在甲烷預混與擴散火焰中合成奈米級鈦化合物顆粒之研究

Comparison of TiO2 Nano-Particles Synthesized in Premixed and Diffusion Flames

楊雄安(Hsiung-An Yang)

指導教授 ： 馬小康

國立臺灣大學/工學院/機械工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.01461

摘要

本研究是以鈦系化合物C12H28O4Ti(TTIP)做為前置物，分別運用預混式和擴散式燃燒器，探討燃燒合成二氧化鈦之差異。前置物 TTIP在室溫下為液態，將 N2通入前置物容器發泡攜帶，以利於燃燒反應。最後，藉由穿透式電子顯微鏡(TEM)和X-ray光譜儀(XRD)觀察合成產物之形態、二氧化鈦晶相純度，以及顆粒尺寸。不同燃燒器的相異特性，將影響產物二氧化鈦的結晶相和顆粒尺寸大小。結果發現 Bunsen燃燒器與 Modified Hencken燃燒器，調整氧化劑的氧氣濃度可有效的控制二氧化鈦晶相純度；而反應溫度和收集產物高度將促使TiO2尺寸發生改變，當收集高度降低時，使得TiO2在火焰中的反應時間和相互碰撞頻率減少，造成產物粒徑縮小。當總流量增加會使得火焰拉長，進而造成二氧化鈦的 Anatase晶相轉換成 Rutile晶相。

關鍵字

二氧化鈦 ； 燃燒合成 ； 燃燒器

並列摘要

Previous studies show that TiO2 crystal phase purity may be effectively controlled by the oxygen concentration in the Bunsen burner. Under flow rate O2/N2=20/80, the weight percent of rutile phase is nearly 100%. On the contrary, it is hard to control the crystal purity phase on the flat burner because of its irregular porous medium. Thus, the modified Hencken burner with regular flow channel, which is designed with characteristics of the Bunsen burner to control TiO2 crystal phase purity and particle size for possible mass production. In the modified Hencken burner, the titanium precursor TTIP was fed into the flame by a carrier N2 flow through a heated TTIP bath. Particles synthesized in the flame were characterized for their morphology, crystal phase purity, and their size, by transmission electron microscopy, and X-ray diffraction. The influence of flame type, flame length, TTIP concentration and O2/N2 molar ratio on crystal phase purity and particle size will be studied in detailed. Under the flow rate O2/N2=20/80, the rutile phase of nanoparticle is as high as 96%. Results also show that the size of TiO2 nanoparticles is highly depending on the TTIP loading and the collecting height in the flame. The range of TiO2 particle size averages from 100nm to 500nm were found under different operation parameters. The modified Hencken burner with shorter flame length is attributed to a decrease in particle reaction time and reduced particle collision frequency in a lower collecting height of the flame.

並列關鍵字

TiO2 nanoparticle ； Flame synthesis ； Burner ； Anatase ； Rutile

參考文獻

30.李國鼎，“添加有機化合物TTIP與AIP在甲烷預混火焰中合成TiO2與Al2O3微粒之研究”，國立台灣大學機械工程研究所碩士論文，(2004).

31.廖思漢，“利用有機化合物TTIP於預混平板火燄中合成TiO2奈米微粒之研究”，國立台灣大學機械工程研究所碩士論文，(2005).

8.Levin, E.M. , Robbins, C.R., and Mxmuride, H.F. , “Phase Diagrams for Ceramists,” The American Ceramic Society,1 (1964).

10.Spurr, R. A., and Myers, H. , “Quantitative Analysis of Anatase- Rutile Mixtures With An X-ray Diffractometer,” Analytical Chemistry,29,760-762(1957).

11.Suyama, Y., and Kato, A. , “Effect of Additives on the Formation of TiO2 Particles by Vapor Phase Reaction,” Journal of American Ceramic Society,68,154-156(1985).