Experimental and Theoretical Tests on the Corrosion Protection of Mild Steel in Hydrochloric Acid Environment by the Use of Pyrazole Derivative

Abstract

In this study, 1,5-diallyl-1H-pyrazolo [3,4-d] pyrimidin-4 (5H)-one (PPD) was evaluated as an anticorrosion agent for mild steel (MS) in 1 M HCl. The analysis was performed by weight loss (WL), potentiodynamic polarization measurement, and electrochemical impedance spectroscopy (EIS). The Tafel polarization showed that PPD is a mixed-type inhibitor and reaches 94% of the protective efficiency at 10−3 M. EIS results indicated that the resistance to charge transfer increases with increasing inhibitor concentration and the corrosion of MS is controlled by a charge transfer process. The inhibitor adsorption on the MS surface obeyed the Langmuir’s adsorption isotherm. Thermodynamic parameters were calculated to elaborate the corrosion inhibition mechanism. The micrographic analysis revealed the existence of a barrier layer on the electrode surface with the presence of PPD. Theoretical examinations performed by electronic/atomic computer simulations confirmed that the obtained results were found to be consistent with experimental findings.

Advancement of Novel Graphene Oxide Embedded Alumina Nickel Composite Coating Developed at Various Current Densities to Evaluate Corrosion Resistance

“…The surface morphology of mild steel before electrodeposition and composite coatings deposited on mild steel at 5, 10, 20, and 30 mA cm -2 of current density is shown in Figure 5. The morphology of bare mild steel seems to be smooth, as shown in Figure 5(a), and this work has been reported earlier [39,40]. The morphology varies from surface to surface, and at low current densities, the coating's morphology is compact and smooth; at high current densities, it becomes less compact and has coarser features.…”

The Inhibition Action of Some Brij-Type Nonionic Surfactants on the Corrosion of OLC 45 in Various Aggressive Environments

“…It can be remarked in Figure 10 b–e that with the Brij (Brij 35, Brij 56, and Brij 58P at 800 ppm) surfactants, the OLC 45 substrate zone presented a superior and improved morphological substrate compared to that of the uninhibited OLC 45 substrate, showing an appreciable ability of the surfactants to protect against corrosion. An adsorbed film is presented on the OLC 45 substrate to produce a diminution in contact (touch) with the OLC 45 specimen and the aggressive environment, which is liable for the corrosion inhibition [ 11 , 40 , 46 , 47 , 48 ].…”

“…In recent years, the progress of new friendly organic substances (surfactants, plants extract, polymers) with anticorrosion properties that have ecological, biodegradable, cheap, and healthy characteristics for active materials represents a large domain of exploration in the area of anticorrosion protection [ 39 , 40 , 41 , 42 , 43 , 44 ]. Surfactants are organic inhibitor molecules which contain hydrocarbonate chains of diversified lengths and these variations of the attached alkyl chains can determine a notable impact on the hydrophobicity of a corrosion inhibitor [ 45 , 46 , 47 , 48 ]. The extent of the alkyl chains and the existence of π-bonds, including heteroatoms, execute a huge effect on the adsorption capacity.…”

Effects of Film Thickness of ALD-Deposited Al2O3, ZrO2 and HfO2 Nano-Layers on the Corrosion Resistance of Ti(N,O)-Coated Stainless Steel

“…In the case of SS/Ti(N,O) coatings, the slopes were quite similar, such that it may be concluded that the hydrogen evolution and metal dissolution were almost in equilibrium [61]. For the ALD-coated samples, except for SS/Ti(N,O)/HfO 2 -110c, the anodic slope became higher than the cathodic slope, indicating an inhibition action of the oxides by simply blocking the metal from interaction with the acidic and oxidising environment [62][63][64]. Considering the Tafel plots (Figure 17b-d), one can see that both the uncoated and Ti(N,O)-coated SS showed a local disruption of the passive layer, evidenced by the breakdown potential (Eb), giving rise to a sharp increase in the ion current density, indicating that local corrosion processes were activated.…”