Surface interaction of expired Brilcure (Ticagrelor) drug on soft-cast steel in 0.5 M H2SO4 medium: Corrosion protection, surface characterizations and computational studies

Background

Soft-cast steel (SCS) is extensively used in industry but is prone to corrosion in acidic solutions, necessitating effective protection methods. Corrosion inhibitors offer a rapid, easy, and economical solution. However, expired ticagrelor (Brilcure) poses environmental risks when discarded due to its active components. Therefore, this study explores the use of expired ticagrelor (TCGL) to prevent SCS corrosion in sulfuric acid, utilizing its active components, such as N and O atoms and conjugated bonds, as adsorption centers while being environmentally friendly.

Methods

The corrosion inhibition and adsorption properties of TCGL on SCS in 0.5 M H₂SO₄ were investigated using weight loss, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) techniques. Surface characterization of SCS was performed using scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), atomic force microscopy (AFM), and water contact angle (WCA) measurements. The adsorption behavior of TCGL followed the Langmuir isotherm model. Additionally, density functional theory (DFT) and molecular dynamics (MD) simulations were employed to elucidate the bonding interactions between TCGL and the metal surface.

Significant findings

Ticagrelor achieved 98.99 % inhibition efficiency at 250 ppm by adsorbing on the steel surface, forming a protective film. PDP studies showed decreased corrosion current density and a potential shift from -0.53 V to -0.49 V. SEM and AFM confirmed significant protection. DFT and MD simulations identified active sites and molecular mechanisms, highlighting Ticagrelor's potential as an effective, eco-friendly corrosion inhibitor for SCS.