Physicochemical studies on the inhibitive properties of a 1,2,4-triazole Schiff’s base,HMATD, on the corrosion of mild steel in hydrochloric acid

The efficiency of 4-(4-hydroxy-3-methoxy benzyledene amino)-4-H-1,2,4-triazole-3, 5-dimethanol, HMATD, as corrosion inhibitor for mild steel in 0.5 M HCl has been determined by weight loss measurements and electro analytical methods. The influence of various parameters such as temperature, inhibitor concentration on the efficiency has been studied. The electrochemical impedance spectroscopic measurements revealed the inhibition action of HMATD by reducing the charge transfer through metal solution interface. Polarization curves indicate the mixed type behaviour of HMATD. The inhibitor molecule functions by blocking the active sites on metal surface by adsorption and which obeys the Langmuir adsorption isotherm. Various kinetic and thermodynamic parameters have also been calculated.     

Comparative studies on the corrosion inhibition characteristics of three different triazine based Schiff’s bases,HMMT, DHMMT and MHMMT,for mild steel exposed in sulfuric acid

The inhibition behavior of three different triazine based Schiff’s bases, HMMT, DHMMT and MHMMT for mild steel corrosion in sulphuric acid has been investigated using weight loss, electrochemical studies, SEM, spectroscopic studies and basic computational studies. The inhibition efficiency increased with increase in inhibitor concentration but decreased with rise in temperature and acid concentration in the case of these three inhibitors. The order of inhibition efficiency expected from the values of band energy is in good agreement with the results obtained from weight loss and electrochemical studies. Polarization studies indicated the mixed type behavior of these inhibitors. Field emission scanning electron microscopic studies revealed that inhibitors protect the metal surface by the forming a protective film through adsorption of inhibitor molecules.     

Cationic surfactant based on alignate as green corrosion inhibitors for the mild steel in 1.0 M HCl

Three cationic surfactants based on alginic acid were laboratory prepared. These compounds were evaluated as corrosion inhibitors utilizing three techniques, namely; weight loss, polarization and electrochemical impedance spectroscopy. The corrosive medium was 1.0?M HCl. The corrosion rate of mild steel in 1.0?M HCl at four different temperatures 25, 40, 55 and 70?°C was investigated gravimetrically. The corrosion rate of mild steel was confirmed electrochemically at 25?°C. It was found that the corrosion inhibition efficiency directly proportionally with the hydrophobic chain length of synthesized inhibitors and also with the plethora of concentration. The inhibition efficiency exhibit a positive trend with raising the solution temperatures as indication for chemisorption. The potentiostatic polarization study revealed that the tested green cationic surfactants act as mixed type inhibitors with predominant control of cathodic reaction. The decreasing in the double layer capacitance obtained from electrochemical impedance measurements refer to increasing the thickness of the formed double layer. The apparent activation energy of the inhibited solution was found to be lower than uninhibited solution as an indication for chemical adsorption.     

Corrosion protection of mild steel in hydrochloric acid up to 313 K using propyl benzimidazole: Electroanalytical,adsorption and quantum chemical studies

The inhibition efficiency of propyl benzimidazole for mild steel in hydrochloric acid in three different concentrations at 303, 308 & 313 K have been studied by polarization, electrochemical impedance spectroscopy, adsorption, surface studies and basic computational calculations. The inhibition efficiencies and the global chemical reactivity relate to total energy, E_HOMO, E_LUMO and gap energy (ΔE). Propyl benzimidazole interact with mild steel surface through adsorption and the process of adsorption follow Langmuir isotherm model. The inhibition efficiency increases with concentration and reaches maximum at 150 ppm. The increase in temperature have an inverse relationship with protection efficiency. The corrosion inhibition efficiencies and the global chemical reactivity relate to total energy, E_HOMO, E_LUMO and gap energy (ΔE).