Enhancing the anticorrosion performance of mild steel in sulfuric acid using synthetic non-ionic surfactants: practical and theoretical studies

Abstract

The anticorrosion potency of Sabic mild steel (MS) in 0.5 M H 2 SO 4 solution was enhanced by three synthetic non-ionic surfactants (NI Surf.) containing pyridine and pyrimidine derivatives. These compounds are safe, environmentally friendly, and harmless to human health. Chemical and electrochemical measurements were used to compute the corrosion parameters. The anticorrosion efficacy increases with increasing the concentration of NI Surf. and with lowering temperature, surface and interfacial tension, and critical micelle concentration. The effectiveness of anticorrosion is interpreted due to the spontaneous horizontal adsorption on the surface of MS by the existence of some active centers that facilitate the adsorption. The adsorption process obeys Temkin isotherm. Potentiodynamic polarization elucidated that the synthetic NI Surf. acted as mixed-type inhibitors. Some surface properties were determined and confirm the anticorrosive effect of these molecules. Quantum chemical parameters as reactivity descriptors were carried out. It should be noted that the results obtained from computational calculations of the specifications are in full agreement with the experimental observations. There is good compatibility between the anticorrosion efficiency obtained from various techniques and surface properties and quantum chemical calculation.

Expired Antifungal Drugs as Effective Corrosion Inhibitors for Carbon Steel in 1 M HCl Solution: Practical and Theoretical Approaches

“…ex drug ads ex drug (15) where C ex-drug is the concentration of the expired drug and K ads is the equilibrium constant of adsorption. Figure 11A,B presents the Langmuir plots (C ex-drug /θ and C ex-drug ) of the adsorption of the two expired drugs (BIF and TER) on the X65CS surface in a 1 M HCl solution at various temperatures (299, 309, 319, and 329 K).…”

“…Most inhibitors are organic molecules with several active centers that accelerate the adsorption process. − The primary mechanism for the inhibitory action of the organic molecules on the steel surface is physical or chemical adsorption. The formation of an adsorbent film isolates the steel surface from the aggressive medium. − The inhibition strength of the organic inhibitors depend on several factors such as the electrode surface employed, the nature of aggressive solutions, the chemical composition of the additives, the physicochemical properties of the molecule with respect to the functional group, the expected steric and electronic effect of the density of donor atoms, and the possible interaction between the inhibitors with the d orbital of the iron atoms. − …”

Investigation of the anticorrosion and adsorption properties of two polymer compounds on the corrosion of SABIC iron in 1 M HCl solution by practical and computational approaches

“…Generally, organic compounds, especially those containing some hetero atoms in their structure are most commonly utilized as corrosion inhibitors for iron and steels in acidic media. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] The inhibition efficiency of these compounds relies on the concentration of the acidic solution, the nature of the metal or alloy used, the chemical composition of the additives and the capability to adsorb on the metal surface.…”