Synthesis of Cellulose Aerogels from Coir Fibers via a NaOH/Urea Method for Methylene-blue Adsorption

Abstract

Coir (i.e., coconut fiber) is one of the popular agricultural waste products, especially in Vietnam, mostly discarded when copra and coconut water are taken, causing environmental pollution and waste of potential biomass. Various research has been done to reuse this resource as advanced materials. In this study, the NaOH-urea-H₂O₂ combination was utilized to make cellulose aerogel from coir fibers for the first time. Cellulose aerogel was synthesized by the sol-gel method combined with the freeze-drying technique. The properties of cellulose aerogel were determined, such as density, porosity, surface morphology analysis by FTIR, SEM, and thermal stability evaluation by TGA analysis. They exhibit low density (0.0099 - 0.0158 g/cm³), high porosity (98.96 - 99.35 vol%), and the methyl blue adsorption experiment shows cellulose aerogel's ability to treat color in water is significant.