Characterisation Of Cellulose Nanocrystals From Oil Palm Fronds For Carboxymethyl Cellulose Bio-Nanocomposites
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Date
2018-07
Authors
Nordin, Noor Afeefah
Journal Title
Journal ISSN
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Publisher
Universiti Sains Malaysia
Abstract
Cellulose nanocrystals (CNC) were produced from oil palm fronds (OPF) to produce carboxymethyl cellulose (CMC)-cellulose nanocrystals bio-nanocomposite. A fundamental study on top, middle and bottom parts of raw oil palm fronds was conducted and based on the scanning electron microscope (SEM) images, it showed that the bottom part of OPF had greater percentage of vascular bundles compared to middle and top parts. It was further supported by chemical analysis that showed bottom part of OPF had the highest α-cellulose content. The top, middle and bottom parts of OPF were further utilised to produce CNC by applying chemo-mechanical treatment. Chemicals such as sodium chlorite, acetic acid, potassium hydroxide and sulphuric acid were used to purify the cellulose and followed by mechanical treatments including homogenizing and sonication to provide good dispersion of CNC suspension. The x-ray diffraction (XRD) analysis showed that the CNC from top part of OPF had the highest crystallinity index. It inferred that the acid hydrolysis treatment managed to hydrolyse the amorphous region in top part of OPF and preserved the crystalline region. The CNC suspension from the bottom part of OPF had the highest zeta potential, indicating a more stable suspension compared to top and middle parts. The top part of OPF was further utilised to investigate the effect of acid concentration and hydrolysis time on properties of CNC. Three sulphuric acid concentrations (58 %, 60 %, 64 %) and hydrolysis time (45 min, 60 min, 75 min) were used during the chemo-mechanical treatment. The variations in yield suggested that it was highly dependent on the acid hydrolysis condition. The CNC hydrolysed with 60 % H2SO4 for 45 min showed the highest crystallinity index (70.1%). The Fourier transform infrared (FTIR) spectra showed similar patterns for all samples indicating that different acid hydrolysis conditions did not change the chemical structure of the CNC.
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Keywords
Cellulose nanocrystals roduced from oil palm fronds , to produce carboxymethyl cellulose