A novel paper-based composite film with enhanced oxygen and water vapor barrier properties

Paper-based composite films have demonstrated significant potential in the field of packaging materials. However, the gas barrier properties of these films have been found to be less than satisfactory, primarily due to the inherent porosity and hydrophilic nature of cellulose-based paper. Consequently, the challenge of enhancing the gas barrier performance, particularly in relation to oxygen and water vapor, remains a formidable obstacle. In this study, drawing inspiration from the well-established multilayer composite model, which incorporates both organic and inorganic layers, an efficient strategy has been devised to enhance the gas barrier performance of paper-based packaging materials. The organic barrier layers in this approach utilize polyvinyl alcohol and polyacrylate. Meanwhile, the critical inorganic barrier layer is composed of functionalized SiO2@polydopamine nanoparticles (SiO2@PDA NPs). Importantly, due to the isotropic nature of the SiO2@PDA NPs, concerns related to the orientation control and exfoliation of 2D layered materials are alleviated within this system. The introduction of a crosslinker, 3-aminopropyl triethoxysilane, serves to bridge the gap between SiO2@PDA NPs, facilitating the tight concatenation of NPs through Schiff base or Michael addition reactions. Utilizing coating technology, a paper-based multilayer film was fabricated. As a result, the oxygen transmission rate of the composite film was substantially reduced to 0.3077 cm3/cm2·24 h·0.1 MPa, and the water vapor transmission rate was lowered to 4.1109 g/m2·24 h. Significantly, these composite films exhibit exceptional water resistance and mechanical properties, rendering them highly suitable for the packaging of a wide range of sensitive products, including food items, pharmaceuticals, electronic devices, and other gas-sensitive products.