 本研究著重在發展低溫型直接甲醇燃料電池（Direct methanol fuel cell, DMFC）之電解質薄膜，用以取代價格昂貴且甲醇滲透率過高的Nafion薄膜。此研究選用價格便宜、成膜性高、具優良化學穩定性且對醇/水系統具有良好選擇率的聚乙烯醇( polyvinyl alcohol , PVA )作為質子交換膜主體，再利用4-醛基-1,3苯磺酸鈉鹽（4-Formyl-1,3-Benzenedisulfonic acid, disodium salt，DSDSBA）作磺酸化處理，引進磺酸根(SO3H)，來提高氫離子的傳導性，然後利用戊二醛當交聯劑行交聯反應，以提高PVA薄膜結構的穩定性及其機械性質。而後並對開發之改質PVA有機膜材作一系列性質分析及研究，包括：合成後薄膜的結構鑑定、熱性質分析、氫離子導電度、甲醇滲透率、含水率、自由水分子和氫鍵鍵結之水分子的比例等性質分析，並探討SPVA薄膜於成膜過程中結構發生的變化。
 從in-situ IR研究結果顯示，H+ type SPVA薄膜，水分子與高分子鏈間之氫鍵、水分子與SO3H 間之氫鍵及分子內與分子間之氫鍵皆於成膜過程中逐漸變強；而Na+ type SPVA 薄膜於成膜過程中氫鍵變化趨勢恰與其相反；由NMR T1ρ分析的結果可知經磺酸化改質後之SPVA薄膜上的CH-OH分子鏈段比未改質前主鏈上CH-OH的分子鏈段還具有柔曲運動性。綜合TGA及TPD/MS分析可知SPVA側鏈上的OH- groups的裂解溫度約150~200℃、SPVA上之磺酸根的裂解溫度約220~380℃、390~480℃則為SPVA側鏈上之苯環結構及主鏈兩端主鏈的裂解溫度範圍、480℃後就為主鏈及其骨架裂解的溫度範圍。
改質的SPVA薄膜於25℃、濕度90%下，以SPVA2-10m的氫離子導電度最佳，可達4.07x10-2 S/cm；而甲醇滲透率以SPVA18.2-20m表現最佳，約為4.09x10-7 cm2/s，顯示改質後之膜材，確實有抑制甲醇滲透的能力，綜合來說以SPVA2-20m的選擇性值為4.81x104最優，約為Nafion的九倍。本研究亦嘗試探討薄膜的物理性質與氫離子導電度及甲醇滲透率之關係。

The main target of this study is to develop a new polymer electrolyte membrane for low temperature direct methanol fuel cell as a possible alternative to the existing state-of-the art Nafion membrane which is having drawbacks such as high cost and poor ability in prevention of methanol crossover. Because of its low cost, film-fabrication ability, good chemical stability and high selectivity of water to alcohols, Poly (vinyl alcohol) was chosen to be the matrix of proton exchange membranes in this study. 4-Formyl-1,3-Benzenedisulfonic acid disodium salt (DSDSBA) was employed as a sulfonating agent to introduce SO3−H+ moieties into the membrane to increase proton conductivity, glutaraldehyde was utilized as the cross-linking agent to form a stable network structure with an improved mechanical property. Various analytical techniques were used to characterize the structure, physico-thermal properties, proton conductivity, water uptake, free water and bound water ratio as well as methanol permeability of the developed membranes. The variation of molecular structure during the film formation was also investigated.
From the in-situ IR spectrum results, it was indicated that the strength of hydrogen bonding between water / polymer chain, water / SO3H groups, and intra-molecular / inter-molecular were enhanced gradually during film formation at the proton type SPVA membrane system. However, the variation tendency of the hydrogen bonding was opposite to that of the sodium type. Furthermore, T1ρ measurement in NMR was illustrated that the CH-OH molecular chain of SPVA membrane was more flexible than that of PVA membrane. It was evidenced from TGA and TPD/MS results that the decomposition temperature of hydroxide groups in SPVA membrane was observed about 150~200℃, and that of the sulfonated groups were about 220~380℃. Moreover, the side chain-benzenz structure of SPVA membrane and the terminal backbone of SPVA were decomposed between 390 and 480℃, as well as most of the backbone of SPVA were decomposed above 480℃.
