GOALI: Flame-based Synthesis of Metal Nanoparticles at Millisecond Residence Times

Pi：Swihart，Mark Institution：SUNY at Buffalo提议编号：1066945标题：GALI：基于火焰的毫秒停留时间金属纳米颗粒合成PI计划应用他们在布法罗大学(SUNY)和Praxair团队的联合专业知识，开发一种新的基于火焰的金属纳米颗粒生产工艺。印刷电子、抗菌塑料等金属纳米颗粒的应用正在迅速增长。目前，这些粒子是用大量的溶剂、高价值表面活性剂和聚合物来制备的。如果气相火焰法制备纳米材料的尺寸、尺寸分布和团聚程度能够得到足够的控制，那么它将提供一种成本更低、更环保的方法。最大规模的金属氧化物纳米材料(二氧化钛、二氧化锆等)的生产由于这些原因，碳黑在火焰过程中被使用。然而，这不是大多数金属的情况，因为它们在火焰中氧化。这里采用的方法基于Praxair开发的热喷嘴技术，提供了生产金属纳米颗粒所需的高温、短停留时间、快速混合和还原条件。喷嘴和下游反应器为颗粒生长提供了高度均匀的环境，与其他气相工艺相比，改善了对颗粒尺寸、尺寸分布和形态的控制。最重要的是，这种方法将前体化学与火焰化学分离，允许使用其他基于火焰的方法不能使用的前体，如低成本的水盐，并允许颗粒形成的停留时间独立于火焰动力学进行控制。本研究的具体目的是：1.系统研究关键操作参数对单组分纳米粒子粒径分布和形貌的影响，优化产率，控制粒度分布。探索多组分(合金和核壳)纳米粒子、包覆金属纳米粒子以及包括树枝状碳在内的其他新型纳米材料的生产和结构控制。开发、验证和应用计算反应器模型，以了解实验结果的物理化学基础，并实现预测性的、合理的工艺改进。完成成本分析和市场分析，以确定商业化的途径。智力价值：这项工作的智力价值来自于对现有技术的新颖改编，以实现有前景的和非常不同的新目的。热喷嘴反应器的优点在于其简单；它只是通过将热燃烧产物通过收敛-发散喷嘴来分离燃烧和颗粒形成。由此产生的热气射流提供了液体前体的有效雾化和极快的混合。快速启动和终止颗粒形成(通过加热和淬火)是在气相中以高通量生产纳米颗粒的关键，而这正是该系统所提供的。此外，PI将研究该系统中合金和核壳粒子以及新型碳纳米材料的形成，可能会产生其他方法无法获得的结构。最先进的气溶胶动力学建模将与实验并行进行，提供对颗粒形成过程的基本见解。UB和Praxair团队的综合专业知识对该项目的成功至关重要。广泛的影响：这项工作将导致开发一种新的高通量、低成本的金属纳米颗粒生产工艺。这将通过降低成本和扩大这些材料的应用范围来产生技术影响。通过这项工作，博士生、硕士研究生和本科生将接受纳米材料气溶胶合成方面的培训，并发展跨学科的化学、材料科学和化学工程技能。所有参与者都将从学术和产业合作中受益。本科生将通过NSF REU计划以及其他有针对性的计划，如麦克奈尔学者计划和路易斯·斯托克斯少数群体参与联盟(LS-AMP)计划参与其中。该项目将使私人投资机构在招募少数族裔参与者方面取得日益成功的基础上，并将其扩展到高中生和教师。该项目的变革性：该项目有可能改变金属和其他非氧化物材料纳米颗粒的生产方式。这是一种用于纳米材料的新型毫秒驻留时间反应堆。这一过程对纳米材料加工和气溶胶反应工程的影响可以很好地与其他毫秒接触时间反应堆的影响相媲美(例如，兰尼·施密特等人开发的那些)。关于重整和部分氧化的反应工程，影响着科研和工业实践的方向。

PI: Swihart, Mark Institution: SUNY at Buffalo Proposal Number: 1066945Title: GOALI: Flame-based Synthesis of Metal Nanoparticles at Millisecond Residence TimesThe PIs plan to apply the combined expertise of their University at Buffalo (SUNY) and Praxair teams to develop a new flame-based process for producing metal nanoparticles. Printed electronics, antimicrobial plastics and other applications of metal nanoparticles are rapidly growing. Currently, these particles are prepared using large quantities of solvents, high-value surfactants and polymers. A gas-phase flame-based process will provide a lower-cost, more environmentally friendly route to these nanomaterials if it can provide sufficient control of size, size distribution, and degree of agglomeration. Most large-scale production of metal oxide nanomaterials (TiO2, ZrO2, etc.) and carbon black is done in flame processes for these reasons. However, this is not the case for most metals, because they oxidize in the flame. The approach pursued here, based on a thermal nozzle technology developed at Praxair, provides the high temperature, short residence time, rapid mixing, and reducing conditions needed for metal nanoparticle production. The nozzle and downstream reactor provide a highly uniform environment for particle growth, improving control of particle size, size distribution, and morphology compared to other gas-phase processes. Most importantly, this approach decouples the precursor chemistry from the flame chemistry, allowing use of precursors such as low-cost aqueous salts that cannot be used in other flame-based methods, and allowing the residence time for particle formation to be controlled independently of the flame dynamics. Specific aims of the proposed research are to:1. Systematically