Obtenção de nanocelulose a partir de resíduo agroindustrial de casca de eucalipto e funcionalização com nanopartículas de prata

Abstract

The cellulose and paper industry reached its highest level of productivity in 2021 and consequently the increase in waste generated in the production chain, such as eucalyptus bark. The barks are generally used in fodder for plantations and obtaining energy, however, the ligninocellulosic residues have interesting characteristics from the point of view of their reuse for cellulose extraction. The present work sought to investigate the application of optimized and ecological parameters, in the extraction of cellulose and production of nanocellulose, to predict the reproducibility of other residues in eucalyptus bark. In the cellulose extraction, the parameters were carried out in a more ecological way and it proved to be promising from readjustments in the chemical treatment used, with relevant results for the use of sodium hydroxide (NaOH) at 1% m/v and bleaching of the fibers for 8h and 42min in 0.6% v/v sodium hypochlorite. There was exposure of cellulose fibers with the removal of lignin and hemicellulose. In obtaining nanocellulose, a combination of physical treatment was performed, with time changes, and chemical treatment with the use of H2SO4 at different times and concentrations, these concentrations being lower than those usually used. In obtaining it, there were indications that it is possible to obtain it in a more ecological way, through the association of treatments, while experimental readjustments are necessary, since nanocellulose and microcrystalline cellulose were obtained. The present study also investigated the functionalization capacity of plant nanocellulose with silver nanoparticles (AgNPs) in situ. Tollens reagent and Ascorbic Acid were used without the use of stabilizers. Obtaining the AgNPs took place under different conditions of swelling of the nanocellulose, with direct deposition of the reducing agent on it. The results were promising in terms of the methodologies employed, requiring optimization investigations to obtain a product with added value.