Among the modified membranes, the SPVA2-10m membrane showed the best proton conductivity of 4.07x10−2 S/cm at 25 oC in flooded state. The lowest methanol permeability of the SPVA18.2-20m membrane was measured to be 4.09x10−7 cm2/s. It was found that a significant improvement in methanol crossover could be achieved using the modified PVA membrane. On sum up these two properties, SPVA2-20m showed the best selectivity value of 4.81×104 which is about nine times higher than that of the Nafion membrane. The relationship between the characteristics and the proton conductivity as well as the methanol permeability for the developed membranes was also discussed in this study.

1.衣寶廉，燃料電池 五南圖書出版公司 (2003)
2.W. R. Grove, Philos .Mag. Ser.3, 14 ,127 (1839)
3.吳滄琪，磺酸化高分子於燃料電池質子交換膜製備之應用，元智大學化工系(2003)
4.鄭耀宗，徐耀昇，燃料電池技術進展的現況，燃料電池論文集，15-27 (1989)
5.詹世弘，二十一世紀之星-燃料電池，燃料電池研討會，元智大學 (2000)
6.鄭煜騰、萬瑞霙、林修正，酸性燃料電池的製成研究，能源季刊，第二十五卷第四期， p.161 (1995)
7.O. Stonehart ,“Development of Alloy Electrocatalysts for Phosphoric Acid Fuel Cells(PAFC)”,J. Apl. Electrochem.,Vol.22，p.995 (1992)
8.李國霖，熔融碳酸鹽燃料電池的研發，能源季刊，第二十四卷 第四期，p.57 (1997)
9.A.J. Apleby and F.R. Folkes ,”Fuel Cell Handbook，Van Nostrand Reinhold”,New York (1989)
10.L. J. M. J. Bolmen and M. N. Megerwa ,”Fuel Cell Systems”, Plenum Press , New York and London (1993)
11.A. Heinzel, R. Nolte, K. Ledjeff-Hey and M. Zedda, “Membrane fuel cells-concepts and system design”, Electrochim. Acta, 43, 3817 (1998).
12.S. Surampudi, S. R. Narayanan, and E. Vamos, ”Advances in direct methanol fuel-cells”, Journal of Power Sources, 47, 377 (1994)
13.M. P. Hogarth, and G. A. Hards, “Platinum Metal Rev.”, 40, 150 (1996)
14.J. Shim, D. Y. Yoo, and J. S. Lee, “Characteristics for electrocatalytic properties and hydrogen-oxygen adsorption of platinum ternary alloy catalysts in polymer electrolyte fuel cell”, Electrochim. Acta, 45, 1943 (2000)
15.陳俊明，直接甲醇燃料電池陽極奈米合金觸媒之製備與鑑定，台灣科技大學化工系。
16.X. Ren, T. A. Zawadzinski, F. Uribe, H. Dai and S. Gottesfeld, “Methanol cross-over in direct methanol fuel cells”, Electrochem. Soc. Proc. 95(23) (1995) 284-298
17.高志勇，「磺酸化磷睛環聚合物電解質之合成及其性質之研究」，工業材料，196期，2003年，P.111-119
18.許義政，磺酸化聚二醚酮奈米複合質子交換膜之研究，長庚大學，化學與材料工程所
19.S. P. S. Yen, S. R. Narayanan, G. Halpert, E. Graham and A. Yavrouian, “Polymer Material For Electrolytic Membranes Fuel Cell”, U.S. Patent 5,795,496 (1998).
20.邱志豪，聚苯咪唑合成及薄膜性質，元智大學化工系
21.T. Schultz, S. Zhou, and K. Sundmacher, “Review: Current status of and recent developments in the direct methanol fuel cell, Chem. Eng. Technol”. 24, 12 (2001)
22.P. S. Kauranen and E. Skou，“Methanol permeability in perfluorsulfonate proton exchange membranes at elevated temperatures” J. Appl. Electrochem. 26(1996) 909.
23.S. R. Narayanan, A. Kindler, B. Jeffries-Nakamura, W. Chum, H. Frank, M. Smart, T. L.Valdez, S. Surampudi, G. Halpert, Annu.Battery Conf. Appl. Adv. 11(1996) 113.
24.D. H. Jung, C. H. Lee, C. S. Kim, and D. R. Shin, “Performance of a direct methanol polymer electrolyte fuel cell”, J. Power Sources 71(1998) 169.
