Characterization of a surface coating formed from carboxylic acid-based coolants

Carboxylic acids are found to adsorb weakly to the native oxide surface of aluminum. Under heat exchange conditions, synergistic carboxylate combinati ons provide superior high-temperature aluminum corrosion protection and sho w excellent heat-transfer characteristics. The surface films formed under t hese dynamic heat-transfer conditions are characterized with the use of X-r ay photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) is also used for the study and characterization of the surface films formed. T he results are compared with the FT-IR data of the pure Al-carboxylate comp lexes. The combination of these results reveals that, under heat transfer c onditions, carboxylates are chemically bonded to the aluminum surface. This molecular film shows excellent inhibition properties for aluminum.