Extraction of cellulose nanofibers from empty palm fruit bunches via mechanical defibrillation

Abstract

In recent years, there has been an increasing interest in finding alternative material to replace fossil-oil based product due to the environmental concern. Lignocellulosic biomass has emerged as the promising candidate due to its low-cost and sustainability. The objective of this work was to prepare cellulose nanofibers (CNFs) from empty palm fruit bunches (EPFB), which are the waste originating from palm oil industry. Cellulose fibers were first extracted from EPFB by chemical treatment, followed by mechanical disintegration using high-pressure homogenization. Fiber concentration and defibrillation time during mechanical treatment were studied to investigate their effects on the properties of produced nanofibers. The obtained micro- and nano-fibers were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), Thermogravimetric analyzer (TGA), Scanning electron microscope (SEM) and Transmission electron microscope (TEM). The results indicated that non-cellulosic components were successfully removed by chemical treatment, as evidenced by the disappearance of lignin and hemicellulose related peaks in FTIR analysis, reduction of their content in chemical composition result, and increase in the thermal stability for purified fibers. Moreover, TEM images and diameter distribution analysis revealed that fiber concentration of 0.5%w/v provided the best diameter size uniformity with the nanofiber’s diameter ranged 6 nm to16 nm, as compared to higher fiber concentration.