Impermeable Barrier Films and Protective Coatings Based on Reduced Graphene Oxide

TL;DR

This paper demonstrates that multilayer reduced graphene oxide films act as highly effective impermeable barriers against gases, liquids, and chemicals, offering a promising solution for protective coatings in various industries.

Contribution

It introduces a cost-effective method to produce large-area, defect-free multilayer graphene oxide films with exceptional barrier properties through chemical reduction.

Findings

Films as thin as 30 nm block all gases and liquids.

Thicker than 100 nm, films become completely impermeable.

Reduced graphene oxide films remain optically transparent.

Abstract

Barrier films preventing permeation of gases and moistures are important for many industries ranging from food to medical and from chemical to electronic. From this perspective, graphene has recently attracted particular interest because its defect free monolayers are impermeable to all gases and liquids. However, it has proved challenging to develop large-area defectless graphene films suitable for industrial use. Here we report barrier properties of multilayer graphitic films made by chemical reduction of easily and cheaply produced graphene oxide laminates. They are found to provide a practically perfect barrier that blocks all gases, liquids and aggressive chemicals including, for example, hydrofluoric acid. In particular, if graphene oxide laminates are reduced in hydroiodic acid, no permeation of hydrogen and water could be detected for films as thin as 30 nm, which remain optically transparent. The films thicker than 100 nm become completely impermeable. The exceptional barrier properties are attributed to a high degree of graphitization of the laminates and little structural damage during reduction. This work indicates a close prospect of thin protective coatings with stability and inertness similar to that of graphene and bulk graphite, which can be interesting for numerous applications.