Preparation of graphene oxide/polyethyleneimine layer-by-layer assembled film for enhanced hydrogen barrier property

A super hydrogen barrier film was prepared via layer-by-layer self-assembly of graphene oxide (GO) and polyethyleneimine (PEI), and the effects of pH of the PEI solution on the performance of LBL films were studied in detail. Results show that the pH value of PEI solution has a significant influence not only on the adsorbed amount of self-assembly materials but also the stacking morphology of GO sheets. When the pH values of GO suspension and PEI solution are identical, the self-assembled film shows a superior hydrogen gas barrier performance under pH of 3.5. When the pH value of GO suspension was fixed and that of PEI solution was varied, the adsorbed amount of the film was increased and reached a maximum value when the pH of PEI solution was 12, and the film prepared under this condition had a 12.7% increase on thickness and a 55.5% decrease on its hydrogen transmission rate (H2TR).