Ultrasound was used to facilitate the fibrillation of prepared chitin flakes using an ultrasound tip sonicator operating at frequency of 24 kHz and 360 W power (UP400S, Hielscher Ultrasound Technology, Germany). Initially, the sample was dispersed in water at 1% (w/v) concentration. The pH was set to 3–4 using acetic acid which helps to increase the repulsive forces between chitin nanofibers thus enhancing the dispersibility (Fan et al., 2008 and Ifuku et al., 2009). Then the sample was transferred to a glass beaker (250 ml) and sonicated for 2 h. Finally a semitransparent solution with slight bluish color was obtained which is characteristic for chitin nanofiber dispersion. The dispersion was stable for days at current pH