Reacting precursor/solvent microdroplets in confined 2-D microflows for tailored nanomaterials synthesis

在受限的二维微流中反应前体/溶剂微滴，以合成定制的纳米材料

• 批准号: 509113367
• 负责人: Professor Dr.-Ing. Lutz Mädler
• 金额: --
• 依托单位: Fachgebiet Mechanische Verfahrenstechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/509113367?language=en
• 关键词: Reacting; precursor; solvent; microdroplets; confined

Flame spray pyrolysis (FSP) is a robust technique that can synthesize chemically complex particles via aerosol combustion of precursor/solvent droplets. The burning microdroplets themselves can be regarded as spatially-confined microreactors, with numerous mechanistic pathways involved in realizing the final product size, composition, and morphology. The key idea of our work is to go beyond conventional FSP, and to further confine the burning microdroplets within a Hele-Shaw cell, creating a novel arrangement of microreactors within a microreactor. Such a device not only offers precise fundamental investigation of the variations in chemical properties and physical dynamics for initially same-sized burning droplets affected by confinement in one-dimension, but also affords the definition of the reaction environment with specific parameter histories for single microdroplets to design nanoparticles of tailored chemical composition and crystal structure, in scalable, uniform, and consistent fashion. The objective of the proposed program focuses on investigating the mechanisms of droplet-to-particle conversion and gas-to-particle conversion in a confined environment by utilizing a reactive multiphase 2D microflow system with controlled individual burning liquid precursor/solvent droplets in precisely adjustable environments. Such ability to define 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 for other uses. The microdroplet reactor can attain 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 same or different precursors. The setup 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 modelling will be conducted to understand, optimize, and guide the experiments. The team of Mädler and Tse have the unique multidisciplinary expertise consisting of combustion, materials synthesis, theoretical and numerical modeling, process engineering, and advanced characterization techniques, along with previous joint work, to address the proposed work.

火焰喷雾热解（FSP）是一种强大的技术，可以通过前体/溶剂液滴的气溶胶燃烧来合成化学复杂的颗粒。燃烧的微滴本身可以被认为是空间受限的微反应器，在实现最终产品的尺寸，组成和形态涉及许多机械途径。我们工作的关键思想是超越传统的FSP，并进一步将燃烧的微滴限制在Hele-Shaw细胞内，在微反应器内创建一种新颖的微反应器布置。这样的装置不仅提供了精确的基本调查的化学性质和物理动力学的变化，最初相同大小的燃烧液滴受限制在一维，但也提供了特定的参数历史的反应环境的定义为单个微滴设计定制的化学组成和晶体结构的纳米粒子，在可扩展的，均匀的，和一致的方式。该计划的目的是通过利用反应性多相二维微流系统，在精确可调的环境中控制单个燃烧液体前体/溶剂液滴，研究在受限环境中液滴到颗粒转化和气体到颗粒转化的机制。这种限定沿着微滴路径的工艺条件的能力应允许在连续系统中制造高质量和定制的纳米颗粒的无与伦比的能力，所述连续系统的输出可被引导到另一系统中用于复合材料的在线加工或用于其它用途。微滴反应器可以获得大的加热和冷却速率，在远离平衡的条件下影响详细的化学和传输。可以使用温度控制（加热或冷却）的壁进行单个液滴研究以维持燃烧或淬灭反应，其中可以表征液滴和所产生的纳米材料（例如，通过取样离线使用色谱法）在不同位置（与不同停留时间相关），从而测量反应动力学和纳米材料演变。燃烧液滴可以与相同或不同前体的燃烧/非燃烧液滴合并。该装置适用于许多原位诊断，包括基于激光的光谱学，高速成像，干涉颗粒成像和彩虹折射法。将进行非原位表征和计算建模，以了解，优化和指导实验。Mädler和Tse的团队拥有独特的多学科专业知识，包括燃烧，材料合成，理论和数值建模，工艺工程和先进的表征技术，沿着以前的联合工作，以解决拟议的工作。