Synergistic effect of halide ions and gum arabic for the corrosion inhibition of API5L X70 pipeline steel in H₂SO₄

Abstract

This paper aims to increase the inhibition efficiency of gum arabic (GA) for the corrosion of API5L X70 pipeline steel in sulfuric acid through the addition of halide ions (potassium iodide [KI], potassium chloride [KCl], and potassium bromide [KBr]). The synergistic effect of GA and halide ions has been studied using potentiodynamic polarization curves, electrochemical impedance spectroscopy, and surface analysis by scanning electron microscope (SEM). The results show that substantial corrosion inhibition (99%) using 2 g L−1 GA and 0.5 mM KI can be obtained in synergistic manner. The adsorption of GA in combination with iodide ions follows Langmuir adsorption isotherm. GA combined with KI acts as a mixed‐type inhibitor in sulfuric acid.

Chitosan as a green inhibitor for mild steel corrosion: Thermodynamic and electrochemical evaluations

“…In addition, it is obvious that the dissolution of chitosan increased the diameter of the capacitive loop indicating an increase in the impedance of the inhibited substrates in the presence of the corrosion inhibitor. [41] Moreover, by further increasing the concentration of chitosan from 0.3 to 1.8 mM, the diameter of the plotted semicircles increased denoting the concentration dependence of the corrosion inhibition process. This also correlates with the calculated potentiodynamic polarization parameters ( Figure 5).…”

“…It has been attributed to the accumulation of corrosion products on the surface of the corroding electrode, [42] nonlinearity in the frequency response, [43] relaxation of the adsorbed charged species such as H þ ads , Cl À ads , inhibitor species on the working electrode. [41] It is common to use an electrical equivalent circuit to analyze the EIS data. Therefore, in this research, a circuit with a configuration similar to the previously proposed ones was employed.…”

Comparative study on two imidazolium‐based ionic liquid surfactants as corrosion inhibitors for N80 steel in 15% hydrochloric acid solution

“…In the circuits, R s is the solution resistance, R ct is the charge transfer resistance, and L and R L represent the inductive elements. Furthermore, the real values of double-layer capacitance (C dl ) and inhibition efficiency (η) were calculated as follows [41,42] :…”

“…After adding either [DDMIM]Cl or [BDMIM]Cl, the diameter of the capacitive loop of Nyquist plots in the middle-frequency range increases with an increase in inhibitor concentration, whereas the shape of Nyquist plots of both inhibitors does not change, except for the degradation of the inductive loop in the low-frequency range, which suggests that the corrosion process of N80 steel in this study is mainly controlled by charge transfer, and steel corrosion will become more difficult with an increase in the difficulty of charge transfer. [41][42][43] Moreover, a slight inductive loop in each Nyquist plot at the very high-frequency range can be observed in Figure 3, which originates from the physical inductance of wires and the N80 steel electrode itself. [43] F I G U R E 3 Nyquist plots of N80 steel in a 15% HCl solution without and with different concentrations of (a) 1-dodecyl-2, As depicted in Figure 4, an increase in the concentration of either [DDMIM]Cl or [BDMIM]Cl results in a more negative value of the phase angle and in the larger value of absolute impedance, which indicates that both inhibitors at higher concentration have a better inhibitive ability.…”

N‐methyl‐2‐hydroxyethylammonium oleate ionic liquid performance as corrosion inhibitor for mild steel in hydrochloric acid medium

“…Being specifically adsorbed, they neutralize a part of the positive charge carried by steel and favor adsorption of cation moiety of [m-2HEA][Ol], at the corrosion potential, leading to an improved inhibition. [99,100] The solution containing 0.05-mol/L sulfuric acid + PIL + chloride exhibits lower corrosion current density values than those without chloride ions (0.05-mol/L sulfuric acid + PIL). Besides, the corrosion potential shifts toward positive values with chloride addition, as revealed by Figure 14.…”