CAREER: In- and Out-of-Equilibrium Behavior of Colloidal Clusters with Broken Symmetries

职业：对称性破缺的胶体团簇的平衡态和非平衡态行为

• 批准号: 1454095
• 负责人: Ning Wu
• 金额: $ 54.84万
• 依托单位: Colorado School of Mines
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1454095&HistoricalAwards=false
• 关键词: CAREER; Out; Equilibrium; Behavior; Colloidal

Colloidal dispersions play an important role in materials processing for industries ranging from electronics to pharmaceuticals. When colloidal particles are organized into arrays and other structures, the resulting materials can exhibit optical and electrical properties that are not found in natural materials. Therefore, colloids serve as building blocks for fabricating advanced functional materials. This project will develop new approaches to make clusters of colloidal particles with well-controlled compositions and geometries, which will expand the range of materials that can be fabricated. The project will investigate how external fields can be used to manipulate the assembly of particles into clusters and ultimately into large ensembles. Results from the project will provide fundamental knowledge that scientists and engineers can use to develop materials and devices, such as new sensors or new coatings with controlled optical properties. In addition, the project team will develop a summer research program in colloidal science targeted to high school students in the Denver area and especially to students from underrepresented groups. A multi-disciplinary course titled "Engineering of Soft Materials" will be developed to engage undergraduate students in colloidal science and train them for careers in the materials industry. New approaches will be developed to make clusters of colloids with well-controlled broken symmetries. A microfluidic device that integrates both electric (for assembly) and optical fields (for structural cross-linking) will be used to fabricate monodisperse higher order colloidal clusters with addressable compositions and geometries. The asymmetric properties of colloidal clusters will be systematically studied within the context of particle propulsion, which constitutes a significant step toward understanding the transport properties of active colloids. A virtually patterned electrode will be used to generate micro-gradients in electric field and direct particles into periodic structures with addressable symmetry at both cluster and lattice levels. The coupled optical effects between neighboring clusters and the feasibility for making functional coatings will also be explored. The overall goal of the project is to understand how the broken-symmetry in colloidal clusters affects their in- and out-of-equilibrium behavior from the level of an individual particle to a large ensemble.

胶体分散剂在从电子到药物的行业的材料加工中起重要作用。当将胶体颗粒组织成阵列和其他结构时，所得材料可以在天然材料中表现出光学和电性能。因此，胶体是制造高级功能材料的基础。该项目将开发新的方法，以使胶体颗粒簇具有控制良好的组成和几何形状，从而扩大可以制造的材料范围。 该项目将研究如何使用外部场来操纵粒子的组装成簇，并最终分成大型合奏。 该项目的结果将提供基本知识，科学家和工程师可以用来开发具有控制光学性能的新传感器或新涂料等材料和设备。 此外，项目团队将制定针对丹佛地区高中学生，尤其是代表人数不足的学生的胶体科学研究计划。 将开发一门名为“软材料工程”的多学科课程，以吸引本科生从事胶体科学，并培训他们从事材料行业的职业。 将开发新的方法来制造具有良好控制的破碎对称性的胶体簇。一种集成电气（用于组装）和光场（用于结构交联）的微流体设备将用于制造具有可寻址组成和几何形状的高级胶体簇。胶体簇的不对称特性将在颗粒推进的背景下进行系统地研究，这构成了理解活性胶体的运输特性的重要步骤。几乎具有图案的电极将用于在电场中生成微梯度，并将颗粒引导到具有可寻址对称性的周期性结构，并在群集和晶格水平下。还将探索相邻簇和制造功能涂层的可行性之间的耦合光学效应。该项目的总体目标是了解胶体簇中的断裂对称性如何影响其从单个粒子到大合奏水平的平衡行为。

项目成果

Reconfigurable microbots folded from simple colloidal chains

• DOI: 10.1073/pnas.2007255117
• 发表时间: 2020-07
• 期刊: Proceedings of the National Academy of Sciences
• 作者: Tao Yang;Brennan Sprinkle;Yang Guo;Jun Qian;D. Hua;A. Donev;D. Marr;Ning Wu