Formation and Analysis of Aerosol Clusters Consisting of Ultrafine Primary Particles

这项研究的目标是开发在线测量和分析燃烧、干法洗涤过程中形成的硫酸铵和硝酸盐颗粒以及硅烷热解产生的硅颗粒的实验和理论方法。在硅生产中，通过在低于发生均匀成核的温度和低浓度的核的情况下操作，选择条件来防止团簇的形成。在电子束清洗过程中，操作和安装成本非常昂贵，因此要求在高剂量下进行较短的辐照时间。这些条件会产生相对较高的水蒸气浓度，至少可以部分补偿，可以预期会出现致密的颗粒。烟尘结构是延伸的链状结构。具体的研究领域是：(1)团簇空气动力学直径的实验测量及其与初级粒子尺寸和分维的关系；(2)基于Kaplan格子方法的凝聚模型的发展；(3)团簇的扩散电荷，特别是它们作为离子汇的作用。

The objectives of this research are to develop experimental and theoretical procedures for online measurement and analysis of combustion, ammonium sulphate and nitrate particles formed in dry scrubbing processes, and silicon particles from the pyrolysis of silane. In silicon production, conditions are chosen to prevent cluster formation by operating at temperatures below where homogeneous nucleation occurs and with low concentration of nuclei. In the electron beam scrubbing processes, operating and installation costs are so expensive that short irradiation times at high doses are mandated. These conditions yield comparatively high water vapor concentrations will at least partially compensate, and a compact particle can be expected. The soot structures are extended chain-like structures. The specific research areas are: (1) the experimental measurement of the aerodynamic diameter of clusters and their correlation with primary particle size and fractal dimension; (2) the development of a coagulation model based on the Kaplan lattice approach; and (3) the diffusional charging of clusters and especially their role as a sink for ions.