Integrated Self & Directed Assembly of Multi-Component Colloidal Structures

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。本研究的目的是开发集成的自定向组装机制，将多组分胶体系统稳稳地组装成更有序和多样化的结构。在之前的研究中，我们已经证明了在未组装的胶体流体中相互作用、动力学和微观结构之间的定量联系，以及作为独立自组装（即胶体自我组装）和定向组装（即外场组装胶体）的一部分。在此基础上，与推进胶体组装相关的问题包括：(1)如何设计工艺以最小化有序结构中的缺陷(2)如何利用胶体组分获得更大的结构多样性（和材料特性）为了解决这些问题，本研究旨在通过整合单组分胶体系统、二元胶体系统以及单组分和二元胶体颗粒链折叠中的自组装机制和定向组装机制，系统地扩展我们目前对胶体组装的理解。为了澄清，二元是指具有不同电位的物质，包括不同大小的胶体，但更一般地指物质A和B具有不同的AA， BB和AB相互作用的任何体系。建议研究的具体目标和相关任务包括：(1)（目标1）通过（任务1）使用基于可调耗尽电位和电场介导的偶极相互作用的kt级致动器建设性地集成2D和3D自定向组装过程，实现前所未有的、可靠的有序、无缺陷的单组分胶体结构的生产；(2)（目标）通过（任务）识别可调的AA、BB、AB电位允许在二元系统中实现可逆的自我和定向组装机制，并且(3)（目标）将这些发现扩展到折叠成2D和3D结构的胶体链上，通过（任务）制造单组分和二元胶体链，通过在非均匀电场中可调的链内吸引力和/或压缩而通过冷凝折叠，从而产生一类新的材料和一种新的微尺度组装机制。提出的研究的意义是基于它的努力，了解如何最好地控制热力学和动力学的胶体组装过程中，利用自和定向组装机制的最佳方面。有了在单组分系统中操纵胶体组装的基本基础，提出的研究还旨在扩展当前的技术状态，以实现更多样化的微观结构和相关材料特性。由于胶体组分可以直接进行实际空间和实时测量，因此拟议的研究还应该为自我和定向组装过程的化学物理提供更广泛的基本见解，而这些过程在较小的长度尺度上无法进行实验。所提出的研究的智力价值在于，通过使用耦合显微镜测量和严格模型直接测量、建模和操纵这些系统的能力，将获得对多组分胶体自我和定向组装的基本理解。这样的理解将使胶体组装过程的定量设计、控制和优化（正式工程）成为可能，并提供超越从试验和错误发现中已经知道的新见解。所提出的研究可以被描述为变革性的，基于其预期的新方法来控制缺陷和扩大微尺度结构的多样性，这些结构可以用作周期性元材料，并通过可调的相互作用和序列连接来操纵。拟议研究计划的广泛影响将源于在各种课堂、实验室、外展和传播活动中使用丰富的视觉数据，包括实验（如图像、视频）、模拟（如效果图、动画）和分析（如动态、多维情节）。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). 0932973BevanThis proposal is concerned with developing integrated self and directed assembly mechanisms to robustly assemble multi component colloidal systems into more ordered and diverse structures. In prior research, we have demonstrated quantitative connections between interactions, dynamics, and microstructure in unassembled colloidal fluids and as part of independent self-assembly (i.e. colloids assembling themselves) and directed assembly (i.e. external fields assembling colloids). With this foundation, questions related to advancing colloidal assembly include: (1) how can processes be designed to minimize defects in ordered structures (2) how can greater structural diversity (and material properties) be accessed using colloidal components To address these questions, the proposed research aims to systematically extend our current understanding of colloidal assembly by integrating self and directed assembly mechanisms in single component colloidal systems, binary colloidal systems, and in the folding of chains of single and binary colloidal particles. For clarification, binary refers to species with different potentials, which includes different sized colloids, but is intended to refer more generally to any system where species A and B have different AA, BB, and AB interactions.Specific objectives and associated tasks in the proposed research include: (1) (objective1) achieve unprecedented, reliable production of ordered, defect free single component colloidal structures, by (task1) constructively integrating 2D and 3D self and directed assembly processes using kT-scale actuators based on tunable depletion potentials and electric field mediated dipolar interactions, (2) (objective) adapt these approaches to develop new capabilities to assemble binary particle systems into atomic analogues, by (task) identifying tunable AA, BB, AB potentials that allow for implementation of reversible self and directed assembly mechanisms in binary systems, and (3) (objective) extend these findings to colloidal chains that fold into 2D and 3D structures to produce a new class of materials and a new micro scale assembly mechanism, by (task) fabricating single component and binary colloidal chains that fold via condensation due to tunable intra chain attraction and/or compression in inhomogeneous electric fields. The significance of the proposed research is based on its effort to understand how to best control the thermodynamics and kinetics of colloidal assembly processes by exploiting the best aspects of self and directed assembly mechanisms. With a fundamental basis for manipulating colloidal assembly in single component systems, the proposed research also aims to extend the current state of the art for realizing more diverse microstructures and associated material properties. Because colloidal components are amenable to direct real space and real time measurements, the proposed research should also provide broader fundamental insights into the chemical physics of self and directed assembly processes that are not accessible to experiments at smaller length scales. The intellectual merit of the proposed research lies in the fundamental understanding that will be gained of multi component colloidal self and directed assembly through the ability to directly measure, model, and manipulate such systems using coupled microscopy measurements and rigorous models. Such understanding should enable quantitative design, control, and optimization (formal engineering) of colloidal assembly processes and provide new insights beyond what is already known from trial and error discovery. The proposed research can be characterized as transformative based on its anticipated identification of new ways to control defects and to expand the diversity of micro scale structures that can be used as periodic meta materials and manipulated via tunable interactions and sequenced connectivity.The broader impacts of the proposed research plan will result from employing rich visual data from experiments (e.g. images, videos), simulations (e.g. renderings, animations), and analyses (e.g. dynamic, multi-dimensional plots) in various classroom, laboratory, outreach, and dissemination activities.