*2.2. Chitosan Nanofiber Preparation*

ACC is a water jet system that uses two high-pressure (200 MPa) water jets colliding with each other to produce a high shear force so as to isolate nanofibers from the original suspension [28,34]. ACC is a benign and environmentally friendly isolation method. Thus, ACC was selected for ChNF isolation by using an ACC machine (ACCNAC–100, CNNT, Korea). The nozzle size of two water jets was 160 μm in diameter. Chitosan suspension of 1% concentration was fed to the ACC machine to extract the ChNF. Different passes of chitosan suspension through the ACC machine was done at 10, 15 and 30 passes. The number of pass indicates how many times the suspension goes through the ACC chamber.
