The graphene oxide coating maintains a film of water on the surface of the membrane. Coupled with surface roughness, the surface repels oil but attracts water. The water may contain naturally occurring chemicals or have picked up chemicals and additives used during the drilling and production process. The amount of contamination will vary from reservoir to reservoir and needs to be separated before the oil can be refined. The water can constitute up to 10 times that of the oil.

The separation is an expensive process which can ultimately impact the financial return from each barrel of oil. The graphene oxide creates a nano scale roughness on the membrane surface and the attributes of graphene oxide means that it attracts water droplets while repelling the oil, therefore capturing and separating the water.

Graphene oxide’s capabilities also mean that fouling – or blocking – of the membrane is considerably reduced and therefore more efficient. This means more of the oil/water mix can be treated in less time, creating cost savings.