Diethanolamine similar to triethanolamine (T775580) is used as a surfactant. It also has the potential to be a corrosion inhibitor by means of chemisorption.
Bhajiwala, H.M et al.: Bull. Electrochem., 17, 441 (2001); Yu, J. et al.: Thin. Solid. Films., 379, 7 (2000);