Control of Microdomain Orientation in Block Copolymer Thin Films by Electric Field for Proton Exchange Membrane

Joonwon  Bae

doi:10.4236/aces.2014.42013

Joonwon Bae^*

Abstract: Owing to the recent push toward efficient energy storage/conversion devices, fuel cells have become a strong candidate for energy conversion equipments. On the other hand, block copolymer polyelectrolytes are interesting materials for proton exchange membranes in fuel cells. Thus a considerable attention has been paid to the development of block copolymer polyelectrolyte membranes. In this study, the microdomains in block copolymer polyelectrolytes were controlled by external electric fields to develop high performance membranes with improved proton conductivity. The microdomain alignments in sulfonated polystyrene-b-hydrogenated poly butadiene-b-polystyrene block copolymer electrolyte were monitored by cross-sectional transmission electron microscopy analysis. The proton conductivities of the block copolymer electrolyte membranes were measured before and after exposure to electric field. In addition, the morphological features of the block copolymer electrolyte were observed with small angle x-ray scattering and atomic force microscopy.

Keywords: Proton Conducting Membrane, Block Copolymer Polyelectrolyte, Microdomain Alignment, Electric Field, Fuel Cell, Proton Conductivity

Cite this paper: Bae, J. (2014) Control of Microdomain Orientation in Block Copolymer Thin Films by Electric Field for Proton Exchange Membrane. Advances in Chemical Engineering and Science, 4, 95-102. doi: 10.4236/aces.2014.42013.

References

[1] Baldauf, M. and Preidel, W. (1999) Status of the Development of Direct Methanol Fuel Cell. Journal of Power Sources, 84, 161-166.
http://dx.doi.org/10.1016/S0378-7753(99)00332-8

[2] Rikukawa, M. and Sanui, K. (2000) Proton-Conduction Polymer Electrolyte Membranes Based on Hydrocarbon Polymers. Progress in Polymer Science, 25, 1463-1502.
http://dx.doi.org/10.1016/S0079-6700(00)00032-0

[3] Elabd, Y.A. and Hickner, M.A. (2011) Block Copolymers for Fuel Cells. Macromolecules, 44, 1-11.
http://dx.doi.org/10.1021/ma101247c

[4] Heitner-Wirguin, C. (1996) Recent advances in Perfluorinated Ionomer Membranes: Structure, Properties and Applications. Journal of Membrane Science, 120, 1-33.
http://dx.doi.org/10.1016/0376-7388(96)00155-X

[5] Costamagna, P. and Srinivasan, S. (2001) Quantum Jumps in the PEMFC Science and Technology from the 1960s to the Year 2000; Part I. Fundamental Scientific Aspects. Journal of Membrane Science, 102, 242-252.

[6] Vielstich, W. and Ives, D.J.G. (1970)Fuel cells; Modern processes for the Electrochemical Production of Energy. Wiley, London.

[7] Tricoli, V. (1998) Proton and Methanol Transport in Poly (Perfluorosulfonate) Membranes Containing Cs+ and H+ Cations. Journal of the Electrochemical Society, 145, 3798-3801.
http://dx.doi.org/10.1149/1.1838876

[8] Tricoli, V., Carretta, N. and Bartolozzi, M. (2000) A Comparative Investigation of Proton and Methanol Transport in Fluorinated Ionomeric Membranes. Journal of the Electrochemical Society, 147, 1286-1290.
http://dx.doi.org/10.1149/1.1393351

[9] Hickner, M.A., Ghassemi, H., Kim, Y.S., Einsla, B.R. and McGrath, J.E. (2004) Alternative Polymer Systems for Proton Exchange Membranes (PEMs). Chemical Reviews, 104, 4587-4612.
http://dx.doi.org/10.1021/cr020711a

[10] Kim, J., Kim, B. and Jung, B. (2002) Proton Conductivities and Methanol Permeabilities of Membranes Made from Partially Sulfonated Polystyrene-Block-Poly (Ethylene-Ran-Butylene)-Block-Polystyrene Copolymers. Journal of Membrane Science, 207, 129-137.
http://dx.doi.org/10.1016/S0376-7388(02)00138-2

