Structural characterization of cellulose nanocrystal-AXf hydrogels during swelling: impact of freeze-drying hydration cycles on their water

Seeds transformation for human nutrition results to the production of large amounts of co-products which contain various polymers with highly interesting functionalities. Among them, feruloylated arabinoxylans (AXf), are able to form covalent hydrogels by oxidation of their ferulic acid units. These hydrogels have a huge swelling capacity, which makes them powerful encapsulation matrices. However, due to high AXf viscosity, strong gels were until now difficult to product. Since AXf bind efficiently to cellulose surfaces, we investigated AXf /cellulose nanocrystals (CNC) gels. Previous results showed these composites gels to have higher mechanical properties and even larger mechanical resistance after a lyophilisation/ hydration cycle. Inversely, swelling capacity of regenerated gels decreased. Characterisation of the multiscale structure of AXf/CNC hydrogels during their swelling is necessary to determine which molecular interactions govern it.