Physicochemical properties of pullulan/chitosan/graphene oxide composite films

We report the production of pullulan (Pul)/chitosan (Chi)/graphene oxide (GO) composite films (CF-Pul/Chi + GO). We observed that the addition of GO increases the film's roughness while keeping good GO dispersion. Both the strong interactions between Pul and Chi and the formation of hydrogen bonds between Chi and GO seem to be responsible for the formation of the composite film. The dielectric constant, Young's modulus and the tensile strength of the CF-Pul/Chi + GO films exhibit maximum values at 1 mu g mL(-1) GO concentration. At GO concentrations higher than 1 mu g mL(-1), the interfacial layers between the polymer matrix and GO overlap, affecting the value of the dielectric constant and the mechanical properties of the films. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay carried out on LL47 fibroblast cells reveals that the CF-Pul/Chi + 1 mu g mL(-1) GO films are not cytotoxic. In this regard, CF-Pul/Chi 50/50 + 1 mu g mL(-1) GO has remarkable properties to be considered for a safe film with potential uses in the food, cosmetic and pharmaceutical industries. (c) 2022 Society of Industrial Chemistry.