Phosphorylated chitosan/poly(vinyl alcohol) based proton exchange membranes modified with propylammonium nitrate ionic liquid and silica filler for fuel cell applications

• Published in: International journal of hydrogen energy Vol. 47; no. 44; pp. 19217 - 19236
• Main Authors: Rosli, Nur Adiera Hanna, Loh, Kee Shyuan, Wong, Wai Yin, Lee, Tian Khoon, Ahmad, Azizan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 22-05-2022
• Subjects: N-methylene phosphonic chitosan; Poly(vinyl alcohol); Propylammonium nitrate ionic liquid; Proton exchange membrane; Silicon dioxide filler; Propylammonium nitrate ionic liquid; Poly(vinyl alcohol); Proton exchange membrane; Silicon dioxide filler; N-methylene phosphonic chitosan
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.04.063

In our previous work, phosphorylated chitosan was modified through polymer blending with poly(vinyl alcohol) (PVA) polymer to produce N-methylene phosphonic chitosan/poly(vinyl alcohol) (NMPC/PVA) composite membranes. The aim of this work is to further investigate the effects of a propylammonium nitrate (PAN) ionic liquid and/or silicon dioxide (SiO2) filler on the morphology and physical properties of NMPC/PVA composite membranes. The temperature-dependent ionic conductivity of the composite membranes with various ionic liquid and filler compositions was studied by varying the loading of PAN ionic liquid and SiO2-PAN filler in the range of 5–20 wt%. As the loading of PAN ionic liquid increased in the NMPC/PVA membrane matrix, the ionic conductivity value also increased with the highest value of 0.53 × 10−3 S cm−1 at 25 °C and increased to 1.54 × 10−3 S cm−1 at 100 °C with 20 wt% PAN. The NMPC/PVA-PAN (20 wt%) composite membrane also exhibited the highest water uptake and ion exchange capacity, with values of 60.5% and 0.60 mequiv g−1, respectively. In addition, in the single-cell performance test, the NMPC/PVA-PAN (20 wt%) composite membrane displayed a maximum power density, which was increased by approximately 14% compared to the NMPC/PVA composite membrane with 5 wt% SiO2-PAN. This work demonstrated that modified NMPC/PVA composite membranes with ionic liquid PAN and/or SiO2 filler showed enhanced performance compared with unmodified NMPC/PVA composite membranes for proton exchange membrane fuel cells.
[Display omitted]
•Modified NMPC/PVA composite membranes with PAN ionic liquid and/or SiO2 filler.•Effects of SiO2 and/or PAN on the characteristics of NMPC/PVA composite membrane.•NMPC/PVA-PAN (20 wt.%) sample showed the highest WUR, IEC, and ionic conductivity.