2301
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Methanol permeability in sulfonated poly(etheretherketone) membranes: A comparison with Nafion membranes. Eur Polym J 2006. [DOI: 10.1016/j.eurpolymj.2005.10.008] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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2302
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2303
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Yin Y, Yamada O, Tanaka K, Okamoto KI. On the Development of Naphthalene-Based Sulfonated Polyimide Membranes for Fuel Cell Applications. Polym J 2006. [DOI: 10.1295/polymj.38.197] [Citation(s) in RCA: 160] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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2304
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Engtrakul C, Davis MF, Gennett T, Dillon AC, Jones KM, Heben MJ. Protonation of carbon single-walled nanotubes studied using 13C and 1H-13C cross polarization nuclear magnetic resonance and Raman spectroscopies. J Am Chem Soc 2006; 127:17548-55. [PMID: 16332107 DOI: 10.1021/ja0557886] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The reversible protonation of carbon single-walled nanotubes (SWNTs) in sulfuric acid and Nafion was investigated using solid-state nuclear magnetic resonance (NMR) and Raman spectroscopies. Magic-angle spinning (MAS) was used to obtain high-resolution 13C and 1H-13C cross polarization (CP) NMR spectra. The 13C NMR chemical shifts are reported for bulk SWNTs, H2SO4-treated SWNTs, SWNT-Nafion polymer composites, SWNT-AQ55 polymer composites, and SWNTs in contact with water. Protonation occurs without irreversible oxidation of the nanotube substrate via a charge-transfer process. This is the first report of a chemically induced change in a SWNT 13C resonance brought about by a reversible interaction with an acidic proton, providing additional evidence that carbon nanotubes behave as weak bases. Cross polarization was found to be a powerful technique for providing an additional contrast mechanism for studying nanotubes in contact with other chemical species. The CP studies confirmed polarization transfer from nearby protons to nanotube carbon atoms. The CP technique was also applied to investigate water adsorbed on carbon nanotube surfaces. Finally, the degree of bundling of the SWNTs in Nafion films was probed with the 1H-13C CP-MAS technique.
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Affiliation(s)
- Chaiwat Engtrakul
- Center for Basic Sciences, National Renewable Energy Laboratory, Golden, Colorado 80401, USA.
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2305
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Bae B, Kim D, Kim HJ, Lim TH, Oh IH, Ha HY. Surface Characterization of Argon-Plasma-Modified Perfluorosulfonic Acid Membranes. J Phys Chem B 2006; 110:4240-6. [PMID: 16509719 DOI: 10.1021/jp055159i] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The perfluorosulfonic acid membranes which are used in direct methanol fuel cells were modified with argon plasma under various conditions, and the physicochemical and transport properties of the resulting membranes were investigated using various analytical techniques. The plasma treatment was found to change the surface morphology and physicochemical properties of the membranes. The surface roughness of the membranes was increased by the etching effect of plasma. From the FTIR and XPS analyses, the incorporation of new oxygen functionalities, such as the peroxide group, was confirmed. The breakage of both the sulfonic acid groups and ether linkages were also found to cause an increase in the equivalent weight of the modified skin layer of the membrane. The incident water contact angle of the modified membrane in a dry state decreased with an increased plasma treatment, because of the hydrophilic groups that developed on the membrane surface. The time-dependent water contact angle, however, increased in proportion to the extent of the plasma treatment, due to the reduced concentration of sulfonic acid groups. Although the equilibrium water uptake of the modified membrane was almost invariable because of the negligible thickness of the modified skin layer, the transport properties of the membrane such as methanol permeability and proton conductivity were significantly reduced.
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Affiliation(s)
- Byungchan Bae
- Polymer Technology Institute, Department of Chemical Engineering, Sungkyunkwan University, Suwon, Kyungki 440-746, Korea
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2306
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Zhang J, Giotto MV, Wen WY, Jones AA. An NMR study of the state of ions and diffusion in perfluorosulfonate ionomer. J Memb Sci 2006. [DOI: 10.1016/j.memsci.2005.06.026] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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2307
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Feindel KW, Bergens SH, Wasylishen RE. The Use of1H NMR Microscopy to Study Proton-Exchange Membrane Fuel Cells. Chemphyschem 2006; 7:67-75. [PMID: 16345115 DOI: 10.1002/cphc.200500504] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
To understand proton-exchange membrane fuel cells (PEMFCs) better, researchers have used several techniques to visualize their internal operation. This Concept outlines the advantages of using 1H NMR microscopy, that is, magnetic resonance imaging, to monitor the distribution of water in a working PEMFC. We describe what a PEMFC is, how it operates, and why monitoring water distribution in a fuel cell is important. We will focus on our experience in constructing PEMFCs, and demonstrate how 1H NMR microscopy is used to observe the water distribution throughout an operating hydrogen PEMFC. Research in this area is briefly reviewed, followed by some comments regarding challenges and anticipated future developments.
