans are seamlessly joined together through their mutual emphasis on visualization techniques and an interdisciplinary approach to science. Specifically, the PI will continue to build upon existing successful collaborations with The Discovery Museum in Action, in order to organize biannual visits to the museum for hands-on demonstrations of various concepts in optical microscopy and materials science. The PI will also extend connections with the local elementary and middle schools by participating in Science Fairs, by organizing class visits, and hosting students in his laboratory. Finally, the PI will continue to provide opportunities to undergraduate students to pursue research projects and will continue to build upon existing local and national connections in order to recruit students form groups that are underrepresented in STEM fields.Technical: Colloidal membranes are comprised from a one-rod-length thick liquid-like monolayer of aligned rods that is held together by the osmotic pressure of the enveloping polymer solution. The goal of this proposal is to elucidate the fundamental laws that govern the assembly processes of colloidal membranes and to use colloidal membranes as a basis for engineering of a new generation of spatially heterogeneous, shape-changing functional materials. The PI will first use colloidal membranes as a robust platform for assembly of well-defined mesoscopic clusters and macroscopic 2D materials with predetermined heterogeneities. In parallel, the PI will devise new methods to measure the mechanical properties of colloidal membranes, and use this knowledge to engineer shape-changing 3D materials. Colloidal membranes are interesting in their own right as they offer a unique opportunity to organize complex 2D materials on micron scales. Furthermore, although distinct on molecular scales, the continuum deformations of colloidal monolayers and lipid bilayers are described by the same free energy expressions. Thus they provide a unique opportunity to gain insight into universal membrane processes that are mainly determined by the fundamental symmetries of the system.