Facile Surface Modification of Polyethylene Film via Spray-Assisted Layer-by-Layer Self-Assembly of Graphene Oxide for Oxygen Barrier Properties

The oxygen barrier properties are essential for the food packaging systems that preserve perishable food. In this research, the facile surface modification method for oxygen barrier properties is introduced by using spray assisted layer-by-layer (LbL) self-assembly. The nano-sized graphene oxide (GO−) multilayer films were developed and characterized. Positively charged amine-functionalized GO+ was synthesized using the negatively charged GO− dispersion, ethylenediamine, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide methiodide (EDC). Alternating layers of GO− and GO+ were deposited onto the flexible polyethylene (PE) substrate which has no intrinsic gas barrier properties. This method is able to modify surfaces which are challenging for the conventional dipping LbL method. The oxygen transmittance rate of coated PE film (3511.5 cc/m ² ·day) decreased significantly to 1091 cc/m ² ·day after a GO film with a thickness of only 60 nm was deposited. The light transmittance in the visible light range was not significantly decreased after coating of GO films, thus ensuring transparency for PE packaging applications.