bacterial cellulose nanofiber on the properties of chitosan-nanosilver nanocomposite film and determination of its optimum concentration by surface response method

In this study, the effects of silver nanoparticles (AgNPs) at 1% wt and different concentrations of bacterial cellulose nanofiber (BCNF) (1.5-6% wt) on tensile properties (tensile strength -TS, elongation at break-EB, and Young’s modulus -YM), water vapor permeability (WVP), solubility, swelling, color properties and structural characteristics of chitosan nanocomposite films were studied. Response surface methodology (RSM) was used to determine the optimum amount of BCNF nanofiller. The optimization was based on maximizing TS, YM, EB, L*and decreasing WVP, solubility and swelling. The results showed that the AgNPs had a negative effect on mechanical and color properties of chitosan films. But incorporation of BCNF in the films improved their mechanical and barrier properties significantly. Lowest WVP, solubility and swelling of nanocomposite films was respectively for 6, 4 and 2%wt of BCNF content. Considering all physical and mechanical parameters, the optimal value calculated for BCNF, was 4.55%. SEM images showed BCNF uniformly distributed in the polymer matrix. DSC analysis confirmed that the addition of BCNF causes to improve the thermal properties of chitosan film.