 |
|
|
|
以作者查詢圖書館館藏 、以作者查詢臺灣博碩士 、以作者查詢全國書目 、勘誤回報 、線上人數：65 、訪客IP：3.147.69.132
姓名 方嘉偲(Chia-Szu Fang) 查詢紙本館藏 畢業系所 化學工程與材料工程學系 論文名稱 合成均一粒徑球形二氧化鈦
(Synthesis of monodisperse spherical titania)相關論文 檔案 [Endnote RIS 格式]
[相關文章]
[文章引用]
[完整記錄]
[館藏目錄]
至系統瀏覽論文 ( 永不開放)
摘要(中) 二氧化鈦廣泛的應用在塗料、光觸媒、填料、披覆材料等。而均一粒徑之球型粉體是近年來對陶瓷粉體的研究重點。此粉體可增加燒結體的緻密度，並降低粉體之燒結溫度。製備二氧化鈦有釵h方法，如：溶凝膠法，但成本昂貴且水解速率快，不易控制。或以水為溶劑之強制水解法或均一沉澱也可得到，但卻受限於濃度太低且反應時間太長之缺點。在本研究中，依據溶劑之溶解度會隨著介電常數減少而降低的原理，以正丙醇和水在四氯化鈦的混合溶劑，於70℃下加熱，以製備均勻分散球型之二氧化鈦。影響製備的條件都將被討論，如：合成的溫度、時間、醇水比、反應物的濃度、分散劑的濃度等，都將被討論。沉澱物的型態是受到混合溶劑中醇水比的控制，二氧化鈦合成時，調整醇與水的體積比，觀察對粉體外型的影響，當醇水比為3時，可得到最像球型且分散的二氧化鈦。當再加入分散劑時，會使得分子分散的最好。當分子在不同固態含量中都會形成二氧化鈦，只是會隨著濃度的增加顆粒變大。當反應溫度不同，分子會變得較不均勻且粒徑會隨著溫度的增加而變大，而反應時間的增加，也會使分子粒徑變大。利用不同醇類來製備二氧化鈦時，正丙醇、異丙醇及丙酮都能形成球型二氧化鈦，而甲醇與乙醇則不容易形成，因其介電常數越低越容易形成二氧化鈦。將製備得到的二氧化鈦以X-ray繞射分析為
非晶相，當鍛燒溫度為600℃時，為銳鈦礦結構，而鍛燒到800℃時，則為板鈦礦結構。摘要(英) Titania has been used extensively in pigment, cosmetics, photocatalyst and coatings. It has been reported that the spherical powders with a narrow size distribution is the most desirable state. Many methods such as sol-gel process, forced hydrolysis and the homogeneous precipitation have been used to prepare TiO2 particles. However, there are some drawbacks: the concentration of reacting species is too low and the reaction time is too long. In this research, titania powders were synthesized by thermal hydrolysis of TiCl4 in a mixed solvent of n-propanol and water. The morphology of the precipitates was controlled by the volume ratio of n-propanol to water (RH ratio) of the mixed solvent. The titania sample synthesized at an RH ratio of 3 was spherical and discreted. Adding hydroxypropyl cellulose (HPC) as a steric dispersant made particles well-discrete. The particles in different solid contents were all spherical but the size increased with an increase of the solid content. When the temperature was 80-100℃, the morphology and the size were the same approximately. After the temperature increased to 150℃, the size became bigger (1.5μm). The particles at 200℃ was also much bigger than that at 150℃ (2.0μm ). The TiO2 particle was much smaller by using supersonics oscillator than those prepared by the conventional stirring, due to the less temperature gradient in the solution. The particle size was bigger and the size distribution was broader as the reaction time was longer. It was not easy to form titania in methanol and ethanol solvents. In n-propanol, isopropanol, and acetone, the titania was
easier to be formed. The lower the dielectric constant is, the easier the spherical titania forms. The phase of particles was analyzed by X-ray. The phase transformed with different calcinations temperature were amorphous, anatase, and rutile.關鍵字(中) ★ 分散劑
★ 四氯化鈦
★ 水熱裂解
★ 均一粒徑球形粉末
★ 二氧化鈦關鍵字(英) ★ monodisperse spherical powders
★ thermal hydrolysis
★ titanium tetrachloride
★ titania
★ dispersant論文目次 Abstract……………………………………………………………….i
Table of contents…………………………………………………….….iii
List of Tables……………………………………………………………v
List of Figures……………………………………………………….….vi
Chapter 1 Introduction…………………………………………………..1
Chapter 2 Literature review……………………………………………….9
2.1 Inorganic salt as a precursor………………………………………9
2.2 Alkoxide as a precursor…………………………………….…….14
2.2.1 The comparison of Ti(OC2H5)4 and Ti(OC3H7)4……….……17
2.3 Others……………………………………………………….……19
2.4 The advantages of HPC…………………………………………..21
Chapter 3. Experimental………………………………………………….24
3.1 Chemicals………………………………………………………...24
3.2 Synthesis…………………………………………………….……24
3.3 Characterization…………………………………………………..27
3.3.1 X-ray diffraction (XRD)……………………………………..27
3.3.2 N2 sorption…………………………………………………...27
3.3.3 Thermogravimetric analysis (TGA)…………………………28
3.3.4 Differential scanning calorimetery (DSC)…………………..28
3.3.5 Scanning electron microscopy (SEM)……………………….29
3.3.6 Transmission electron microscopy (TEM)…………………..29
3.3.7 Dynamic light scattering (DLS)…………………………...29
3.3.8 Ultravillet /visible absorption (UV-vis)……………………..30
Chapter 4. Results and discussion………………………………...………31
4.1 Effect of RH ratio………………………………………………...31
4.2 Effect of concentration on particle morphology …………………38
4.3 Effect of reaction temperature……………………………………44
4.4 Effect of reaction time……………………………………………55
