Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Enhancement of anhydrous proton transport by supramolecular nanochannels in comb polymers

Abstract

Transporting protons is essential in several biological processes as well as in renewable energy devices, such as fuel cells. Although biological systems exhibit precise supramolecular organization of chemical functionalities on the nanoscale to effect highly efficient proton conduction, to achieve similar organization in artificial systems remains a daunting challenge. Here, we are concerned with transporting protons on a micron scale under anhydrous conditions, that is proton transfer unassisted by any solvent, especially water. We report that proton-conducting systems derived from facially amphiphilic polymers that exhibit organized supramolecular assemblies show a dramatic enhancement in anhydrous conductivity relative to analogous materials that lack the capacity for self-organization. We describe the design, synthesis and characterization of these macromolecules, and suggest that nanoscale organization of proton-conducting functionalities is a key consideration in obtaining efficient anhydrous proton transport.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Structures and synthesis of benzotriazole-based polymers.
Figure 2: Conductivity and SAXS results for benzotriazole polymers.
Figure 3: Results for imidazole-based polymers

Similar content being viewed by others

References

  1. Williams, R. J. P. Proton circuits in biological energy interconversions. Annu. Rev. Biophys. Biophys. Chem. 17, 71–97 (1988).

    Article  CAS  Google Scholar 

  2. Kreuer, K. D. Proton conductivity: materials and applications. Chem. Mater. 8, 610–641 (1996).

    Article  CAS  Google Scholar 

  3. Sass, H. J. et al. Structural alterations for proton translocation in the M state of wild-type bacteriorhodopsin. Nature 406, 649–653 (2000).

    Article  CAS  Google Scholar 

  4. Schnell, J. R. & Chou, J. J. Structure and mechanism of the M2 proton channel of influenza A virus. Nature 451, 591–560 (2008).

    Article  CAS  Google Scholar 

  5. Stouffer, A. L. et al. Structural basis for the function and inhibition of an influenza virus proton channel. Nature 451, 596–600 (2008).

    Article  CAS  Google Scholar 

  6. Carrette, L., Friedrich, K. A. & Stimming, U. Fuel cells – fundamentals and applications. Fuel Cells 1, 5–39 (2001).

    Article  CAS  Google Scholar 

  7. Steele, B. C. H. & Heinzel, A. Materials for fuel-cell technologies. Nature 414, 345–352 (2001).

    Article  CAS  Google Scholar 

  8. Mauritz, K. A. & Moore, R. B. State of understanding of Nafion, Chem. Rev. 104, 4535–4585 (2004).

    Article  CAS  Google Scholar 

  9. Diat, O. & Gebel, G. Proton channels. Nature Mater. 7, 13–14 (2008).

    Article  CAS  Google Scholar 

  10. Schmidt-Rohr, K. & Chen, Q. Parallel cylindrical water nanochannels in Nafion fuel-cell membranes. Nature Mater. 7, 75–83 (2008).

    Article  CAS  Google Scholar 

  11. Elliott, J. A., Hanna, S., Elliott, A. M. S. & Cooley, G. E. Interpretation of the small-angle X-ray scattering from swollen and oriented perfluorinated ionomer membranes. Macromolecules 33, 8708–8713 (2000).

    Article  Google Scholar 

  12. Hickner, M. A., Ghassemi, H., Kim, Y. S., Einsla, B. R. & McGrath, J. E. Alternative polymer systems for proton exchange membranes (PEMs). Chem. Rev. 104, 4587–4612 (2004).

    Article  CAS  Google Scholar 

  13. Rikukawa, M. & Sanui, K. Proton-conducting polymer electrolyte membranes based on hydrocarbon polymers. Prog. Polym. Sci. 25, 1463–1502 (2000).

    Article  CAS  Google Scholar 

  14. Li, Q., He, R., Jensen, J. O. & Bjerrum, N. J. Approaches and recent development of polymer electrolyte membranes for fuel cells operating above 100 °C. Chem. Mater. 15, 4896–4915 (2003).

    Article  CAS  Google Scholar 

  15. Kreuer, K. D. Fast proton conductivity: a phenomenon between the solid and the liquid state? Solid State Ionics 94, 55–62 (1997).

    Article  CAS  Google Scholar 

  16. Kreuer, K. D., Fuchs, A., Ise, M., Spaeth, M. & Maier, J. Imidazole and pyrazole-based proton conducting polymers and liquids. Electrochim. Acta 43, 1281–1288 (1998).

    Article  CAS  Google Scholar 

  17. Scharfenberger, G. et al. Anhydrous polymeric proton conductors based on imidazole functionalized polysiloxane. Fuel Cells 6, 237–250 (2006).

    Article  CAS  Google Scholar 

  18. Zhou, Z., Li, S. W., Zhang, Y. L., Liu, M. L. & Li, W. Promotion of proton conduction in polymer electrolyte membranes by 1H-1,2,3-triazole. J. Am. Chem. Soc. 127, 10824–10825 (2005).

    Article  CAS  Google Scholar 

  19. Granados-Focil, S., Woudenberg, R. C., Yavuzcetin, O., Tuominen, M. T. & Coughlin, E. B. Water-free proton-conducting polysiloxanes: a study on the effect of heterocycle structure. Macromolecules 40, 8708–8713 (2007).

