Colloidal membranes and assembly of heterogeneous 2D materials

胶体膜和异质二维材料的组装

• 批准号: 1609742
• 负责人: Zvonimir Dogic
• 金额: $ 42万
• 依托单位: Brandeis University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2017-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1609742&HistoricalAwards=false
• 关键词: Colloidal; membranes; assembly; heterogeneous; 2D

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.

非技术性：两亲分子由亲水和亲油的成分组成，它们彼此永久连接，从而阻碍了大量分离。当加入水中时，这些分子自组装成膜，具有显着特性的薄柔性片，在生物学，物理学和材料科学中发挥着重要作用。 通常认为，两亲分子的拮抗性质是膜组装的基本要求。在本提案中，PI将研究一种根本不同的方法，用于组装基于胶体的膜状材料。新型胶体膜的组装发生在化学上均质的丝状病毒和聚合物的简单混合物中，丝状病毒具有台球杆的形状，聚合物类似于台球。除了提供对所有膜状材料的通用方面的基本见解外，结果还将描述一种新的且易于扩展的过程，用于将棒状纳米颗粒组装成可用作高效光伏器件的新型纳米结构。PI的研究和教育计划通过相互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将继续与The Discovery Museum in Action建立现有的成功合作关系，以便组织一年两次的博物馆参观活动，亲自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，组织班级参观和在他的实验室接待学生来扩大与当地小学和中学的联系。最后，PI将继续提供机会，本科生追求的研究项目，并将继续建立在现有的地方和国家的连接，以招收学生的形式在STEM领域代表性不足的团体。技术：胶体膜是由一个一杆长的厚液体状单层的对齐杆，是由包围聚合物溶液的渗透压保持在一起。该提案的目标是阐明控制胶体膜组装过程的基本定律，并使用胶体膜作为新一代空间异质性，形状变化功能材料的工程基础。PI将首先使用胶体膜作为一个强大的平台，用于组装定义明确的介观簇和具有预定异质性的宏观2D材料。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，因为它们提供了在微米尺度上组织复杂2D材料的独特机会。此外，虽然不同的分子尺度上，胶体单层和脂质双层的连续变形所描述的相同的自由能表达式。因此，它们提供了一个独特的机会，以深入了解主要由系统的基本对称性决定的普遍膜过程。