Novel quaternized mesoporous silica nanoparticle modified polysulfone-based composite anion exchange membranes for alkaline fuel cells

A series of novel composite anion exchange membranes (AEMs) for alkaline fuel cells were prepared by incorporating quaternized mesoporous silica nanoparticles (QMSNs) into the chloromethylated polysulfone (CMPSU), and followed by quaternization and alkalization. The influence of the content of QMSNs on the properties of the obtained composite membranes was studied. It is demonstrated that the performance of the composite membranes is greatly improved by the incorporation of QMSNs as compared with that of the pure quaternized PSU (QPSU) membrane such as the bicarbonate conductivity, the water uptake (WU) and ion exchange capacity (IEC) values, and the swelling-resistant properties. The morphology studies show that the QMSNs can be homogeneously dispersed in the QPSU matrix without phase separation. The high thermal resistance, acceptable mechanical properties, high alkaline resistance and oxide stability were also obtained for the composite membranes. The composite membrane containing 15 wt% QMSNs exhibits the highest bicarbonate conductivity, which has nearly a twofold increase compared to the pristine QPSU membrane. Therefore, this research demonstrates that the incorporation of the functionalized mesoporous silica nanoparticles opens up a new strategy for fabricating the organic-inorganic composite AEMs with improved properties.