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Heterogeneous anion-selective membranes
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| Heterogeneous anion-selective membranes were prepared by blending anion-exchange particles, linear polyethylene, low density polyethylene or poly(ethylene-co-methacrylic acid) and a water-soluble additive poly(ethylene glycol-ran-propylene glycol) at 140 °C with subsequent compression moulding into the shape of a flat membrane. SEM micrographs showed that the membranes based on linear polyethylene or low density polyethylene had voids around the anion-exchange particles, while the membranes comprising poly(ethylene-co-methacrylic acid) had the particles completely encapsulated with the matrix polymer. The membranes with the voids around the particles were ion conductive, whereas the membranes with encapsulated particles were nonconductive. The presence of the water-soluble additive in the system resulted after extraction with water in a microporous membrane skin and in a considerable increase in conductivity. The conductivity of the membrane consisting (before extraction) of 66 wt.% anion-exchange particles, 3.4 wt.% water-soluble additive and 30.6 wt.% linear polyethylene was (70 °C) 7.1 S/m, whereas the conductivity of a similar membrane prepared without the water-soluble additive was only 3.5 S/m. |
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vivanslum
木虫 (正式写手)
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爱与雨下: 金币+2 2013-01-02 20:22:00
辉少一号: 金币+20, 翻译EPI+1, ★★★★★最佳答案, 很好，急用就采纳了、、 2013-01-02 23:26:54
Carena: 金币+30, 金币代发 2013-01-03 15:17:47
爱与雨下: 金币+2 2013-01-02 20:22:00
辉少一号: 金币+20, 翻译EPI+1, ★★★★★最佳答案, 很好，急用就采纳了、、 2013-01-02 23:26:54
Carena: 金币+30, 金币代发 2013-01-03 15:17:47
| 非均相阴离子选择性膜的制备是通过在140℃条件下将阴离子交换颗粒，线性聚乙烯，低密度聚乙烯或多聚（乙烯 - 共 -甲基丙烯酸），和水溶性添加剂聚（乙二醇-RAN-丙二醇）混合，再进行压缩成型为平膜。SEM显微照片表明，基于线性聚乙烯或低密度聚乙烯的膜，其阴离子交换颗粒周围具有空隙；然而含聚（乙烯 - 共 -甲基丙烯酸）的膜，其颗粒则完全被基体聚合物包封。颗粒周围有空隙的膜是离子导电性的，而颗粒包封的膜是不导电的。经水萃取后，系统中水溶性添加剂的存在使得形成微多孔膜表层，并引起电导性的显著增加。（在提取前）包含66 wt.（重量比）％的阴离子交换颗粒，3.4 wt.％的水溶性添加剂和30.6 wt.％的线性聚乙烯的膜，其电导率为7.1 S / m（70℃下）；而未经水溶性添加剂所制备的类似的膜，其导电率只有3.5 S / m |
2楼2013-01-02 20:02:04
亲，太感谢您了、、、3楼2013-01-02 23:14:03
辉少一号: 回帖置顶 2013-01-02 23:30:27
辉少一号: 取消置顶 2013-01-03 16:44:48
辉少一号: 取消置顶 2013-01-03 16:44:48
哪位大神有空帮忙翻译下介绍和总结部分！万分感谢！！！急用。。。 Introduction Hydrogen will play an important role as an energy carrier for sustainable development in the future [1] and [2]. Today hydrogen is mainly produced by steam reforming of fossil fuels [3]. Hydrogen produced by water electrolysis would be an alternative if the electrolysis uses the electricity from wind turbines and solar panels. Alkaline water electrolysis [4] and [5] is a well-established technology but it has two major disadvantages: the use of asbestos diaphragms as separators (which are toxic and carcinogenic [6]) and the use of highly concentrated (25–30%) potassium hydroxide as an electrolyte (corrosive medium). Therefore, alternative conductive separators are needed. Such prospective separators can be anion-selective nonporous membranes. Today polymer anion-selective membranes are used as active separators in electrochemical processes, such as electrodialysis, electrodeionization and cataphoresis and are considered for use in alkaline fuel cell technology. They contain positively charged groups (almost exclusively quaternary ammonium groups) attached to the polymer backbone. The largest group of anion-selective membranes comprises homogeneous ones [7], which are the membranes consisting only of one polymer or one random copolymer. These membranes are prepared either by casting a solution containing a polymer with anion-exchange groups and evaporating the solvent or by introducing anion-exchange groups into an existing polymer film [7] and [8]. Homogeneous membranes are predominantly based on quaternized aromatic polymers such as copolymers of styrene [9] and [10], polyetherketons [11] and [12], poly(ether sulfone)s [13] and [14], polyimides [15] or poly(phenylene oxide) [16]. Homogeneous membranes with high ion-exchange capacities have excellent electrochemical properties but this is at the expense of their mechanical strength and dimensional stability in a water-swollen state [17].The membranes prepared of two polymers or of a block copolymers do not exhibit these drawbacks: one copolymer block or one polymer imparts the membrane mechanical strength and controls the swelling properties while the other block or polymer with charged groups controls transport properties. Block copolymers are promising for the preparation of anion-selective membranes as the immiscibility and molecular connectivity between the block segments give rise to well-organized periodic domain microstructures [18]. Anion-exchange membranes based on a block copolymer have recently been subject of several publications [19], [20], [21] and [22]; the commercial availability of copolymers comprising polystyrene and polyolefin blocks made them attractive for the preparation of ion-exchange membranes. There are several methods used commercially or on a laboratory scale for the preparation of two-polymer membranes: (a) chemical or radiation-grafting of monomers that can be functionalized (e.g., styrene or chloromethylstyrene in a mixture with divinylbenzene) usually onto partially or fully fluorinated polyolefin films followed by functionalization [23] and [24], (b) mixing a film-forming polymer and a polyelectrolyte generating semi-interpenetrating network membranes [25] and [26], (c) incorporating the polyelectrolyte within the pores of a microporous host membrane [27] and [28], (d) dispersing finely powdered ion-exchange particles in a solution of an inert polymer, casting the film and evaporating the solvent [29] and [30] and (e) blending finely powdered ion-exchange particles (usually 10–40 μm in size) with a matrix polymer at the temperature higher than the melting temperature of the matrix polymer followed by calendering, extruding or compression moulding into the shape of a flat membrane [31], [32], [33] and [34]. The advantage of heterogeneous membranes consists in their low cost, but they are usually less conductive than the other types of ion-selective membranes. The ionic conductivity of heterogeneous membranes depends: • on the concentration of ion-exchange particles in the membrane. The maximum possible concentration of the particles is limited by the mechanical strength of resulting membrane in a dry and in a water-swollen state. The maximum particle concentration is about 70 wt.% if the matrix is a polyolefin [33], • on the bulk morphology of the membrane. The efficient transport of ions through a heterogeneous membrane requires either a contact between the ion-exchange particles or an ion conducting solution between the particles [33] and [35], • on the surface morphology (“skin”) of the membrane. In the membrane skin, there are conducting and nonconducting areas formed by the ion-exchanger and matrix polymer, respectively, but the matrix polymer dominates [32] and [33]. The aim of this work is to find relations between heterogeneous membranes morphology and their electrochemical properties and, using the obtained knowledge, to prepare anion-selective membranes for water electrolysis with an increased conductivity. Conclusions • The membrane conductivity depends both on the structure of membrane core and membrane skin. • The membrane core of conductive membranes contains interconnection channels between the individual anion-exchange articles. • The porosity of the skin and thus the membrane conductivity is increased by the addition of a water-soluble additive to the matrix polymer/anion-exchange particles blend. [1] J.A. Turner Sustainable hydrogen production Science, 305 (2004), pp. 972–974 View Record in Scopus | Full Text via CrossRef | Cited By in Scopus (264) [2] S. Dunn Hydrogen futures: toward a sustainable energy system