Magnetic field-oriented ferroferric oxide/poly(2, 6-dimethyl-1, 4-phenylene oxide) hybrid membranes for anion exchange membrane applications. Issue 39 (28th September 2018)

• Record Type: Journal Article
• Authors: Chen, Nanjun; Wang, Dong; Long, Chuan; Li, Yunxi; Lu, Chuanrui; Wang, Fanghui; Zhu, Hong
• Is Part Of: Nanoscale. Volume 10:Issue 39(2018)
• Page Start: 18680
• Page End: 18689
• Publication Date: 2018-09-28
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c8nr06048g
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : A magnetic-field-oriented hybrid membrane constructs successive and effective QA-Fe3 O4 ion channels to improve the comprehensive performance. Abstract : Concentrating on the ion conductivity of anion exchange membranes (AEMs), we present a magnetic-field-oriented strategy to address the insufficient ion conductivity and the lifetime problem of AEMs used in alkali membrane fuel cells (AMFCs). Magnetic ferroferric oxide (Fe3 O4 ) is functionalized with quaternary ammonium (QA) groups to endow the QA-Fe3 O4 with ion-exchange ability. A series of aligned QA-Fe3 O4 /poly(2, 6-dimethyl-1, 4-phenylene oxide) (PPO) hybrid membranes were fabricated by doping QA-Fe3 O4 in a triple-ammonium-functionalized PPO (TA-PPO) solution in an applied magnetic field. The structure of aligned QA-Fe3 O4 in the TA-PPO membrane is clearly observed by using a scanning electron microscope (SEM). More importantly, the aligned QA-Fe3 O4 constructs successive and effective ion-transport channels in the QA-Fe3 O4 /TA-PPO membrane, which dramatically improves the ion conductivity of the membranes. Notably, the magnetic-field-induced ion channels (MICs) are different from microscopic phase-induced ion channels (PICs). These MICs display much shorter ion transport distances and broader water channels than traditional PICs in AEMs. The aligned QA-Fe3 O4 /TA-PPO hybrid membrane displays a further 55% increase in ion conductivity after magnetic-field orientation compared to the normal QA-Fe3 O4 /TA-PPO membrane. Surprisingly, the aligned QA-Fe3 O4 also improves the alkali stability and fuel cell performance of the hybrid membrane. The aligned 6%-QA-Fe3 O4 /TA-PPO hybrid membrane realizes a maximal power density of 224 mW cm −2 . In summary, this work provides a novel and effective method to prepare high-performance AEMs.