Kinetics of sub-2 nm TiO2 particle formation in an aerosol reactor during thermal decomposition of titanium tetraisopropoxide
Kinetics of sub-2 nm TiO2 particle formation in an aerosol reactor during thermal decomposition of titanium tetraisopropoxide
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四异丙醇钛热分解过程中气溶胶反应器中亚 2 nm TiO2 颗粒形成的动力学
DOI：
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发表时间：
2015
影响因子：
2.5
通讯作者：
P. Biswas
中科院分区：
文献类型：
--
作者：
Yang Wang;Pai Liu;Jiaxi Fang;Wei;P. Biswas
来自差示迁移率分析仪（DMA）的粒度分布测量可用于研究颗粒形成机制。然而，关于颗粒形成的初始阶段的知识是不完整的，因为在传统的DMA中，布朗增宽效应限制了它们测量亚2 nm尺寸颗粒的能力。以前的研究已经证明了高流量DMA（如Half Mini DMA）测量亚2 nm颗粒的能力，其分辨率明显高于传统DMA。采用半微型DMA研究了四异丙醇钛（TTIP）在炉内气溶胶反应器中热分解生成亚2 nm TiO2纳米颗粒的动力学。研究了反应温度、停留时间、前驱体浓度、双极电荷引入等参数对亚2 nm粒径分布的影响。一级反应速率从尺寸分布对反应温度的依赖性与现有的文献数据相匹配。前驱体停留时间和前驱体浓度的变化相应地改变了粒径分布，表明TTIP热分解的发生。在气溶胶反应器中引入双极电荷增强了反应物的消耗，这可能是由于离子诱导成核和诱导偶极效应。
Particle size distribution measurements from differential mobility analyzers (DMAs) can be utilized to study particle formation mechanisms. However, knowledge on the initial stages of particle formation is incomplete, since in conventional DMAs, the Brownian broadening effect limits their ability to measure sub-2 nm-sized particles. Previous studies have demonstrated the capability of high-flow DMAs, such as the Half Mini DMAs, to measure sub-2 nm particles with significantly higher resolutions than conventional DMAs. A Half Mini DMA was applied to study the kinetics of sub-2 nm TiO2 nanoparticle formation in a furnace aerosol reactor, through the thermal decomposition of titanium tetraisopropoxide (TTIP). The influence of parameters such as reaction temperature, residence time, precursor concentration, and the introduction of bipolar charges on sub-2 nm particle size distributions were studied. A first order reaction rate derived from the dependence of size distributions on reaction temperature matched well with existing literature data. The change in precursor residence time and precursor concentration altered the size distributions correspondingly, indicating the occurrence of TTIP thermal decomposition. The introduction of bipolar charges in aerosol reactors enhanced the consumption of reactants, possibly due to ion-induced nucleation and induced dipole effects.