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Affiliation(s)
- Kirk W Feindel
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, AB T6G 2G2, Canada
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2308
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Yin Y, Suto Y, Sakabe T, Chen S, Hayashi S, Mishima T, Yamada O, Tanaka K, Kita H, Okamoto KI. Water Stability of Sulfonated Polyimide Membranes. Macromolecules 2006. [DOI: 10.1021/ma0523769] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yan Yin
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
| | - Yoshiki Suto
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
| | - Takaaki Sakabe
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
| | - Shouwen Chen
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
| | - Shunsuke Hayashi
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
| | - Takashi Mishima
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
| | - Otoo Yamada
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
| | - Kazuhiro Tanaka
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
| | - Hidetoshi Kita
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
| | - Ken-ichi Okamoto
- Venture Business Laboratory, Yamaguchi University, Ube, Yamaguchi 755-8611, Japan, and Department of Advanced Materials Science & Engineering, Faculty of Engineering, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611, Japan
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2309
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Allcock HR, Wood RM. Design and synthesis of ion-conductive polyphosphazenes for fuel cell applications: Review. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20864] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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2310
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Huang X, Solasi R, Zou Y, Feshler M, Reifsnider K, Condit D, Burlatsky S, Madden T. Mechanical endurance of polymer electrolyte membrane and PEM fuel cell durability. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20863] [Citation(s) in RCA: 256] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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2311
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Wang H, Badami AS, Roy A, McGrath JE. Multiblock copolymers of poly(2,5-benzophenone) and disulfonated poly(arylene ether sulfone) for proton-exchange membranes. I. Synthesis and characterization. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/pola.21837] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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2312
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Hu Z, Yin Y, Chen S, Yamada O, Tanaka K, Kita H, Okamoto KI. Synthesis and properties of novel sulfonated (co)polyimides bearing sulfonated aromatic pendant groups for PEFC applications. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/pola.21374] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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2313
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Phillips AK, Moore RB. Mechanical and transport property modifications of perfluorosulfonate ionomer membranes prepared with mixed organic and inorganic counterions. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20866] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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2314
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Proton conducting phosphated zirconia–sulfonated polyether sulfone nanohybrid electrolyte for low humidity, wide-temperature PEMFC operation. Electrochem commun 2006. [DOI: 10.1016/j.elecom.2005.10.025] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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2315
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Roy A, Hickner MA, Yu X, Li Y, Glass TE, McGrath JE. Influence of chemical composition and sequence length on the transport properties of proton exchange membranes. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20859] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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2316
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Paddison SJ, Elliott JA. On the consequences of side chain flexibility and backbone conformation on hydration and proton dissociation in perfluorosulfonic acid membranes. Phys Chem Chem Phys 2006; 8:2193-203. [PMID: 16751878 DOI: 10.1039/b602188c] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The flexibility of the side chain and effects of conformational changes in the backbone on hydration and proton transfer in the short-side-chain (SSC) perfluorosulfonic acid fuel cell membrane have been investigated through first principles based molecular modelling studies. Potential energy profiles determined at the B3LYP/6-31G(d,p) level in the two pendant side chain fragments: CF(3)CF(-O(CF(2))(2)SO(3)H)-(CF(2))(7)-CF(-O(CF(2))(2)SO(3)H)CF(3) indicate that the largest CF(2)-CF(2) rotational barrier along the backbone is nearly 28.9 kJ mol(-1) higher than the minimum energy staggered trans conformation. Furthermore, the calculations reveal that the stiffest portion of the side chain is near to its attachment site on the backbone, with CF-O and O-CF(2) barriers of 38.1 and 28.0 kJ mol(-1), respectively. The most flexible portion of the side chain is the carbon-sulfur bond, with a barrier of only 8.8 kJ mol(-1). Extensive searches for minimum energy structures (at the B3LYP/6-311G(d,p) level) of the same polymeric fragment with 4-7 explicit water molecules reveal that the perfluorocarbon backbone may adopt either an elongated geometry, with all carbons in a trans configuration, or a folded conformation as a result of the hydrogen bonding of the terminal sulfonic acids with the water. These electronic structure calculations show that the fragments displaying the latter 'kinked' backbone possessed stronger binding of the water to the sulfonic acid groups, and also undergo proton dissociation with fewer water molecules. The calculations point to the importance of the flexibility in both the backbone and side chains of PFSA membranes to effectively transport protons under low humidity conditions.
