TY - JOUR
T1 - Anion exchange membranes and ionomer properties of a polyfluorene-based polymer with alkyl spacers for water electrolysis
AU - Lim, Haeryang
AU - Jeong, Insu
AU - Choi, Jiyong
AU - Shin, Giwon
AU - Kim, Jeongsu
AU - Kim, Tae Hyun
AU - Park, Taiho
N1 - Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) ( 2021R1A5A1084921 , 2021M3H4A1A02055684 and 2021R1A2C3004420 ). Part of this work was also supported by a grant from the National Research Foundation of Korea (NRF) funded by the Ministry of Education ( 2021M1A2A2038114 ).
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2023/2/1
Y1 - 2023/2/1
N2 - Aryl ether-free polymers have attracted considerable attention in recent years for their application in anion exchange membrane (AEM) fuel cells (AEMFCs) and water electrolysis (AEMWE). Here, an aryl ether-free polyfluorene-based polymer bearing pendent ammonium groups in side chains and propyl spacers in its polymer backbone is synthesized through the Suzuki cross-coupling reaction. The propyl spacer introduced into the backbone improves the flexibility of the polymer and allows effective ionic cluster formation by the polymer. Compared to polyphenylene oxide (PPO), which has a similar molecular weight, quaternized poly[9,9-bis(6-bromohexyl)fluorene]–co-[4,4-bis((4-phenyl)propyl)biphenyl)] (PFPB-QA) polymers show significantly superior membrane-forming properties owing to the propyl spacers. The PFPB-QA membrane also exhibits high ionic conductivity (122 mS cm−1 at 80 °C) and excellent alkaline stability (1 M KOH at 80 °C for 720 h). Moreover, the AEMWE utilizing PFPB-QA exhibits a current density of 1.53 A cm−2 at 2.0 V in 1 M KOH at 70 °C. Therefore, the present study shows that an aryl ether-free polymer with an alkyl spacer has excellent mechanical properties, ionic conductivity, alkaline stability, and cell performance.
AB - Aryl ether-free polymers have attracted considerable attention in recent years for their application in anion exchange membrane (AEM) fuel cells (AEMFCs) and water electrolysis (AEMWE). Here, an aryl ether-free polyfluorene-based polymer bearing pendent ammonium groups in side chains and propyl spacers in its polymer backbone is synthesized through the Suzuki cross-coupling reaction. The propyl spacer introduced into the backbone improves the flexibility of the polymer and allows effective ionic cluster formation by the polymer. Compared to polyphenylene oxide (PPO), which has a similar molecular weight, quaternized poly[9,9-bis(6-bromohexyl)fluorene]–co-[4,4-bis((4-phenyl)propyl)biphenyl)] (PFPB-QA) polymers show significantly superior membrane-forming properties owing to the propyl spacers. The PFPB-QA membrane also exhibits high ionic conductivity (122 mS cm−1 at 80 °C) and excellent alkaline stability (1 M KOH at 80 °C for 720 h). Moreover, the AEMWE utilizing PFPB-QA exhibits a current density of 1.53 A cm−2 at 2.0 V in 1 M KOH at 70 °C. Therefore, the present study shows that an aryl ether-free polymer with an alkyl spacer has excellent mechanical properties, ionic conductivity, alkaline stability, and cell performance.
KW - Anion exchange membrane
KW - Aryl ether-free polymer
KW - Polyfluorene-based polymer
KW - Suzuki cross-coupling
KW - Water electrolysis
UR - http://www.scopus.com/inward/record.url?scp=85141796743&partnerID=8YFLogxK
U2 - 10.1016/j.apsusc.2022.155601
DO - 10.1016/j.apsusc.2022.155601
M3 - Article
AN - SCOPUS:85141796743
SN - 0169-4332
VL - 610
JO - Applied Surface Science
JF - Applied Surface Science
M1 - 155601
ER -