Isolation and characterization of cellulose nanofibrils from Helicteres isora plant

In this work, cellulose nanofibrils were extracted from isora fiber by steam explosion method. The technique adopted includes alkaline treatment, bleaching, acidic steam treatment and homogenization. The material obtained after each stage of the treatments was carefully characterized and its chemical composition was determined. Morphological investigation was performed using scanning electron microscopy (SEM), atomic force microscopy (AFM) and transmission electron microscopy (TEM). Fourier transform infrared (FTIR) spectroscopy showed the progressive removal of noncellulosic constituents. X-ray diffraction (XRD) analysis revealed that the crystallinity increased with successive treatments. The thermal stability of the fibers was investigated using thermogravimetric analysis (TGA). The results showed that the prepared cellulose nanofibers showed nanofibrillar network like structure with high crystallinity (90%) and good thermal stability.