Preparation and Characterization of Bacterial Cellulose/Carboxymethyl Cellulose Composite Films

Bacterial cellulose (BC) is a natural nanofibrous material, but its limited functional tunability restricts its use in moisture-management applications. In this study, BC/carboxymethyl cellulose (CMC) composite films were prepared by in situ fermentation using a kombucha-derived high-yield strain, followed by citric acid post-treatment. The films were characterized by FTIR, XPS, XRD, SEM, and physicochemical tests. CMC incorporation regulated the BC nanofibrous network while preserving cellulose I, and citric acid post-treatment promoted possible ester-linkage-assisted network stabilization. The modified films showed improved water-management behavior, water-vapor barrier performance, and mechanical response while maintaining high surface hydrophilicity; notably, BC/CMC-3 reduced the water vapor transmission rate from 106.13 ± 4.24 to 71.07 ± 2.46 g/(m2·24 h). These results suggest that CMC dosage is an effective strategy for tailoring BC-based films for moisture-management applications.