Disruptive burning of precursor/solvent droplets in flame‐spray synthesis of nanoparticles
Disruptive burning of precursor/solvent droplets in flame‐spray synthesis of nanoparticles
复制标题
DOI：
10.1002/aic.14234
复制
发表时间：
2013-12
期刊：
影响因子：
3.7
通讯作者：
C. Rosebrock;N. Riefler;T. Wriedt;L. Mädler;S. Tse
中科院分区：
文献类型：
--
作者：
C. Rosebrock;N. Riefler;T. Wriedt;L. Mädler;S. Tse
火焰喷雾热解是一种用于通过前体/溶剂液滴的气溶胶燃烧在气相中合成纳米颗粒的成熟技术。对微米级前驱体/溶剂液滴的燃烧特性进行了实验研究。纯溶剂液滴燃烧均匀，经典的准稳态，而前体/溶剂液滴表现出破坏性的燃烧行为。液滴破裂的快速发生，这只发生在溶解的金属前体的溶液中，不是由于液滴内的固体颗粒沉淀。相反，破坏性液滴燃烧的机制类似于浆料液滴的机制，由三个主要步骤组成：（1）高挥发性溶剂的扩散控制燃烧，（2）由于低挥发性金属前体的分解而形成粘性壳，以及（3）由于非均质成核而随后破坏。这三个步骤的时间顺序取决于金属前体的浓度和分解特性，随着浓度的增加和分解温度的升高而缩短。© 2013美国化学工程师学会AIChE J，59：4553-4566，2013
Flame spray pyrolysis is an established technique for synthesizing nanoparticles in the gas phase through aerosol combustion of precursor/solvent droplets. The combustion characteristics of isolated micron-sized precursor/solvent droplets are investigated experimentally. Pure solvent droplets burn uniformly and classically quasisteady, whereas precursor/solvent droplets manifest disruptive combustion behavior. The fast onset of droplet disruption, which occurs only for solutions with dissolved metal precursors, is not due to solid-particle precipitation within the droplet. Instead, the mechanism of disruptive droplet burning is similar to that of slurry droplets, consisting of three main steps: (1) diffusion-controlled burning of the high-volatile solvent, (2) viscous-shell formation due to decomposition of the low-volatile metal precursor, and (3) subsequent disruption due to heterogeneous nucleation. The time sequence of the three steps depends on the concentration and decomposition characteristics of the metal precursor, shortening with increased concentration and higher incremental decomposition temperature. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4553–4566, 2013