臺灣博碩士論文加值系統

摘 要

基於膜電荷之量測有助於膜過濾時對膜材之選擇及操作條件等提供重要的參考依據，但目前膜電荷量測的技術仍未成熟，本研究比較以電滲透及流線電位所決定之PC與PVDF等薄膜之膜孔及膜面界達電位的差異，並嘗試建立量測膜內淨電荷密度之方法。
薄膜界達電位深受pH 值及離子濃度之影響，結果顯示， PC薄膜在所操作之pH=3.8~7範圍內皆帶負電荷，對同材質但孔徑不同之PC膜，其膜面電位有明顯差異。由白金、氧化銥及銀/氯化銀等三種電極所測得之膜面電位，其中銀/氯化銀與氧化銥兩電極所獲致的定量結果較為接近，整體而言，由白金電極所測得之膜電位較小，此與各別電極的過電壓有關。
以流線電位法決定所選用孔徑之PC及PVDF兩微過濾膜之膜面與膜孔電位，結果顯示膜面電位甚接近於膜孔電位。而由電滲透法與流線電位法兩電動方法獲得之膜孔電位，於小孔徑之薄膜在10-3M低離子濃度下，二者則有明顯的差距約10mV，且以電滲透法所得之界達電位較大。
由電滲透法與流線電位法所決定之淨電荷密度值，顯示不同孔徑之PC薄膜有明顯差異之淨電荷密度值，不同電動方式所決定之淨電荷密度值於定量上仍有明顯的差異，至於何者較接近真實淨電荷密度值仍有待進一步研究。
本文所探討之兩種商業型奈米過濾膜，雖然其膜面界達電位之差異甚小，但膜內淨電荷密度卻有很大差異，基於膜面電位及膜內淨電荷密度對NF膜之離子阻擋各有其作用，故不能單獨從膜面界達電位預估其分離效能，本研究提出此方法以對奈米過濾膜之分離效能的預估能建立有效之參考數據。

ABSTRACT

It has been recognized that the charge of membrane plays an important role in the performance of membrane separation, and so there is much interesting in charactering the charge of membrane. However, there is still an inadequate knowledge in the technique for measuring the membrane charge.
In this study, the solution conductivity in the fine pore was measured and used to determine the zeta potential in membrane pore. Experiments of electroosmosis and streaming potential were implemented to determine the zeta potential of PC and PVDF membranes. The differences between the zeta potential of membrane pore and that of membrane surface were analyzed. Besides, we attempted to develop a method for determining bulk charge density of membranes.
Experiments results indicated that in the pH range from 3.8 to 7.0 used in the study the zeta potential of PC membrane are negative and decrease with the increase of the pH value. There is an obvious difference between various pore size PC membranes. This is due to the membrane pore size is controlled by changing the chemical/physical conditions during membrane formulation. A comparison of the zeta potential of membrane determined using three different electrodes showed that the zeta potential measured by Ag/AgCl and IrO2 electrodes are very close, but the platinum electrode gives the least zeta potential as a whole.
The zeta potentials of PC and PVDF membranes determined by streaming potential measurement revealed that each ζsurface is approach its ζpore. As compared the �瘼ore values measured by the streaming potential with that by electroosmosis methods, it indicated that both methods give a similar result for the larger pore size membranes. However, for the smaller pore size membranes at low electrolyte concentration both methods show an obvious difference in �瘼ore and a larger zeta potentials were always obtained from the latter method.
A combination of hydraulic permeability and electrokinetic flow tests was used to design a method for determining the bulk charge density of membranes. Experimental results from PC membranes showed that the bulk charge density varies with the membrane pore and there is a quite difference between the bulk charge density determined from electroosmosis and that from streaming potential method. The causes of leading to such a result is needed to be probed into yet.
In this study, two nanofiltration membranes were also used to determine its membrane surface zeta potential and bulk charge density. Although both membranes have very close surface zeta potential, but there is a considerable difference in the net charge density. Due to the surface zeta potential and the bulk charge density both are the important parameters in determining NF’s ionic rejection, we could not give a qualitative prediction of the NF performance only based on the surface zeta potential data.

