Ibarra, DavidMartín Sampedro, RaquelWicklein, BerndBorrero López, Antonio MaríaValencia Barragán, ConcepciónValdehíta, AnaNavas, José M.Eugenio, María Eugenia2022-06-032022-06-032022Ibarra, D., Martín-Sampedro, R., Wicklein, B., Borrero-López, A. M., Valencia, C., Valdehíta, A., Navas, J. M., & Eugenio, M. E. (2021). Populus alba L., an Autochthonous Species of Spain: A Source for Cellulose Nanofibers by Chemical Pretreatment. In Polymers (Vol. 14, Issue 1, p. 68). MDPI AG. https://doi.org/10.3390/polym140100682073-4360 (electrónico)http://hdl.handle.net/10272/20942In order to identify new sustainable sources for producing cellulose nanofibers (CNFs), fast-growing poplar (Populus alba L.) wood was evaluated herein. For that purpose, bleached poplar kraft pulp was produced and submitted to TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) mediated oxidation (TEMPO-ox) chemical pretreatment followed by microfluidization. The resulting CNFs were thoroughly characterized, including a rheological study at different pH values. Poplar CNFs showed properties comparable to eucalypt CNFs (reference material for CNFs production), showing high carboxylate content (1048 ± 128 µmol g−1 ), fibrillation yield (87.3% ± 8.1%), optical transmittance (83% at 700 nm) and thermal stability (up to more than 200 ◦C). Regarding the rheological study, whereas pH from 4 to 10 did not produce significant changes in rheological behavior, a reduction of pH down to 1 led to an order-of-magnitude increase on the viscoelastic functions. Therefore, poplar CNF shows potential in the pH-sensitive hydrogels application field. Finally, the possible ecotoxicity of poplar CNF was assessed. The decrease in cell viability was very low so that only concentrations causing a 10% cytotoxicity could be calculated for the assay detecting alterations in cell metabolism (10 µg mL−1 ) and plasma membrane integrity (60 µg mL−1)engAtribución-NoComercial-SinDerivadas 3.0 Españahttp://creativecommons.org/licenses/by-nc-nd/3.0/es/Cellulose nanofibersChemical pretreatmentCytotoxicityNanocellulosePopulus alba L.Rheologyjournal article10.3390/polym14010068open access23 Química