本研究以平板式掃流微過濾探討多醣體與蛋白質之分離純化。以孔徑0.025 micrometer之醋酸纖維濾膜，在pH=7下，過濾分子量為67 kDa的牛血清蛋白(BSA)與2000 kDa之葡聚醣(Dextran)，探討在不同的掃流速度與過濾壓差下，過濾速度、過濾阻力、物質的阻擋率與薄膜結垢情形。
研究結果顯示，過濾牛血清蛋白與葡聚醣雙成分懸浮液時，掃流速度愈大，濾速也會愈快。增加過濾壓差時，濾速會上升，但過濾阻力也會顯著增加。牛血清蛋白與葡聚醣會在膜面上形成可逆及不可逆的結垢層，這些結垢層即為過濾時的主要阻力來源。利用共軛焦掃描式雷射顯微鏡(CSLM)觀察濾膜中的結垢情形，發現牛血清蛋白較葡聚醣容易吸附在膜面上，提高過濾壓差則會增加牛血清蛋白在膜面的吸附量，而此結果也與傅氏紅外線吸收光諎儀(FTIR)所分析出來的膜面結垢物成分相同。以HPLC分析濾液中各成分之含量，發現牛血清蛋白與葡聚醣之阻擋率皆會隨著掃流速度的上升而增加，而隨著過濾壓差增加，牛血清蛋白之阻擋率會上升，葡聚醣則是隨之下降。若操作在低掃流速度、高過濾壓差的條件下，葡聚醣的回收率可達70 %，而牛血清蛋白則為15 %，顯示此過濾程序能夠獲得良好的選擇率，達到分離、濃縮雙成分物質的目的。量測實驗後濾膜表面之平均孔徑，在不同的過濾壓差下，其變化量很小，而由理論所估算出來之平均孔徑，則會隨著過濾壓差的升高有變小的趨勢，這表示薄膜結垢的型態主要是縮小膜孔。以所推導的理論分析薄膜結垢，發現可將通過結垢層壓為43 kPa時差視為一分界點，大於此壓力時的結垢層較薄，反之則較厚，且其厚度不會隨著過濾壓差而改變。以此分界點推算出濾液流向的臨界雷諾數為1.75×10-5，在大於此臨界雷諾數的操作條件下，會使具有可變形的葡聚醣分子產生拉伸行為，使之較易通過膜孔道，故其穿透率增加，但球形的牛血清蛋白則較不易受到流體流態的影響，所以阻擋率會隨著過濾壓差的上升而增加。

The separation and purification of polysaccharide/protein mixture using two-parallel-plate cross-flow microfiltration are studies. A binary suspension prepared by bovine serum albumin (BSA) with a molecular weight of 67 kDa and dextran with a molecular weight of 2000 kDa is filtered using a 0.025 micrometer cellulose acetate membrane. The effects of operating conditions, such as cross-flow velocity and filtration pressure, on the filtration flux, filtration resistance, molecular rejections and membrane fouling are discussed.
The results show that an increase in cross-flow velocity or filtration pressure leads to higher flux. The reversible and irreversible fouling layers on the membrane surface formed by BSA and dextran molecular adsorptions are the main filtration resistance sources. The results of CSLM and FTIR analyses indicate that BSA is the major foulant adsorbed on the membrane surface. The BSA adsorption increases with increasing filtration pressure. The concentrations of BSA and dextran in the filtrate are measured using HPLC. The results show that both BSA and dextran rejections increase with increasing cross-flow velocity. However, BSA rejection increases but dextran rejection contrarily decreases with increasing filtration pressure. An optimal condition can be achieved by operating at low cross-flow velocity and high filtration pressure. The dextran recovery is as high as 70%, but BSA recovery is only 15% in such conditions. The membrane surface pore sizes are measured before and after experiments using SEM and image analyses. The results indicate that the membrane fouling is mainly caused by pore size reduction. However, the effect of filtration pressure on the mean pore size is trivial. The mean pore sizes under various conditions are also estimated using a model derived based on hydrodynamics. The calculated mean pore size decreases with increasing filtration pressure. According to the proposed model, the critical pressure drop through the fouled membrane is found as 43 kPa. When the pressure drop is lower than 43 kPa, the fouled layer is thicker, and the thickness doesn’t vary with cross-flow velocity or pressure drop. In contrast, the fouled layer is thinner when the pressure drop exceeds the critical value. A critical Reynolds number in the filtration direction is determined as 1.75 × 10-5 from the critical pressure drop. When Reynolds number is higher than the critical value, the stretch (deformation) of dextran molecules leads them to be easier to penetrate through the membrane pores, as a result, to increase the molecular transmission. However, the morphology of BSA molecules is not affected by flow pattern since the low molecular weight and spherical shape. Therefore, the BSA rejection slightly increases with filtration pressure.

