STUDY OF KETOCONAZOLE INHIBITION MECHANISM WITH THE ADDITION OF HALIDE SALT IN ACID CHLORIDE SOLUTION

• Main Author: Narendra Garini, Cheryl
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/57935
• Institution: Institut Teknologi Bandung

ASTM A36 steel is low carbon steel which is widely used for constructing buildings such as pipes, tanks and can also be used for shipbuilding materials. In its application, this type of steel is easily corroded[3]. One of the corrosion prevention efforts that can be done is adding additives in the form of corrosion inhibitors in small concentrations (ppm) in the corrosion media. One of the inhibitors that have been shown to have an excellent inhibitory effect is ketoconazole. Several studies have shown an increase in the efficiency and degree of surface coverage of the inhibitor on steel immersed in an acid solution to which an organic inhibitor has been added with the addition of halide ions[7–17]. In this study, the effect of adding halide salts in the form of potassium iodide, potassium bromide, and potassium chloride in various concentrations on the efficiency of ketoconazole inhibitors at various temperatures to prevent corrosion of ASTM A36 steel in 1 M HCl solution was investigated. Furthermore, calculations were also carried out to predict the adsorption mechanism of ketoconazole inhibitors with and without the addition of halide salts. In this study, immersion tests were carried out at 25 ? using halide salts in the form of KI, KBr, and KCl. In addition, immersion tests were also performed at 35 ?, 45 ?, and 55 ? using KCl salt. The halide salts' concentration variations in this experiment were 0.001 M, 0.003 M, 0.005 M, and 0.01 M. The data obtained from the immersion test were then processed to obtain the corrosion rate, inhibitor efficiency, adsorption isotherm model, adsorption mechanism, and other thermodynamic parameters. In general, the addition of inhibitors has a synergistic effect that can increase the efficiency of ketoconazole inhibitors in 1 M HCl solution. The efficiency of the inhibitor will decrease with increasing temperature. The highest inhibitor efficiency (97.41%) was obtained by adding ketoconazole inhibitor with KCl as much as 0.01 M at a temperature of 25 C. The mechanism of adsorption of ketoconazole inhibitors with and without the addition of halide salts follows the Langmuir adsorption isotherm model, where it is estimated that a single layer of inhibitor is formed on the metal surface. The inhibitor adsorption process on the metal surface in this study is a combined adsorption process involving chemisorption and physisorption processes. The equivalent electrical circuit model of the system in solution with the addition of ketoconazole inhibitor with and without the presence of halide salts in the form of KI and KCl is Rs- (CPEi(Ri(CPEdl/Rp))) which indicates the formation of an uneven passive layer on the metal surface.