Polyethylene-based radiation grafted anion-exchange membranes for alkaline fuel cells

• Published in: Journal of membrane science Vol. 441; pp. 148 - 157
• Main Authors: Sherazi, Tauqir A., Yong Sohn, Joon, Moo Lee, Young, Guiver, Michael D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-08-2013; Elsevier
• Subjects: anion exchange; Anion exchange membrane; Applied sciences; artificial membranes; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Exchange resins and membranes; Forms of application and semi-finished materials; Fourier transform infrared spectroscopy; Fuel cell; Fuel cells; Grafting; melting; Membranes; methanol; Methyl alcohol; molecular weight; Permeability; Polyethylene; Polyethylenes; Polymer industry, paints, wood; pressing; Radiation grafting; Scanning electron microscopy; Technology of polymers; trimethylamine; UHMWPE; Uptakes; Radiation grafting; Polyethylene; UHMWPE; Anion exchange membrane; Fuel cell; Polymeric membrane; Grafting
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2013.03.053

Vinyl benzyl chloride was grafted onto ultra-high molecular weight polyethylene powder (UHMWPE) by radiation grafting. The grafted powder was subsequently fabricated into membrane by melt pressing. The effect of absorbed radiation dose on the degree of grafting (DG) is discussed. The melt-flow properties of PVBC grafted PE with low degree of grafting was conducive to forming homogeneous pore-free membranes, which was confirmed by scanning electron microscopic analysis. The grafted polyethylene membranes were post functionalized with trimethylamine, followed by alkalization to obtain anion-exchange membranes (AEMs). The structures of the resulting AEMs were characterized by Fourier transform infrared spectroscopy, which showed that the grafted membranes were successfully functionalized. The properties of the AEMs, including ion exchange capacity, water uptake, in-plane swelling, methanol uptake, methanol permeability and hydroxide ion conductivity were investigated. The AEMs showed reasonably good chemical stability, as evidenced by the ion exchange capacity being maintained for a long duration, even in highly alkaline conditions. The membranes exhibited a maximum ionic conductivity of 47.5mScm−1 at 90°C (30mScm−1 at 60°C). Methanol permeability was found to be in the order of 10−8cm2s−1, which is considerably lower than that of Nafion®. The membranes have useful properties consistent with anion exchange membranes suitable for alkaline fuel cells.
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•Polyethylene-based AEMs (PE-g-PVBC-TOH) were prepared by radiation grafting onto powder substrate.•Grafting onto powder followed by membrane fabrication was better practice than membrane grafting.•Anion exchange membranes had maximum hydroxide conductivity of 47.5mScm−1 at 90°C.•IEC values were maintained after exposure to 10M sodium hydroxide at 60°C for 120h.•Methanol permeability was in the order of 10−8cm2s−1.