Int. J. Hydrogen Energy, 27 (2002), pp. 235–264 Article | PDF (490 K) | View Record in Scopus | Cited By in Scopus (306) [3] N. Lior Sustainable energy development: the present (2009) situation and possible paths to the future Energy, 35 (2010), pp. 3976–3994 Article | PDF (657 K) | View Record in Scopus | Cited By in Scopus (35) [4] K. Zeng, D.K. Zhang Recent progress in alkaline water electrolysis for hydrogen production and applications Prog. Energ. Combust., 36 (2010), pp. 307–326 Article | PDF (716 K) | View Record in Scopus | Cited By in Scopus (73) [5] D. Pletcher, X.H. Li Prospects for alkaline zero gap water electrolysers for hydrogen production Int. J. Hydrogen Energy, 36 (2011), pp. 15089–15104 Article | PDF (655 K) | View Record in Scopus | Cited By in Scopus (11) [6] R.F. Dodson, M.A.L. Atkinson, J.L. Levin Asbestos fiber length as related to potential pathogenicity: a critical review Am. J. Ind. Med., 44 (2003), pp. 291–297 View Record in Scopus | Full Text via CrossRef | Cited By in Scopus (44) [7] G. Couture, A. Alaaeddine, F. Boschet, B. Ameduri Polymeric materials as anion-exchange membranes for alkaline fuel cells Prog. Polym. Sci., 36 (2011), pp. 1521–1557 [8] G. Merle, M. Wessling, K. Nijmeijer Anion exchange membranes for alkaline fuel cells: a review J. Membr. Sci., 377 (2011), pp. 1–35 [9] T. Sata, K. Teshima, T. Yamaguchi Permselectivity between two anions in anion exchange membranes crosslinked with various diamines in electrodialysis J. Polym. Sci. Polym. Chem., 34 (1996), pp. 1475–1482 View Record in Scopus | Full Text via CrossRef | Cited By in Scopus (35) [10] H.S. Wu, Y.K. Wu Preliminary study on the characterization and preparation of quaternary ammonium membranes Ind. Eng. Chem. Res., 44 (2005), pp. 1757–1763 View Record in Scopus | Full Text via CrossRef | Cited By in Scopus (5) [11] Y. Xiong, Q.L. Liu, Q.H. Zeng Quaternized Cardo polyetherketone anion-exchange membrane for direct methanol alkaline fuel cells J. Power Sources, 193 (2009), pp. 541–546 Article | PDF (214 K) | View Record in Scopus | Cited By in Scopus (50) [12] H. Zhang, Z. Zhou Alkaline polymer electrolyte membranes from quaternized poly(phthalazinone ether ketone) for direct methanol fuel cell J. Appl. Polym. Sci., 110 (2008), pp. 1756–1762 View Record in Scopus | Full Text via CrossRef | Cited By in Scopus (23) [13] E.N. Komkova, D.F. Stamatialis, H. Strathmann, M. Wessling Anion exchange membranes containing diamines: preparation and stability in alkaline solution J. Membr. Sci., 244 (2004), pp. 25–34 Article | PDF (217 K) | View Record in Scopus | Cited By in Scopus (57) [14] J. Wang, J. Wang, S. Li, S. Zhang Poly(arylene ether sulfone)s ionomers with pendant quaternary ammonium groups for alkaline anion exchange membranes: preparation and stability issues J. Membr. Sci., 368 (2011), pp. 246–253 Article | PDF (816 K) | View Record in Scopus | Cited By in Scopus (15) [15] G. Wang, Y. Weng, J. Zhao, D. Chu, D. Xie, R. Chen Developing a novel alkaline anion exchange membrane derived from poly(ether-imide) for improved ionic conductivity Polym. Adv. Technol., 21 (2010), pp. 554–560 [16] T. Xu, W. Yang Fundamental studies of a new series of anion-exchange membranes: membrane preparation and characterization J. Mater. Sci., 190 (2001), pp. 159–166 [17] J. Schauer, J. Llanos, J. Žitka, J. Hnát, K. Bouzek Cation-exchange membranes: comparison of homopolymer, block copolymer and heterogeneous membranes J. Appl. Polym. Sci. (2011) [18] S. Krause Polymer–polymer miscibility Pure Appl. Chem., 58 (1986), pp. 1553–1560 [19] R. Vinodh, A. Ilakkiya, S. Elamathi, D. Sangeetha A novel anion-exchange membrane from polystyrene (ethylene butylene) polystyrene: synthesis and characterization Mater. Sci. Eng. B, 167 (2010), pp. 43–50 [20] Q.H. Zeng, Q.L. Liu, I. Broadwell, A.M. Zhu, Y. Xiong, X.P. Tu Anion-exchange membranes based on quaternized polystyrene block-poly(ethylene-ran-butylene)-block-polystyrene for direct methanol alkaline fuel cells J. Membr. Sci., 349 (2010), pp. 237–243 [21] G.