Sustainable corrosion resistance of piroxicam- cyclodextrin inclusion complex to mild steel and its mechanism

Finding new cost-effective and environmentally friendly anti-corrosion materials is a never-ending task. Herein, the main objective is to prepare a new formulation based on piroxicam-cyclodextrin inclusion complex (PX@3-CD) as an efficient green inhibitor to protect mild steel against corrosion in 1 M HCl. The inhibition performance of PX@3-CD was determined by electrochemical tests coupled with theoretical study like as DFT calculation to assess the reactivity and interaction mechanisms between PX@3-CD and Fe. The obtained results revealed that PX@3-CD performs excellently inhibition performance where its inhibition efficiency reached 98.65% at 0.4 mM, and it acted as a mixed type inhibitor with anodic predominance. SEM and contact angle analysis showed the forma-tion of compact PX@3-CD film on steel surface. The adsorption of PX@3-CD inhibitor fol-lowed the Langmuir adsorption model according to the gravimetric corrosion measurement. Thermodynamic analysis and DFT calculations revealed the chemisorption of the inhibitors on the steel surface.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study develops a new formulation based on piroxicam-cyclodextrin inclusion complex (PX@3-CD) as a cost-effective and environmentally friendly anti-corrosion material for protecting mild steel in 1 M HCl. Electrochemical tests and theoretical study reveal that PX@3-CD demonstrates excellent inhibitive performance with an efficiency of 98.65% at 0.4 mM, acting as a mixed type inhibitor with anodic predominance. SEM and contact angle analysis confirm the formation of a compact PX@3-CD film on the steel surface, and gravimetric corrosion measurement validates the Langmuir adsorption model for PX@3-CD inhibitor. Thermodynamic analysis and DFT calculations disclose the chemisorption of inhibitors on the steel surface.