Isolation and characterization of cellulose nanomaterials from jute bast fibers

This work describes a simple yet effective pathway for extracting cellulose nanomaterials from jute bast fibers by chemical pretreatment to isolate microfibrillated cellulose followed by either mechanical or acid hydrolysis to ultimately isolate cellulose nanofibers (CNFs) and cellulose nanocrystals (CNCs), respectively. Analyses carried out through Fourier transform infrared spectroscopy (FTIR), X-ray photon spectroscopy (XPS) and solid state 13C nuclear magnetic resonance (NMR) demonstrated that the pretreatments gradually removed lignins and hemicelluloses from the fibers. The yield of microfibrillated cellulose was 56.5% with respect to the initial dry mass of untreated fibers. Scanning electron microscopy (SEM) evaluated the morphological variation in the fiber dimension during the initial chemical pretreatment stages leading to extraction of microfibril 12–15 µm in average width. Transmission electron microscopy (TEM) images confirmed the nano-scale dimension of these nanocelluloses. The thermal stability of jute fibers at different stages of treatment was studied by thermogravimetric analysis. The high yield and high crystallinity of the nanocelluloses demonstrated effective isolation protocol confirming that jute bast fibers can be a valuable source for generation of nanomaterials.