Morphology and molecular dynamics of hard α-keratin based micro-tubes by 1H and 13C solid-state NMR

► Keratin-based micro-tubes were investigated by 1H and 13C NMR methods. ► The micro-tubes are characterized by rigid, interfacial and amorphous fractions. ► 13C NMR reveals the significant presence of beta-sheet morphology in micro-tubes.