1-(3-bromopropyl)-4-(dimethylamino)pyridinium bromide (DPB) ionic liquid prepared via microwave-assisted synthesis was investigated as a potential corrosion inhibitor for carbon steel in molar hydrochloric acid solution by means of weight-loss method. The obtained results revealed the high inhibitive activity of the prepared ionic liquid with increasing inhibition efficiency reaching ca. 87.1% in the presence of 3×10-3 M DPB. The adsorptive nature of the inhibition process was proven by 3 - kinetics and thermodynamics investigations with a large adsorption constant (Kads = ca. 3.8 × 10 mol 1 -1 .L) and an elevated activation energy (Ea = ca. 83.1 kJ.mol ). DPB was found to show a predominant -1 physical adsorption onto the corroding carbon steel surface (?Gads = ca. ?35.9 kJ.mol ). Electrochemical investigations revealed that DPB acted as a mixed-type corrosion inhibitor hindering both anodic and cathodic processes via blocking their respective active sites. The inhibitor was shown to form a protective layer resulting in increasing charge transfer resistance along with a decreasing double layer capacitance.
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