目 錄

中文摘要 …………………………………………………………… Ⅰ
英文摘要 …………………………………………………………… Ⅲ
誌謝 ………………………………………………………………… Ⅴ
目錄 ………………………………………………………………… Ⅵ
圖表索引 …………………………………………………………… Ⅹ
第一章 緒論………………………………………………………… 1
第二章 文獻回顧…………………………………………………… 4
2-1 多孔體內的電動象………………………………… 4
2-1-1 電滲透…………………………………… 4
2-1-2 流線電位………………………………… 7
2-1-3 電動黏度效應…………………………… 10
2-2 膜界達電位的決定………………………………… 11
2-2-1 以電滲透法量測………………………… 11
2-2-2 以平行膜面流線電位法量測…………… 13
2-2-3 垂直膜孔之流線電位量測……………… 19
2-2-4 比較兩種電動量測所決定之膜界達電位 22
2-2-5 電動現象量測之其他應用……………… 27
2-3 多孔體單位體積淨電荷密度的決定……………… 29
第三章 理論背景 ………………………………………………… 30
3-1 電滲透……………………………………………… 30
3-2 流線電位…………………………………………… 34
3-2-1 膜孔(孔徑均一)之流線電位 …………… 34
3-2-2 兩平行板間之流線電位………………… 37
3-3 由膜電阻量測決定膜孔內溶液之電導度………… 41
3-4 多孔體單位體積淨電荷密度之量測……………… 43
第四章 實驗設備及步驟…………………………………………… 46
4-1 實驗材料…………………………………………… 46
4-2 實驗裝置…………………………………………… 47
4-2-1 膜內部電導度實驗……………………… 47
(a) 膜電阻量測系統……………………… 47
(b) 交流阻抗分析法……………………… 48
4-2-2 流線電位量測系統……………………… 48
(a) 膜孔流線電位量測系統……………… 49
(b) 膜面流線電位量測系統……………… 49
4-2-3 電滲透量測系統………………………… 49
4-3 實驗儀器…………………………………………… 58
4-4 實驗步驟…………………………………………… 62
4-4-1 膜內部電導度實驗……………………… 62
(a) 膜電阻量測實驗……………………… 62
(b) 交流阻抗分析法……………………… 62
4-4-2 流線電位實驗…………………………… 63
(a) 膜面流線電位之量測………………… 63
(b) 膜孔流線電位之量測………………… 64
4-4-3 電滲透實驗……………………………… 65
(a) 機械滲透係數量測…………………… 65
(b) 膜孔電滲透實驗……………………… 66
第五章 結果討論…………………………………………………… 68
5-1 電動方程修正因子………………………………… 68
5-1-1 毛細管內之電動現象…………………… 68
5-1-2 兩平行面間之電動現象………………… 69
5-1-3 膜孔洞內電導度修正…………………… 70
5-2 溶液pH值對薄膜電性之影響……………………… 76
5-2-1 PC膜之膜面界達電位………………… 76
5-2-2 PVDF膜之膜面界達電位……………… 79

5-2-3 比較白金、銀/氯化銀及氧化銥等電極所決
定之膜面界達電位…………………………

81
5-3 離子濃度對薄膜界達電位之影響………………… 83
5-3-1 PC膜界達電位………………………… 83
5-3-2 PVDF膜界達電位……………………… 90
5-3-3 奈米過濾膜之膜面界達電位…………… 90
5-4 膜內部淨電荷密度………………………………… 93
5-4-1 滲透係數之決定………………………… 93
5-4-2 PC薄膜之淨電荷密度………………… 94
5-4-3 奈米過濾膜之淨電荷密度……………… 96
第六章 結論………………………………………………………… 102
符號說明 …………………………………………………………… 104
參考文獻 …………………………………………………………… 108
附錄 A …………………………………………………………… 115
附錄 B …………………………………………………………… 117
附錄 C …………………………………………………………… 119
附錄 D …………………………………………………………… 120
自述 ………………………………………………………………… 121

