High-performance cellulose acetate-based gas barrier films via tailoring reduced graphene oxide nanosheets

Improving the gas molecule barrier performance and structural stability of bio-plastic films dramatically contribute to packaging and protective fields. Herein, we proposed a novel nanocomposite film consisting of cellulose acetate (CA)/polyethyleneimine (PEI)/reduced graphene oxide (rGO)-NiCoFeO_x) with high gas barrier property by applying "molecular glue" and "nano-patching" strategies. Systematical investigations demonstrated that the CA/rGO interfacial interaction was effectively enhanced due to the "molecular glue" role of PEI chains via physical/chemical bonds and the defective regions in rGO plane were nano-patched through hydrophilic interactions between edged oxygen-containing functional groups and ultrafine NiCoFeO_x nanoparticles (~3 nm). As a result, the oxygen and moisture transmission rates of the prepared CA/PEI/rGO-NPs hybrid film were significantly reduced to 0.31 cm³ ∗ μm/(m² ∗ d ∗ kPa) and 314.23 g/m² ∗ 24 h, respectively, which were 99.60% and 54.69% lower than pristine CA films. Meanwhile, the tensile strength of hybrid film was increased from 25.90 MPa to 40.67 MPa. More importantly, the designed nanocomposite film possesses excellent structural stability without obvious GO layer shedding and hydrophobicity attenuation after persistent bending at least 100 times. The exceptional robust and high gas barrier film displays great promising application in food, agriculture, pharmaceuticals and electronic instruments packaging industry.