25.Y. Higuchi, N. Terada, H. Shimoda, S.U.S. Hommura “Patent application”, 0026883A1 ; EP1139472, 2001
26.M. Watanabe, H. Uchida, Y. Seki, and M. Emori “The Electrochemical Society Meeting”, PV94-2, Abstract No. 606, Electrochemical Society: Pennington, NJ, 1994, pp 946-947
27.P. L. Antonucci, A. S. Arico, P. Creti, E. Ramunni and V. Antonucci, Solid State Ionics 125 (1999) 431.
28.K. A. Mauritz, Mater. Sci. Eng., C 6 (1998) 121.
29.N. Miyake, J.S. Wainwright and R.F. Savinell, J. Electrochem. Soc. 148(2001)
30.K.T. Adjemian, S.J. Lee, S. Srinivasan, J. Benziger and A.B. Bocarsly, J. Electrochem. Soc.149(2002)A256.
31.G. Alberti, L. Boccali, M. Casciola, L. Massinelli, and E. Montoneri Solid State Ionics 84 (1996) 97.
32.M. Rikukawa and K. Sanui, ”Proton-conducting polymer electrolyte membranes base on hydrocarbon Polymers,” Prog. Polym. Sci., 25,1463-1502 (2000)
33.F. Donoso, W. Gorecki and C. Berthier, “NMR, conductivity and neutron scattering investigation of ionic dynamics in the anhydrous polymer protonic conductor PEO (H3PO4)x“ Solid State Ionics, 28 -30, 969-974(1988)
34.M. G. Fiona, Polymer Electrolytes, RSC Materials Monographs, UK,1997.
35.M. F. Daniel, B. Desbat, F. Cruege, O. Trinquet and J. C.Lassegues, ”Solid state protonic conductors: poly (ethylene imine)sulfates and phosphates,” Solid State Ionics, 28-30, 637-641 (1988)
36.J. C. Lassegues, D. Scoolmann and O. Trinquet, ”Proton conducting acid/polymer blends,” Solid State Ionics, 51, 443-448 (1992)
37.R. Tanaka, H. Yamamoto, S. Kawamura and T. Iwase, “Proton Conducting behavior of Poly (etheylenimine)-H3PO4 System,”Electrochimica Acta, 40, 2421-2424 (1995)
38.G.K.R. Senadeera, M. A. Careem, S. Skaarup and K. West, ”Enhance ionic conductivity of poly(ethylene imine) Phosphate,“ Solid State Ionics, 85, 37–42 (1996)
39.D. Rodriguez, C. Jegat, O. Trinquet, J. Grondin and J. C. Lassegues, “Proton conduction in poly(acrylamide)-acid blends, ”Solid State Ionics, 61, 195-202 (1993)
40.S. Petty-Weeks, J. J. Zupancic and J. R. Swedo, ”Proton conducting Interpenetranting polymer networks,” Solid State Ionics, 31, 117-125(1988)
41.P. N. Gupta and K. P. Singh, ”Characterization of H3PO4 based PVA complex system,“ Solid State Ionics, 86-88, 319-323 (1996)
42.M. A. Vargas, R. A. Vargas and B. Mellander, “More studies on the PVA+H3PO2 +H2O proton conductor gels,“ Electrochimica Acta, 45,1399-1403 (2000)
43.M. Suzuki and T. Yoshida, “Ionic conduction in partially phosphorylated poly(vinyl alcohol) as polymer electrolytes”, Polymer 41 (2000) 4531-4536.
44.H. Wu and Y. Wang, “A methanol barrier polymer electrolyte membrane in direct methanol fuel cells”, J. New. Mat. Electrochem. Systems, 251-254 (2002).
45.A. K. Sharma, “Conductivity and discharge characteristics of polyblend (PVP+PVA+KIO3) electrolyte”, Journal of Power Sources 114 (2003) 338-345.
46.C. C. Yang, “Chemical composition and XRD analyses for alkaline composite PVA polymer electrolyte”, Materials Letter 58 (2003) 33-38.
47.W. Xu and C. Liu, “New proton exchange membranes based on poly (vinyl alcohol) for DMFCs”, Solid State Ionics 171 (2004) 121–127
48.J. W. Rhima and H. B. Park, “Crosslinked poly(vinyl alcohol) membranes containing sulfonic acid group: proton and methanol transport through membranes”, Journal of Membrane Science 238 (2004) 143–151.
