Extraction of eucalyptus pulp nanofibers by enzymatic hydrolysis with and without acid pre-treatment
International Journal of Development Research
Extraction of eucalyptus pulp nanofibers by enzymatic hydrolysis with and without acid pre-treatment
Received 27th July, 2019; Received in revised form 29th August, 2019; Accepted 17th September, 2019; Published online 16th October, 2019
Copyright © 2019, Borges G. Josileide et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Cellulose nanofibers are used as reinforcement in polymeric matrices, as they allow to improve properties of these materials. Cellulose nanofibers are commonly prepared by conventional acid hydrolysis using strong acids (H2SO4 / HCl) that pollute the environment, corrode reactors unlike enzymatic hydrolysis with fungal cellulases whose products are biodegradable, non-polluting. This study aimed to extract nanofibers obtained by enzymatic hydrolysis with and without pretreatment with dilute acid. Nanofibre suspensions were characterized by molecular weight determination by chromatography, Transmission Electron Microscopy (MET), Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD). Molecular masses, molecular mass distribution of hydrolysates are less than 100.000 Da, regardless of hydrolysis condition tested. Nanofibers produced by enzymatic hydrolysis showed better crystallinity indices when compared to produced using acid pretreatment. Nanofiber obtained using 90% of cellulase enzymes for 240 minutes produced nanofibers with 75.58% critalinity index, higher than produced by concentrated sulfuric acid, diameters of 27.5 ± 8 nm. Although, production of nanofibers using cellulases showed good results, pretreatment of enzymes would further increase nanofiber crital indexes.