study the effects of key operating parameters on single-component nanoparticle size distribution and morphology, to optimize yield and control particle size distribution.2. Explore production and structure control of multicomponent (alloy and core-shell) nanoparticles, coated metallic nanoparticles, and additional novel nanomaterials including dendritic carbon.3. Develop, validate and apply computational reactor models to understand the physico-chemical basis of the experimental results and enable predictive, rational process improvement.4. Complete a cost analysis and market analysis to identify pathways to commercialization.Intellectual Merit: The intellectual merit of this work derives from the novel adaptation of an existing technology for a promising and very different new purpose. The thermal nozzle reactor is elegant in its simplicity; it merely separates combustion from particle formation by passing the hot combustion products through a converging-diverging nozzle. The resulting hot gas jet provides effective atomization of liquid precursors and extraordinarily fast mixing. Rapid initiation and termination of particle formation (by heating and quenching) are the keys to the production of nanoparticles in the gas phase at high throughput, and this is exactly what this system provides. Moreover, the PIs will investigate the formation of alloy and core-shell particles and novel carbon nanomaterials in this system, potentially generating structures that cannot be obtained by other methods. State-of-the-art aerosol dynamics modeling will be performed in parallel with experiments, providing fundamental insight into the particle formation process. The combined expertise of the UB and Praxair teams is essential to the success of the project.Broader Impacts: The work will lead to development of a new high-throughput low-cost process for the production of metallic nanoparticles. This will have technological impact by lowering costs and expanding the range of application of these materials. Through this work, a Ph.D. student, MS students, and undergraduates will be trained in aerosol synthesis of nanomaterials and develop cross-disciplinary chemistry, materials science, and chemical engineering skills. All participants will benefit from the academic-industrial collaboration. Undergraduates will participate through the NSF REU program, and additional targeted programs such as the McNair Scholars and Louis Stokes Alliance for Minority Participation (LS-AMP) programs. This project will allow the PIs to build on their growing success in recruiting minority participants, and expand it with outreach to high-school students and teachers.Transformative Nature of this Project: This project has potential to transform the way nanoparticles of metals and other non-oxide materials are produced. This is a novel millisecond residence-time reactor for nanomaterials. The impact of this process on nanomaterials processing and aerosol reaction engineering could very well match the impact of other millisecond contact-time reactors (e.g. those developed by Lanny Schmidt et al.) on reaction engineering for reforming and partial oxidation, affecting directions of both scientific research and industrial practice.