圖表索引

圖目錄
Fig. 2-1 Schematic diagram of the electrical double layer.…………… 5
Fig. 3-1 Schematic diagram of potential distribution in a capillary in
cylindrical coordinates（r,θ,z）…………………………… 32
Fig. 3-2 Effect of κR on the value of corrected factor F. …………… 36
Fig. 3-3 Schematic diagram of potential distribution between two
parallel plates in rectangular coordinates（y,z）……………… 39
Fig. 3-4 Effect of κb on the value of corrected factor F.……………… 40
Fig. 3-5 Schematic diagram of measuring electrical resistance inside
membrane pores. …………………………………………… 42
Fig. 3-6 Schematic diagram of fluid through porous membrane. …… 44
Fig. 4-1 Experiment for measuring electrical resistance inside
membrane pores. …………………………………………… 51
Fig. 4-2 Details of the chamber for measuring electrical resistance
inside membrane pores……………………………………… 52
Fig. 4-3 Schematic diagram of ion conductivity measurement system
for membrane pores.………………………………………… 53
Fig. 4-4 Details of membrane test cell for measuring ion conductivity
inside membrane pores.……………………………………… 54
Fig. 4-5 Schematic diagram of the streaming potential measurement. 55
Fig. 4-6 Details of the chamber for measuring streaming potential
through membrane pores.…………………………………… 56
Fig. 4-7 Details of the chamber for measuring streaming potential at
membrane surfaces. ………………………………………… 57
Fig. 4-8 Experimental device for measuring electroosmotic flow
through membrane. ………………………………………… 60
Fig. 4-9 Details of the chamber for measuring electroosmotic flow.… 61
Fig. 5-1 Effect of the KCl concentration on the km/kb ratio. ………… 74
Fig. 5-2 Effect of the KCl concentration on the km/kb ratio measured
by EIS ……………………………………………………… 75
Fig. 5-3 Streaming potential for 10-3 M KCl solution flow between
two parallel 0.8μm PC membranes. ………………………… 77
Fig. 5-4 Zeta potential of PC membranes determined by tangential
streaming potential（TSP）measurement under various
pH values. …………………………………………………… 78
Fig. 5-5 Zeta potential of 0.22μm PVDF membranes determined by
tangential streaming potential（TSP）measurement under
various pH values.…………………………………………… 80
Fig. 5-6 Zeta potential of 0.8μm PC membranes determined by
tangential streaming potential（TSP）measured with
different various electrodes. ………………………………… 82
Fig. 5-7 Streaming potential across 0.2μm PC membrane at different
KCl concentrations. ………………………………………… 84
Fig. 5-8 Electroosmotic flow rate across 0.2μm PC membrane at
different KCl concentrations. ……………………………… 85
Fig. 5-9 Zeta potential of PC membranes determined by tangential
streaming potential（TSP）measurement at different KCl
concentrations. ……………………………………………… 87
Fig.5-10 Comparison of zeta potential of 0.2μm PC membrane
determined by tangential streaming potential（TSP）、
Electroosmosis（EO）and filtration streaming potential
（FSP）measurement under various KCl concentrations. …… 88
Fig.5-11 Comparison of zeta potential of 0.8μm PC membrane
determined by tangential streaming potential（TSP）、
Electroosmosis（EO）and filtration streaming potential
（FSP）measurement under various KCl concentrations. …… 89
Fig.5-12 Comparison of zeta potential of PVDF membrane
determined by tangential streaming potential（TSP）、
and filtration streaming potential （FSP）measurement
under various KCl concentrations.…………………………… 91
Fig.5-13 Zeta potential of NF membranes determined by tangential
streaming potential（TSP）measurement at different KCl
concentrations. ……………………………………………… 92
Fig.5-14 Net charge density in PC membrane at different KCl
concentrations determined by electroosmosis（EO）and
streaming potential（SP）. …………………………………… 95
Fig.5-15 Electroosmotic flow rate across NF（DL）membrane at
different KCl concentrations.………………………………… 97
Fig.5-16 Electroosmotic flow rate across NF（NF-90）membrane at
different KCl concentrations.………………………………… 98
Fig.5-17 Net charge density in NF membrane at different KCl
concentrations. ……………………………………………… 100

表目錄
Table 5-1 F vs. KCl concentration & pore size. ……………………… 69
Table 5-2 Electrical resistance and porosity measured data of 0.2μm
PC membrane.……………………………………………… 71
Table 5-3 Electrical resistance and porosity measured data of 0.4μm
PC membrane.……………………………………………… 71
Table 5-4 Electrical resistance and porosity measured data of 0.8μm
PC membrane.……………………………………………… 72
Table 5-5 Electrical resistance and porosity measured data of 0.22μm
PVDF membrane. ………………………………………… 72
Table 5-6 Permeability measured data of membranes used. ………… 93
Table 5-7 Electrical resistance and porosity measured data of NF
membrane. ………………………………………………… 99

