TY - JOUR
T1 - Tuning hydrophobic composition in terpolymer-based anion exchange membranes to balance conductivity and stability
AU - Ozawa, Yoshihiro
AU - Shirase, Yuto
AU - Otsuji, Kanji
AU - Miyatake, Kenji
N1 - Funding Information:
This work was partly supported by the New Energy and Industrial Technology Development Organization (NEDO), the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan, through Grants-in-Aid for Scientific Research (KAKENHI 18H05515), Japan Science and Technology (JST) through SICORP (JPMJSC18H8), the JKA promotion funds from AUTORACE, the Iwatani Naoji Foundation, and the thermal and electric energy technology foundation. We thank Tosoh Fine Chem for kindly supplying 1,6-diiodoperfluorohexane.
Publisher Copyright:
© 2022 The Royal Society of Chemistry.
PY - 2022/3/30
Y1 - 2022/3/30
N2 - We designed and synthesized novel terpolymer-based anion conductive polymers, where the effect of hydrophobic composition on the membrane properties was investigated in detail. Precursor terpolymers were first prepared from 2,2-bis(4-chlorophenyl)hexafluoropropane (BAF), 1,6-bis(3-chlorophenyl)perfluorohexane (PAF), and 2,7-dichloro-9,9-bis[6′-(N,N-dimethylamino)hexyl]fluorene via Ni(0)-promoted polycondensation reaction. The following quaternization reaction with dimethyl sulfate was successful to obtain five terpolymers, QBPA with different PAF/(BAF + PAF) compositions and supposed chemical structures. QBPA provided thin and bendable membranes by solution casting. TEM images suggested that the membranes exhibited a phase-separated morphology similar to those of the corresponding parent copolymer membranes. SAXS profiles indicated that QBPA-4 containing 83 mol% PAF exhibited the most distinct periodic structure based on the hydrophobic component. The hydroxide ion conductivity of the membranes showed a volcano-type dependence on the hydrophobic composition, and the highest conductivity (161 mS cm−1) was achieved with the QBPA-1 membrane at 80 °C. Taking also the other properties into account, QBPA-1 and QBPA-5 containing 17 mol% PAF seemed the best-balanced membranes. An alkaline fuel cell using the QBPA-1 membrane achieved a maximum power density of 273 mW cm−2, exceeding that using the copolymer BAF-QAF membrane (185 mW cm−2).
AB - We designed and synthesized novel terpolymer-based anion conductive polymers, where the effect of hydrophobic composition on the membrane properties was investigated in detail. Precursor terpolymers were first prepared from 2,2-bis(4-chlorophenyl)hexafluoropropane (BAF), 1,6-bis(3-chlorophenyl)perfluorohexane (PAF), and 2,7-dichloro-9,9-bis[6′-(N,N-dimethylamino)hexyl]fluorene via Ni(0)-promoted polycondensation reaction. The following quaternization reaction with dimethyl sulfate was successful to obtain five terpolymers, QBPA with different PAF/(BAF + PAF) compositions and supposed chemical structures. QBPA provided thin and bendable membranes by solution casting. TEM images suggested that the membranes exhibited a phase-separated morphology similar to those of the corresponding parent copolymer membranes. SAXS profiles indicated that QBPA-4 containing 83 mol% PAF exhibited the most distinct periodic structure based on the hydrophobic component. The hydroxide ion conductivity of the membranes showed a volcano-type dependence on the hydrophobic composition, and the highest conductivity (161 mS cm−1) was achieved with the QBPA-1 membrane at 80 °C. Taking also the other properties into account, QBPA-1 and QBPA-5 containing 17 mol% PAF seemed the best-balanced membranes. An alkaline fuel cell using the QBPA-1 membrane achieved a maximum power density of 273 mW cm−2, exceeding that using the copolymer BAF-QAF membrane (185 mW cm−2).
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U2 - 10.1039/d2me00027j
DO - 10.1039/d2me00027j
M3 - Article
AN - SCOPUS:85129196651
SN - 2058-9689
VL - 7
SP - 798
EP - 808
JO - Molecular Systems Design and Engineering
JF - Molecular Systems Design and Engineering
IS - 7
ER -