Targeted isolation of cellulose nanofibers of specific length distributions from potato residue

Recently, cellulose nanofibers (CNFs) have attracted attention because of their potential as building blocks in materials science. Their production, however, is often seen as inefficient and the tuning of their properties is not straightforward. Contrary to exploiting costly and environmentally taxing delignified wood pulp as a raw material, this study demonstrates CNF production using agricultural waste: potato fibers. The process for obtaining typical long (μm scale) CNFs involved alkali treatment, NaClO₂ addition, and gaseous HCl hydrolysis, while TEMPO-mediated oxidation enabled tuning of the CNF length to much shorter (∼500 nm) nanofibres with substantial carboxylate content (1.0 mmol/g). Subsequent film preparation demonstrated that even short CNFs could form strong transparent films (nanopapers). These findings provide a foundational understanding of the practical implementation of cellulose gaseous HCl hydrolysis and TEMPO-mediated oxidation techniques, extending from the potato fiber industry to nanocellulose applications.