Enhancement of mechanical properties of nanocellulose xerogels using TEMPO-oxidized fibers.

We report xerogels prepared from TEMPO-oxidized cellulose nanofiber (Ox-CNF) that have enhanced yield stresses and Young's Modulus (E) up to 15.4 MPa. The xerogels were highly porous (>95 %) and were measured by density determination, SEM, Brunauer-Emmet-Teller (BET) experiments, and microCT analysis. The xerogels had a density of 0.0182 to 0.0471 g/cm. We report that the solvent exchange process introduces a distribution of pore sizes and leads to enhanced mechanical properties. Mechanical properties were evaluated by monotonic and cyclical uniaxial compression measurements using a flat punch. These highly porous Ox-CNF xerogels have superior mechanical properties to other CNF xerogels and aerogels.