參考文獻

Afonso, M. D., Hagmeyer, G., Gimbel, R., “Streaming Potential Measurements to Assess the Variation of Nanofiltration Membranes Surface Charge with the Concentration of Salt Solutions,” Separation and Purification Technology , 22-23, 529-541（2001）

Ariza, M.J., Cañas , A., Benavente, “Electrokinetic and Electrochemical Characterizations of Porous Membranes,” Colloids and Surfaces A： Physicochemical and Engineering Aspects , 189, 247-256（2001）

Ariza, M. J., Benavente, J., “Streaming Potential Along the Surface of Polysulfone Membranes : A Comparative Study Between Two Different Experimental Systems and Determination of Electrokinetic and Adsorption Parameters,” J. Membrane Sci., 190, 119-132（2001）

Ariza, M. J., Cañas, A., Malfeito, J., Benavente, J., “Effect of pH on Electrokinetic and Electrochemical Parameters of Both Sub-layers of Composite Polyamide/polysulfone Membrane,” Desalination, 148, 377-382（2002）

Bowen, W. R. and Clark, R. A., “Electro-osmosis at Microporous Membranes and the Determination of Zeta-Potential,” J. Colloid Interface Sci. 97, 401-409（1984）

Bowen, W. R., and Cao, X., “Electrokinetic Effects in Membrane Pores and the Determination of Zeta Potential,” J. Membrane Sci., 140, 267-273（1998）

Condom, S.,Chemlal, S., Chu, W., Persin, M.,Larbot, A., “Correlation Between Selectivity and Surface Charge in Cobalt Spinel Ultrafiltration Membrane,” Separation and Purification Technology ,25 ,545-548（2001）

Condom, S., Cretin, M.., Persin, M., Larbot, A., “Characterization of Three Low UF Mineral Membranes by Streaming Potential Measurements,” Desalination, 149, 447-451（2002）

Chun, Myung-Suk, Cho, Hong Il, Song, In Kyu, “Electrokinetic Behavior
of Membrane Zeta Potential During the Filtration of Colloidal Suspensions,” Desalination, 148, 363-367（2002）

Deshmukh, Shivaji, Childress, Amy E., “Zeta Potential of Commercial RO Membranes : Influence of Source Water Type and Chemistry,” Desalination, 140, 87-95（2001）

Elmarraki, Y., Persin, M., Sarrazin, J.,Cretin, M., Larbot, A., “Filtration of electrolyte solutions with new TiO2-ZnAl2O4 ultrafiltration membranes in relation with the electric surface properties,” Separation and Purification Technology, 25, 493-499（2001）

Fievet, P., Aoubiza, B., Szymczyk, A. and Pagetti, J., “Membrane Potential in Charged Porous Membranes,” J. Membrane Sci., 160, 267-275（1999）

Fievet, P., Szymczyk, A. Labbez, C., Aoubiza, B., Simon, C., Foissy, A., Pagetti, J., “Determining the Zeta Potential of Porous Membranes Using Electrolyte Conductivity inside Pores,” J. Colloid Interface Sci., 235, 383-390 ( 2001 )

Fievet, P., Sbaï, M., Szymczyk, A., Vidonne, A., “Determining the ζ-potential of Plane Membranes from Tangential Streaming Potential Measurements：Effect of the Membrane Body Conductance,” J. Membrane Sci., 226, 227-236（2003）

Gu, Yongan and Li, Dongqing, “The ζ-Potential of Glass Surface in Contact with Aqueous Solutions,” J. Colloid Interface Sci., 226, 328-339（2000）

Huisman, I. H., Tragardh, G. and Pihlajamaki, A., “Determining the Zeta- Potential of Ceramic Microfiltration Membranes Using the Electroviscous Effect,” J. Membrane Sci. 147, 187-194（1998）

Huisman, I. H., Pradanos, P., Calvo, J. I., Hernandez, A., “Electroviscous Effects, Streaming Potential, and Zeta Potential in Polycarbonate Track-Etched Membranes,” J. Membrane Sci., 178, 79-92（2000a）

