Method for functionalizing a polymer-based substrate by chemical deposition of a thin layer

A method for functionalizing a cellulose-based substrate by chemical deposition of at least one layer, from gaseous precursors, comprising:

• a provision of a cellulose-based substrate:
• comprising a plurality of distinct three-dimensional objects at least partially superposed, the plurality of distinct three-dimensional objects including first and second distinct three-dimensional objects, the first distinct three-dimensional object having a first face and the second distinct three-dimensional object having a second face opposite the first face, at least one face having a surface roughness greater than or equal to 0.1 μm, the substrate being a closed substrate having a porosity not enabling the gaseous precursors to pass through the substrate, and
• the first face having a part superposed to another part belonging to the first face of the first distinct three-dimensional object or to the second face of the second distinct three-dimensional object, said parts being superposed,
• so as to conserve at least locally, a spacing between said parts, configured to enable a diffusion of the gaseous precursors, then
• a gaseous chemical deposition of at least one layer on the substrate such as provided, by diffusion of gaseous precursors, the gaseous precursors diffusing at least in each spacing,
• wherein each three-dimensional object of the plurality of distinct three-dimensional objects, is in the form of a capsule, a bottle, a can, a packaging tray, a plate, a straw, a glass or a cup, without an additional intercalation compound in the spacing separating the plurality of distinct three-dimensional objects.