中文摘要	I
英文摘要	II
目錄	IV
圖目錄	VII
表目錄	XI
第一章 緒論	1
1-1 前言	1
1-2 研究目的	6
第二章 文獻回顧	7
2-1 蛋白質的過濾	7
2-1-1 蛋白質特性之影響	8
2-1-2 濾膜性質之影響	9
2-1-3 操作條件對蛋白質過濾之影響	11
2-2 多醣體的過濾	13
2-3 蛋白質/多醣體混合物的過濾	16
第三章 理論	19
3-1 過濾基本公式	19
3-2 阻擋率(Rejection)	20
3-3 回收率(Recovery)	21
3-4 薄膜結垢分析	22
第四章 實驗裝置與方法	24
4-1 實驗裝置	24
4-2 實驗材料	26
4-2-1 實驗藥品	26
4-2-2 實驗濾材	28
4-3 實驗設備與儀器	29
4-3-1 實驗設備	29
4-3-2 分析儀器	30
4-4 實驗方法與步驟	35
4-4-1 緩衝溶液與懸浮液之配置	35
4-4-2 掃流過濾之步驟	35
4-5 實驗數據分析	38
4-5-1 單成分濃度測定	38
4-5-2 雙成分濃度測定之步驟	39
4-5-3 濾膜表面結垢物的觀察	42
4-5-4 濾膜表面結垢物之染色與觀察	43
第五章 實驗結果與討論	44
5-1 單成分過濾的濾速及阻力分析	44
5-2 BSA-Dextran雙成分過濾的濾速及阻力分析	49
5-3 掃描式電子顯微鏡 (SEM)之結垢層分析	58
5-3-1 可逆與不可逆結垢層	58
5-3-2 不可逆結垢層	61
5-4 共軛焦掃描式雷射顯微鏡 (CSLM)之分析	63
5-5 傅氏紅外線吸收光譜儀 (FTIR)之分析	66
5-6 液相層析儀 (HPLC)之分析	69
5-7 薄膜結垢分析	74
第六章 結論	87
符號說明	89
參考文獻	92
附錄	97
附錄A實驗藥品之詳細資料	97
附錄B實驗設備與儀器之詳細資料	101
附錄C濾膜之詳細資料	103

圖目錄
                                                    
第一章
Fig.1- 1 Schematics of dead-end filtration and cross-flow filtration.2
Fig.1- 2 The filtration spectrum.	3

第四章
Fig.4- 1 A schematic diagram of cross-flow filtration system.	25
Fig.4- 2 The calibration curve of BSA concentration of 0~0.15 wt% in UV/Vis Spectrophotometer.	39
Fig.4- 3 The calibration curve of Dextran concentration of 0~0.2 wt% in HPLC.	41
Fig.4- 4 The calibration curve of BSA concentration of 0~0.2 wt% in HPLC.	42

