Aesculus hippocastanum seeds extract as eco-friendly corrosion inhibitor for desalination plants: Experimental and theoretical studies

Abstract

In this work, Aesculus Hippocastanum Seeds (AHS) extract has been used as a sustainability and environmentally corrosion inhibitor to reduce the risk of copper alloy corrosion during the acid cleaning process in desalination plants. This extract contains mostly Quercetin 3,4-diglucoside, Aesculin, escin Ia, escin Ib, isoescin Ia, isoescin Ib, Leucocyanidin, Fraxin, Procyanidin A2, Quercetin, and Kaempferol, according to HPLC analysis. At 100 ppm, the AHS extract showed a 96.1 percent inhibitory efficacy as a corrosion inhibitor. The findings demonstrate that AHS is an effective mixed–type corrosion inhibitor. The AHS extract solution has a greater activation energy value (i.e. 7.32 kJ mol−1) than the blank system (i.e. 15.65 kJ mol−1), indicating a physical adsorption process. Furthermore, the Langmuir adsorption pattern is applied to describe AHS extract adsorption. The electron dispersion in inhibitor compounds was revealed by quantum calculations, revealing their capacity to accept/donate charges from Cu-Ni atoms in vacuum and in water solvation. The extract molecules adsorbed on the copper alloy surface in a nearly flat orientation to acquire maximal surface coverage and contact, according to a molecular dynamics simulation.