4. Conclusion
This work presented a new concept to isolate nanometric cel¬lulose fibrils from banana peels and described a comparative study that evaluated the difference between the chemical and enzymatic treatment procedures. TEM confirmed the presence of nanofibers in the treated samples. The treatments affected the dimensions and the surface charge of the resulting nanoparticles. The milder method used enzymes and furnished longer nanofibers with higher aspect ratio; nanofibers obtained by this method culminated in a more stable suspension, with higher zeta potential than the nanofibers obtained by chemical treatment. On the other hand, the chemically treated banana fibers had 300% larger crystallinity as compared with the 200% higher crystallinity of the enzymatically treated samples. Hence, the chemical method removed amorphous components more effectively and enhanced the crystalline content in the sample. FTIR spectra of the cellulose nanofibers confirmed this finding. Finally, both treatments successfully isolated cellulose nanofibers from the banana peel, encouraging the use of this agroindustrial residue as a renewable source of nanofibers. A future study will investigate the potential reinforcement that nanofibers produced by both treatments promote in composites.