Liao Ying-Chih, Nienow Amanda M, Roberts Jeffrey T
University of Minnesota, Department of Chemistry, Minneapolis, Minnesota 55455, USA.
J Phys Chem B. 2006 Mar 30;110(12):6190-7. doi: 10.1021/jp054195e.
The kinetics of reaction between silicon nanoparticles and molecular oxygen were studied by tandem differential mobility analysis. Aerosolized silicon nanoparticles were extracted from a low-pressure silane plasma into an atmospheric pressure aerosol flow tube reactor. Particles were initially passed through a differential mobility analyzer that was set to transmit only those particles having mobility diameters of approximately 10 nm. The monodisperse particle streams were mixed with oxygen/nitrogen mixtures of different oxygen volume fractions and allowed to react over a broad temperature range (600-1100 degrees C) for approximately one second. Particles were size-classified after reaction with a second differential mobility analyzer. The particle mobility diameters increased upon oxidation by up to 1.3 nm, depending on the oxygen volume fraction and the reaction temperature. Oxidation is described by a kinetic model that considers both oxygen diffusion and surface reaction, with diffusion becoming important after formation of a 0.5 nm thick oxide monolayer.
通过串联差分迁移率分析研究了硅纳米颗粒与分子氧之间的反应动力学。将雾化的硅纳米颗粒从低压硅烷等离子体中提取到常压气溶胶流管反应器中。颗粒首先通过一个差分迁移率分析仪，该分析仪设置为仅传输迁移直径约为10nm的那些颗粒。将单分散颗粒流与不同氧体积分数的氧气/氮气混合物混合，并在较宽的温度范围（600-1100℃）下反应约一秒钟。反应后用第二个差分迁移率分析仪对颗粒进行尺寸分级。氧化后颗粒的迁移直径增加高达1.3nm，这取决于氧体积分数和反应温度。氧化过程由一个动力学模型描述，该模型同时考虑了氧扩散和表面反应，在形成0.5nm厚的氧化物单层后扩散变得重要。
