Structure and morphology of fractions separated from mechanical-assisted enzyme hydrolyzed chitin microfibrils

Chitin whiskers with diameter of 10-50 nm were prepared by a green way of mechanical-assisted enzyme hydrolysis, and several nanowhisker fractions were successfully separated by centrifugation at 3,000, 5,000, and 7,000 rpm, respectively. The size, morphology and crystalline form of as-prepared nanowhiskers were analyzed by scanning electron microscopy, transmission electron microscopy and wide angle X-ray diffraction, respectively. And the results showed that the particle size was decreased with an increase of enzyme concentration or hydrolysis time. The crystallinity of nanowhisker fragments after treatment by enzyme was increased effectively although no crystalline form was changed.