-J. Hwang, H. Ohya Preparation of anion-exchange membrane based on block copolymers: Part 1. Amination of the chloromethylated copolymers J. Membr. Sci., 140 (1998), pp. 195–203 [22] D. Valade, F. Boschet, B. Ameduri Random and block styrenic copolymers bearing ammonium and fluorinated side-groups as binders for alkaline fuel cells J. Polym. Sci. Polym. Chem., 49 (2011), pp. 4668–4679 [23] J.R. Varcoe, S.D. Poynton, R.C.T. Slade Alkaline anion-exchange membranes for low-temperature fuel cell application W. Vielstich, H.A. Gasteiger, H. Yokokawa (Eds.), Handbook of Fuel Cells – Fundamentals, Technology and Applications, vol. 5John Wiley & Sons Ltd, Chichester, UK (2009), pp. 322–333 [24] R.C.T. Slade, J.R. Varcoe Investigations of conductivity in FEP-based radiation-grafted alkaline anion-exchange membranes Solid State Ionics, 176 (2005), pp. 585–597 Article | PDF (302 K) | View Record in Scopus | Cited By in Scopus (125) [25] L. Lebrun, N. Follain, M. Metayer Elaboration of a new anion-exchange membrane with semi-interpenetrating polymer networks and characterization Electrochim. Acta, 50 (2004), pp. 985–993 Article | PDF (222 K) | View Record in Scopus | Cited By in Scopus (20) [26] B.G. Shah, V.K. Shahi, S.K. Thampy, R. Rangarajan, P.K. Ghosh Comparative studies on performance of interpolymer and heterogeneous ion-exchange membranes for water desalination by electrodialysis Desalination, 172 (2005), pp. 257–265 Article | PDF (649 K) | View Record in Scopus | Cited By in Scopus (10) [27] K. Pandey, A. Goswami, D. Sen, S. Mazumder, R.F. Childs Formation and characterization of highly crosslinked anion-exchange membranes J. Membr. Sci., 217 (2003), pp. 117–130 [28] M. Stachera, R.F. Childs Tuning the acid recovery performance of poly(4-vinylpyridine)-filled membranes by the introduction of hydrophobic groups J. Membr. Sci., 187 (2001), pp. 213–225 [29] G.S. Gohil, V.K. Shahi, R. Rangarajan Comparative studies on electrochemical characterization of homogeneous and heterogeneous type of ion-exchange membranes J. Membr. Sci., 240 (2004), pp. 211–219 Article | PDF (240 K) | View Record in Scopus | Cited By in Scopus (48) [30] V. Balaji, S.K. Adhikary, P. Ray Studies on the electrical diffusivities of monocarboxylates through heterogeneous anion exchange membranes J. Appl. Polym. Sci., 106 (2007), pp. 2615–2624 [31] J. Schauer, L. Brožová Heterogeneous ion-exchange membranes based on sulfonated poly(1,4-phenylene sulfide) and linear polyethylene: preparation, oxidative stability, methanol permeability and electrochemical properties J. Membr. Sci., 250 (2005), pp. 151–157 [32] E. Volodina, N. Pismenskaya, V. Nikonenko, C. Larchet, G. Pourcelly Ion transfer across ion-exchange membranes with homogeneous and heterogeneous surfaces J. Colloid Interface Sci., 285 (2005), pp. 247–258 [33] K. Bouzek, S. Moravcová, J. Schauer, L. Brožová, Z. Pientka Heterogeneous ion-selective membranes: the influence of inert matrix polymer on membrane properties J. Appl. Electrochem., 40 (2010), pp. 1005–1018 View Record in Scopus | Full Text via CrossRef | Cited By in Scopus (4) [34] J. Hnát, M. Paidar, J. Schauer, J. Žitka, K. Bouzek, J. Hnát, M. Paidar, J. Schauer, J. Žitka, K. Bouzek Polymer anion selective membranes for electrolytic splitting of water. Part I: stability of ion-exchange groups and impact of the polymer binder J. Appl. Electrochem., 41 (2011), pp. 1043–1052 View Record in Scopus | Full Text via CrossRef | Cited By in Scopus (3) [35] H. Strathmann Ion-exchange membrane separation processes Membrane Science and Technology Series, vol. 9Elsevier, Amsterdam (2004) p. 104 [36] N.D. Pismenskaya, E.I. Belova, V.V. Nikonenko, V.I. Zabolotsky, G.Y. Lopatkoya, Y.N. Karzhayin, C. Larchet Desalin. Water Treat., 21 (2010), pp. 109–114 View Record in Scopus | Full Text via CrossRef | Cited By in Scopus (4) [37] https://www.mega.cz |
4楼2013-01-02 23:29:45