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Affiliation(s)
- Stephen J Paddison
- Department of Chemistry and Materials Science, University of Alabama in Huntsville, 35899, USA.
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2317
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Tanigami T, Iwata H, Mori T. Ion-exchange membrane based on poly(styrene sulfonic acid-co-n-(2-hydroxyethyl) acrylamide). J Appl Polym Sci 2006. [DOI: 10.1002/app.25447] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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2318
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DeLuca NW, Elabd YA. Polymer electrolyte membranes for the direct methanol fuel cell: A review. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20861] [Citation(s) in RCA: 380] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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2319
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Liu D, Kyriakides S, Case SW, Lesko JJ, Li Y, McGrath JE. Tensile behavior of Nafion and sulfonated poly(arylene ether sulfone) copolymer membranes and its morphological correlations. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20813] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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2320
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Choi P, Jalani NH, Thampan TM, Datta R. Consideration of thermodynamic, transport, and mechanical properties in the design of polymer electrolyte membranes for higher temperature fuel cell operation. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20858] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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2321
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Cho CG, Kim YS, Yu X, Hill M, McGrath JE. Synthesis and characterization of poly(arylene ether sulfone) copolymers with sulfonimide side groups for a proton-exchange membrane. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/pola.21565] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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2322
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2323
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Siu A, Pivovar B, Horsfall J, Lovell KV, Holdcroft S. Dependence of methanol permeability on the nature of water and the morphology of graft copolymer proton exchange membranes. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20860] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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2324
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Satterfield MB, Majsztrik PW, Ota H, Benziger JB, Bocarsly AB. Mechanical properties of Nafion and titania/Nafion composite membranes for polymer electrolyte membrane fuel cells. ACTA ACUST UNITED AC 2006. [DOI: 10.1002/polb.20857] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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2325
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Evans CE, Noble RD, Koval CA. A Nonmechanical, Membrane-Based Liquid Pressurization System. Ind Eng Chem Res 2005. [DOI: 10.1021/ie0504708] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christine E. Evans
- Department of Chemistry and Biochemistry, and Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309
| | - Richard D. Noble
- Department of Chemistry and Biochemistry, and Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309
| | - Carl A. Koval
- Department of Chemistry and Biochemistry, and Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309
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2326
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Paul R, Paddison SJ. Effects of dielectric saturation and ionic screening on the proton self-diffusion coefficients in perfluorosulfonic acid membranes. J Chem Phys 2005; 123:224704. [PMID: 16375492 DOI: 10.1063/1.2131051] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Proton transport in perfluorosulfonic acid (PFSA) membranes is investigated through a statistical mechanical model that includes the effects of the interaction of the tethered sulfonate groups with both the water and solvated protons. We first derive a potential that describes the electrostatic field due to the dissociated sulfonic acid groups by extending the work of Gronbech-Jensen et al. [ Mol. Phys. 92, 941 (1997)] to a finite array of point charges. A highly convergent series is obtained which includes the effects of screening due to the protons. We then investigate the effects of both dielectric saturation and two distinct formulations of ionic screening on the proton self-diffusion coefficient in Nafion membranes over a range of water contents. Our computations show that the two phenomena (i.e., dielectric saturation and ionic screening) under constant temperature conditions result in canceling affects. Our calculations provide a radial dependence of the proton mobility suggesting that the dominant self-diffusion occurs in the central region of the pores, well separated from the sulfonate groups. Through comparison of our calculated diffusion coefficients with the experimental values we derived a slightly smaller average separation distance of the hydronium ion from the sulfonate ions than suggested by either electronic structure calculations or multistate empirical valence bond molecular-dynamics simulations.
