Synthesis and characterization of cross-linked quaternized poly(vinyl alcohol)/chitosan composite anion exchange membranes for fuel cells

Novel cross-linked composite membranes were synthesized to investigate their applicability in anion exchange membrane fuel cells. These membranes consist of quaternized poly(vinyl alcohol) (QAPVA) and quaternized chitosan (2-hydroxypropyltrimethyl ammonium chloride chitosan, HACC) with glutaraldehyde as the cross-linking reagent. The membranes were characterized in term of their water content, ion exchange capacity (IEC), ion conductivity and methanol permeability. FTIR, X-ray diffraction and scanning electron microscopy (SEM) were also used to investigate the relation between the structure and performance of the composite membranes. The composite membranes have a high conductivity (10−3 to 10−2 S cm−1), and a low methanol permeability (from 5.68 × 10−7 to 4.42 × 10−6 cm2 s−1) at 30 °C. After reviewing all pertinent characteristics of the membranes, we find that the membrane structure is the principal factor affecting the conductivity and methanol permeability of these membranes.