Transmission Infrared Spectroscopy as a Probe of Nafion Film Structure: Analysis of Spectral Regions Fundamental to Understanding Hydration Effects

Abstract

Transmission infrared spectroscopy was applied to investigate properties of the perfluorosulfonated polymer Nafion. Measurements were made on thin films formed by casting the polymer from solution onto ZnSe windows. Effects of water vapor permeation were studied. A complex band structure between 1350 and 1100 cm⁻¹ was analyzed qualitatively by fitting the region to Gaussian functions. Features associated with vibrational modes of –CF₂ and –SO₃⁻ groups were identified and observed to be sensitive to film hydration. The intensities of bands for the –SO₃⁻ modes increased with film hydration, while bands assignable to –CF₂ modes decreased. The results were applied to interpret infrared difference spectra of Nafion and shed light on the complicated features that appear. Vibrational bands for water were also examined. In partially hydrated films, the stretching mode of the free –OH group for interfacial water present in pores and channels of the polymer and bands for hydrated proton clusters were detected.

Keywords

Infrared spectroscopy Fourier transform infrared spectroscopy FT-IR spectroscopy Polymers Nafion Hydration

Get full access to this article

View all access options for this article.

References

Mauritz

K. A.

and Moore

R. B

, Chem. Rev. 104, 4535 (2004).

Gottesfeld

and Zawodzinski

T. A

, “Polymer Electrolyte Fuel Cells”, in Advances in Electrochemical Science and Engineering, Alkire

R. C.

Gerischer

Kolb

D. M.

and Tobias

C. W

, Eds. (Wiley-VCH, New York, 1997), Vol. 5, p. 195.

Blanchard

R. M.

and Nuzzo

R. G

, J. Polym. Sci., Part B: Polym. Phys. 38, 1512 (2000).

Lowry

S. R.

and Mauritz

K. A

, J. Am. Chem. Soc. 102, 4665 (1980).

Falk

, “Infrared spectra of perfluorosulfonated polymer and of water in perfluorosulfonated polymer”, in Perfluorinated Ionomer Membranes, Eisenberg

and Yeager

H. L

, Eds. (American Chemical Society, Washington, D.C., 1982), Vol. 180, p. 139.

Malevich

Zamlynny

Sun

S.-G.

and Lipkowski

, Z. Phys. Chem. 217, 513 (2003).

Gruger

Regis

Schmatko

and Colomban

, Vib. Spectrosc. 26, 215 (2001).

Ludvigsson

Lindgren

and Tegenfeldt

, Electrochim. Acta 45, 2267 (2000).

Falk

, Can. J. Chem. 58, 1495 (1980).

10.

Buzzoni

Bordiga

Ricchiardi

Spoto

and Zecchina

, J. Phys. Chem. 99, 11937 (1995).

11.

Zecchina

Geobaldo

Spoto

Bordiga

Ricchiardi

Buzzoni

and Petrini

, J. Phys. Chem. 100, 16584 (1996).

12.

Wang

Y. Q.

Kawano

Aubuchon

S. R.

and Palmer

R. A

, Macromolecules 36, 1138 (2003).

13.

Iwamoto

Oguro

Sato

and Iseki

, J. Phys. Chem. B 106, 6973 (2002).

14.

Laporta

Pegoraro

and Zanderighi

, Phys. Chem. Chem. Phys. 1, 4619 (1999).

15.

Parry

D. B.

Samant

M. G.

and Melroy

O. R

, Appl. Spectrosc. 45, 999 (1991).

16.

Huang

Barham

M. D.

and Korzeniewski

, Microchem. J. 62, 114 (1999).

17.

Freysz

and Shen

Y. R

, Science (Washington, D.C.) 264, 826 (1994).

18.

Brown

M. G.

Raymond

E. A.

Allen

H. C.

Scatena

L. F.

and Richmond

G. L

, J. Phys. Chem. A 104, 10220 (2000).

19.

Scatena

L. F.

Brown

M. G.

and Richmond

G. L

, Science (Washington, D.C.) 292, 908 (2001).

20.

Raymond

E. A.

Tarbuck

T. L.

Brown

M. G.

and Richmond

G. L

, J. Phys. Chem. B 107, 546 (2003).

21.

Ritzhaupt

and Devlin

J. P

, J. Phys. Chem. 95, 90 (1991).

22.

Devlin

J. P.

Sadlej

and Buch

, J. Phys. Chem. A 105, 974 (2001).

23.

Devlin

J. P.

Severson

M. W.

Mohamed

Sadlej

Buch

and Parrinello

, Chem. Phys. Lett. 408, 439 (2005).

24.

Asmis

K. R.

Pivonka

N. L.

Santambrogio

Brümmer

Kaposta

Neumark

D. M.

and Wöste

, Science (Washington, D.C.) 299, 1375 (2003).

25.

Headrick

J. M.

Diken

E. G.

Walters

R. S.

Hammer

N. I.

Christie

R. A.

Cui

Myshakin

E. M.

Duncan

M. A.

Johnson

M. A.

and Jordan

K. D

, Science (Washington, D.C.) 308, 1765 (2005).