Huisman, I. H., Pradanos, P., Hernandez, A., “Electrokinetic Characterization of Ultrafiltration Membrane by Streaming Potential , Electroviscous Effect ,and Salt Retention,” J. Membrane Sci., 178, 55-64（2000b）

Kang, Y., Yang, C., Huang, X., “Electroosmotic Flow in a Capillary Annulus with High Zeta Potentials,” J. Colloid Interface Sci., 253, 285-294（2002）

Kim, K. J., Fane, A. G., Nystrom, M., Pihlajamaki A., Bowen, W. R., and Mukhtar H., “Evaluation of Electroosmosis and Streaming Potential for Measurement of Electric Charges of Polymeric Membranes,” J. Membrane Sci., 116, 149-159（1996）

Kobayashi,K., Yukawa, H.,Iwata,M. and Hosoda ,T., “Fundamental Study of Electroosmotic Flow Through Perforated Membrane,” J. Chem. Eng. Japan, 12, 466-471（1979）

Lettmann, Christian, Mockel, Dirk, Staude, Eberhard, “Permeation and Tangential Flow Streaming Potential Measurements for Electrokinetic Characterization of Track-Etched Microfiltration Membranes,” J. Membrane Sci.159, 243-251（1999）

Makino, K., Suzuki, K., Sakurai, Y., Okano, T., Ohshima, H., “Electroosmotic Flow on a Poly (N-isopropylacrylamide) Hydrogel Surface,” Colloids and Surfaces A: Physicochemical and Engineering Aspects, 103, 221-226（1995）

Martín, A., Martínez, F., Malfeito, J., Palacio, L., Prádanos, P., Hernández, A., “Zeta Potential of Membranes as a Function of pH: Optimization of Isoelectric Point Evaluation,” J. Membrane Sci.213, 225-230（2003）

Mockel, Dirk, Staude, Eberhard, Mauro, Dal-Cin, Darcovich, Ken, Guiver, Michael, “Tangeential Flow Streaming Potential Measurements: Hydrodynamic Cell Characterization and Zeta Potentials of Carboxylated Polysulfone,” J. Membrane Sci 145, 211-222（1998）

Moritz, T., Benfer, S., Arki, P., Tomandl, G., “Influence of Surface Charge on the Permeate Flux in the Dead-end Filtration with Ceramic Membrane,” Separation and Purification Technology 25, 501-508（2001a）

Moritz, T., Benfer, S., Arki, P., Tomandl, G., “Investigation of Ceramic Membrane Materials by Streaming Potential Measurements,” Colloids and Surfaces A: Physicochemical and Engineering Aspects, 47, 25-33（2001b）

Pontie, M., Chasseray, X., Lemordant, D., Laine, J.M., “The Streaming Potential Method for the Characterization of Ultrafiltration Organic Membranes and the Control of Cleaning Treatments,” J. Membrane Sci.129, 125-133（1997）

Pontie, M., “Effect of Aging on UF Membranes by a Streaming Potential（SP） Method,” J. Membrane Sci.154, 213-220（1999）

Ren Liqing and Li Dongqing, “Electroosmotic Flow in Heterogeneous Microchannels,” J. Colloid Interface Sci., 243, 255-261（2001）

Rice, C. L. and Whitehead R., “Electrokinetic Flow in a Narrow Cylindrical Capillary,” J. Phys. Chem., 69, 4017-4024（1965）

Ricq, L., Pieere, A., Reggiani, J. C., Pagetti, J., “Electrokinetic Characterization of Polyethersulfone UF Membranes,” Desalination 109, 253-261（1997a）

Ricq, L., Pieere, A., Reggiani, J. C., Pagetti, J., “Streaming Potential and Ion Transmission During Ultra- and Microfiltration on Inorganic Membranes,” Desalination 114, 101-109（1997b）

Ricq, L., Pagetti, J., “Inorganic Membrane Selectivity to Ions in Relation with Streaming Potential,” J. Membrane Sci., 155, 9-18（1999）

Sbaï, M., Szymczyk A., Fievet, P., Sorin, A., Vidonne, A., Pellet-Rostaing, S., Favre-Reguillon, A., Lemaire, M., “Influence of the Membrane Pore Conductance on Tangential Streaming Potential,” Langmuir,. 19 (21), 8867-8871（2003a）

