臺灣博碩士論文加值系統

本研究成功地利用連續式水熱技術合成出不同形態及不同粒徑大小的片狀單水鋁以及粒子狀的氧化鋁。依據加熱方式的不同，本研究獲致以下結論：
一、直接加熱方式
1.以向上流動的系統可得到六角板狀的單水鋁，其粒徑分布為0.7 ~1.0 um；
2.以向下流動的系統可得到長六角板狀的單水鋁，其粒徑分布為1.43~2.69 um；
3.單水鋁的形態與粒徑大小主要和滯留時間的長短有關；
4.溫度範圍在220~290 C且濃度為0.01 M時，可得到較佳的片狀單水鋁。
二、點火加熱方式
1.所產生的單水鋁形態主要由pH與溫度所控制，當溫度高於420 C，會有球狀的氧化鋁被形成，當溫度低於420 C，則只形成單水鋁；
2.在酸性環境下，一旦發生水解反應將立即成核，而且單水鋁粒子隨即成長。當高於臨界溫度後才予以冷卻，則因為在臨界點附近的溶解度急遽下降，所以可能導致第二次的成核現象發生，因此可能產製雙峰式的粒徑分佈。當超臨界水之下的火焰溫度在400到420 C之間，本研究觀察到了此一現象。
3.如果超臨界水的火焰溫度低於400 C，則在反應系統冷卻後，其pH隨之增加。因此，單水鋁的溶解度也隨之減少。因此單水鋁的粒子大小將不會因為降溫而隨之變小，所以可以觀察到比較均勻而且略大的單水鋁。

This study utilized continuous hydrothermal synthesis to produce flake boehmite with various morphology and size and spherical aluminum oxide.Based on the difference of heating,this study concluded that:
(1) Produced by direct heating:
1.By up-flowing reactor,hexagonal flake of boehmite was obtained,and its mean size was 0.7 ~1.0 um.;
2.By down-flowing reactor,long hexagonal flake of boehmite was obtained, and its mean size was 1.43~2.69 um;
3.Morphology and size of the boehmite was mainly affected by the residence time in hydrothermal condition;
4.Flake boehmite without agglomeration can be obtained in the range of 220~290 C with 0.01 M of aluminum nitrate solution as the nutrition.
(2) Produced in Supercritical Water Flame
1.Morphology of the produced boehmite was mainly determined by temperature.Aluminum oxide was obtained as temperature higher than 420 C,and only boehmite was found as lower than 420 C.
2.Nucleation occurred right after hydrolysis.Particles grow as temperature increases because of decrease of solubility of boehmite in acidic environment.While the growing particles were cooled after temperature passed over the critical temperature,the dramatic decrease of solubility could lead to another additional nucleation.Therefore,the obtained particles could show bimodal distribution.This was observed,if temperature of the supercritical water flame was ranged from 400 to 420 C.
3.While temperature of the supercritical water flame was below 400 C,the solubility of boehmite in acidic was higher than that in alkaline environment.Therefore the particle was remained its size as grown at high temperature.A little larger and much narrower particle of boehmite could be obtained.

