Graphite oxide nanocoatings as a sustaibale route to extend the applicability of biopolymer-based film

In this work, the Layer-by-Layer assembly of multilayered coatings comprising graphite oxide (GO) in combination with either chitosan or branched polyethylenimine was employed to modify the surface functional properties of polylactic acid (PLA) films. The aim is to extend the applicability of this biopolymer, which is of great industrial interest. Surface analyses by contact angle measurements and electron microscopy demonstrated the formation of a uniform GO layer, which enhanced the surface hydrophilicity. A 10 bi-layer coated film showed oxygen permeability reduced by 70% in both dry and humid conditions, compared to the neat PLA film. The use of a water soluble reducing agent allowed for the effective room temperature reduction of the GO deposited within the film, as evidenced by IR and contact angle measurements. GO reduction resulted in a significantly decreased surface resistivity and remarkable antistatic properties, suggesting possible applications in the field of antistatic packaging.