4.5 The effect of the type of alcohol………………………………….55
4.6 Effect of oscillator………………………………………………..58
4.7 The effect of HPC on particles…………………………………...61
4.8 Effect of Acetylacetone (ACAC) as a dispersant………………...64
4.9 The comparison of HPC and ACAC……………………………..64
4.10 Crystallities patterns of TiO2 powders………………………….65
4.11 TGA……………………………………………………………..77
4.12 DSC……………………………………………………………..77
Chapter 5 Conclusion…………………………………………………...80
References ……………………………………………………………...82參考文獻 Andrew Mills, Richard H. Daries, and David Worsley, Water purification by semiconductor photocatalysis, Chem. Soc. Reviews, 1993, 417-25
Agnes pottier, Corinne Chaneac, Elisabeth Tronc, Leo Mazerolles and Jean-pierre Jolivet, Synthesis of brookite TiO2 nanoparticles by thermalysis of TiCl4 in strongly acidic aqueous media, J. Mater. Chem., 2001, 11, 1116-21
Choi J. Y., Kim C. H., and Kim D. K., Hydrothermal synthesis of spherical perovskite oxide powders using spherical gel powders, J. Am. Ceram. Soc., 1998, 81, 1353-56
Chrysanthe D. Terwilliger and Yet-Ming Chiang, Measurements of excess enthalpy in ultrafine-grained titanium dioxide, J. Am. Ceram. Soc., 1995, 78, 2045-55
Eric A. Barringer, and H. Kent Bowen, Formation, packing, and sintering of monodisperse TiO2 powders, Comm. Of the Am. Ceram. Soc., 1982, 199-201
Hunter R. J., Foundation of colloid science, Clarendon Press, 1987, 1, 443
Jean T. H., and Ring T. A., Processing monosized TiO2 powders generated with HPC dispersant, Am. Ceram. Soc., 1986, 65, 1574-77
Jean T. H., and Ring T. A., Effect of a sterically stabilizing surfactant on the nucleation growth and agglomeration of monosized ceramic powders, Colloids surf, 1988, 29, 273-91
Jang H. D., Kim S. K. and Kim S. J., Effect of particle size and phase composition of titanium dioxide nanoparticles on the photocatalytic properties, J. of nanoparticle research, 2001, 141-47
Kim E. J., Seung H. O. and Hahn S. H., Influence of calcinations on microstructures and photoactivities of alkoxide-derived TiO2 nanoparticles prepared in W/O microemulsions, Chem. Eng. Comm., 2001,187, 171-184
Lawrence H. Edelson and Andreas M. Glaeser, Role of particle substructure in the sintering of monosized titania, J. Am. Ceram. Soc., 1988, 71, 225-35
Look J. L. and Zukoski C. F., Alkoxide-derived titania particles: use of electrolytes to control size and agglomeration levels, J. Am. Ceram. Soc., 1992, 75, 1587-95
Look J. L. and Zukoski C. F., Colloidal stability and titania precipitate morphology: influence of short-range repulsions, J. Am. Ceram. Soc., 1995, 78, 21--32
Moon Y. T., Park H. K., Kim D. K., and Kim C. H., Preparation of monodisperse and spherical zirconic powders by heating of alcohol-aqueous salt solution, J. Am. Ceram. Soc., 1995, 79, 2690-94 (A)
Moon Y. T., Kim D. K., and Kim C. H., Preparation of monodisperse ZrO2 by the microwave heating of zirconyl chloride solutions, J. Am. Ceram. Soc., 1995, 78, 1103-106 (B)
Masaru Yoshinaka, Ken Hirota, and Osamu Yamaguchi, Formation and sintering of TiO2 (anatase) solid solution in the system TiO2-SiO2, J. Am. Ceram. Soc., 1997, 80, 2749-53
Michael Z. C. Hu, Vino Kurian, E. Andrew Payzant, Clandia J. Rawn, Rodney D. Hunt, Wet-chemical synthesis of monodispersed barium titanate particles hydrothermal conversion of TiO2 microspheres to nanocrystalline BaTiO3, Powder Technology, 2000, 2-14
Park H. K., Moon Y. T., Kim D. K., and Kim C. H., Formation of monodisperse spherical TiO2 powders by thermal hydrolysis of Ti(SO4)2, J. Am. Ceram. Soc., 1996, 79, 2727-32
Park H. K., Kim D. K., and Kim C. H., Effect of solvent on titania particle formation and morphology in thermal hydrolysis of TiCl4, J. Am. Ceram. Soc., 1997, 80, 743-49
Takashi Ogihara, Masaki Ikeda, Masanori Kato, and Nobuyasu Mizutani, Continuous processing of monodispersed titania powders, J. Am. Ceram. Soc., 1989, 72, 1598-1601
Yasuro Ikuma, Takashi Shigemura, and Takeshi Hirose, Temperature profile of anatase-TiO2 powder compact during microwave heating, J. Am. Ceram. Soc., 1996, 79, 2533-38指導教授 陳郁文(Yu-Wen Chen) 審核日期 2002-6-24 推文 plurk
funp
live
udn
HD
myshare
netvibes
friend
youpush
delicious
baidu
網路書籤 Google bookmarks
del.icio.us
hemidemi
facebook
twitter
google
reddit