臺灣博碩士論文加值系統

本研究以溶膠-凝膠法來製備無機多孔SiO2濾材塊體。實驗過程中，Si(OC2H5)4的醇溶液藉由水解與縮合反應來形成一矽酸鹽溶膠液。所形成之矽酸鹽溶膠液在倒入模具後，在一預先控制的環境下進行膠化與熟化處理以便轉換成具有三度空間立體結構之塊狀濕膠。濕膠中殘留之揮發性物質經適當的乾燥步驟來移除。濕膠乾燥過程中需特別留意以避免膠體結構中因毛細現象而產生微裂縫。最後，乾燥後之塊狀膠體置入高溫爐中加熱以形成做為無機濾材所需之SiO2塊體。 所製成之SiO2塊體經由氣體比重儀、BET比表面積測量儀、X-光繞射儀、掃瞄式電子顯微鏡等來作特性分析，以瞭解其密度、比表面積、相態、孔隙大小與孔徑分佈、及孔隙之形狀。從特性分析結果顯示，當水解縮合反應是在pH值1,2,4,7,10,11以及12進行時，我們所得到的主要粒子尺寸約為3,5,6,7,8.5,10以及15nm，並且粒子的形態為球型。在乾燥程序中，快速的移除揮發性組成膠體將會破裂，而破裂現象是因著毛細管力的作用產生。此外，由氮氣的吸附脫附恆溫曲線顯示塊體的孔洞型態是酒瓶型的。同時，乾膠經由1173K熱處理後其材料是非結晶相態。所有塊體的平均孔洞將隨著溫度的增加而增加，所有塊體的比表面積、孔洞體積將會隨著溫度的增加而減少。從這研究中，我們可以得到所期望的無破裂SiO2濾材塊體。

SiO2 monoliths with controlled porosity for inorganic porous filters were prepared via sol-gel routes. An alcoholic solution of Si(OC2H5)4 experienced hydrolysis and condensation reactions to form the suspension of silicate sols. After placing the sol suspension into the mold, gelation and aging were taken place at predesigned conditions and resulted in the formation of the wet gels with 3-dimensional network structure. The obtained wet gels were then dried at a controlled temperature and atmosphere to remove the residual volatile compounds. During the drying step, special cares were taken to avoid the impact of capillary forces on the microstructure of the gels. The capillary forces, due to the evaporation of the volatile compounds may cause the formation of microcracks inside the gels. The required SiO2 monoliths were then obtained by thermally treating the dried gels at higher temperatures. The obtained SiO2 monoliths were characterized using the gas pycnometer, BET sorptometer, XRD, SEM, to investigate the corresponding density, specific surface area, phases, pore sizes and pore size distribution, and pore shapes. Effects of the pH of starting solutions, the ratios of H2O/TEOS, and the processing temperatures on the characterizatics of resultant monoliths were studied. Using the starting solution of pH=1, 2, 4, 7, 10, 11, 12, the obtained primary particle size were 3, 5, 6, 7, 8.5, 10 and 15 nm, respectively. The morphology of particles is spherical. In drying, the gels would crack in the rapidly removing the volatile components, which was due to capillary forces interaction inside the gel. In addition, the N2 adsorption-desorption isotherms indicated that the pore type of all monoliths is bottle-shape. After thermally heat-treating the gel at 1173K, the monolith is non-crystalline. The average pore size of all the monoliths was increased with heat treatment temperatures. The specific surface area and pore volume of all monoliths were decreased with heat treatment temperatures. This study shows that SiO2 monolith with free of structure cracks can be prepared by carefully handling the xerogels.

CONTENTS
ABSTRACT I
CONTENTS Ⅲ
CONTENTS OF FIGURES VI
CONTENTS OF TABLES XV
CHAPTER ONE INTRODUCTION 1
CHAPTER TWO LITERATURE REVIEW 3
2.1 Principles of Inorganic Filter Synthesis 3
2.1.1 Glass membrane flters 8
2.1.2 Anodic Membrane Filters 8
2.1.3 Track-Etch Membrane Filters 9
2.1.4 Pyrolysis 10
2.1.5 Dense Membranes 10
2.2 Sol-gel method with Support System 11
2.2.1 Preparation of Support Systems 11
2.2.2 Preparation of separation layer by Sol-Gel method 12
2.3 Gel-Derived Silica Filters 16
2.3.1 Hydrolysis and Condensation 17
2.3.2 Gelation 20
2.3.3 Drying 20
2.3.4 Thermal treatment 24
CHAPTER THREE EXPERIMENTAL 25
3.1 Preparation of Silica Monoliths 25
3.2 Characterization 32
3.2.1 X-ray Diffraction 32
3.2.2 Scanning Electron Microscopy 33
3.2.3 Gas Pycnometer 34
3.2.4 BET sorptometer 36
CHAPTER FOUR RESULTS AND DISCUSSION 42
4.1 pH Effect on Particle size 42
4.2 Drying Process 44
4.2.1 Nature Drying 45
4.2.2 Drying by Light 46
4.2.3 Drying by Light with Flowing Air 47
4.3 Xerogel’s appearance of drying process 48
4.4 Characteristics of Gel-derived SiO2 48
4.4.1 XRD analysis 49
4.4.2 N2 adsorption and desorption isotherms 49
4.4.3 Effect of Heat Treatment Temperature for Filter''s
Pores 51
4.4.4 Effect of Heat Treatment Temperature for Pore Volume
of monoliths 52
4.4.5 Effect of Heat Treatment Temperature for Specific
Surface Area of monoliths 53
4.4.7 Bubble-Point Method analysis 53
CHAPTER 5 CONCLOSION 75

REFERENCES
1.A. J. Burggraff, K. Keizer and B. A. van Hessel. Solid State Ionics 32/33 (Part 2): 771-82.
