Gas-phase synthesis of functional nanomaterials: Challenges to kinetics, diagnostics, and process development
Gas-phase synthesis of functional nanomaterials: Challenges to kinetics, diagnostics, and process development
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DOI：
10.1016/j.proci.2018.06.231
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
C. Schulz;T. Dreier;M. Fikri;H. Wiggers
中科院分区：
文献类型：
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作者：
C. Schulz;T. Dreier;M. Fikri;H. Wiggers
通过气相合成纳米颗粒，可以在连续流动过程中生产出性能可控的高纯度材料。这是一项成熟的技术，适用于几种或多或少具有特定材料特性的商品(主要是无机商品)。然而，不断加深对过程的了解和控制，为将用于制造独特材料的高度专业化的实验室规模技术扩大到工业规模提供了机会。具有可调组成和尺寸分布的纳米粒子具有广泛的应用，从涂层到电子产品再到功能材料，例如用于能量转换和存储。为了合成具有所需性能的材料，必须很好地控制反应条件。了解蒸发前体化合物的分解动力学和机理、团簇的形成以及与浴气和火焰化学的潜在相互作用是有针对性地合成材料的先决条件。有关前体化学和颗粒形成的科学挑战以及克服这些挑战的实验和理论方法与燃烧科学中的挑战有很大重叠。动力学实验是在激波管反应器中进行的，中间和产物物种的光学和质谱学检测，以及基于激光的温度和物种浓度检测以及分子束采样技术的流动反应器中进行的。必须在实验室规模的纳米粒子反应器中确定反应条件，如温度、中间物种浓度和颗粒大小，并且定义标准化实验以建立用于模型开发的大型数据库是重要的。在实验验证的模拟基础上扩大到中试规模最终有助于证明新技术的可行性及其在大众市场上的应用，如电池或催化材料。
Gas-phase synthesis of nanoparticles enables production of high-purity materials with well-controlled properties in continuous flow processes. It is an established technology for a couple of (mostly inorganic) commodities with more or less specific materials characteristics. However, increasing process understanding and control provides a chance for scale-up of highly specialized lab-scale technologies used for the manufacturing of unique materials to industrial scale. Nanoparticles with adjustable composition and size distributions are of interest for a wide variety of applications from coatings to electronics to functional materials, e.g., for energy conversion and storage. For the synthesis of materials with desired properties, the reaction conditions must be well controlled. Understanding the decomposition kinetics and mechanisms of vaporized precursor compounds, cluster formation, and the potential interaction with bath gases and flame chemistry is a prerequisite for a targeted synthesis of materials. The scientific challenges concerning the precursor chemistry and particle formation and the experimental and theoretical approaches to overcome them have a large overlap with those in combustion science. Kinetics experiments are carried out in shock-tube reactors with optical and mass spectrometric detection of intermediate and product species, and in flow reactors with laser-based detection of temperature and species concentration as well as molecular-beam sampling techniques. Reaction conditions such as temperature, intermediate species concentration and particle size must be determinedin situin lab-scale nanoparticle reactors and the definition of standardized experiments that allow to build-up large data bases for model development is important. The scale-up to pilot-plant-scale based on experimentally validated simulations finally helps to prove the viability of new technologies and their application on mass markets such as materials for batteries or catalysis.