Isolation and Characterization of Cellulose Nanofibrils from Banana Pseudostem, Oil Palm Trunk, and Kenaf Bast Fibers Using Chemicals and High-intensity Ultrasonication

Abstract

The adoption of high-intensity ultrasonication in the isolation process of cellulose nanofibrils (CNF) as an economical, timesaving, and environmental-friendly process has been explored. Three types of raw organic fibers, i.e., banana pseudostem, oil palm trunk, and kenaf bast were analyzed for the production of CNF using the process mentioned earlier. Before the raw organic fibers were subjected to a high-intensity ultrasonication process, it underwent an alkaline treatment to eliminate the non-cellulosic compounds. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) micrographs confirmed the presence of nanofibrils in all three different types of CNF. The frequency, amplitude, and duration of ultrasonication used in this study were sufficient to produce CNF. Fourier-transform infrared spectroscopy (FTIR) results indicated that the chemical treatment employed in this paper was effective in removing the compounds, especially lignin and hemicellulose. The increase in crystallinity, which is one of the advantages of CNF, was observed from the X-ray diffraction (XRD) results. Hence, it can be deduced that high-intensity ultrasonication could simplify the complex process of CNF isolation compared to the conventional method, widening the utilization and source of CNF in the industry.