Preparation and characterization of highly stable protic-ionic-liquid membranes

• Main Authors: Zakeri, Masoumeh, Abouzari-Lotf, Ebrahim, Nasef, Mohamed Mahmoud, Ahmad, Arshad, Ripin, Adnan, Ting, Teo Ming, Sithambaranathan, Paveswari
• Format: Article
• Published: Elsevier Ltd 2019
• Subjects: TP Chemical technology
• Online Access: http://eprints.utm.my/id/eprint/89336/; http://dx.doi.org/10.1016/j.ijhydene.2018.04.015
• Institution: Universiti Teknologi Malaysia

A highly durable proton exchange membranes (PEM)s based on covalently supported ionic liquid (IL) bearing sulfonic acid imidazolium groups were successfully fabricated. The membrane preparation involved radiation induced grafting of 1-vinyl imidazole (1-VIm) onto poly(ethylene-co-tetraflouroethene) (ETFE) film, followed by covalent immobilization of 3-sulfopropyl and subsequent treatment with trifluoromethanesulfonic acid. The ionic conductivity of the supported IL membranes was increased with the increase in the concentration of IL and reached a maximum value of 138 mS cm−1 in a fully hydrated state with an ion exchange capacity of 4.82 mmol g−1 that is higher than Nafion with a similar thickness. The membranes displayed excellent chemical and mechanical stability. In addition, the dimensional and thermal stability of supported IL-membranes were significantly higher than commercial Nafion membranes.