Enhanced properties of quaternized graphenes reinforced polysulfone based composite anion exchange membranes for alkaline fuel cell

Abstract

A series of novel composite anion exchange membranes for alkaline fuel cell were prepared by incorporating quaternized graphenes (QGs) into the chloromethylated polysulfone (CMPSU), and followed by quaternization and alkalization. The highly exfoliated quaternized graphenes (QGs) were obtained by epoxide ring opening reaction of APTES-functionalized graphenes (A-FGs) with glycidyltrimethylammonium chloride (GDTMAC). The influence of the content of QGs on the properties of the obtained composite membranes was studied. The results indicated that the QPSU−0.5%-QGs showed a 4-fold improvement in the bicarbonate conductivity than that of pristine QPSU membrane at 80°C, and the QPSU−0.25%-QGs showed a 3-fold increase in Young׳s modules and tensile strength. The performance improvement of the membranes could be attributed to the formation of the interconnected transfer channels provided by the QGs and the excellent compatibility between QPSU and QGs. In addition, the good morphologies without phase separation, acceptable thermal properties, alkaline resistances and oxide stabilities, low water uptakes and swelling ratios were also presented in the composite membranes. Our study demonstrated that the incorporation of proper content of QGs into the polymer matrix to fabricate the composite membranes is a facile way to improve the properties of the anion fuel cell membranes, especially in the anion conductivity and mechanical property.