Sbaï, M., Fievet, P., Szymczyk, A., Aoubiza, B., Vidonne, A., Foissy, A., “Streaming potential, electroviscous effect, pore conductivity and membrane potential for the determination of the surface potential of a ceramic ultrafiltration membrane,” J. Membrane Sci., 215, 1-9（2003b）

Schaep, Johan, Vandecasteele, carlo, “Evaluating the Charge of Nanofiltration Membranes,” J. Membrane Sci.188, 129-136（2001）

Szymczyk, A., Pierre, A., Reggiani, C.R., Pagetti, J., “Characterization of the Electrokinetic Properties of Plane Inorganic Membranes Using Streaming Potential Measurements,” J. Membrane Sci., 134, 59-66 （1997）

Szymczyk, A., Fievet, P., Reggiani, J.C., Pagetti, J., “Electrokinetic Characterization of Mixed Alumina-titania-silica MF Membranes by Streaming Potential Measurements,” Desalination 115, 129-134（1998a）

Szymczyk, A., Fievet, P., Reggiani, J. C., Pagetti, J., “Comparison of Two Electrokinetic Methods –Electroosmosis and Streaming Potential – to Determine the Zeta Potential of Plane Ceramic Membrane,” J. Membrane Sci. 143, 189-195（1998b）

Szymczyk, A., Fievet, P.,Mullet, M., Reggiani, J.C., Pagetti, J., “Study of electrokinetic properties of plate ceramic membranes by electroosmosis and streaming potential,” Desalination 119, 309-313（1998c）

Szymczyk, A., Fievet, P., Aoubiza, B., Simon, C., Pagetti, J., “An Application of the Space Model to the Electrolyte Conductivity Inside a Charged Microporous Membrane,” J. Membrane Sci. 161, 275-285（1999）

Teixeira, M. R., Rosa, M. J., Nyström, M., “The Role of Membrane Charge on Nanofiltration Performance,” J. Membrane Sci. 265, 160-166（2005）

Tsao, Heng-Kwong, “Electroosmotic Flow through an Annulus,” J. Colloid Interface Sci., 225, 247-250（2000）

Walker, Sharon L., Bhattacharjee, Subir, Hoek, Eric M. V., Elimelech, Menachem, “A Novel Asymmetric Clamping Cell for Measuring Streaming Potential of Flat Surfaces,” Langmuir, 18, 2193-2198 ( 2002 )

Wang, J., Liu, Z., Liu, J., He, Q., “Determination of Zeta-Potential by Measuring Electroosmotic Flux in an Alternating Electric Field and Its Applications in the Study of Membrane Fouling,” Separation Science and Technology, 35(8), 1195-1206（2000）

Welzel, Petra B., Rauwolf, Cordula, Yudin, Olexandr, Grundke, Karina, “Influence of Aqueous Electrolytes on the Wetting Behavior of Hydrophobic Solid Polymers-Low-Rate Dynamic Liquid/Fluid Contact Angle Measurements Using Axisymmetric Drop Shape Analysis,” J. Colloid Interface Sci., 251, 101-108（2002）

Wu, R.C. and Papadopoul, K.D., “Electroomotic Flow through Porous Media: Cylindrical and Annular Models,” Colloids and Surfaces A:161, 469-476（2000）

Zembala, Maria, Adamczyk, Zbigniew, “Measurements of Streaming
Potential for Mica Covered by Colloid Particles,” Langmuir, 16, 1593-1601（2000）

曹鴻富,“電泳動、電滲透ζ-電位的差異,” 碩士學位論文, 中央大學化工所,（1999）

李維倫,“含浸磺酸化聚苯乙烯之聚四氟乙烯膜於燃料電池質子交換膜之應用,” 碩士學位論文,元智大學化工所,（2002）

連俊旭, “電滲透脫水床脫水速率及含水率分佈的探討,” 碩士學位論文, 中原大學化工所,（1998）

許惠如, “以電滲透及流線電位決定薄膜之界達電位,” 碩士學位論文, 中原大學化工所,（2002）

江宜蓁,“薄膜電荷量測與膜過濾電動現象分析,”碩士學位論文,中原大學化工所,（2003）

張有義和郭蘭生,“膠體及界面化學入門,”高立圖書,台北（2001）

鄭領英和王學松,“膜的高科技應用,”五南圖書,台北（2003）