NSF-DFG Confine: Reacting precursor/solvent microdroplets in confined 2-D microflows for tailored nanomaterials synthesis

NSF-DFG Confine：在受限的二维微流中反应前体/溶剂微滴，以实现定制的纳米材料合成

• 批准号: 2234283
• 负责人: Stephen Tse
• 金额: $ 36万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-11-01 至 2025-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2234283&HistoricalAwards=false
• 关键词: NSF; DFG; Confine; Reacting; precursor

This project was awarded through the “Chemistry and Transport in Confined Spaces (NSF-DFG Confine)" opportunity, a collaborative solicitation that involves the National Science Foundation and Deutsche Forschungsgemeinschaft (DFG).Ubiquitously, our daily life involves the use of high surface-area materials. Frequently, these materials are the key to the sustainable use of energy and resources. Examples of their applications include catalytic components, batteries, electrodes, composite materials, gas sensors, flowing agents, 3D printing, and artificial slag systems. The demand for high surface area per unit mass and fast mass transfer in most applications requires using very small particles with a large external surface area. The way to success is by producing and using such nanoparticles, mostly in the form of oxides and often with specific composition, stoichiometry, and multi-material interactions. Their bottom-up synthesis involves reaction, nucleation, surface growth, coagulation, coalescence, and often crystallization. A novel microreactor involving combusting microdroplets is proposed to synthesize nanoparticles of tailored chemical composition and crystal structure in a scalable, uniform, and consistent fashion. Successful results of this project will reveal fundamental processes and improve practical process control to bridge the current gap between laboratory studies and industrial large-scale and high-rate manufacturing of functional flame-synthesized nanoparticles. This project unites the capabilities of researchers from the U.S.A. (Rutgers University) and Germany (University of Bremen), who are recognized specialists in the emerging field of flame synthesis of nanomaterials. Curricula will be developed as an integrated, multidisciplinary research and education project to train a future nano-manufacturing workforce. Through a joint Ph.D./MBA curriculum on technology entrepreneurship, new business ventures based on the IP from this project will be assessed.The proposed program’s objective focuses on investigating the mechanisms of droplet-to-particle conversion (DPC) and gas-to-particle conversion (GPC) in a confined environment by utilizing a reactive multiphase 2D microflow system with controlled individual burning liquid precursor/solvent droplets in precisely adjustable gas composition and temperature environments. Defining process conditions along a microdroplet’s path should allow unparalleled ability to fabricate high-quality and tailored nanoparticles in a continuous system whose output can be directed into another system for inline processing of composite materials or other uses. Our microfluidic geometry and available operational parameters allow basic and isolated studies of various phenomena hardly discernable in other macroscopic systems. The microdroplets in the microreactor can experience large heating and cooling rates, affecting detailed chemistry and transport in far-from-equilibrium conditions. Individual droplet investigation can be conducted using temperature-controlled (heated or cooled) walls to sustain combustion or quench reactions, where the droplets and as-produced nanomaterials can be characterized (e.g., offline using chromatography by sampling) at different locations (correlating to different residence times), thereby measuring reaction kinetics and nanomaterials evolution. Burning droplets can coalesce with burning/non-burning droplets of the same or different precursors. The setup of burning microdroplets moving through a transparent microfluidic reactor (Hele-Shaw cell) is amenable to a host of in-situ diagnostics, including laser-based spectroscopy, high-speed imaging, interferometric particle imaging, and rainbow refractometry. Ex-situ characterization and computational modeling will be conducted to understand, optimize, and guide the experiments. Perhaps hitherto unseen in conventional combustion synthesis, the combinations and direct manipulation of uniform droplets in the proposed setup can produce a variety of nanoparticles, such as organic, inorganic, hybrid, and complex nanoparticles, with exceptional control of size, size distribution, morphology, composition, and crystallinity.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.

该项目是通过“密闭空间的化学与运输（NSF-DFG Confine）”机会获得的，这是一项涉及美国国家科学基金会和德国研究协会（DFG）的合作招标。我们的日常生活无处不在，涉及使用高表面-通常，这些材料是能源和资源可持续利用的关键，其应用示例包括催化组件、电池、电极、复合材料、气体。传感器、流动剂、3D 打印和人造渣系统 在大多数应用中，对单位质量的高表面积和快速传质的需求需要使用具有大外表面积的非常小的颗粒。成功的方法是生产和使用。这种纳米颗粒大多以氧化物的形式存在，通常具有特定的组成、化学计量和多材料相互作用，它们的自下而上合成涉及反应、成核、表面生长、凝结、聚结，并且通常是结晶。微反应器燃烧微滴被提议以可扩展、均匀和一致的方式合成具有定制化学成分和晶体结构的纳米颗粒，该项目的成功结果将揭示基本过程并改进实际过程控制，以缩小当前实验室研究和工业化研究之间的差距。 - 功能性火焰合成纳米颗粒的大规模和高速率制造结合了来自美国（罗格斯大学）和德国（不来梅大学）的研究人员的能力。纳米材料火焰合成新兴领域的知名专家将开发一个综合的、多学科的研究和教育项目，通过关于技术创业、新业务的博士/MBA联合课程来培训未来的纳米制造劳动力。基于该项目知识产权的企业将受到评估。拟议项目的目标是利用反应性多相研究受限环境中液滴到颗粒转化（DPC）和气体到颗粒转化（GPC）的机制二维微流系统在精确可调的气体成分和温度环境中控制单独燃烧的液体前体/溶剂液滴，沿着微滴路径定义工艺条件应该具有在连续系统中制造高质量和定制纳米粒子的无与伦比的能力，其输出可以直接进入。我们的微流体几何结构和可用的操作参数允许对其他宏观系统中难以辨别的各种现象进行基本和孤立的研究。可以经历较大的加热和冷却速率，影响远离平衡条件下的详细化学和传输，可以使用温度控制（加热或冷却）的壁来维持燃烧或淬灭反应，其中液滴和as-进行。可以在不同位置（与不同的停留时间相关）对产生的纳米材料进行表征（例如，使用色谱法离线），从而测量反应动力学和燃烧液滴可以聚结的演变。相同或不同前体的燃烧/非燃烧液滴通过透明微流体反应器（Hele-Shaw 池）移动的燃烧微滴的设置适合​​多种原位诊断，包括基于激光的光谱、高速。将进行成像、干涉粒子成像和异位折射测量，以理解、优化和指导传统燃烧合成中可能迄今未见的实验。在所提出的装置中组合和直接操纵均匀液滴可以产生各种纳米颗粒，例如有机、无机、混合和复合纳米颗粒，并且对尺寸、尺寸分布、形态、组成和结晶度具有出色的控制。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。