[11] Elabd, Y.A., Napadensky, E., Sloan, J.M., Crawford, D.M. and Walker, C.W. (2003) Triblock Copolymer Ionomer Membranes: Part I. Methanol and Proton Transport. Journal of Membrane Science, 217, 227-242.
http://dx.doi.org/10.1016/S0376-7388(03)00127-3

[12] Shi, Z.Q. and Holdcroft, S. (2005) Synthesis and Proton Conductivity of Partially Sulfonated Poly ([Vinylidene Difluoride-co-Hexafluoropropylene]-b-Styrene) Block Copolymers. Macromolecules, 38, 4193-4201.
http://dx.doi.org/10.1021/ma0477549

[13] Park, M.J., Downing, K.H., Jackson, A., Gomez, E.D., Minor, A.M., Cookson, D., Weber, A.Z. and Balsara, N.P. (2007) Increased Water Retention in Polymer Electrolyte Membranes at Elevated Temperatures Assisted by Capillary Condensation. Nano Letters, 7, 3547-3552.
http://dx.doi.org/10.1021/nl072617l

[14] Xu, K., Li, K., Khanchaitit, P. and Wang, Q. (2007) Synthesis and Characterization of Self-Assembled SulfonatedPoly (Styrene-b-Vinylidene Fluoride-b-Styrene) Triblock Copolymers for Proton Conductive Membranes. Chemistry of Materials, 19, 5937-5945.
http://dx.doi.org/10.1021/cm071626s

[15] Saito, T., Moore, H.D. and Hickner, M.A. (2010) Synthesis of Midblock-Sulfonated Triblock Copolymers. Macromolecules, 43, 599-601.
http://dx.doi.org/10.1021/ma9023125

[16] Chen, L., Hallinan, Jr., D.T., Elabd, Y.A. and Hillmyer, M.A. (2009) Highly Selective Polymer Electrolyte Membranes from Reactive Block Polymers. Macromolecules, 42, 6075-6085.
http://dx.doi.org/10.1021/ma901272s

[17] Lee, H.-S., Roy, A., Lane, O., Dunn, S. and McGrath, J.E. (2008) Hydrophilic-Hydrophobic Multiblock Copolymers Based on Poly (Arylene Ether Sulfone) via Low-Temperature Coupling Reactions for Proton Exchange Membrane Fuel Cells. Polymer, 49, 715-723.
http://dx.doi.org/10.1016/j.polymer.2007.12.023

[18] Bae, B., Miyatake, K. and Watanabe, M. (2010) Sulfonated Poly (Arylene Ether Sulfone Ketone) Multiblock Copolymers with Highly Sulfonated Block. Synthesis and Properties. Macromolecules, 43, 2684-2691.
http://dx.doi.org/10.1021/ma100291z

[19] Csernica, J., Baddour, R.F. and Cohen, R.E. (1987) Gas Permeability of a Polystyrene-Polybutadiene Block Copolymer with Oriented Lamellar Domains. Macromolecules, 20, 2468-2471.
http://dx.doi.org/10.1021/ma00176a024

[20] Brinkmann, S., Stadler, R. and Thomas, E.L. (1998) New Structural Motif Inhexagonally Ordered Cylindrical Ternary (ABC) Block Copolymer Microdomains. Macromolecules, 31, 6566-6574.
http://dx.doi.org/10.1021/ma980103q

[21] Hajduk, D.A., Gruner, S.M., Rangarajan, P., Register, R.A., Fetters, L.J., Honeker, C., Albalak, R.J. and Thomas, E.L. (1994) Observation of a Reversiblethermotropic Order-Order Transition in a Diblock Copolymer. Macromolecules, 27, 490-501.
http://dx.doi.org/10.1021/ma00080a024

