Fabrication and Characterization of Chitosan Nanoparticle-Incorporated Quaternized Poly(Vinyl Alcohol) Composite Membranes as Solid Electrolytes for Direct Methanol Alkaline Fuel Cells

•Preparation of chitosan nanoparticles from bulk to enhance the degree of deacetylation.•The incorporation of chitosan nanoparticles into a QPVA matrix to form a nanocomposite membrane.•The nanocomposite constructed into thin-film membranes using the solution casting method.•To improve permeability, glutaraldehyde was cross-linked with the nanocomposite membranes.•A direct methanol alkaline fuel cell was studied at different temperatures.