A Study of Anatase Titania Nanoparticles Synthesized in Premixed and Diffusion Flames

• Main Authors: Hsiung-An Yang, 楊雄安
• Other Authors: 馬小康
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/34028654794138974958

博士 === 國立臺灣大學 === 機械工程學研究所 === 99 === Previous studies have shown that titanium tetra-isopropoxide (TTIP) can be a substitute in the production of non-poisonous and inexpensive titania (TiO2) nanoparticles. This study discusses the combustion characteristics of synthesized titania obtained while adding TTIP into the premixed methane/air flames via premixed flame from a Bunsen burner and a porous flat burner. In the meanwhile, a modified Hencken burner was used to synthesize smaller titania nanoparticles via short diffusion flames. ANSYS 12.0 FLUENT computational fluid dynamics (CFD) code is used to simulate diffusion turbulent flames and coagulation of particles using a user-defined function (UDF). The results show that the frequency of collisions among particles would decrease and reduce titania nanoparticle size in a short diffusion flame height. The crystalline structure of the synthesized nanoparticles was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), Barrett-Joyner-Halenda (BJH) and Brunauer-Emmett-Teller (BET) measurements. The characteristic properties of titania nanoparticles synthesized from a modified Hencken burner were compared with the results from a Bunsen burner and commercial titania (Degussa P25). The results showed that the average particle size of 6.63 nm from BET method was produced by a modified Hencken burner which was smaller than the titania in a Bunsen burner and commercial titania. Also, the size of titania nanoparticles was highly dependent on the TTIP loading and the collecting height in the flame.