Slippery omniphobic covalently attached liquid coatings mitigate carbon deposition by autoxidation of jet fuel

Abstract

The decomposition of jet fuel at elevated temperatures leads to fuel fouling and deposit formation on metallic walls. Here, we develop and study an innovative sol-gel silicon dioxide (SiO 2 ) hybrid anti-fouling coating to mitigate fuel fouling. Our coating has low surface roughness (<1 nm) and low surface energy (<12 mJ/m 2 ), reducing the heterogeneous nucleation rate during deposition. The sol-gel SiO 2 , which forms the base coating, further minimizes exposure of the metal substrate to the fuel, which can act as a catalyst and increase the decomposition reaction rate. We tested the fouling behavior in a custom-built fuel fouling test loop. Tests were able to characterize the efficacy of our coatings and to benchmark performance with bare copper, stainless steel, and Inconel 600 metals as well as commercial anti-fouling coatings, such as alumina and SilcoTek. Our coating demonstrated reduced fouling rates of at least 96% when compared with bare samples. • Hybrid low surface energy and smooth coating for carbon deposition mitigation • Scalable coating methodology applicable for complex heat exchangers • Reduced jet fuel autoxidation by reduction of metal surface catalytic effects • Comparison with jet fuel fouling on copper, stainless steel, and alumina The autoxidation of jet fuel results in carbon deposition on metals. Khodakarami et al. use a scalable hybrid coating to combine SiO2 and a slippery omniphobic covalently attached liquid to mitigate carbon deposition by eliminating the interface between the fuel and substrate and to provide a low surface energy smooth interface.