Figure 2: Proton conductivity and mechanism.
(a) Conductivity as a function of humidity for a maleic–chitosan thin film (1 cm2×1 cm2, 300 μm thick) sandwiched between PdHx electrodes. (b) Grotthuss mechanism for H+ conduction along the hydrogen bonds formed by water and polysaccharide polar groups. (c) A four-monomer segment of maleic–chitosan. The intra- and inter-molecular hydrogen bonds as well as the hydrogen bonds between the water of hydration and the polar parts of the molecule form a continuous network comprised by hydrogen-bond chains. The maleic group donates a H+ to the hydrogen-bond network and forms an H3O+ (hydronium) ion.
