Extraction of Cellulose Nanofibrils with Ultraviolet Blocking from Agro-industrial Wastes: A Comparative Study

Cellulose nanofibrils (CNFs) were successfully isolated from agro-industrial waste (cornstalk, corn flesh, and corncob) by subjecting the raw materials to organosolv and peroxide treatment, followed by ultrasonication. A detailed comparative study was performed. Characterization results showed that the CNFs from cornstalk (CS) exhibited higher yield and lignin content (20.81%), compared with CNFs from corn flesh (CF) and corncob (CC). The CNFs from CF and CC exhibited similar morphology, particle size, crystallinity, and thermal stability but showed improved ultraviolet blocking ability and optical transparency relative to those of CS. The CNFs from CF showed higher dispersion stability and mechanical properties than those from CS and CC. Peroxide treatment negatively influenced crystallinity and thermal stability, but exerted no apparent effect on optical transparency and mechanical strength. Thus, this study demonstrates that agro-industrial wastes are sustainable resources for CNF production, which can potentially have a wide range of value-added applications. Ionic liquid-aided solvothermal treatment followed by ultrasonication is a facile and ideal method to produce CNFs with ultraviolet blocking ability.