Speaker
Description
Oil palm empty fruit bunch (OPEFB) is one of Indonesia's abundant lignocellulosic biomass wastes and has great potential as a raw material for producing nanocrystalline cellulose (NCC) due to its high cellulose content. The quality of NCC is strongly influenced by the pretreatment process prior to acid hydrolysis; therefore, an effective pretreatment method is required to enhance the removal of non-cellulosic components while preserving the crystalline structure of cellulose. This study aimed to investigate the effect of steam-assisted hydrochloric acid (HCl) pretreatment on the optical properties of nanocrystalline cellulose isolated from OPEFB. The synthesis process began with 37 wt% HCl pretreatment, followed by steam pretreatment at room temperature for 24 h to facilitate the disruption of the lignocellulosic structure and improve cellulose fiber accessibility. Subsequently, the treated cellulose was hydrolyzed using 60 wt% sulfuric acid (H₂SO₄) to produce nanocrystalline cellulose particles. The optical properties of the obtained NCC were characterized using UV–Visible spectroscopy over a wavelength range of 200–800 nm, while the optical band gap energy was determined using the Tauc Plot method. The results demonstrated that the steam-assisted HCl pretreatment produced nanocrystalline cellulose exhibiting a dominant absorption in the ultraviolet region and a wide optical band gap, indicating the characteristics of a wide-band-gap semiconductor material. These findings suggest that steam-assisted HCl pretreatment enhances the quality of the nanocrystalline structure, thereby improving the optical properties of NCC and highlighting its potential for environmentally friendly optoelectronic and light-sensing applications.
Keywords: oil palm empty fruit bunch, nanocrystalline cellulose, steam-assisted hydrochloric acid pretreatment, optical properties, UV–Visible spectroscopy, optical band gap.
