Optimization of Synthesis of Nanocrystalline Cellulose Extracted from Rice Straw

Cellulose is a natural biopolymer that shows some attractive properties such as recyclability, biodegradability, renewability, non-toxicity, low density and high functionality. Nanocrystalline Cellulose is (NCC) obtained from acid hydrolysis of cellulose fibres but compared to cellulose fibres, NCC possesses many more advantages, such as higher specific strength and modulus, higher surface area, unique optical properties, etc. This research work extracts cellulose from locally available rice straw variety. The extraction process included dewaxing, delignification, bleaching, acid hydrolysis, centrifugation, dialysis, sonication and freeze drying. It was observed using FTIR analysis that almost all the silica content of fibres was solubilized in the dewaxing step. XRD analysis concluded the decrement of crystallinity with an increment of the temperature and time of the centrifugation. The dialysis conditions and sonication parameters were optimized. Finally, the aqueous suspension was freeze dried to obtain Nanocrystalline cellulose powder. The results of the image analysis showed that almost 50% of Cellulose fibres within the range of 64–98 nm with 70% crystallinity and maximum yield 18.68% of NCC.