Synthesis of Composite Particles by Liquid Aerosol Thermolysis

液体气溶胶热裂解（LAT）是指将液体前驱体溶液雾化成离散液滴并随后通过时间/温度/大气调节反应器输送的一般颗粒合成过程。该计划的总体目标是建立一门基础工程科学，用于通过液体气溶胶热裂解合成亚微米复合颗粒。设计了颗粒合成和溶液实验，以确定影响固体复合颗粒形成和化学分布的因素。原位技术将用于监测液滴在蒸发阶段的生成和收缩，作为雾化，前驱体溶液特性和蒸发条件的函数。蒸发阶段后，在线采样将用于获取和表征粒子作为时间和温度的函数。将使用上述实验中产生的信息对每个过程步骤进行数学分析，并根据这些过程的现有或派生模型进行评估。模型系统，基于氧化铝前驱体作为基体相，已经选择检查第一均相复合系统的合成，其中纳米晶相均匀分散，第二，其中一个相封装另一个相。氧化铝中的锌和铂可以用来检查与均匀沉淀相关的问题，而氧化铝-SiC可以让我们检查一个相（SiC）在另一个相（即颗粒内）中的隔离。​所提出的技术旨在生产具有广泛成分范围和100纳米结晶度的纳米晶体材料，具有所需的均匀性和第二相分布。

Liquid aerosol thermolysis (LAT) refers to the general class of particle synthesis processes in which a liquid precursor solution is atomized into discrete droplets and subsequently transported through a time/temperature/atmosphere-regulated reactor. The overall objective of the proposed program is to establish a fundamental engineering science for the synthesis of submicron, composite particles by liquid aerosol thermolysis. Particle synthesis and solution experiments are designed to identify those factors affecting solid composite particle formation and chemical distribution. In situ technique will be used to monitor droplets generation and shrinkage during the evaporation stage as a function of atomization, precursor solution characteristics and evaporation conditions. After the evaporation stage, on-line sampling will be used to obtain and characterize particles as a function of time and temperature. Each process step will be mathematically analyzed using information generated in the above experiments and evaluated against existing or derived models for those processes. Model systems, based on alumina precursors as the matrix phase, have been selected examine first the synthesis of homogeneous composite systems in which the nanocrystalline phases are uniformly dispersed and second, those in which one phase encapsulates the other. Zinconia and platinum in alumina allow use to examine issues associated with uniform precipitation whereas alumina-SiC allows us the possibility to examine the isolation of one phase (SiC) within another (i.e. intragranular). The proposed techniques aim to production of nanocrystalline materials of a wide compositional range and having 100 nm crystallinity, of desired uniformity and second phase distribution.