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Affiliation(s)
- Reginald Paul
- Department of Chemistry, University of Calgary, Calgary, Alberta T2N 1N4, Canada
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2327
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Elabd YA, Napadensky E, Walker CW, Winey KI. Transport Properties of Sulfonated Poly(styrene-b-isobutylene-b-styrene) Triblock Copolymers at High Ion-Exchange Capacities. Macromolecules 2005. [DOI: 10.1021/ma051958n] [Citation(s) in RCA: 154] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yossef A. Elabd
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104; Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005; Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, Maryland 20783; and Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Eugene Napadensky
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104; Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005; Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, Maryland 20783; and Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Charles W. Walker
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104; Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005; Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, Maryland 20783; and Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Karen I. Winey
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104; Weapons and Materials Research Directorate, U.S. Army Research Laboratory, Aberdeen Proving Ground, Maryland 21005; Sensors and Electron Devices Directorate, U.S. Army Research Laboratory, Adelphi, Maryland 20783; and Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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2328
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Selvaraju T, Ramaraj R. Electrochemically deposited nanostructured platinum on Nafion coated electrode for sensor applications. J Electroanal Chem (Lausanne) 2005. [DOI: 10.1016/j.jelechem.2005.09.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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2329
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Gargas DJ, Bussian DA, Buratto SK. Investigation of the connectivity of hydrophilic domains in Nafion using electrochemical pore-directed nanolithography. NANO LETTERS 2005; 5:2184-7. [PMID: 16277450 DOI: 10.1021/nl051218s] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A method of determining the connectivity of ion-conducting hydrophilic channels within the Nafion polymer electrolyte membrane by way of pore-directed nanolithography has been developed. Electrochemical etching of a silicon surface is performed through a Nafion-membrane mask. The resulting silicon surface imaged by tapping-mode atomic force microscopy (TMAFM) provides a footprint of the hydrophilic channels at the Nafion-silicon interface. In a similar fashion, a TMAFM phase-contrast image of the top surface of the Nafion mask prior to etching reveals the spatial distribution of hydrophilic domains at the surface of the polymer membrane. Collectively, these images provide detailed information about the structure of the hydrophilic channels at the top and bottom surfaces of the Nafion membrane. Autocorrelation statistical analysis of these two sets of images shows that only 48% of hydrophilic channels beginning at the Nafion surface connect to the silicon-Nafion interface.
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Affiliation(s)
- Daniel J Gargas
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, USA
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2330
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Au nanoparticles self-assembled onto Nafion membranes for use as methanol-blocking barriers. Electrochem commun 2005. [DOI: 10.1016/j.elecom.2005.08.019] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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2331
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Kuwabara T, Teraguchi M, Kaneko T, Aoki T, Yagi M. Analysis and Regulation of Unusual Adsorption of Phthalocyanine Zinc(II) into a Nafion Film as Investigated by UV−vis Spectroscopic Techniques. J Phys Chem B 2005; 109:21202-8. [PMID: 16853747 DOI: 10.1021/jp052218j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Phthalocyanine zinc(II) (ZnPc) was found to be adsorbed well into a Nafion (Nf) film. The kinetic analysis suggested that the adsorption of ZnPc into the Nf film is controlled by its diffusion in the Nf film with a diffusion coefficient of D = 1.9 x 10(-6) cm(2) s(-1) that is higher than those (10(-9)-10(-12) cm(2) s(-1)) of cationic redox molecules in the Nf film by 3-6 orders of magnitude. The adsorption isothermal was analyzed by a Brunauer-Emmett-Teller (BET) equation suggesting multilayer adsorption of ZnPc into the film. The BET analysis provided the amount of ZnPc for monolayer adsorption (w(m) = 1.50 x 10(-7) mol cm(-2)), from which the effective area for the ZnPc adsorption was estimated to be larger by a factor of 1.7 x 10(3) than the Nf film area (1.0 cm(2)). The absorption spectra of a Nf film adsorbing ZnPc ((Nf/ZnPc)(ads) film) exhibited two broad absorption bands at 385 and 680-750 nm without any structural features, which is significantly different from the absorption spectra of either ZnPc solution in DMF or a (Nf/ZnPc)(mix) film prepared from a DMF solution containing Nf and ZnPc by solvent evaporation. This is ascribed to the formation of a ZnPc aggregate in the (Nf/ZnPc)(ads) film. Photoluminescence data for the (Nf/ZnPc)(mix) film suggested the presence of a ZnPc monomer and dimer at equilibrium in the film with a concentration of 0.1 M and that energy transfer occurs from the monomer to the dimer in excitation of the monomer (at lambda(ex) = 609 nm) to yield emission from the dimer. By contrast, photoluminescence data for the (Nf/ZnPc)(ads) film suggested that the excited ZnPc is self-quenched significantly by the formation of the ZnPc aggregate in the film. The lesser electroactivity of ZnPc in the (Nf/ZnPc)(ads) film compared with that in the (Nf/ZnPc)(mix) film could be ascribable to more difficult diffusion of ZnPc in the former film due to the formation of the ZnPc aggregate. The adsorption of ZnPc into the Nf film was significantly regulated by simple pretreatments of the Nf film such as immersion in solvents and storage under solvent vapors. The regulation was explained by controlled physical and chemical properties of a channel for mass and ion transport that is formed by sulfonate groups, countercations, and solvent molecules in the Nf film.
