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) Scm(-1)), and a low methanol permeability (from 5.68 x 10(-1) to 4.42 x 10(-6) cm(2) s(-1)) at 30 degrees 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. (C) 2008 Elsevier B.V. All rights reserved.