2.N. N. Balagopal, K Keizer, W. J. Elferink, M. J. Gilde, H. Verweij, A. J. Burrggraaf. J. Membrane Sci., 116, 161-169 (1996).
3.K. S. W. Sing, D. H. Everett, R. A. W. Haul, L. Moscou, R. A. Pierotti, J. Rouquerol and T. Siemieniewaka, “Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity,” Pure and Appl. Chem. 57(4): 603-19 (1985).
4.K. Venkataraman, W. T. Choate, E. R. Torre, R. D. Husung and Hanu R. Batchu, “Characterization studies of ceramic membranes. A novell technique using a coulter porometer,” J. Membrane Sci., 39, 259-271 (1988).
5.Chuan Lin, James A. Ritter, Michael D. Amiridis, “Effect of thermal treatment on the nanostructure of SiO2-Al2O3 xerogels,” J. Non-Crys. Solids, 215, 146-154 (1997).
6.F. M. Tiller and C. D. Tsai, Theory of filtration of ceramics: I. Slip casting, J. Am. Ceram. Soc., 69, 882 (1986).
7.L. L. Murrell, “ Sols and mixtures of sols as precursors of uniqure oxides,” Catalysis Today, 35, 225-245 (1997).
8.黃定加 陳慧英, “陶瓷薄膜,” 化工, 第40卷第3期(1993).
9.L. L. Murrell and S. J. Tayster, Proc. 2nd Int. Congress on Catalysis and Automotive Pollution Control, CAPoC, Brussels, Belgium, p. 547 (1990).
10.L. L. Murrell, S. J. Tauster and D. R. Anderson, in L. Guczi, F. Solymosi and P. Tetenyi (Eds.), New Frontiers in Catalysis A. Elsevier, p.681 (1993).
11.R. K. Iler, The Chemistry of Silica, John Wiley & Sons, New York, NY, 1979.
12.H. P. Hsieh, Inorganic membranes, A.I.Ch.E Symp. Ser. 261. (84):1-18 (1988).
13.H.P. Hsieh, R. R. Bhave and H. L. Fleming, ”Microporous alumina membranes,” J. Membrane Sci. 39: 221-43.
14.A.W. Smith, “Porous anodic aluminum oxide membrane,” J. Electrochem. Soc. 120(8): 1068-1069 (1973).
15.J. A. Quinn, J. L. Anderson, W. S. Ho and W. J. Petzny,” Model pores of molecular dimension. Preparation and characterization of track-etched membrames,” Biophys. J. 12(8): 990-1007(1972).
16.J. Koresh and A. Soffer, “ Study of molecular sieve carbons Part I — Pore structure, gradual pore opening and mechanism of molecular sieving,” J. C. S. Faraday I 76: 2457-71 (1980).
17.Uhlhorn, R. J. R., M. H. B. J. Huis in’t Veld, Keizer and Burggraaf 1989. High permselectivities of microporous silica-modified τ-alumina membranes. J. Mater. Science Lett. 8(10) p.1135-39.
18.V. M. Gryaznov, “Hydrogen permeable palladium membrane catalysts,” Platinum Met. Rev., 30, 68 (1986).
19.Y. Nigara and B. cales, ”Production of carbon monoxide by direct thermal splitting of carbon dioxide at high temperature,” Bull. Chem. Soc. Jpn., 59, 1997 (1986).
20.J. Messing, G., E. Fuller and H. Hausner, eds. 1998. Ceramic Powder Processing. Westerville, OH. Am. Ceram. Soc. Inc.
21.J. Livage, “The gel route to transition metal oxide,” J. Solid state Chem, 64, 322-330 (1986).
22.B. E. Yoldas,” Alumina gel that forms porous transparent Al2O3,” J. Mater. Science, 10:1856-60 (1975).
23.B. E. Yoldas,” Alumina sol preparation from alkoxides,” American Ceramic Society Bulletin, V54, n3 Mar, 1975 p289-290.
