Influence of morphology on physical properties of poly(2,5-benzimidazole) membranes

In this work, the structural properties of pristine and phosphoric acid doped poly(2,5-benzimidazole) membranes have been investigated by small angle neutron- and X-ray scattering, X-ray diffraction, polarized light microscopy and transmission electron microscopy. The results of our investigation demonstrate formation of crystalline regions with a fractal-like distribution upon aging on length scales ranging from sub-nm up to some micrometres. Transport properties of phosphoric acid doped poly(2,5-benzimidazole) membrane measured by pulsed-field-gradient nuclear magnetic resonance spectroscopy reveal proton self-diffusion coefficients of the system.