Superhydrophobic and oleophobic coating for aluminum heat exchangers based on textured surfaces

Aluminum heat exchangers suffer from reduced performance and increased maintenance due to fouling. Of the coatings currently available for heat exchangers, most are severely fouled when the coating surface comes in contact with oils and dust. A superhydrophobic and oleophobic coating would reduce fouling and make cleaning easier. Nano Terra has developed a coating for aluminum parts, called NT-AL, based on a textured, low energy surface which completely resists wetting by water and oil. The coating is < 30 micrometers thick and so would not interfere with heat transfer. It is erosion resistant and is intimately bonded to the aluminum surface so that the coating will be robust even in high particulate environments. In this program, Nano Terra will refine the NT-AL process for the Navys heat exchangers and verify the maintained performance, fouling resistance and wear resistance. In parallel, Nano Terra will develop a low-surface energy polymer coating with a textured surface that will provide similar superhydrophobicity and oleophobicity to NT-AL but potentially better erosion resistance and different chemical stability. Finally, Nano Terra will apply the best two of these approaches to heat exchangers and show improved performance in fouling conditions.