Abstract:
High-yield production improvement of nanocrystal cellulose (CNC) from water hyacinth is essential to meet the industrial demand. It is necessary to develop methods that can not only increase production efficiency ( % yield) but also account for costeffectiveness and cost- efficiency of the process. Recently, the production of nanocellulose from natural fibers has gained more attention in terms of environmental friendliness. This research focused on fibers of water hyacinth (WHF) , a fast-growing prolific plant that would block a canal. Nanocrystal cellulose, a market-valued material, was successfully synthesized from water hyacinth fibers.
The production of CNC from WHF was divided into two primary processes. The initial process entailed the pretreatment of WHF to obtain purified microcellulose fibers ( MCF) . This consisted of two distinct steps: an alkaline pretreatment and a bleaching process. The subsequent process involved an acid hydrolysis to produce CNC. In this research, various parameters were systematically explored. Specifically, different acid concentrations of 40, 50, 60, and 70% were employed, coupled with varying reaction temperatures of 40, 50, 60, and 70°C, along with diverse reaction durations of 15, 30, 45, 60, 75, 90, 105, and 120 min, respectively. The characteristics of the obtained CNC, namely morphology, crystalline structure, chemical structure, zeta potential, crystallinity index, and % yield were comprehensively analyzed to identify the optimal conditions.
The results of MCF treated with the alkaline pretreatment and bleaching process revealed the following: lignin, hemicellulose and other impurities were removed compared to the neat WHF, which was confirmed by the FTIR technique. Then, the purified MCF were subjected to acid hydrolysis. The most suitable condition was at the sulfuric acid concentration of 50%, the temperature of 60°C, and the reaction time of 30 min, yielding up to 88. 85% , sufficient for production if applied in industrial applications. This finding is the best acid hydrolysis condition compared to those in previous studies. The outstanding property of the CNC produced as a stable suspension was the milky white appearance with a crystallinity index of 87.67% . It had a zeta potential value of 46.88 mV, indicating water stability, which resulted in good dispersion. It is suitable for use in packaging, cosmetics, and medical supplies in liquid form.