Facile isolation of cellulose nanofibers from water hyacinth using water-based mechanical defibrillation: Insights into morphological, physical, and rheological properties.

The utilization from biomass feedstocks to fabricate the advanced nanomaterials has greatly attracted a great interest due to their low cost and sustainability. This work aimed to explore a simple way to prepare cellulose nanofibers using water-based approach via mechanical defibrillation. Cellulose fibers were first extracted from water hyacinth towards chemical treatments and then mechanically disintegrated as a function of defibrillation cycles. The morphologies, thermal stabilities, physical properties, and rheological characteristics of the micro- and nanofibers were demonstrated. It was found that the obtained nanofibers having a diameter of 5-50 nm and were successfully prepared within 10 defibrillation cycles. Even though longer defibrillation cycles greatly provided higher water retention value and specific surface area, a gradual decrease in crystallinity index, thermal degradation temperatures, and degree of polymerization was also observed. Based on the rheological properties, the storage modulus and steady viscosity of the as-prepared nanofibers suspension increased significantly as a function of defibrillation, resulting in a gel-like structure with a shear-thinning behavior. Additionally, the rheological parameters of the obtained nanofibers estimated using a Herschel-Bulkley model were more accurate than that estimated using a Bingham-Plastic model. The obtained nanofibers could be used as a prime candidate for many potential applications.