摘要I
AbstractII
誌謝IV
目錄V
圖目錄VII
表目錄IX
第一章 緒論1
1.1 氧化鋁合成1
1.1.1 Boehmite 2
1.1.2 γ-Al2O3 2
1.1.3 δ-Al2O3 3
1.1.4 θ-Al2O3 3
1.1.5 α-Al2O3 3
1.2 奈米微粒的製備6
1.2.1 水熱法6
1.2.2 超臨界水熱法8
1.2.2.1 超臨界水的性質8
1.2.2.2 超臨界水中的水熱結晶9
1.3 水熱結晶的成核與晶體成長11
1.4 研究目的15
1.5 調查範圍與研究方法15
2.1 實驗設備17
2.1.1 向上流動方式17
2.1.2 向下流動方式22
2.1.3 超臨界水火焰設備28
2.1.4 實驗藥品33
2.2 產物特性分析33
2.2.1 X光粉末繞射分析 (Power X-ray Diffraction, XRD)33
2.2.2 顯微結構分析33
2.2.3傅立葉轉換紅外線光譜分析 (Fourier transform infrared spectrometer, FTIR)33
第三章 結果與討論34
3.1 連續式水熱合成之產物34
3.1.1 向上流動方式34
3.1.2 向下流動方式36
3.1.3 超臨界水火焰合成鋁氧化物41
3.1.4 形成單水鋁及氧化鋁的機制探討46
3.1.4.1系統pH值不變46
3.1.4.2 系統pH值增加48
3.1.4.3 系統pH值降低51
第五章 未來研究及建議55
5.1 連續式反應器55
5.2 晶粒大小的控制55
參考文獻56
圖目錄
圖1.1 Al2O3-H2O相圖2
圖1.2 Boehmite的晶形結構4
圖1.3 γ-Al2O3的晶形結構4
圖1.4 θ-Al2O3的晶形結構5
圖1.5 α-Al2O3的晶形結構5
圖1.6 等壓下，水的密度(a)，介電常數(b)，離子積(c)隨溫度變化的情形9
圖1.7 單水鋁的成核與成長路徑圖13
圖1.8 連續式水熱合成系統單水鋁的形態及成長示意圖14
圖1.9 實驗架構圖16
圖2.1 向上流動方式系統流程圖18
圖2.2 向上流動反應器設計圖19
圖2.3 向下流動方式系統流程圖23
圖2.4 氣液分離槽的設計圖24
圖2.5 向下流動反應器設計圖25
圖3.1 合成片狀單水鋁的操作條件34
圖3.2 硝酸鋁在不同溫度下的產物35
圖3.3 硝酸鋁在不同濃度反應後所形成的產物36
圖3.4 粒子的軸長比37
圖3.5 單水鋁的粒子型態轉變示意圖37
圖3.6 不同流動方式合成的單水鋁 (A)向上；(B)向下38
圖3.7 單水鋁的XRD分析39
圖3.8 單水鋁的FT-IR分析40
圖3.9 溫度低於420 C，反應時所收集之產物41
圖3.10 溫度低於420 C的產物42
圖3.11 溫度高於420 C，反應時所收集之產物43
圖3.12 溫度高於420 C的產物43
圖3.13 溫度低於420 C，降溫後所收集之產物44
圖3.14 溫度低於420 C經降溫後所收集的產物44
圖3.15 溫度高於臨界溫度，降溫後所收集之產物45
圖3.16 溫度高於420 C經降溫後所收集的產物45
圖3.17 向上流動方式的路徑示意圖47
圖3.18 向下流動方式的路徑示意圖48
圖3.19 向下流動方式粒子排列的情況48
圖3.20 溫度高於臨界溫度強酸轉變成弱酸的路徑示意圖49
圖3.21 溫度低於臨界溫度強酸轉變成弱酸的路徑示意圖50
圖3.22 中性轉變成弱酸的晶粒成長示意圖52
圖3.23 Ostwald ripening機制示意圖53
表目錄
表1.1 製備奈米微粒之分類及其優缺點6
表1.2 超臨界狀態下水熱合成法製備氧化物顆粒研究10
表2.1 超臨界水熱合成系統元件一覽表20
表2.2 超臨界水熱合成系統元件一覽表26
表2.3 超臨界水火焰系統元件一覽表30

中文部份
[1]吳昌霖，超臨界水醇熱製備奈米氧化物之研究，碩士論文，私立義守大學生物技術與化學工程研究所，高雄，2007。
[2]徐國財，張立德，奈米複合材料，五南圖書出版股份有限公司，2003。
[3]張立德，奈米材料，五南圖書出版股份有限公司，2002。
[4]張俊龍，奈米級氧化鋁粉末θ至α的相轉換活化能研究，碩士論文，國立成功大學資源工程研究所，台南，2002。
[5]劉吉平，郝向陽，奈米科學與技術，世茂出版社，2004。
英文部份
[1]Cabanas A, Poliakoff M, “The continuous hydrothermal synthesis of nano-particulate ferrites in near critical and supercritical water”, J. Mater. Chem., vol.11, pp.1408-1416, 2001.
[2]D. Mishra, S. Anand, R.K. Panda, R.P. Das, “Statistical optimization of conditions for the hydrothermal precipitation of boehmite”, Hydrometallurgy, vol. 58, pp.169-174, 2000.
