Antibacterial drugs as inhibitors for the corrosion of stainless steel type 304 in HCl solution

Abstract

The effect of three antibacterial drugs (3-thiazinonyl-bicyclo [4.2.0] octene-carboxylate derivatives) on the corrosion behavior of stainless steel type 304 in 1.0 M HCl solution has been investigated using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. The inhibition efficiency increased with increase in inhibitor concentration but decreased with increase in temperature. The thermodynamic functions of corrosion and adsorption processes were evaluated. The potentiodynamic polarization measurements indicated that the inhibitors are of mixed type. The adsorption of these inhibitors was found to obey Langmuir's adsorption isotherm. Synergism between iodide ion and inhibitors was proposed. The inhibitive action was satisfactory explained by using both thermodynamic and kinetic models. The results obtained from the three different techniques were in good agreement.

Inhibitory Properties of Neomycin Thin Film Formed on Carbon Steel in Sulfuric Acid Solution: Electrochemical and AFM Investigation

“…The following arguments support this statement: (i) the increase of the NMS concentration leads to i corr breakdown while R ct increases and C dl decreases; (ii) IE follows the same increasing trend as the inhibitor concentration; and (iii) the NMS inhibition action is due to the adsorption of its molecules on carbon steel surface, contributing to the formation of a surface protective layer [23][24][25][26].…”

“…The fitting of the degree of surface coverage (θ) values with the maximum regression coefficient (R 2 ) enables the accurate determination of the adsorption-desorption equilibrium constant (K), and then the calculation of the standard adsorption free energy (∆G 0 ads ) [20][21][22][23][24][25][26][27][28]. In our study, the experimental data were successfully fitted by applying the Langmuir adsorption isotherm (Figure 3a), its linearized form being expressed by Equation (8) [27]:…”

“…By plotting θ/(1 − θ) as a function of C, the straight line was obtained with the slope equal to K (3379.1 L·mol −1 ) and the R 2 value of 0.97. Equation (9) was used to determine the standard adsorption free energy (∆G 0 ads ) [26,27]:…”

Inhibitory Properties of Neomycin Thin Film Formed on Carbon Steel in Sulfuric Acid Solution. Electrochemical and AFM Investigation

“…The experimental data listed in Table 1 shows that NMS behaves as corrosion inhibitor for carbon steel, in 1.0 M H2SO4 at the room temperature. The following arguments support this statement: (i) the increase of the NMS concentration leads to icorr breakdown while Rct increases and Cdl decreases; (ii) IE follows the same increasing trend as the inhibitor concentration; (iii) the NMS inhibition action is due to the adsorption of its molecules on carbon steel surface, contributing to formation of a surface protective layer [23][24][25][26].…”

“…The fitting of the degree of surface coverage (θ) values with the maximum regression coefficient (R 2 ) enables the accurate determination of the adsorption-desorption equilibrium constant (K) and then the calculation of the standard adsorption free energy (ΔG o ads) [20][21][22][23][24][25][26][27][28].…”