Electrochemical, gravimetric and quantum chemical analysis of mild steel corrosion inhibition by colchicine in 1 M HCl medium

Abstract

The inhibition effect of colchicine (CC) on mild steel (MS) corrosion in 1 M HCl solution has been investigated by electrochemical techniques such as electrochemical impedance spectroscopy, potentiodynamic polarization, chronoamperometry and also by the gravimetric method. Polarization studies showed that CC acts as mixed type corrosion inhibitor. The inhibitor adsorption process in the MS/ CC/HCl system was studied at different temperatures (303-333 K). The adsorption of CC on MS surface is an exothermic process and obeys the Langmuir adsorption isotherm. Based on potential of zero charge values and quantum chemical parameters, the mechanism of adsorption has been proposed.

Bio‐/Environment‐Friendly Cationic Gemini Surfactant as Novel Corrosion Inhibitor for Mild Steel in 1 M HCl Solution

“…The charge on the metal surface is determined from the value of E corr -E q=0 , where E q=0 is the zero charge potential. In the present investigation, the obtained E corr value of MS in 1 M HCl is -0.413 mV (Ag/ AgCl), whereas E q=0 of iron in HCl solution is reported to be -498 mV (Ag/AgCl) [62]. As reported in the literature, if E corr -E q=0 [ 0, the metal surface is positively charged [63][64][65].…”

“…The adsorption of inhibitor on the MS surface is influenced by several factors including the chemical structure of the inhibitor and the charge at the metal/solution interface [8,61]. In the HCl solution, at a free corrosion potential, the MS surface is positively charged [62]. The charge on the metal surface is determined from the value of E corr -E q=0 , where E q=0 is the zero charge potential.…”

Electrochemical and anticorrosion properties of 5-hydroxytryptophan on mild steel in a simulated well-acidizing fluid

“…Experiments were carried out in triplicate, and the mean values of the weight losses (g) were used for computation. The corrosion rate (CR), inhibition efficiency ( WL ) and degree of surface coverage () were calculated as follows [22]:…”

Outstanding inhibitive effect of colchicine on aluminium alloy 6061 corrosion

“…The inhibitor CC get adsorbed on metal surface by donor acceptor interactions between free electron pairs of four oxygen atoms present in the methoxy group and π electrons of the phenyl ring and the vacant orbital of aluminium atom. According to the quantum chemical studies carried out by our research group, nitrogen and oxygen atoms, and π-electrons in the phenyl ring and cycloheptatrienone ring, are the main active sites of adsorption of CC on metal surface [32]. As a result, CC gets adsorbed on AA6061 surface through these active sites and it prevents the formation of oxychloride complexes and inhibits metal dissolution reaction.…”