Production and Characterization of Cellulose Nanofibrils from Cotton Noil Waste

Highlights Cotton noil is a waste short fiber from the cotton yarn industry. Cellulose nanofibrils were produced by ball-milling and high-pressure homogenization processes. The width of nanofibrils ranged from 50 to 70 nm, with about 80% crystallinity index. The 5% CNF had a tensile strength of about 25 MPa and can be used as a reinforcing material. Abstract. Cellulose nanofibrils (CNF), the nanostructured cellulose, are promising nanomaterials for bio-based barrier coating and packaging applications. In this study, we investigated the production of cellulose nanofibrils from cotton noil, a waste short-fiber from the cotton yarn industry. The cotton noil fibers were subjected to ball milling for 10 min and dispersed in water to prepare slurries with three different concentrations (1%, 5%, and 10% w/v). Then, the slurry was passed through a high-pressure homogenizer at 700 bar pressure for 14 cycles or until the fibers were fibrillated into CNF hydrogels. The CNF with 1% and 5% concentrations had an average width of 70 and 52 nm, respectively, while the 10% CNF concentration had a mix of both nanofibrils and microfibrils due to inconsistent fibrillation. Fourier Transform InfraRed (FTIR) spectroscopy and X-ray diffraction techniques on the isolated CNFs demonstrated that the manufacturing process did not affect the cellulose molecular structure or crystallinity. The tensile strength of CNF from 5% concentration was about 25 MPa. This simple manufacturing method can be applied to utilize cotton noil fibers to produce CNF for various applications. Keywords: Ball milling, Cellulose nanofibrils, Cotton noil, Homogenization, Tensile strength.