| Summary: | 碩士 === 元智大學 === 化學工程學系 === 90 === The objectives of this study are two folds: (1) to establish a prototype lab-scale low-pressure flat flame system for nanoparticle production, and (2) to apply computational fluid dynamics package FLUENT to assist in the investigation of flow behaviors and temperature profiles around the burner in the low pressure chamber system. Simulations showed that the application of an inert sheath flow has the effect of suppressing the flame from going out- and up-wards. It was also shown that the simulated flame thickness increases with decreasing chamber pressure.
A series of experiments were conducted to investigate the effect of precursor concentration, chamber pressure, and burner-to-substrate distance on product yield and powder properties. The powders collected from each experiments were examined using TEM and XRD. From TEM results, it was shown particles were largely loose agglomerates. Diameter of primary particles derived from TEM counting was in the range of 10-50 nm. XRD results indicated that the particles were mixed phase of anatase and rutile. Without proper dispersion of the powders, analyses using N4 plus yielded secondary particle diameter of around 0.2 μm.
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