In this work, we evaluated the extraction of nanocellulose from agro-industrial residue of yerba mate (YM, Ilex paraguariensis, St.Hil) sticks through chemical (bleaching and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation), physical (steam Stools explosion) and mechanical (ultra-fine friction grinding) treatments, divided into three distinct sequences for method comparison.The results showed that steam explosion as the initial treatment step makes an increase of up to 23% in the crystallinity index of cellulose nanofiber (CNF) in 108 relation to the raw sample.The TEMPO-mediated oxidation resulted in more dispersed CNF, verified by transmission electron microscopy (TEM).Samples treated by steam-explosion and ultrafine grinding showed a higher yield in relation to steam-explosion and oxidative treatment (24.
3% versus 16.2% respectively).CNFs with a diameter of 6 nm and a length range of 2200 to 2600 nm were obtained.