Effects of Post-Processing on the Properties of Nanofiber/Carboxymethyl Cellulose-Based Hydrogels

Superabsorbent polymers (SAPs) are functional materials characterized by a porous network structure and a high capacity for water absorption. However, most commercial SAPs are synthesized from petroleum-based polymers, which are major contributors to environmental pollution. This study aims to develop a sustainable absorbent material with excellent mechanical strength and stable water retention capacity. Herein, we compared two production routes for fabricating hydrogels composed of carboxymethyl cellulose nanofibers (CMCNF) and carboxymethyl cellulose (CMC) cross-linked with acrylic acid. The results demonstrated that homogenizing the cross-linking reactants immediately after the reaction and the addition of CMC powder improved the final water retention capacity of the hydrogels. The incorporation of CNF acted as a reinforcing agent, improving the elasticity, stiffness, and structural stability of the gels, although the swelling ratio decreased with increasing CNF content. Therefore, the addition of additional CMC powder partially compensated for the reduction in swelling, maintaining a balanced water absorption performance.