第五章
Fig.5- 1 Time courses Filtration flux in cross-flow microfiltrateion of dextran under different filtration pressures.	44
Fig.5- 2 Filtration resistances of dextran in cross-flow microfiltrateion under different filtration pressures.	46
Fig.5- 3 Time courses Filtration flux in cross-flow microfiltrateion of BSA under different filtration pressures.	47
Fig.5- 4 Filtration resistances of BSA in cross-flow microfiltrateion under different filtration pressures.	48
Fig.5- 5 Filtration pressures courses of pseudo steady state filtration rates in cross-flow microfiltrateion under various cross-flow velocities.	50
Fig.5- 6 Filtration resistances in cross-flow microfiltrateion under different filtration pressures.	51
Fig.5- 7 Filtration resistances in cross-flow microfiltrateion under different filtration pressures.	52
Fig.5- 8 Filtration resistances in cross-flow microfiltrateion under different filtration pressures.	53
Fig.5- 9 Filtration resistance of concentration polarization in cross-flow microfiltrateion under different cross-flow velocity.	55
Fig.5- 10 Filtration resistance of reversible fouled layer in cross-flow microfiltrateion under different cross-flow velocity.	56
Fig.5- 11 Filtration resistance of irreversible fouled layer in cross-flow microfiltrateion under different cross-flow velocity.	57
Fig.5- 12 The side view of membrane surface after binary suspension filtration experiment without flush by SEM.	59
Fig.5- 13 The side view of membrane surface after binary suspension filtration experiment with flush by SEM.	59
Fig.5- 14 The side view of membrane surface after binary suspension filtration experiment without flush by SEM.	60
Fig.5- 15 The side view of membrane surface after binary suspension filtration experiment with flush by SEM.	60
Fig.5- 16 The side view of membrane surface after binary suspension filtration experiment with ultrasonication by SEM.	61
Fig.5- 17 The side view of membrane surface after binary suspension filtration experiment without ultrasonication by SEM.	62
Fig.5- 18 The 3D reconstruction of image stacks obtained clean membrane by CSLM.	63
Fig.5- 19 The 3D reconstruction of image stacks obtained after filtration experiment of binary suspension.	64
Fig.5- 20 The 3D reconstruction of image stacks obtained after filtration experiment of binary suspension.	64
Fig.5- 21 The FTIR analysis of membrane, BSA powder and dextran powder.	66
Fig.5- 22 The FTIR analysis of membrane, BSA powder, dextran powder and membrane surface after filtration experiment.	68
Fig.5- 23 The response signal curve of single and binary suspension by HPLC.	70
Fig.5- 24 Effect of filtration pressures and cross-flow velocities on the transmission of BSA and dextran.	71
Fig.5- 25 Effect of filtration pressures and cross-flow velocities on recovery of BSA and dextran.	73
Fig.5- 26 The average   of experiment and theory.	75
Fig.5- 27 A plot of   to   under different cross-flow velocity	77
Fig.5- 28 A plot of   to   under different cross-flow velocity at low  .	78
Fig.5- 29 The fouled layer thickness under different cross-flow velocity and different range  .	79
Fig.5- 30 A plot of   to   under different cross-flow velocity.	80
Fig.5- 31 A plot of   to   under different cross-flow velocity.	81
Fig.5- 32 Effect of filtration pressures and cross-flow velocities on the rejection of BSA and dextran.	83
Fig.5- 33 Effect of   on the rejection of BSA and Dextran.	85

附錄
Fig.A- 1 Size distribution of BSA.	97
Fig.A- 2 Size distribution of Dextran.	98
Fig.C- 1 The top view of the 0.025 

