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Supercritical fluid CO 2 processing and counter ion substitution of nafion® membranes
Author(s) -
GuerreroGutiérrez Edward M. A.,
Suleiman David
Publication year - 2012
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.38689
Subject(s) - thermogravimetric analysis , differential scanning calorimetry , nafion , membrane , small angle x ray scattering , fourier transform infrared spectroscopy , supercritical fluid , materials science , analytical chemistry (journal) , chemical engineering , polymer chemistry , chemistry , scattering , organic chemistry , thermodynamics , biochemistry , physics , electrode , optics , electrochemistry , engineering
Nafion®‐117 was exposed to supercritical fluid (SCF) CO 2 and a cation solution using two different approaches: first was processed with SCF CO 2, and then exchanged using six different cations: K +1 , Ca +2 , Ba +2 , Cu +2 , Fe +3 , and Al +3 . The second method performed the cation substitution first, followed by the SCF CO 2 processing. The resulting composite membranes were characterized using several techniques: thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transforms infrared spectroscopy (FT‐IR), small angle X‐ray scattering (SAXS), and X‐ray diffraction (XRD). These techniques were used to identify the changes in the chemical and thermal properties of the membranes, as well as to evaluate changes in the resulting morphologies and crystallinities. Proton conductivity and methanol permeability were measured to understand how the different approaches promoted or inhibited the transport of certain substances through the membrane. Significant differences in their thermal, physical and transport properties were observed when Nafion® was processed with SCF CO 2 and exchanged with cations. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013