Novel thiophene symmetrical Schiff base compounds as corrosion inhibitor for mild steel in acidic media

Corrosion Inhibition of Zinc Metal in 2M Hydrochloric Acid Solution by Using GuaifenesinDrug as an Inhibitor and Theoretical Calculations

“…(2) showed that the lowest corrosion rate was at 300 ppm, so it is the optimum concentration for inhibition, and this is might be attributed to the maximum coating of zinc strips at this concentration, and the guaifenesin molecules are distributed homogenously on the surface of zinc strips, and at 300 ppm the accommodation of guaifenesin molecules on the surface of zinc strips might be relatively non-homogeneous. The surface coverage θ, of the zinc strips by the adsorbed inhibitor was calculated from weight loss measurements using equation (4). The maximum surface coverage was found to be at 300 ppm, and this is could be attributed to the moderate concentration and the molecules of guaifenesin at this concentration diffuse from the bulk solution into the surface of zinc to cover it and inhibit the corrosion.…”

“…While corrosion inhibitors will not halt or completely prevent corrosion, they can reduce the rate at which corrosion occurs, and block early corrosion damage. A wide variety of chemicals can be used for this purpose, although many are toxic, and must therefore be used with care to protect the environment [3,4]. We choose some drugs as corrosion inhibitors because drug molecules contain oxygen, nitrogen and sulphur as active centers, drugs are reportedly environmentally friendly and important in biological reaction, anddrugs can be easily produced and purified [5,6].…”

Studies on the inhibition of carbon steel corrosion in hydrochloric acid solution by expired Carvedilol drug

“…The EFM is a non-destructive corrosion measurement technique that can directly give values of the corrosion current without prior knowledge of Tafel constants (37). Figure 9(a,b) shows the EFM spectrum obtained for CS corrosion in 1 M HCl solution in the absence and presence of 1 × 10 −4 M of the investigated Carvedilol at 25°C, respectively.…”

“…The impedance spectra exhibit a single semicircle corresponding to one time constant in the Bode plots (Figure 7(b)). It can be concluded that the charge transfer resistance R ct value increased with increase in the dose of the drug, whereas the values of double-layer capacitance (C dl ) decreased, with an increase in the inhibitor dose, which is most probably due to the decrease in the local dielectric constant and/or increase in the thickness of the electrical double layer (37). The equivalent circuit model shown in Figure 8 was used to analyze the Table 5.…”

Some Water-Soluble Polymers as Corrosion Inhibitors for Carbon Steel in Acidic Medium

“…The values of electrochemical parameters such as corrosion potential (Ecorr), cathodic and anodic Tafel slopes (βa and βc) and corrosion current density (Icorr) were extracted by Tafel extraploting the anodic and cathodic lines and are listed in Table 1. The percentage of inhibition efficiency (IE %) was calculated using the following equation [28]:…”