Nano-scale morphology in graft copolymer proton-exchange membranes cross-linked with DIPB
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Nano-scale morphology in graft copolymer proton-exchange membranes cross-linked with DIPB. / Balog, Sandor; Gasser, Urs; Mortensen, Kell; Ben youcef, Hicham; Gubler, Lorenz; Scherer, Günther G.
I: Journal of Membrane Science, Bind 383, Nr. 1-2, 2011, s. 50-59.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Nano-scale morphology in graft copolymer proton-exchange membranes cross-linked with DIPB
AU - Balog, Sandor
AU - Gasser, Urs
AU - Mortensen, Kell
AU - Ben youcef, Hicham
AU - Gubler, Lorenz
AU - Scherer, Günther G.
PY - 2011
Y1 - 2011
N2 - The relationships between the nano-scale structure and the monomer composition of proton exchange membranes (PEMs) are reported. The PEMs are synthesized by preirradiation-induced grafting ETFE with styrene and cross-linker, 1,3-diisopropenylbenzene (DIPB), where the styrene moieties are sulfonated subsequently. The degree of grafting is constant, while the DIPB level is varied systematically. The SAXS spectra of the dry membranes are isotropic and dominated by a single correlation peak, which results from the phase separation of the ion-rich phase from the polymer matrix. By analyzing the correlation peak we find that the number density and the typical size of the ion-rich domains decrease when the level of cross-linking is increased. The proton conductivity in the fully hydrated state is proportional to the volume fraction of the ion-rich phase. This suggests that the structure of the ion-rich phase found in the dry state has fundamental impact on the conductivity of the hydrated membrane. The relationship between the proton conductivity and the water volume fraction follows a power law in good agreement with percolation theory.
AB - The relationships between the nano-scale structure and the monomer composition of proton exchange membranes (PEMs) are reported. The PEMs are synthesized by preirradiation-induced grafting ETFE with styrene and cross-linker, 1,3-diisopropenylbenzene (DIPB), where the styrene moieties are sulfonated subsequently. The degree of grafting is constant, while the DIPB level is varied systematically. The SAXS spectra of the dry membranes are isotropic and dominated by a single correlation peak, which results from the phase separation of the ion-rich phase from the polymer matrix. By analyzing the correlation peak we find that the number density and the typical size of the ion-rich domains decrease when the level of cross-linking is increased. The proton conductivity in the fully hydrated state is proportional to the volume fraction of the ion-rich phase. This suggests that the structure of the ion-rich phase found in the dry state has fundamental impact on the conductivity of the hydrated membrane. The relationship between the proton conductivity and the water volume fraction follows a power law in good agreement with percolation theory.
KW - Cross-linking
KW - Graft copolymer
KW - Percolation
KW - Proton-exchange membrane
KW - SAXS
KW - Stochastic real-space reconstruction
U2 - 10.1016/j.memsci.2011.08.031
DO - 10.1016/j.memsci.2011.08.031
M3 - Journal article
VL - 383
SP - 50
EP - 59
JO - Journal of Membrane Science
JF - Journal of Membrane Science
SN - 0376-7388
IS - 1-2
ER -
ID: 37586939