摘要
This study is using HMDSA (C6H19NSi2) or HMDSO (C6H18OSi2) vapor into C3H8/air premixed flames to form SiO2 thin film on the surface of an aluminum plate. With the addition of HMDSO or HMDSA to premixed flames, an orange secondary flame or a flame brush appeared and was contributed to the formation of Sio2 particles. Based upon the EDS, XPS and FTIR analysis, it is believed that the synthesized products consist of mainly SiO2 and a small amount of SiO. The pure SiO2 crystal structure, was proved by XRD analysis, which may form from the SiO2 amorphous structure after high temperature (1300C) thermal treatment. The nano-size SiO2 particles, which ranged from 2.5-25 nm, are proved by analysis of the BET and TEM. A 2-D CFD-RC code with 12 reduced chemical reaction mechanism, based upon the SIMPLER procedure, was successfully employed to predict the flame temperature and both of the SiO2 and SiO concentration profiles. Compared with the experimental results, the calculated temperature profiles in the post-flame region are in good agreement with the measured data and observation phenomena.
基金
This research was funded by the National Science Council (NSC 90-2212-E- 212-015)
