Graphene as hydrophobic surface coating presented in new paper

04/22/2015

Assistant Professor Nenad Miljkovic, along with researchers at MIT, has demonstrated that graphene can be used as a surface coating on condensers during heat transfer, particularly in the power generation industry.

Miljkovic and his colleagues published their findings in a recent issue of NanoLetters in a paper titled, “Scalable Graphene Coatings for Enhanced Condensation Heat Transfer.”

For industrial heat exchangers, it is highly advantageous for the surface of the condenser to be hydrophobic, as this increases the efficiency of the heat transfer by up to 10 times. This can be achieved by coating the surface with a thin hydrophobic substance or polymer. For the coating to be effective, it must be ultra-thin so it doesn’t interfere with the transfer of heat.

An ultra-thin coating, however, wears away easily in both industrial and lab settings, resulting in a need for coatings that are durable, have good transport properties, and are still thin enough.

Graphene, an atomically thin hydrophobic material, fit the bill. It forms ultra-strong covalent bonds between carbon atoms, and when Miljkovic and colleagues tested it as a coating material, they were able to show that it enhanced condensation heat transfer, and was much more durable than other common promoter materials.

Their findings demonstrate graphene as a promising hydrophobic surface coating in many potential applications such as anti-friction, anti-corrosion, de-icing, mildew and mold resistance, and others. “Hydrophobic surfaces have many uses all over the world. The ability of graphene to be more durable and attain hydrophobicity, as shown in our paper, is highly desired and can pave the way for further use of hydrophobic surfaces in the future,” said Miljkovic.

Miljkovic earned an MS and PhD in mechanical engineering from MIT in 2011 and 2013, and started at Illinois as an assistant professor in the fall of 2014. His research intersects the multidisciplinary fields of thermo-fluid sciences, interfacial phenomena, and renewable energy.