The functional cellulose products have attracted increasing attention due to their natural characteristics and extensive application. Here, we develop a high oxygen barrier composite film by laminating layered double hydroxides (LDHs) with bamboo-based cellulose nanocrystals, which are extracted from wasted bamboo and bamboo pulp, and explore the innovative "solid-gas" barrier structure via CO 2 adsorption. Three laminated structures with various layers and LDHs distributions were designed. The laminated composite films exhibit a decreasing oxygen transmission rate with the increasing layers. TGA, FTIR and temperature-programmed desorption confirm that CO 2 is chemically adsorbed on LDHs and can effectively reduce the oxygen transmission rate of these composite films, while having no significant influence on tensile properties. The optimal film achieves the lowest oxygen transmission rate of 0.17 cm³ /(m²·24 h·0.1 MPa). LDHs distribution affects the oxygen transmission rate and CO 2 adsorption capacity of composite films. This work innovatively integrates CO 2 adsorption into barrier films, realizing molecular-scale barrier structure design. The generated LDHs/bamboo nanocellulose composite films with superior oxygen barrier hold great potential for applications in food, pharmaceutical, and electronic packaging. • A “solid-gas” strategy to construct oxygen barrier microstructure breaks the traditional “solid-solid” structures. • LDHs play dual functions in prolonging the O 2 pathway and filling the free volumes by adsorbed CO 2 . • LDHs distribution affects the OTR and CO 2 adsorption capacity of the composite films.
Ma et al. (Fri,) studied this question.