Dalle Vacche, SaraKarunakaran, VijayaletchumyPatrucco, AlessiaZoccola, MarinaDouard, LoreleiRonchetti, SilviaGallo, MartaSchreier, AigoulLeterrier, YvesBras, JulienBeneventi, DavideBongiovanni, Roberta2021-09-112021-09-112021-09-112021-08-0110.3390/molecules26164723https://infoscience.epfl.ch/handle/20.500.14299/181362WOS:000690119300001Nanocellulose was extracted from short bast fibers, from hemp (Cannabis sativa L.) plants harvested at seed maturity, non-retted, and mechanically decorticated in a defibering apparatus, giving non-aligned fibers. A chemical pretreatment with NaOH and HCl allowed the removal of most of the non-cellulosic components of the fibers. No bleaching was performed. The chemically pretreated fibers were then refined in a beater and treated with a cellulase enzyme, followed by mechanical defibrillation in an ultrafine friction grinder. The fibers were characterized by microscopy, infrared spectroscopy, thermogravimetric analysis and X-ray diffraction after each step of the process to understand the evolution of their morphology and composition. The obtained nanocellulose suspension was composed of short nanofibrils with widths of 5-12 nm, stacks of nanofibrils with widths of 20-200 nm, and some larger fibers. The crystallinity index was found to increase from 74% for the raw fibers to 80% for the nanocellulose. The nanocellulose retained a yellowish color, indicating the presence of some residual lignin. The properties of the nanopaper prepared with the hemp nanocellulose were similar to those of nanopapers prepared with wood pulp-derived rod-like nanofibrils.Biochemistry & Molecular BiologyChemistry, MultidisciplinaryChemistrynanocellulosehempwaste valorizationnanopaperlignocellulosic fiberssativa l. cultivarsmechanical-propertiescellulosewoodperformancereinforcementspectroscopymorphologycottonyieldtext::journal::journal article::research article