[3]E. Lester, P. Blood, J. Denyer, D. Giddings, B. Azzopardi, M. Poliakoff, “Reaction engineering: the supercritical water hydrothermal synthesis of nano-particles”, J. Supercritical Fluids, vol.37, pp.209-214, 2006.
[4]F. J. Ewing, “The Crystal Structure of Lepidocrocite,” J. Chem. Phys., vol.3, pp.420-424, 1935.
[5]G. C. Kennedy, “Phase relations in the system Al2O3-H2O at high temperatures and pressures”, Am. J. Sci., vol.257, pp.563-573, 1959.
[6]G. D. Chukin, and Yu. L. Seleznev, “Mechanism of the Thermal Decomposition of Boehmite and a Model of the Aluminum Oxide Structure”, Kinet. Catal., vol.30, pp.55-62, 1989.
[7]H. Elderfield and J. D. Hem, “The Development of Crystallite Structure in Aluminum Hydroxide Polymorphs on Aging,” Miner. Magazine, vol.39, pp.89-96, 1973.
[8]H. Hou, Y. Xie, Q. Yang, Q. Guo, C. Tan, “Preparation and characterization of γ-AlOOH nanotubes and nanorods”, Nanotechnology, vol. 16, pp.741-745, 2005.
[9]http://zh.wikipedia.org/zh-tw/File:Ostwaldpic.png
[10]I. M. Low and R. McPherson, “Crystallization of Gel-Derived Alumina and Alumina-Zirconia Ceramics,” J. Mat. Sci., vol.24, pp.892-898, 1989.
[11]J. A. Kohn, G. Katz, and J. D. Broder, “β-Ga2O3 and Its Alumina Isomorph, θ-Al2O3,” Am. Miner., vol.42, pp.398-408, 1957.
[12]J. Wan, X. Chen, Z. Wang, X. Yang, Y. Qian, “A soft-template-assisted hydrothermal approach to single-crystal Fe3O4 nanorods”, Journal of Crystal Growth, vol.276, pp.571-576, 2005.
[13]J. Zheng, S. Wei, J. Lin, J. Luo, S. Liu, H. Song, E. Elawad, X. Ding, J.Gao, S. Qi, C. Tang, “Template-Free Preparation of Bunches of Aligned Boehmite Nanowires” , J. Phys. Chem. B, vol.110, pp.21680-21683, 2006.
[14]J.M. Simonson, H.F. Holmes, R.H. Busey, R.E. Mesmer, D.G. Archer and R.H. Wood, “Modeling of the thermodynamics of electrolyte solutions to high temperatures including ion association: application to hydrochloric acid”, J. Phys. Chem., vol.94, pp.7675-7681, 1990.
[15]K. Okada, T. Nagashima, Y. Kameshima, A. Yasumori, T. Tsukada, “Relationship between formation conditions, properties, and crystallite size of boehmite”, J. Colloid Interface Sci., vol.253, pp.308-314, 2002.
[16]K. Sue, Y. Hakut R.L. Smith, Jr., T. Adshiri, and Kunio, Arai, “Solubility of Lead(II) Oxide and Copper(II) Oxide in Subcritical and Supercritical Water”, J. Chem. Eng. Data, vol.44, pp.1422-1426, 1999.
[17]Krokidis X, Raybaud P, Gobichon A.E., Rebours B, Euzen P, Toulhoat H, “Theoretical Study of the Dehydration Process of Boehmite to γ-Alumina”, J. Phys. Chem. B, vol.105, no.22, pp.5121-5130, 2001.
[18]Ragnarsdottir, K. V., Walther, J.V., “Experimental determination of corundum solubilities in pure water between 400-700degree.C and 1-3 kbar”, Geochimica et Cosmochimica Acta, vol.49, pp.2109-2115, 1985.
[19]Rumyantsev, V. N., and Rumyantseva, G. V., ZH NeorgKhim, vol.14, pp.1634, 1969.
[20]S. J. Wilson and J. D. McConnel, “A Kinetic Study of the System γ-AlOOH,” J. Solid State Chem., vol.34, pp.315-322, 1980.