表目錄
                                                   
第四章
Table4- 1 Operating condition	37

Bird, R. B., W.E. Stewart, E.N. Lightfoot, Transport phenomena, 2nd edition, Chap.2, Wiley & Sons, NY, USA (2002). 
de la Casa, E. J., A. Guadix, R. Ibáñez, and E. M. Guadix, "Influence of pH and salt concentration on the cross-flow microfiltration of BSA through a ceramic membrane", Biochem.Eng.J, 33, (2), 110-115 (2007). 
Ehsani, N., S. Parkkinen, and M. Nyström, "Fractionation of natural and model egg-white protein solutions with modified and unmodified polysulfone UF membranes", J. Membr. Sci., 123, (1), 105-119 (1997). 
García-Molina, V., S. Esplugas, T. Wintgens, and T. Melin, "Ultrafiltration of aqueous solutions containing dextran", Desalination, 188, (1-3), 217-227 (2006). 
Ghosh, R. and Z. F. Cui, "Fractionation of BSA and lysozyme using ultrafiltration: effect of pH and membrane pretreatment", J. Membr. Sci., 139, (1), 17-28 (1998). 
Ghosh, R. and Z. F. Cui, "Protein purification by ultrafiltration with pre-treated membrane", J. Membr. Sci., 167, (1), 47-53 (2000). 
Güell, C. and R. H. Davis, "Membrane fouling during microfiltration of protein mixtures", J. Membr. Sci., 119, (2), 269-284 (1996). 
Güell, C., P. Czekaj, and R. H. Davis, "Microfiltration of protein mixtures and the effects of yeast on membrane fouling", J. Membr. Sci., 155, (1), 113-122 (1999). 
Huisman, I. H., P. Prádanos, and A. Hernández, "The effect of protein–protein and protein–membrane interactions on membrane fouling in ultrafiltration", J. Membr. Sci., 179, (1-2), 79-90 (2000). 
Hwang, K. J. and K. P. Lin, "Cross-flow microfiltration of dual-sized submicron particles", Sep. Sci. Technol., 37, (10), 2231-2249 (2002). 
Hwang, K. J. and Y. H. Cheng, "The role of dynamic membrane in cross-flow microfiltration of macromolecules", Sep. Sci. Technol., 38, (4), 779-795 (2003). 
Hwang, K. J., Y. H. Cheng, and K. L. Tung, "Modeling of cross-flow microfiltration of fine particle/macromolecule binary suspension", J. Chem. Eng. Jpn., 36, (12), 1488-1497 (2003). 
Hwang, K. J. and H. C. Hwang, "The purification of protein in cross-flow microfiltration of microbe/protein mixtures", Sep. Purif. Technol., 51, (3), 416-423 (2006). 
Kanani, D. M., X. Sun, and R. Ghosh, "Reversible and irreversible membrane fouling during in-line microfiltration of concentrated protein solutions", J. Membr. Sci., 315, (1-2), 1-10 (2008). 
Kelly, S. T. and A. L. Zydney, "Mechanisms for BSA fouling during microfiltration", J. Membr. Sci., 107, (1-2), 115-127 (1995). 
Lu, W. M., K. L. Tung, and K. J. Hwang, "Effect of woven structure on transient characteristics of cake filtration", Chem. Eng. Sci., 52, (11), 1743-1756 (1997). 
Nakamura, K. and K. Matsumoto, "Adsorption behavior of BSA in microfiltration with porous glass membrane", J. Membr. Sci., 145, (1), 119-128 (1998). 
Nataraj, S., R. Schomäcker, M. Kraume, I. M. Mishra, and A. Drews, "Analyses of polysaccharide fouling mechanisms during crossflow membrane filtration", J. Membr. Sci., 308, (1-2), 152-161 (2008). 
Ouammou, M., N. Tijani, J. I. Calvo, C. Velasco, A. Martín, F. Martínez, F. Tejerina, and A. Hernández, "Flux decay in protein microfiltration through charged membranes as a function of pH", Colloids Surf. Physicochem. Eng. Aspects, 298, (3), 267-273 (2007). 
Polotsky, A. E. and A. N. Cherkasov, "On the mechanism of flexible chain polymer ultrafiltration", Sep. Sci. Technol., 41, (9), 1773-1787 (2006). 
Ramesh Babu, P. and V. G. Gaikar, "Membrane characteristics as determinant in fouling of UF membranes", Sep. Purif. Technol., 24, (1-2), 23-34 (2001). 
Rodriguez, S., C. Romero, M. L. Sargenti, A. J. Muller, A. E. Saez, and J. A. Odell, "Flow of polymer solution through porous media", J. Non-Newtonian Fluid mech., 49, (1), 63-85 (1993).
Susanto, H. and M. Ulbricht, "Influence of ultrafiltration membrane characteristics on adsorptive fouling with dextrans", J. Membr. Sci., 266, (1-2), 132-142 (2005). 
Susanto, H., H. Arafat, E. M. L. Janssen, and M. Ulbricht, "Ultrafiltration of polysaccharide-protein mixtures: Elucidation of fouling mechanisms and fouling control by membrane surface modification", Sep. Purif. Technol., 63, (3), 558-565 (2008). 
Vernhet, A. and M. Moutounet, "Fouling of organic microfiltration membranes by wine constituents: importance, relative impact of wine polysccharides and polyphenols and incidence of membrane properties", J. Membr. Sci., 201, (1-2), 103-122 (2002). 
Wavhal, D. S. and E. R. Fisher, "Membrane surface modification by plasma-induced polymerization of acrylamide for improved surface properties and reduced protein fouling", Langmuir, 19, (1), 79-85 (2003). 
Ye, Y., P. L. Clech, V. Chen, and A. G. Fane, "Evolution of fouling during crossflow filtration of model EPS solutions", J. Membr. Sci., 264, (1-2), 190-199 (2005). 
Ye, Y., P. Le Clech, V. Chen, A. G. Fane, and B. Jefferson, "Fouling mechanisms of alginate solutions as model extracellular polymeric substances", Desalination, 175, 7-20 (2005). 
Zator, M., M. Ferrando, F. López, and C. Güell, "Membrane fouling characterization by confocal microscopy during filtration of BSA/dextran mixtures", J. Membr. Sci., 301, (1-2), 57-66 (2007). 
Zydney, A. L., "Protein Separations Using Membrane Filtration: New Opportunities for Whey Fractionation", Int. Dairy J., 8, (3), 243-250 (1998).