Inclusion of zeolitic imidazolate framework-8 (ZIF-8) crystals within porous polyether sulfone (PES) via filtration methods as potential electrolytes for DMFC applications

• Main Authors: Junoh, H., Jaafar, J., Nordin, N.A.H.M., Ismail, A.F., Othman, M.H.D., Rahman, M.A., Yusof, N., Aziz, F.
• Format: Conference or Workshop Item
• Published: Elsevier Ltd 2020
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112520462&doi=10.1016%2fj.matpr.2020.12.1185&partnerID=40&md5=d9dd17f534436e252f1180bf3065af90; http://eprints.utp.edu.my/29692/
• Institution: Universiti Teknologi Petronas

The imidazolate framework-8 (ZIF-8) crystals were synthesized by in -situ growth techniques inside the pore of porous poly ether sulfone (PES) in order to fabricate a composite PES/ZIF-8 electrolyte membrane for direct methanol fuel cell (DMFC) applications. In situ techniques by adapting the filtration method was adhered in this study. It was found that the proton conductivity (17.9 � 10-3Scm-1) was drastically increased for PES/ZIF-8 as compared to pristine PES membrane (0.21 � 10-3Scm-1). However, the methanol barrier property was slightly decreased from 2.07 � 10-7cm2s-1to 3.88 � 10-7cm2s-1for PES and PES/ZIF-8 membranes, respectively. The introduction of ZIF-8 in PES membranes not only improve proton conductivity, but also positively affected the mechanical stability of PES/ZIF-8 with 1.73-fold lower of swelling ratio even though the water uptake increased by 2.08 folds. In spite of the increment in methanol permeability, selectivity of PES/ZIF-8 membrane was 6 folds and 2 folds higher than pristine PES and Nafion®, respectively which indicated that the potential for PES/ZIF-8 to be a good candidate for electrolyte in DMFC applications. Nonetheless, via scanning electron microscopy (SEM) showed a good distribution of ZIF-8 crystals inside the pore of PES membranes which proven that the effectiveness of filtration techniques for ZIF-8 crystals in-situ growth synthesized within the pores. © 2020 Elsevier Ltd. All rights reserved.