[22] Morrison, F.A. and Winter, H.H. (1989) The Effect of Unidirectionalshear on the Structure of Triblock Copolymers. I. Polystyrene-Polybutadiene-Polystyrene. Macromolecules, 22, 3533-3540.
http://dx.doi.org/10.1021/ma00199a006

[23] Heck, B., Arends, P., Ganter, M., Kressler, J. and Stühn, B. (1997) SAXS and TEM Studies on Poly(strene)-blockpoly(ethene-co-but-1-ene)-block-poly(styrene) in Bulk and at Various Interfaces. Macromolecules, 30, 4559-4566.
http://dx.doi.org/10.1021/ma9617072

[24] Csernica, J., Baddour, R.F. and Cohen, R.E. (1989) Gas Permeability of Apolystyrene/Polybutadiene Block Copolymer Possessing a Misoriented Lamellar Morphology. Macromolecules, 22, 1493-1496.
http://dx.doi.org/10.1021/ma00193a085

[25] Weiss, R.A., Sen, A., Willis, C.L. and Pottick, A. (1991) Block Copolymer Ionomers: 1. Synthesis and Physical Properties of Sulfonated Poly(styrene-ethylene/butylene-styrene). Polymer, 32, 1867-1874.

[26] Jacobs, P.M. and Jones, F.R. (1989) Diffusion of Moisture into Two-Phase Polymers. Journal of Materials Science, 24, 2331-2336.
http://dx.doi.org/10.1007/BF01174492

[27] Weiss, R.A., Sen, A., Pottick, A. and Willis, C.L. (1991) Block Copolymer Ionomers: 2.Viscoelastic and Mechanical Properties of Sulfonated Poly(styrene-ethylene/butylene-styrene). Polymer, 32, 2785-2792.
http://dx.doi.org/10.1016/0032-3861(91)90109-V

[28] Wu, C., Woo, K. and Jiang, M. (1996) Light-Scattering Studies of Styrene-(ethylene-co-butylene)-Styrene Triblock Copolymer and Its Sulfonated Ionomers in Tetrahydrofuran. Macromolecules, 29, 5361-5367.
http://dx.doi.org/10.1021/ma960247+

[29] Adams, J.L., Quiram, D.J., Graessley, W.W., Register, R.A. and Marchand, G.R. (1998) Interaction Strengths in Styrene-Diene Block Copolymers and Their Hydrogenated Derivatives. Macromolecules, 31, 201-204.
http://dx.doi.org/10.1021/ma9710500

[30] Ovejero, G., Perez, P., Romero, M.D., Guzman, I. and Diez, E. (2007) Solubility and Flory Huggins Parameters of SBES, Poly(Styrene-b-butene/ethylene-b-styrene) Triblock Copolymer, Determined by Intrinsic Viscosity. European Polymer Journal, 43, 1444-1449.
http://dx.doi.org/10.1016/j.eurpolymj.2007.01.007

[31] Blackwell, R.I. and Mauritz, K.A. (2004) Dynamic Mechanical Properties of Annealed Sulfonated Poly(styrene-b-[ethylene/butylene]-b-styrene) Block Copolymers. Polymer, 45, 3457-3463.
http://dx.doi.org/10.1016/j.polymer.2004.02.010

[32] Chen, H., Hassan, M.K., Peddini, S.K. and Mauritz, K.A. (2011) Macromolecular Dynamics of Sulfonated Poly(Styrene-b-ethylene-ran-butylene-b-styrene) Block Copolymers by Broadband Dielectric Spectroscopy. European Polymer Journal, 47, 1936-1948.
http://dx.doi.org/10.1016/j.eurpolymj.2011.07.005

[33] Han, C.D., Chun, S.B., Hahn, S.F., Harper, S.Q., Savickas, P.J., Meunier, D.M., Li, L. and Yalcin, T. (1998) Phase Behavior of Polystyrene/Polybutadiene and Polystyrene/Hydrogenated Polybutadiene Mixtures: Effect of the Microstructure of Polybutadiene. Macromolecules, 31, 394-402.
http://dx.doi.org/10.1021/ma971309e

