All-polysaccharide composite films based on calcium alginate reinforced synergistically by multidimensional cellulose and hemicellulose fractionated from corn husks

Lignocellulosic components in corn husk were fractionated successfully by sonication-assisted mild alkaline treatment followed by deep eutectic solvent (DES) treatment. The extracted hemicelluloses included a water-soluble macromolecular hemicellulose with Mn of 25.21 kDa as well as a water-insoluble hemicellulose, which formed a stable nano-particle dispersion after mechanical homogenization. The fractionated cellulose dispersed stably in water in nano-sheets after ball-milling. The obtained nano-hemicellulose and nano-cellulose were employed collaboratively for the first time to modify marine bio-based calcium alginate film. It was found collaboration of small amount of nano-cellulose and nano-hemicellulose had a synergistic reinforcing effect and significant gas barrier effect. A maximum tensile strength and breakage elongation of-98 MPa and-4.5% was achieved respectively with 2 wt% loading at 9:1 wt ratio of cellulose to hemicellulose, 2.2 and 1.7 times higher respectively than pristine alginate film. The moisture and oxygen permeability of the composite film decreased by-46% and-83% respectively at the same dosage. Additionally, the toughness of the bio-composite films can be improved with moderate addition of glycerol. The excellent performance makes the composite films potential candidates for substituting synthetic plastics in packaging.