Stronger hierarchical filament prepared by orderly assembling of cellulose nanofibrils from wasted jute

TEMPO-oxidized cellulose nanofibrils (TOCNF) were prepared from wasted jute by TEMPO-mediated oxidation combined with short-time ultrasonic mechanical treatment. Then a simple and environmentally friendly wet-spinning technology was used to assemble TOCNF into hierarchical macroscopic filament. In order to analyze the influence of different TOCNF preparation processes directly, the properties of TOCNF suspensions and their effects on spun filaments were studied from the perspective of rheology. And on the basis of this, response surface analysis method was used to optimize the process parameters, the optimized process parameters were: the dosage of NaClO added in oxidation process, the oxidation reaction time and the ultrasonic treatment time of 5.33 mmol/g-cellulose, 68 min and 80 s, respectively. Under this preparation process, filaments with the tensile strength of 327.06 MPa were prepared. The spun filaments were straight and flexible, with fold structure on surface along the axis direction due to the orientation arrangement of TOCNF, which provided great potential for wide application and functional design.