Hydrophobic graphene coating improves power plant efficiency

In laboratory tests the team also found the one atom thick coating to be highly durable compared to polymer coatings.

The findings are reported in Nano Letters by MIT graduate student Daniel Preston, professors Evelyn Wang and Jing Kong. 

Condensers are used in power stations to turn the steam that drives turbines back into water so that the process can be repeated. An  improvement in condenser heat transfer could lead to an overall improvement in power plant efficiency of 2 to 3 per cent based on figures from the Palo Alto, California-based Electric Power Research Institute, Preston said in a statement.

When the steam forms a film, Preston said, it impedes heat transfer - and reduces the efficiency - of condensation. The goal, therefore, of much research has been to enhance droplet formation on these surfaces by making them water repelling.

Often this has been accomplished using polymer coatings, but these tend to degrade rapidly in the high heat and humidity of a power plant. And when the coatings are made thicker to reduce that degradation, the coatings themselves impede heat transfer.