Application of a repellent urea–siloxane hybrid coating in the oil industry

Urea–siloxane hybrid coatings were prepared by the sol–gel method from a dipodal diurea silane and methyltriethoxysilane. The coatings combine corrosion protection and scratch and solvent resistance in one layer and enable the incorporation of polydimethylsiloxane (PDMS) to achieve repellent properties. PDMS of different molecular weights were investigated with a molecular weight of 2000–3500 g/mol providing a repellent surface with the best durability. The coating was applied on plate heat exchangers mounted on North Sea oil platforms to prevent crude-oil derived fouling. While the uncoated heat exchangers get clogged by waxy substances and require costly maintenance in regular intervals, the coated heat exchanger significantly prolongs the service interval by at least a factor of 3.