ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Microwave-synthesized cinnamyl-imidazolium ionic liquid for efficient aluminium corrosion protection in acidic media: experimental and theoretical insights

Shikha Sharma, Yogesh Paridwal, Shriniwas Gurjar, Renu Joshi, Shobhana Sharma, Abhinay Thakur, Ankit Sharma, and Sushil Kumar Sharma

Department of Pure and Applied Chemistry, University of Kota, Kota, India

E-mail: shobhna.sharma51@gmal.com

Received: 23 February 2026  Accepted: 3 June 2026

Abstract:

A cinnamyl-functionalized imidazolium ionic liquid, 1-cinnamyl-3-propylimidazolium bromide (CPrImBr), was synthesized via an energy-efficient microwave-assisted route and evaluated as a corrosion inhibitor for aluminium in 1.0 M HCl. Gravimetric and electrochemical investigations reveal that CPrImBr exhibits outstanding inhibition performance, achieving a maximum efficiency of 91.69 ± 0.4% at 1000 ppm and 298 K. Electrochemical impedance spectroscopy and potentiodynamic polarization analysis demonstrate that CPrImBr acts as a mixed-type inhibitor, significantly lowering corrosion current densitywhile increasing charge-transfer resistance through the formation of a compact interfacial film. The adsorption of the inhibitor obeys the Langmuir isotherm, with calculated Gibbs free energy values (− 31.92 ± 0.02 to − 34.11 ± 0.2 kJ mol⁻¹) indicating a combined physisorption–chemisorption mechanism. Surface analyses using SEM–EDX, XPS,and AFM confirm the development of a chemically stable, nitrogen-rich protective layer that mitigates chloride-induced surface degradation.The experimental data were confirmed by quantum chemical calculations using the DFT approach.

Graphical abstract

Keywords: 1-cinnamyl-3-propyl imidazolium bromide; Ionic liquid; Adsorption; Corrosion; Aluminium; Inhibition efficiency

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05164-y

Chemical Papers 80 (11) 13055–13078 (2026)