Understanding and engineering geometrically frustrated self-assembly

理解和设计几何受阻的自组装

• 批准号: 2349818
• 负责人: Gregory Grason
• 金额: $ 49.66万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-06-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2349818&HistoricalAwards=false
• 关键词: Understanding; engineering; geometrically; frustrated; self; Understanding; engineering; geometrically; frustrated; self

NONTECHNICAL SUMMARYThis award supports theoretical research, computation, and associated education to investigate self-assembly. Self-assembly is a process by which nanometer-scale “building blocks” spontaneously associate into multi-unit structures, which underlies structure formation of a vast range of useful materials structures in the biological and synthetic world. This project aims to advance our basic understanding of an emerging “class” of such systems, known as geometrically-frustrated assemblies (GFAs). Geometric-frustration occurs when the shape and interaction between building-blocks lead to “misfitting” arrangements when they aggregate. Such frustrated building blocks are not unlike warped puzzle pieces that fit neatly together edge to edge, but whose shape misfit requires more and more straining to piece together larger and larger patches of the puzzle. In the assemblies of these nanoscale “misfits” – composed of polymers, proteins, or colloidal particles – frustration can give rise to new mechanisms for the assembly process to “sense its size”, which are not possible in assemblies without shape misfit. The buildup of shape misfit in GFAs is related to a unique behavior known as self-limiting assembly, in which the self-assembly process can autonomously and robustly terminate at a finite number of building blocks, which itself may be predetermined based on properties of the sub-unit shape, interactions and flexibility. As such, GFAs pose a potential pathway to engineer new types of self-assembling systems, whose finite sizes can be “programmed” from the design and synthesis of building block properties. Realizing the ability to engineer the self-limiting size of material assemblies through programmed frustration may reveal potentially transformative, bottom-up pathways to fabricate functional nanostructured material architectures, such as injectable biomedical scaffolds or paintable photonic coatings, with the complexity and size control that is currently only accessible via top-down techniques like 3D printing or lithography.Capitalizing on this potential requires an understanding of the basic principles that connect the properties of nanoscale, frustrated building blocks (e.g. their shape misfit, interactions, flexibility) as well as the impacts of various types of disorder on the emergent structures they form on size scales much bigger than those subunits. This project will develop theoretical frameworks that address this core objective and facilitate the translations of theoretical principles to experimental study of synthetic and biological systems.Beyond potential impacts on materials science deriving from advancing the principles of GFA, the project will achieve several additional broader impacts. These include the training and mentorship of students (undergraduate and graduate) and a postdoctoral researcher in statistical and computational approaches to materials physics, as well as efforts of the PI to advance participation of K12 student populations from under-resourced communities in graduate student-led STEM outreach and education.TECHNICAL SUMMARYThis award supports theoretical research, computation, and associated education to investigate Geometrically-frustrated assembly (GFA). GFA is an emerging paradigm in which the local misfits between soft matter “building blocks” give rise to intra-domain stress gradients on size scales that far exceed the block dimensions. The accumulation of long-range stresses in GFA underlies a range of scale-dependent behaviors without counterpart in canonical assemblies without frustration, including the existence of a self-limiting state where the equilibrium assembly dimensions are finite, yet much larger than subunits themselves. Recent efforts aim to capitalize on this phenomenon as a means to program the mesoscopic size and morphology of self-assembled structures through the engineered misfit of synthetic building blocks, fabricated for example through state-of-the-art colloidal synthesis or DNA nanotechnology approaches. Meeting this challenge requires predictive understanding that traces microscopic features of GFA – misfit shape, interactions, and deformability – onto the finite-temperature assembly behavior that emerges at the mesoscale. Research in this project will address three critical gaps in the theoretical understanding of and engineering principles for GFA: I) the statistical physics of frustration escape to bulk assembly via both elastic (shape-flattening) and inelastic (defect-mediated) modes; II) the ability to extend the propagation of self-limiting stress by engineering floppy modes in frustrated assembly; and III) the behaviors of mixed and polydisperse frustration assemblies. The proposed aims to advance a range of modeling approaches to capture the intrinsically multiscale nature of GFA behavior. Scientific impacts of this research are further advanced through collaborations with experimentalists studying both existing GFA systems as well as those targeting “GFA by design".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.

