Effect of Sonication Time on Cellulose Nanofiber Disintegration from Locally Available Rice Straw

Abstract

AbstractUltrasonication is an important step which influences the disintegration of cellulose fibers. Ultrasonic energy is generally applied to disperse the nanoparticles. Cavitation bubbles develop and grow when high‐intensity ultrasound is applied. During the collapse of these bubbles, a considerable amount of energy is released. This creates a mechanical shock wave effect thus leads to the disruption of agglomerated particles. In this research, initially cellulose is derived from locally available rice straw varieties through a three step chemical extraction and purification process. Then, high‐intensity ultrasonication process is applied for 90 min on the chemically extracted cellulose fibers at 15 min time interval and the disintegration of cellulose nanofibers (CNFs) is studied. From the scanning electron microscopy (SEM) images, it is noticed that the high‐intensity ultrasonication process had significant effect on the disintegration of cellulose fibers. After 90 min treatment, fibrils with diameter in nanometer range are obtained whereas the lengths of the fibers are observed to be in micrometer range. Structural and thermal properties of disintegrated CNFs are also determined. From this study, it is evident that the sonication time had a greater impact on the efficiency of the disintegration of chemically extracted cellulose fibers.