Shape and Deformation of Colloidal Membranes

胶体膜的形状和变形

基本信息

批准号：
2020098
负责人：
Thomas Powers
金额：
$ 38.35万
依托单位：
Brown University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-01 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2020098&HistoricalAwards=false
关键词：
Shape Deformation Colloidal Membranes

项目摘要

This grant will support the development of the theoretical framework for the design and control of colloidal membranes. Colloidal membranes are made of filamentous viruses and held together by osmotic forces from polymers in solution. Like cell membranes, colloidal membranes self-assemble; in other words, these membranes form spontaneously from a solution of just the right concentration of rod-like viruses and polymers. Although colloidal membranes resist bending like a solid plate, they also flow like a liquid. Unlike an orange peel, a colloidal membrane shaped like a spherical cap can conform to a flat surface without tearing because the material can redistribute by flowing. Likewise, holes can heal because the material flows. Self-assembly and the ability to easily reconfigure make colloidal membranes attractive for developing artificial micron-scale materials with life-like properties. The focus of this grant is to mathematically model the shape-changing processes using tools from applied mathematics, mechanical engineering, and physics. This grant will support the scientific training of undergraduate and graduate students. The investigators will mentor undergraduates from historically underrepresented groups in engineering and physical science through the Leadership Alliance Summer Research Early Identification Program. Soft matter topics related to this work will be integrated into undergraduate and graduate courses in engineering and physics. Graduate students will receive training in presentation and communication skills, and develop YouTube videos explaining soft matter topics to the general public.The specific goal of this research is to apply continuum mechanics techniques to the study of colloidal membranes composed of mixtures of long and short rods in the presence of polymers which hold the rods together via the depletion force. Previous efforts have focused on flat membranes or membrane ribbons composed of a single kind of rod. Membranes consisting of a mixture of rods typically display a rich variety of complex three-dimensional shapes, and the emerging evidence is that many of these shapes are neither minimal surfaces nor constant mean curvature shapes. The shapes can be tuned by controlling experimental conditions such as polymer depletant concentration, and the theory the team will develop will quantitatively determine how shape depends on experimental conditions. The particular aims are to (1) determine how the Gaussian curvature modulus depends on the concentration of short rods as well as the concentration of depleting polymers, (2) determine the conditions that lead to tilting of the constituent rods of the membrane away from the normal to the mid-surface in the bulk of the membrane, and (3) develop a Monte Carlo technique that incorporates the rod degrees of freedom together with the shape degrees of freedom.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.

该赠款将支持为胶体膜设计和控制的理论框架的发展。胶体膜由丝状病毒制成，并由溶液中聚合物的渗透力组合在一起。像细胞膜一样，胶体膜自组装；换句话说，这些膜是从纯棒状病毒和聚合物浓度的溶液中自发形成的。尽管胶体膜像实心板一样抵抗弯曲，但它们也像液体一样流动。与橙皮不同，形状像球形帽的胶体膜可以符合平坦的表面而不会撕裂，因为材料可以通过流动而重新分配。同样，孔可以治愈，因为材料流动。自组装和轻松重新配置的能力使胶体膜对于开发具有真人般特性的人工微分尺度材料有吸引力。该赠款的重点是使用应用数学，机械工程和物理学的工具在数学上对变化的过程进行建模。该赠款将支持本科生和研究生的科学培训。研究人员将通过领导力联盟夏季研究早期身份证明计划指导从历史上代表性不足的工程和物理科学领域的本科生。与这项工作相关的软件主题将集成到工程和物理学的本科和研究生课程中。研究生将接受演讲和沟通技巧的培训，并开发YouTube视频向公众解释软件主题。这项研究的具体目标是将连续力学技术应用于研究胶体膜的研究，该胶体由长杆和短杆组成的混合物组成，这些混合物由聚合物的存在，这些聚合物的存在，这些聚合物的存在，这些聚合物通过消耗量将杆固定在一起。以前的努力集中在平坦的膜或膜缎带上，该膜由一种杆组成。由棒组成的膜通常显示出丰富的复杂三维形状，而新兴的证据是，许多这些形状既不是最小的表面，也不是恒定的平均曲率形状。可以通过控制聚合物消耗浓度等实验条件来调整形状，并且团队将开发的理论将定量确定形状如何依赖于实验条件。 The particular aims are to (1) determine how the Gaussian curvature modulus depends on the concentration of short rods as well as the concentration of depleting polymers, (2) determine the conditions that lead to tilting of the constituent rods of the membrane away from the normal to the mid-surface in the bulk of the membrane, and (3) develop a Monte Carlo technique that incorporates the rod degrees of freedom together with the shape自由度。该奖项反映了NSF的法定使命，并被认为是值得通过基金会的知识分子优点和更广泛影响的评论标准来评估值得支持的。