Studies on a novel anion-exchange membrane based on chitosan and ionized organic compounds with multiwalled carbon nanotubes for alkaline fuel cells

In this work, a novel hydroxyl-anion-conducting membrane composed of chitosan (CTS), an ionized organic compound ([QAIM]OH), and hydroxylated multiwalled carbon nanotubes (MWCNTs-OH) has been fabricated through a blending-casting method assisted by a glutaraldehyde (GA) crosslinking process that can improve the mechanical properties of the membrane effectively. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy revealed that [QAIM]OH and MWCNTs-OH were successfully introduced into the CTS matrix. A chemical crosslinking reaction between CTS and GA could be confirmed by FTIR, X-ray photoelectron spectroscopy, and contact angle tests. By tuning the mass fraction of [QAIM]OH and MWCNTs-OH in the membrane, the maximum OH- conductivity (5.66x10(-3) S cm(-1) at room temperature) could be achieved for the composition CTS:[QAIM]OH (1:0.75 in mass) blend doped with 3% MWCNTs-OH. At a current density of 59.9 mA cm(-2), a membrane electrode assembly fabricated with the CTS/[QAIM]OH/ MWCNTs-OH membrane (1:0.5/3%) achieved a power density of 31.6 mW cm(-2) in a H-2/O-2 system at room temperature. Under the condition of intermediate temperature (100-140 degrees C) without water, the conductivities of the membranes increased with increasing temperature and the amount of [QAIM]OH, which acted as an ionic liquid in the membrane, indicating that the ionic transport behaviors could still be occurring. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46323.