非技术摘要这一奖项支持理论研究，计算和相关教育，以调查自组装。自组装是一个过程，纳米尺度的“构建块”赞助将其与多单元结构相关联，这是生物学和合成世界中各种有用的材料结构的结构形成的基础。该项目旨在促进我们对这种系统的新兴“类”的基本理解，即几何施加的组件（GFAS）。当构建块之间的形状和相互作用导致汇总时“不适合”排列时，几何施法就会发生。如此沮丧的构建块与扭曲的拼图零件没有什么不同，这些拼图将边缘整齐地融合到边缘，但是其形状误差需要越来越多的紧张才能将越来越大的拼图拼凑在一起。在这些纳米级的“不合适”（由聚合物，蛋白质或胶体颗粒组成）的组装中，挫败感可能会引起组装过程的新机制，以“感知其大小”，而在没有形状误差的组装中，这是不可能的。 GFA中的形状MIDSFIT的堆积与称为自限制组件的独特行为有关，其中自组装过程可以在有限数量的构建块中自主，稳健地终止，这本身可以基于子单元形状，相互作用，相互作用，相互作用和灵活性的属性进行预先确定。因此，GFA为设计新型的自组装系统提供了潜在的途径，该系统的最终尺寸可以从构建块属性的设计和合成中“编程”。实现通过编程的挫败来设计材料组件的自限制的能力，可能会揭示潜在的变革性，自下而上的途径，以制造功能性的纳米结构材料体系结构，例如可注入的生物医学脚手架或可涂有油漆的光子涂层，并具有诸如3D绘制范围的基本技术可以访问的复杂性和尺寸控制。纳米级的特性，令人沮丧的构建块（例如它们的形状误差，相互作用，灵活性）以及各种类型疾病对它们在尺寸尺度上形成的紧急结构的影响，远大于这些亚基。该项目将开发理论框架，以解决这一核心目标，并支持理论原理对合成和生物系统的实验研究的翻译。BEYOND对材料科学的潜在影响源于促进GFA原理的材料科学，该项目将实现更多的更广泛的影响。这些包括学生（本科和研究生）的培训和心态以及材料物理学统计和计算方法的博士后研究人员，以及PI的努力，以提高研究生群体中研究生群体中的K12学生人群的参与。 （GFA）。 GFA是一种新兴的范式，其中软物质“构建块”之间的局部误差会导致尺寸尺寸超过块尺寸的尺寸尺度上的内域应力梯度。 GFA中远程应力的积累构成了一系列依赖规模的行为，而没有挫败感的规范组件中没有对应的行为，包括存在等效组装维度有限的自限制状态，但比亚基本身大得多。最近的努力旨在利用这一现象，以此作为通过合成构建块的工程型贴身构件编程自组装结构的介观尺寸和形态的一种手段，例如通过先进的胶体合成或DNA纳米技术方法制造。应对这一挑战需要预测性的理解，即在中尺度出现的有限温度组装行为上追踪GFA的微观特征（MISDFIT形状，相互作用和可变形性）。该项目中的研究将解决有关GFA的理论理解和工程原理的三个关键差距：i）挫败感的统计物理学通过弹性（形状贴式）和非弹性（缺陷介导的）模式逃到了散装组装； ii）通过沮丧的组装中的工程软盘模式扩展自限制压力的传播的能力； iii）混合和多分散挫败感的行为。拟议的旨在推进一系列建模方法，以捕获GFA行为的本质多尺度。通过与研究现有的GFA系统以及针对“设计GFA”的实验者的合作，这项研究的科学影响进一步提高了。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响审查标准通过评估来获得的支持。