Patent Report

Patent report

The invention is a thin film which acts as a gas barrier that serves to prevent external gas and water vapour from infiltrating the polymer beneath. The film has a high transparency and is

flexible making it suitable for display casing made from transparent polymers.

Carbon based gas barriers are typically made with carbon nanotubes mixed into a coating but

these have poor adhesion and do not bond well to certain transparent polymers. The presented

invention uses graphene and provides much greater adhesion.

The graphene layer has a thickness of about 0.4 nm to 5 nm and has a transparency of 76%

or more for light of 550 nm wavelength. The gas barrier has a water vapour transmission rate

of about to and an oxygen transmission rate of about to for a surrounding atmosphere with a

relative humidity of 70%.

Manufacturing of the gas barrier film involves dissolving graphene in a solvent such as water in

a concentration of 0.001 to 30 wt% and coating a polymer with it. Several coats may be applied

to increase the thickness.

The patent also details the experiments done to measure the transparency and the gas

transmission rates.

Invention use

The gas barrier film has a high light transparency making it useful for applications such as

display cases where the object under the polymer must be visible.

The barrier has a higher resistance to oxygen and water vapour passing through it than

transparent polymers do and so the addition of the film becomes useful when typical transparent

polymers used to encase an object do not provide enough protection from water vapour or

oxygen. Some objects may need to be protected if they corrode or age quickly when exposed to

water vapour and oxygen