    Article  CAS  Google Scholar 

  20. Persson, J. C. & Jannasch, P. Intrinsically proton-conducting benzimidazole units tethered to polysiloxanes. Macromolecules 38, 3283–3289 (2005).

    Article  CAS  Google Scholar 

  21. Shogbon, C. B., Brousseau, J.-L., Zhang, H., Benicewicz, B. C. & Akpalu, Y. Determination of the molecular parameters and studies of the chain conformation of polybenzimidazole in DMAc/LiCl. Macromolecules 39, 9409–9418 (2006).

    Article  CAS  Google Scholar 

  22. Subbaraman, R., Ghassemi, H. & Zawodzinski, T. A. Jr 4,5-Dicyano-1H-[1,2,3]-triazole as a proton transport facilitator for polymer electrolyte membrane fuel cells. J. Am. Chem. Soc. 129, 2238–2239 (2007).

    Article  CAS  Google Scholar 

  23. Won, J. et al. Fixation of nanosized proton transport channels in membranes. Macromolecules 36, 3228–3234 (2003).

    Article  CAS  Google Scholar 

  24. Serpico, J. M. et al. Transport and structural studies of sulfonated styrene–ethylene copolymer membranes. Macromolecules 35, 5916–5921 (2002).

    Article  CAS  Google Scholar 

  25. Shi, Z. & Holdcroft, S. Synthesis and proton conductivity of partially sulfonated poly([vinylidene difluoride-co-hexafluoropropylene]-b-styrene) block copolymers. Macromolecules 38, 4193–4201 (2005).

    Article  CAS  Google Scholar 

  26. Rubatat, L., Shi, Z., Diat, O., Holdcroft, S. & Frisken, B. J. Structural study of proton-conducting fluorous block copolymer membranes. Macromolecules 39, 720–730 (2006).

    Article  CAS  Google Scholar 

  27. Cho, B. K., Jain, A., Gruner, S. M. & Wiesner, U. Mesophase structure – mechanical and ionic transport correlations in extended amphiphilic dendrons. Science 305, 1598–1601 (2004).

    Article  CAS  Google Scholar 

  28. Kishimoto, K. et al. Nano-segregated polymeric film exhibiting high ionic conductivities. J. Am. Chem. Soc. 127, 15618–15623 (2005).

    Article  CAS  Google Scholar 

  29. Wanakule, N. S. et al. Ionic conductivity of block copolymer electrolytes in the vicinity of order–disorder and order–order transitions. Macromolecules 42, 5642–5651 (2009).

    Article  CAS  Google Scholar 

  30. Savariar, E. N., Aathimankandan, S. V. & Thayumanavan, S. Supramolecular assemblies from amphiphilic homopolymers: testing the scope. J. Am. Chem. Soc. 128, 16224–16230 (2006).

    Article  CAS  Google Scholar 

  31. Basu, S., Vutukuri, D. R. & Thayumanavan, S. Homopolymer micelles in heterogeneous solvent mixtures. J. Am. Chem. Soc. 127, 16794–17695 (2005).

    Article  CAS  Google Scholar 

  32. Wintersgill, M. C. & Fontanella, J. J. Complex impedance measurements on Nafion. Electrochim. Acta 43, 1533–1538 (1998).

    Article  CAS  Google Scholar 

  33. Sanders, E. H. et al. Characterization of electrosprayed Nafion films. J. Power Sources 129, 55–61 (2004).

    Article  CAS  Google Scholar 

  34. Ruotsalainen, T. et al. Structural hierarchy in flow-aligned hexagonally self-organized microphases with parallel polyelectrolytic structures. Macromolecules 36, 9437–9442 (2003).

    Article  CAS  Google Scholar 

  35. Roy, A. et al. Influence of chemical composition and sequence length on the transport properties of proton exchange membranes. J. Polym. Sci. B 44, 2226–2239 (2006).

    Article  CAS  Google Scholar 

  36. Schuster, M. F. H. & Meyer, W. H. Anhydrous proton-conducting polymers. Annu. Rev. Mater. Res. 33, 233–261 (2003).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This work was supported by the National Science Foundation through the Fueling the Future Center for Chemical Innovation at the University of Massachusetts Amherst (CHE-0739227). We thank W. de Jeu for discussions on the X-ray scattering results.

Author information

Authors and Affiliations

Authors

Contributions

S.T. and Y.C. conceived the molecular design. S.T., R.H. and Mark T. planned the project. Y.C, Michael T., S.C. and C.V. carried out the experiments and analysed the data. Y.C. and A.P. synthesized the discussed compounds, Michael T. and C.V. measured ionic conductivities, and S.C. performed SAXS. Results were discussed by R.H., Mark T. and S.T. All authors contributed to writing the manuscript.

Corresponding authors

Correspondence to Ryan C. Hayward, Mark T. Tuominen or S. Thayumanavan.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Chen, Y., Thorn, M., Christensen, S. et al. Enhancement of anhydrous proton transport by supramolecular nanochannels in comb polymers. Nature Chem 2, 503–508 (2010). https://doi.org/10.1038/nchem.629

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nchem.629

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing