Optimized pure cellulose from rice straw using low alkali concentration for sustainable nanocellulose and...

Conversion of rice straw into nanocellulose offers a sustainable approach to agricultural waste management, yielding an industrially important product with potential applications. This work focuses on effectively extracting pure cellulose from both widely used Basmati and Parmal rice straw (BRS and PRS) using less alkali concentrations (3-5 % NaOH). The process was optimized via Box Behnken design at 90-150 °C temperatures for 90-150 min, which resulted in 88.8 ± 2.07 % cellulose for BRS and 89.10 ± 2.67 % for PRS. The cellulose was then processed into nanocellulose (BRSNC and PRSNC) through the combined approach of citric acid and ferric chloride hydrolysis. Various characterization techniques confirmed the removal of lignin and hemicellulose from the rice straws at different stages of hydrolysis. Nanocellulose was further transformed into nanohydrogel (BRSHG and PRSHG) using neem oil. In comparison to nanocellulose, the nanohydrogels exhibited remarkable dye reduction under UV light. The antimicrobial activity revealed superior efficacy of nanohydrogels against E. coli and S. aureus highlighting their potential in environmental remediation and antimicrobial applications.