[34] Wang, Y., Shen, J.S. and Long, C.F. (2001) The Effect of Casting Temperature on Morphology of Poly(Styrene-ethylene/butylene-styrene) Triblock Copolymer. Polymer, 42, 8443-8446.
http://dx.doi.org/10.1016/S0032-3861(01)00325-1

[35] Wang, L., Hong, S., Hu, H., Zhao, J. and Han, C.C. (2007) The Surface Morphology Evolution of an Ultrathin Film of Poly[styrene-b-(ethylene-co-butylene)-b-styrene] during Its Dewetting Process. Langmuir, 23, 2304-2307.
http://dx.doi.org/10.1021/la063314u

[36] Wang, L., Zhao, J. and Han, C.C. (2008) Phase Separation of Polystyrene-b-(Ethylene-co-butylene)-b-styrene (SEBS) Deposited on Polystyrene Thin Films. Polymer, 49, 2153-2159.

[37] Wang, D., Fujinami, S., Liu, H., Nakajima, K. and Nishi, T. (2010) Investigation of True Surface Morphology and Nanomechanical Properties of Poly(styrene-b-ethylene-co-butylene-b-styrene) Using Nanomechanical Mapping: Effects of Composition. Macromolecules, 43, 9049-9055.
http://dx.doi.org/10.1021/ma100959v

[38] Kim, J., Kim, B., Jung, B., Kang, Y.S., Ha, H.Y., Oh, I.H. and Ihn, K.J. (2002) Effect of Casting Solvent on Morphology and PhysicalProperties of Partially Sulfonated Polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene Copolymers. Macromolecular Rapid Communications, 23, 753-756.
http://dx.doi.org/10.1002/1521-3927(20020901)23:13<753::AID-MARC753>3.0.CO;2-G

[39] Kim, B., Kim, J. and Jung, B. (2005) Morphology and Transport Properties of Protons and Methanol through Partially Sulfonated Block Copolymers. Journal of Membrane Science, 250, 175-182.
http://dx.doi.org/10.1016/j.memsci.2004.10.025

[40] Park, M.J. and Balsara, N.P. (2010) Anisotropic Proton Conduction in Aligned Block Copolymer Electrolyte Membranes at Equilibrium with Humid Air. Macromolecules, 43, 292-298.
http://dx.doi.org/10.1021/ma901980b

[41] Mauritz, K.A., Blackwell, R.I. and Beyer, F.L. (2004) Viscoelastic Properties and Morphology of Sulfonated Poly(styrene-b-ethylene/butylene-b-styrene) Block Copolymers (sBCP), and sBCP/[silicate] Nanostructured Materials. Polymer, 45, 3001-3016.
http://dx.doi.org/10.1016/j.polymer.2003.12.078

[42] Matsen, M.W. (2000) Equilibrium Behavior of Asymmetric ABA Triblock Copolymer Melts, Journal of Chemical Physics, 113, 5539.
http://dx.doi.org/10.1063/1.1289889

[43] Shibayama, M., Hashimoto, T. and Kawai, H. (1983) Ordered Structure Inblock Polymer Solutions. 5. Equilibrium and Nonequilibrium Aspects of Microdomain Formation. Macromolecules, 16, 1434-1443.
http://dx.doi.org/10.1021/ma00243a006

[44] Krevelen, V. (1990) Properties of Polymers. 3rd Editon, Elsevier, New York, 189.

[45] Xu, T., Hawker, C.J. and Russell, T.P. (2003) Interfacial Energy Effects on the Electric Field Alignment of Symmetric Diblock Copolymers. Macromolecules, 36, 6178-6182.
http://dx.doi.org/10.1021/ma034511s

[46] Wang, J.Y., Chen, W., Roy, C., Sievert, J.D. and Russell, T.P. (2008) Influence of Ionic Complexes on Phase Behavior of Polystyrene-b-poly(methyl methacrylate) Copolymers. Macromolecules, 41, 963-969.
http://dx.doi.org/10.1021/ma071908d