Using Graphene Oxide to Enhance the Barrier Properties of Poly(lactic acid) Film

The ultra-thin (polyethyleneimine/graphene oxide) n [(PEI/GO) n ]multilayer films on poly(lactic acid) (PLA) were constructed via the layer-by-layer assembly. Here, the electrostatic interactions between PEI and GO were used to obtain the nanoscale composite membrane of (PEI/GO) n on the surface of PLA film. With the number of assembling layers increased, the oxygen permeability (PO 2 ) of PLA film decreased substantially. As a 0.06 wt% GO solution was used with only four layers, the PO 2 decreased from 53.8 to 0.377 × 10 −4 cm 3 /m 2 /d/Pa, only 0.7% of the original PLA film. At the same time, the coated PLA film also presented a good transparency and better mechanical properties. It is a novel way to use GO on biodegradable packaging materials. Copyright © 2014 John Wiley & Sons, Ltd.