Preparation and characterization of apoacynum venetum cellulose nanofibers reinforced chitosan-based composite hydrogels.

Addition of nanomaterials into polymer matrix is a promising avenue to reinforce the mechanical properties of composites. In this work, chitosan-based hydrogels reinforced by cellulose nanofibers (CNFs) have been prepared by chitosan as matrix. The effect of CNFs (1vt%, 1.5vt% and 2vt%) on the structure-property relationship in mechanical, swelling capability, pH sensitivity and antibacterial have been investigated, respectively. Different from normal reinforced particle, CNFs with special fiber shape and abundant hydrogen bonding can form interconnected porous structure with chitosan hydrogel, which can spread stress and defer permanent damage under compressing. And the compressive strength increases nearly 20 % and swelling capacity achieve 140 %, when 1.5vt% CNFs added. Thanks to CNFs which obtained from apocynum venetum generated positive effect on the antibacterial rate against E. coli and S. aureus of composite hydrogel. It proves that CNFs display an excellent mechanical and antibacterial enhancement in composite, and it provided a new prospect for the rational selection of the different shapes and aspect ratio of reinforced materials. The obtained CNFs reinforced composite hydrogels could be potentially applied in antibacterial biological and food packaging area.