Process optimization for the production of cellulose nanocrystals from rice straw derived α-cellulose

Abstract

Nanocrystalline cellulose has emerged out as a substantial nanomaterial in recent years due to its peculiar characteristics such as bio renewability and sustainability while having high mechanical strengths, optical transparency and much more. In this study, we prepared cellulose nanocrystals (CNC) by acid hydrolysis of rice straw derived cellulose. The aim was to maximize the product yield by using RSM (response surface methodology) and also to investigate the interaction between 3 design factors; concentration of acid, temperature of reaction and time period of the reaction to unriddle their effects on yield of the product. A high CNC yield of 90.28% was found when the reactions conditions were kept at temperature 30 °C, acid concentration 75 wt% and time 5 h. Morphological characterization through scanning electron microscopy (SEM) clearly showed the formation of rod shaped CNCs. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) revealed that CNC’s have higher crystallinity (76%) than that of rice straw derived α-cellulose and higher thermal stability respectively. Thus, the isolated CNC may be suitable for use as reinforcing agent in the fabrication of bio-nanocomposites for different applications.

Keywords

• Rice straw
• Acid hydrolysis
• Cellulose nanocrystal (CNC)
• α-Cellulose
• SEM
• XRD