Dielectric response of hydrated water as a structural component of nanofibrillated cellulose (NFC) from different...

The current work illuminates the interplay between nanofibrillated cellulose (NFC) films and hydrated water. The NFC films from three sources of technological importance, i.e. cotton, wood and flax, are compared. It is shown that cellulose materials present slight variations in supramolecular structure depending on the plant origin. The structural differences determine both quantity and state of the water adsorbed by cellulose. Dielectric spectroscopy was employed to study the state of hydrated water as a probe of both the overall and specific marks of NFCs' structure. The measurements, carried out in the wide frequency (10^-2Hz -10⁶Hz) and temperature (123 K-293 K) ranges, revealed the formation of non-interactive water clusters at low water content. At high water content, additional states of water were identified: Water in saturated glass-forming solution and bulk. These water states were shown to be determined by the NFC's structure and morphology.