Abstract
Aluminum alloy AA5052 has recently been chosen to replace titanium tubes in desalination plants' multiple effect distillation (MED) units. The high corrosion rate of AA5052 during the acid cleaning process to remove the scale layer, on the other hand, remains a significant challenge. In this paper, we describe for the first time the use of an ionic liquid, tributyl(ethyl)phosphonium diethyl phosphate (Ph-IL), as a corrosion inhibitor for aluminum alloy AA5052 during the acid cleaning process with a 4% sulfamic acid solution. Remarkably, the addition of ionic liquid Ph-IL to sulfamic acid results in enhanced corrosion resistance of AA5052 with the efficiency reached to 93.0%. Through the adsorption of both the cationic and anionic parts of the ionic liquid, Ph-IL molecules can cover the anodic and cathodic sites. Furthermore, the Ph-IL forms a significant activation energy barrier against the corrosion process. In addition, SEM-EDX analysis confirms the formation of protective layers of Ph-IL molecules on the surface of AA5052. This finding may be helped in the expansion of the use of many ionic liquids with their new properties in the field of desalination. (C) 2021 Elsevier B.V. All rights reserved.