Gas-phase Combustion Synthesis of TiO2 Nanoparticles with TTIP in Premixed Flat Flame

奈米材料科技為未來新興科技的主要技術，世界各國也已投入大量人力與資金積極發展，而奈米光觸媒（TiO2）更是在目前已被廣泛使用，TiO2具有強大的氧化還原能力、化學穩定性高以及無毒等特性。本實驗利用氣相燃燒合成法合成奈米TiO2粉體，利用火焰高溫所擁有的自我純化、同質成核、可連續生產、均質度高等特性。同時採用新的鈦前置源TTIP取代傳統具腐蝕性的TiCl4，藉著改變燃燒器、前置源濃度、氧氮比例、流量等參數來觀察火焰結構、溫度對產物特性的影響。實驗結果顯示，平板火焰與本生式火焰在結構上差異大，進而影響溫度分佈趨勢、產物晶相及粒徑大小。當氧氮比例增加，Anatase晶相含量比例增加；若濃度增加則Rutile晶相含量增加，而流量的改變對於晶相的影響較小。結果可看出對產物晶相而言，其操作參數的影響大小依序為 : 氧氮比例＞濃度＞流量。就粒徑而言，不同操作參數下平板式燃燒器生成的粒徑範圍為 100 ~ 500nm，最小的粒徑約 40nm。本生式的粒徑結果較不均勻，分佈廣泛。而平板式較均勻、較短的火焰可生成較細且均勻的產物；但本生式燃燒器控制晶相的能力則比平板式好。Nanotechnology is the promisingly rising technology. Massive attention from countries around the world has appealed lots resources and money in related research. Photocatalyst (TiO2) is presently and widely used with its strong comprehension of oxidation, decomposition, atmospheric purification, deodorization, water purification, and stability. This research is to study the formation mechanism of nanosized TiO2 particles through gas-phase combustion synthesis because its high flame temperature brings fine self-purifying, homologous nucleation, and continuously uniform producing. Also, a new precursor, TTIP, is introduced to replace the conventional corrodible precursor, TiCl4. Flame temperature profile, TiO2 crystallinity, and particle size are studied under different burners, concentration of precursor, O2/N2 molar ratio, and flow rate. The results show that significant variations on the flame structure occur in different burners, leading to a further influence on temperature distribution, crystallinity and particle size of product. When O2/N2 molar ratio rises, the Anatase wt% grows. The rise of TTIP concentration leads to a climb of Rutile wt%. The range of TiO2 particle size averages from 100nm to 500nm under different operation parameters in flat flame burner while the smallest is about 40nm. In Bunsen burner, the particle size distributes wider and larger, and it shows better comprehension in crystallinity control than flat flame burner which produces smaller and more uniform particles due to its short constant flame structure.第一章 導論...................................................................................................1 1.1 前言...................................................................................................1 1.1.1奈米材料的種類......................................................................2 1.1.2奈米材料的特性......................................................................3 1.2 文獻回顧...........................................................................................5 1.3 研究背景.........................................................................................12 1.4 研究動機.........................................................................................14 1.5 研究目的.........................................................................................15 第二章 化學反應機構................................................................................17 2.1 化學反應機構.................................................................................17 2.2 反應機構與化學反應速率的關係................................................18 2.3 甲烷燃燒化學反應機構的介紹....................................................20 第三章 實驗研究方法................................................................................22 3.1 實驗架構說明.................................................................................22 3.1.1 TTIP介紹...............................................................................22 3.1.2 實驗架構與參數定義...........................................................22 3.2 實驗設備.........................................................................................23 3.2.1 燃燒器系統...........................................................................24 3.2.2 燃料輸送系統.......................................................................25 3.2.3 其他設備...............................................................................26 3.3 儀器校正.........................................................................................27 3.3.1流量計校正............................................................................27 3.3.2熱電偶校正............................................................................27 3.4實驗步驟..........................................................................................29 3.4.1 實驗前之準備.......................................................................29 3.4.2 實驗操作條件.......................................................................30 3.4.3 火焰溫度場之量測及現象觀察...........................................30 3.4.4 燃燒產物的收集與分析.......................................................31 第四章 結果與討論....................................................................................33 4.1 火焰的量測與觀察.........................................................................33 4.1.1 火焰結構...............................................................................33 4.1.2 火焰溫度分佈及趨勢...........................................................36 4.2 產物晶相分析.................................................................................40 4.2.1 氧氮比例對產物晶相的影響...............................................40 4.2.2 前置物濃度對產物晶相的影響...........................................41 4.2.3 流量對產物晶相的影響.......................................................42 4.2.4 不同燃燒器的產物晶相差異...............................................43 4.3 產物粒徑之分析.............................................................................45 4.3.1 氧氮比例對產物粒徑的影響...............................................45 4.3.2 前置物濃度對產物粒徑的影響...........................................45 4.3.3 流量對產物粒徑的影響.......................................................45 4.3.4 不同燃燒器對產物粒徑的影響...........................................46 第五章 結論與建議....................................................................................48 5.1 結論.................................................................................................48 5.2 建議.................................................................................................50 參考文獻.......................................................................................................82 附錄...............................................................................................................85作者簡歷...............................................................................................................9