[21]T. Adschiri, K. Kanazawa, K. Arai, “Rapid and Continuous Hydrothermal Crystallization of Metal Oxide Particles in Supercritical Water”, J. Am. Ceram. Soc., vol.75, pp.1019-1023, 1992.
[22]T. Adschiri, K. Kanazawa, K. Arai, “Rapid and Continuous Hydrothermal Synthesis of Boehmite Particles in Subcritical and Supercritical Water”, J. Am. Ceram. Soc., vol.75, pp.2615-2620, 1992.
[23]T. Adschiri, Y. Hakuta, and Kunio Arai, “Hydrothermal synthesis of metal oxide fine particles at supercritical conditions”, Ind. Eng. Chem. Res., vol.39, pp.4901-4907, 2000.
[24]Takeshi Tsuchida, “Hydrothermal synthesis of submicrometer crystals of boehmite”, Journal of the European Ceramic Society, vol.20, pp.1759-1764, 2000.
[25]U. Janosovits, G. Ziegler, U. Scharf, A. Wokaun, “Structural characterization of intermediate species during synthesis of Al2O3-aerogels”, J. Non-Crystalline Solids, vol. 210, pp.1-13, 1997.
[26]W. D. Kingery, H. K. Bowen, and D.R. Uhlmann, Introduction to Ceramics, 2nd Eds., John Wiley & Sons Inc., New York, 1976.
[27]Wang T , Smith R L Jr, Inomata H, Arai K., “Reactive phase behavior of aluminum nitrate in high temperature and supercritical water”, Hydrometallurgy, vol.65, pp.159-175, 2002.
[28]X. Y. Chena, Z. J. Zhangb, X. L. Lia, S. W. Leec, “Controlled hydrothermal synthesis of colloidal boehmite (γ-AlOOH) nanorods and nanoflakes and their conversion into γ- Al2O3 nanocrystals”, Solid State Communications, vol.145, pp.368~373, 2008.
[29]Y. Hakuta, H. Terayama, S. Onai, “Production of Ultra-fine Particles by Hydrothermal Synthesis Under Supercritical Condition”, Journal of Materials Science Letters., vol.17, pp.1211-1213, 1998.
[30]Y. Hakuta, H. Terayama, S. Onai, T. Adschiri, and K. Arai, in Proc. 4th Int. Symp. on Supercritical Fluids, Sendai, Japan, pp. 255-258, 1997.
[31]Y. Hakuta, Haruo Ura, Hiromichi Hayashi, Kunio Arai, “Effects of hydrothermal synthetic conditions on the particle size of γ-AlO(OH) in sub and supercritical water using a flow reaction system”, Materials Chemistry and Physics, vol.93, pp.466-472, 2005.
[32]Y. Hakuta, Seino K, Ura H, Adschiri T, Takizawa H, Arai K, “Continuous production of phosphor YAG:Tb nanoparticles by hydrothermal synthesis in supercritical water”, Materials Research Bulletin, vol.38, pp.1257-1265, 2003.
[33]Y. Hakuta, Seino K, Ura H, Adschiri T, Takizawa H, Arai K, “Production of phosphor (YAG/Tb) fine particles by hydrothermal synthesis in supercritical water”, J. Mater. Chem., vol.9, pp.2671-2675, 1999.
[34]Y. Hakuta, T. Adschiri, H. Hirakoso, K. Arai, “Chemical equilibria and particle morphology of boehmite (AlOOH) in sub and supercritical water”, Fluid Phase Equilibria, vol.158-160, pp.733-742, 1999.
[35]Y. Hakuta, T. Adschiri, T. Suzuki, T. Chida, K. Seino and K. Arai, “Flow method for rapidly producing single phase barium hexa-ferrite particles in supercritical water”, J. Am. Ceram. Soc., vol.81, pp.2461-2465, 1998.
[36]Y. M. Chiang, D. P. Birnie, III, and W. D. Kingery, Physical Ceramics-Principles for Ceramic Science and Engineering, John Wiley & Sons Inc., New York, 1997.
[37]Ziemniak, S., Jones, M., Combs, K., “Solubility and Phase Behavior of Cr(III) Oxides in Alkalines Media at Elevated Temperatures”, J. Solution Chem., vol.27, pp.33-66, 1998.