Effects of preparation methods on the morphology and properties of nanocellulose (NC) extracted from corn husk

The aim of this work is to improve the economic value of corn husk, and to make better use of corn husk nanocellulose (NC). Corn husk NC was extracted via acid hydrolysis, TEMPO oxidation and high intensity ultrasonication methods, which was named AH-NC, TO-NC and US-NC, respectively. The NC was carefully characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and particle size and zeta potential analyzer. The results showed the preparation methods didn't change the main chemical structure of cellulose. The crystallographic form of the three kinds of NC still was cellulose I. However, the effects of preparation methods on the morphology and properties were obvious. Among the three kinds of NC, TO-NC had the largest aspect ratio, and the best dispersion stability in diameter, but very low thermal stability. The AH-NC exhibited the highest crystallinity and best thermal stability, but a small aspect ratio. US-NC possessed low crystallinity and poor dispersion stability.