24.A. F. M. Leenaars, K. Keizer and A. J. Burggraaf, “The preparation and characterization of alumina membranes with ultra-fine pores, Part I. Microstructural investigations on non-supported membranes, J. Mater. Science 19: 1077-88 (1984).
25.J. Livage, “The gel route to transition metal oxide,” J. Solid state Chem. 64: 322-30 (1986).
26.J. Livage and M. Henry, “A predictive model for inorganic polymerization reactions. In Ultrafiltration Processing of Advanced Ceramics eds. J. D. Mackenzie and D. R. Ulrich, pp.183-95, John Wiley & Sons, New York (1985).
27.M. A. Anderson, M. J. Gieselmann and Qunyin Xu, “Titania and Alumina ceramic membranes,” J. Membrane Sci., 39, 243-258 (1988).
28.A. Larbot, J. P. Fabre, C. Guizard and L. Cot,” Inorganic membranes obtained by Sol-gel techniques,” J. Membrane Sci., 39, 203-212 (1988).
29.A. Kaiser and H. Schmidt, “Generation of silica-membranes from alkoxisilanes on porous support,” J. Non-Cryst. Solids 63, 261-271 (1984).
30.L. C. Klein and D. Gallagher ,“Pore structures of sol-gel silica membranes,” J. Membrane Science 39(3) : 213-20 (1988).
31.L. Cot, C. Guizard and A. Larbot, “Novel ceramic material for liquid seperation process: Present and prospective applications in microfiltration and ultrafiltration,” Industrial Ceramics 8(3): 143-148(1988).
32.R. J. R. Uhlhorn, K. Keizer and A. J. Burggraaf, “Gas transport and separation with ceramic membranes. Part II. Synthesis and separation properties of microporous membranes,” J. Membrane Sci. 66, 271-287 (1992).
33.J. Tsubaki, M. Naito, K. Nakahira, Y. Fukuda, H. Mori,” Process condition on the preparation of supported microporous SiO2 membranes by sol-gel modification techniques,” J. Membrane Sci., 129, (263-269) 1997.
34.R. J. P. Corriu, D. Leclercq, A. Vioux, M. Pauthe and J. Phalippou, “Some new possibilities for the preparation of silica gels, in: J. D. McKenzie and D. R. Ulrich (Eds.), Ultrastructure Processing of Advenced Ceramics, Wiley, New York, N Y, pp.113-127 (1988).
35.S. Sakka, H. Kozuka and S. H. Kim, “Various factors affecting the conversion of silicon alkoxide solutions to gels,” in: J. D. Mckenzie and D. R. Ulrich (Eds.), Ultrastructure Processing of Advenced Ceramics, Wiley, New York, N Y, pp. 159-173(1988).
36.C. J. Brinker, K. D. Keefer, D. W. Schaeffer and C. S. Ashley, “Sol-gel transitions in simple silicates. I., J. Non-Cryst. Solids, 48, 47-64(1982).
37.C. J. Brinker, K. D. Keefer, D. W. Schaeffer, T. A. Assink, B. D. Key and C. S. Ashley, “Sol-gel transitions in simple silicates. II., J. Non-Cryst. Solids, 63, 45-59(1984).
38.C. J. Brinker and G. W. Scherer, “Sol-Gel Science”, Academic, New York, (1990)
39.E. Pope and J. Mackenzie, J. Non-Cryst. Solids, 87 (1986) 185
40.R. K. Iler ,”The Chemistry of Silica,” John Wiley & Sons, New York 1979.
41.A. Larbot, A. Julbe, C. Guizard and L. Cot., “Silica membranes by the sol-gel process,” J. membrane Sci., 44, 289-303 (1989).
42.J. Visser, “Adhesion of colloidal particles,” E. Matijevic (Ed.), surface and Colloid Science, Vol. 8, John Wiley & Sons, New York, N Y, p3. (1976).
43.Frédéric Mange, David Fauchadour, Loïc Barré, Laurent Normand, Loï Rouleau,” A microstructural investigation of nonstructural boehmite films prepared by the sol-gel route” Colloids and Surfaces, A: Physicochemical and Engineering Aspects, 155, 199-210 (1999).
44.Jeffrey Chi-Sheng Wu, Li-Chuen Cheng, An improved synthesis of ultrafiltration zirconia membranes via the sol-gel route using alkoxide precursor,” J. Membrane Sci. 167, 253-261(2000).
45.M. Mulder, Basic Principles of Membrane Technology, 茂昌圖書, 1990.
46.翁建龍, 「溶膠-凝膠法在製備均混合氧化物上的應用」, 私立淡江大學碩士論文, 1996.
47.王勝民, 「TiO2-SiO2觸媒載體的製備與應用」, 私立淡江大學碩士論文, 1998.
48.陳炫良,「除硝觸媒的製備與特性分析」, 私立淡江大學碩士論文, 2000.
49.溶膠凝膠法專輯, 化工, 第四卷第四期, 2000.