Isolation of Nanocellulose from Rice Waste via Ultrasonication

In this work, nanocellulose was obtained from rice husk and rice straw. Initially, the samples were subjected to different types of chemical treatment and the obtained purified cellulose fibers were separated using ultrasonication. Nanocellulose isolated by mechanical treatment has been characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Surface morphology and nanocellulose size studies using SEM and AFM revealed that there was a reduction in fiber diameter during ultrasonication. XRD results indicated that the crystallinity of nanocellulose was approximately 62% and 71% for rice straw and rice husk, respectively. The TGA curve of the isolated nanocellulose after ultrasonic treatment showed that the degradation behavior is quite similar to purified cellulose fibers, suggesting that the ultrasonic treatment had a slight effect on the thermal decomposition of the nanocellulose.