49.M. S. Kang, “Highly charged proton exchange membranes prepared by using water soluble polymer blends for fuel cells”, Journal of Membranes Science 247 (2005) 127-135.
50.J. S. Wainright, J. T. Wang, D. Weng, R. F. Savinell, and M. Litt , “Acid-doped polybenzimidazoles: A New polymer electrolyte”, J. Electrochem. Soc. 142(1995) L121
51.J. T. Wang, S. Wasmus, and R. F. Savinell, “Real-time spectrometric study of the methanol crossover in a direct methanol fuel cell”, J. Electrochem. Soc. 143(1996) 1233
52.S. Wasmus and A. Kuver, “Methanol oxidation and direct methanol fuel cells: a selective review”J. Electroanal. Chem., 461(1999) 14
53.A. Heinzel and V. M. Barragan, “A review of the state-of-the-art of the methanol crossover in direct methanol fuel cells”, J. Power Sources 84(1999) 70.
54.M. Kawahara, J. Morita, M Rikukawa, Kohei Sanui, Naoya Ogata, “Synthesis and proton conductivity of thermally stable polymer electrolyte: poly (benzimidazole) complexes with strong acid molecules,” electrochimica Acta, 45, 1395-1398 (2000).
55.K. Tsuruhara, M. Rikukawa, K. Sanui, N. Ogata, Y.Nagasaki and M. Kato, ”Synthesis of proton conducting polymer basedon Poly( silamine ), ” Electrochimica Acta, 45, 1391-1394 (2000)
56.F. Wang, M. Hickner, Y.S. Kim, T.A. Zawodinski and J.E. J. McGrath, Membr. Sci. 197 (2002)231.
57.M. Hogarth and X. Glipa, High temperature membranes for sold polymer fuel cells, Johnson Matthey Technology Centre.
58.吳千舜，”新穎質子交換膜”，中央大學化學研究所
59.U. Tadashi, O. Kenji, M. Hiroshi and M. Takashi, Structure and permeation characterisics of an aqueous ethanol solution of organic-inorgaic hybrid membranes composed of poly(vinyl alcohol) and tetraethoxysiliane, Macromolecules, 35, 9156 (2002)
60.S.P. Nunes, B. Ruffmann, E. Rikowski, S. Vetter and K. Richau, Inorganic modification of proton conductive polymer membranes for direct methanol fuel cells, J. Membr. Sci., 203, 215 (2002)
61.K.T. Adjemiana, S. Srinivasana, J. Benzigerb and A.B. Bocarslya, Investigation of PEMFC operation above 100℃ employing perfluorosulfonic acid silicon oxide composite membranes, Journal of Power Sources, 109, 356-364 (2002)
62.K. D. Kreuer, On the complexity of proton conduction phenomena, Solid state ionics, 136-137, 149-160 (2000)
63.S. P. Tung and B. J. Hwang, Synthesis and characterization of xP2O5-(100-x)SiO2 glass electrolytes prepared by accelerated sol-gel process with water/vapor management, in press.
64.A. Apicella, H. B. Hopfenberg, and S. Piccarolo. “Low temperature thermal aging of ethylene vinyl alcohol copolymers.” Polymer Engineering and Science 1982;22:382-7
65.H. Strathmann, J. membr. sci. 1981; 9: 121-189
66.R. E. Kesting. “Synthetic Polymeric Membranes”. John Wiley and Sons, New York, NY, 1985.
67.黃鼎翰，以低溫水熱法合成奈米級釤及鉍摻雜鈰系固態氧化物燃料電池電解質與其電化學性質之研究，台灣科技大學材料科技研究所。
68.C. K. Yeom and K. H. Lee, Prevaporation separation of water-acetic acid mixtures through poly(vinly alcohol) membranes crosslinked with glutaraldehyde, J. Membr. sci. 109, 257-265 (1996)
69.E. J. Shin, Study on the Structure and Processibility of the Iodinated Poly(Vinyl Alcohol). I. Thermal Analyses of Iodinated Poly(vinyl alcohol) Films, J. of Applied Polymer Science, Vol. 91, 2407-2415 (2004)
70.J. Qiao, T. Hamaya and T. Okada* , Chemically Modified Poly(vinyl alcohol)-Poly(2-acrylamido-2-methyl-1-propanesulfonic acid) as a Novel Proton-Conducting Fuel Cell Membrane , Chem. Mater. , 17, 2413-2421(2005)