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Affiliation(s)
- Takayuki Kuwabara
- Faculty of Education and Human Sciences, Niigata University, 8050 Ikarashi-2, Niigata 950-2181, Japan
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2332
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KUDO K, MITSUSHIMA S, KAMIYA N, OTA KI. Ionic conductivity and Oxygen Reduction Reaction on Pt in Proton Conductive Room Temperature Molten Salts for 2-Alkylimidazolium and Brønsted-Acid Added Systems. ELECTROCHEMISTRY 2005. [DOI: 10.5796/electrochemistry.73.668] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Kenji KUDO
- Department of Energy and Safety Engineering, Yokohama National University
| | | | - Nobuyuki KAMIYA
- Department of Energy and Safety Engineering, Yokohama National University
| | - Ken-ichiro OTA
- Department of Energy and Safety Engineering, Yokohama National University
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2333
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Phillips AK, Moore RB. Ionic actuators based on novel sulfonated ethylene vinyl alcohol copolymer membranes. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.02.123] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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2334
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Tang H, Pan M, Jiang S, Wan Z, Yuan R. Self-assembling multi-layer Pd nanoparticles onto Nafion™ membrane to reduce methanol crossover. Colloids Surf A Physicochem Eng Asp 2005. [DOI: 10.1016/j.colsurfa.2005.04.011] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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2335
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Page KA, Cable KM, Moore RB. Molecular Origins of the Thermal Transitions and Dynamic Mechanical Relaxations in Perfluorosulfonate Ionomers. Macromolecules 2005. [DOI: 10.1021/ma0503559] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kirt A. Page
- Department of Polymer Science, The University of Southern Mississippi, Hattiesburg, Mississippi 39406-0001
| | - Kevin M. Cable
- Department of Polymer Science, The University of Southern Mississippi, Hattiesburg, Mississippi 39406-0001
| | - Robert B. Moore
- Department of Polymer Science, The University of Southern Mississippi, Hattiesburg, Mississippi 39406-0001
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2336
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Saarinen V, Kallio T, Paronen M, Tikkanen P, Rauhala E, Kontturi K. New ETFE-based membrane for direct methanol fuel cell. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2004.12.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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2338
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Chen YL, Meng YZ, Hay AS. Novel Synthesis of Sulfonated Poly(phthalazinone ether ketone) Used as a Proton Exchange Membrane via N−C Coupling Reaction. Macromolecules 2005. [DOI: 10.1021/ma047591o] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Y. L. Chen
- Institute of Energy & Environment Materials, School of Physics & Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R.China; Guangzhou Institute of Chemistry, Chinese Academy of Sciences, P.O. Box 1122, Guangzhou 510650, People's Republic of China; and Department of Chemstry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 2K6, Canada
| | - Y. Z. Meng
- Institute of Energy & Environment Materials, School of Physics & Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R.China; Guangzhou Institute of Chemistry, Chinese Academy of Sciences, P.O. Box 1122, Guangzhou 510650, People's Republic of China; and Department of Chemstry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 2K6, Canada
| | - A. S. Hay
- Institute of Energy & Environment Materials, School of Physics & Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R.China; Guangzhou Institute of Chemistry, Chinese Academy of Sciences, P.O. Box 1122, Guangzhou 510650, People's Republic of China; and Department of Chemstry, McGill University, 801 Sherbrooke Street West, Montreal, Quebec H3A 2K6, Canada
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Pervaporation of water from aqueous HI using Nafion®-117 membranes for the sulfur–iodine thermochemical water splitting process. J Memb Sci 2005. [DOI: 10.1016/j.memsci.2004.12.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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