Highly surface-selective nitration of cellulose nanofibers under mildly acidic reaction conditions

Abstract Cellulose nitrate (CN) is used in numerous industrial materials, such as propellants, lacquers, and plastics, exploiting its highly flammable, hydrophobic, plastic characters. The downsizing of cellulose fibers may enhance their properties. Although a direct nitration nanofiber (CNF) prospective method for preparing nanosized CN it difficult because the susceptibility CNF to acids. In previous study, we prepared nitrated nanofibers (NCNFs) using never-dried CNFs relatively dilute H 2 SO 4 , obtaining high yield degree substitution. this describe novel surface-selective dried CNFs. To prevent acid hydrolysis CNFs, mildly acidic conditions (acetic acid/acetic anhydride/HNO 3 ) were instead conventional mixed-acid systems. Solid- gel-state NMR studies revealed that original crystalline structure produced NCNF core was retained, even after nitration, whereas molecules on surface completely converted pernitrates. NCNFs exhibited morphologies comprising thin diameters approximately 10–50 nm with specific areas 260 m g –1 . Thus, unique core–shell prepared, potentially leading development derivatives applications functions. Graphical abstract