Interfacial directed assembly and attachment of interconnected nanoparticle networks

互连纳米粒子网络的界面定向组装和附着

基本信息

批准号：
1803878
负责人：
Tobias Hanrath
金额：
$ 37.5万
依托单位：
Cornell University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-01 至 2022-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1803878&HistoricalAwards=false
关键词：
Interfacial directed assembly attachment interconnected

项目摘要

Nanoparticles are particles with diameters roughly one thousandth the width of a human hair. This award supports research to investigate how nanoparticles assemble and attach at the surface of a fluid. The process is not unlike how some fine powders can form a layer that floats on top of the surface of quiescent water. Nanoparticle building blocks with programmable size, shape, and composition have become available thanks to recent advances in chemistry. Connecting these building blocks to each other to form "sheets" can give rise to new classes of materials and devices with emergent properties that have intrigued scientists and engineers alike. Unfortunately, assembly instructions are not yet available. This project will close this knowledge gap with a combination of experiments and computer models. This synergistic approach will unveil key details of the mechanism by which the building blocks self-assemble and attach. Hence, the results will lead to strategies to design new building blocks that assemble into desirable patterns with minimal defects. This project will produce new knowledge of scientific and societal importance and may lead to the development of new nanostructured materials. Graduate students will receive extensive training in advanced experimental and modeling approaches, and research opportunities will be provided for undergraduates. Interactive learning modules for local K-12 programs will also be developed.The combination of self-assembly and directed attachment of colloidal nanoparticles at fluid interfaces presents scientifically interesting and technologically important research challenges. Remarkable strides have been made in the synthesis of polyhedral nanoparticle building blocks with precisely defined shapes and their self-assembly into highly ordered superstructures. Recent advances have revealed intriguing synergies between interfacial self-assembly and directed epitaxial attachment into ordered and connected superstructures. Access to superstructures with programmable symmetry opens new opportunities to create materials with properties by design. The main goal of this work is to attain a better understanding of the basic kinetic and thermodynamic factors governing the interplay of self-assembly and directed-attachment. The investigators hypothesize that the key to predicting and creating coupled assemblies with programmable structures lies in understanding and controlling the nanoparticle orientation at the fluid interface as well as the interactions among particles. The nanoparticle orientation at the liquid-liquid interface and subsequent directed attachment is a complex function of the interfacial energies, the nature of multi-particle interactions and the coupled dynamics of interfacial nanoparticle diffusion, ligand displacement from the nanoparticle surface and epitaxial fusion of adjacent nanoparticles through mutually exposed facets. The mechanism describing how the nanoparticle assembly transforms into an epitaxially connected superstructure presents an interesting unresolved scientific question, and competing hypotheses will be tested via a combination of experiments and simulations. In fact, this provides both a challenge and an opportunity to closely integrate in-situ X-ray structure analysis with multi-scale modeling. The proposal presents a hypothesis-driven collaborative approach with two objectives that aim to understand: (1) how specific nanoparticle superlattice polymorphs assemble at fluid interfaces and (2) how directed attachment can transform the assembled superlattice into an epitaxially connected quasi-2D solid.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.

纳米颗粒是直径大约是人头发宽度的颗粒。该奖项支持研究，以研究纳米颗粒如何在流体表面组装和附着。该过程与某些细粉末如何形成在静态水表面顶部的层没有什么不同。由于最近的化学进展，具有可编程尺寸，形状和组成的纳米颗粒构建块已获得。将这些构建块彼此连接起来形成“床单”，可能会产生新的材料和设备，并具有引起科学家和工程师的新兴特性。不幸的是，尚无组装说明。该项目将结合实验和计算机模型的组合来缩小这一知识差距。这种协同方法将揭示构件阻止自组装和附加机制的关键细节。因此，结果将导致设计新的构建块的策略，这些构建块组装成最小的缺陷的理想模式。该项目将产生有关科学和社会重要性的新知识，并可能导致新的纳米结构材料的发展。研究生将接受高级实验和建模方法的广泛培训，并为大学生提供研究机会。还将开发针对本地K-12程序的交互式学习模块。自我组装和胶体纳米颗粒在流体接口上的固定依恋的结合提出了科学有趣且在技术上重要的研究挑战。在合成具有精确定义形状的多面体纳米颗粒构建块的合成中，已经取得了显着的进步，它们的自组装成高度有序的上层建筑。最近的进步揭示了界面自我组装和定向外延依恋之间令人着迷的协同作用。使用可编程对称性的上层建筑访问可以为使用设计属性创建材料的新机会。这项工作的主要目的是更好地理解管理自组装和定向跟踪相互作用的基本动力学和热力学因素。研究人员假设与可编程结构预测和创建耦合组件的关键在于理解和控制流体界面处的纳米颗粒方向以及粒子之间的相互作用。液态液体界面和随后的定向附件处的纳米颗粒取向是界面能量的复杂功能，多粒子相互作用的性质以及界面纳米颗粒扩散的耦合动力学，结合纳米颗粒表面和偶像外部融合的偶像构造的互联体位移。描述纳米颗粒组件如何转化为外延连接的上层建筑的机制提出了一个有趣的未解决的科学问题，并且将通过实验和模拟的结合来测试竞争的假设。实际上，这既提供了一个挑战，也是与多尺度建模紧密整合原位X射线结构分析的机会。该提议提出了一种以假设为导向的协作方法，其目的有两个目标，旨在理解：（1）特定的纳米颗粒超晶状体超晶状体多晶型物如何在流体界面聚集在流体界面上，（2）有方向的附件如何将组装的超级峰值转化为通过表达相互连接的Quasi-2D Solide的支持，并反映了nsf的基础。优点和更广泛的影响审查标准。