The adsorption and inhibition effect of calcium lignosulfonate on Q235 carbon steel in simulated concrete pore solution

Corrosion inhibition of carboxylate inhibitors with different alkylene chain lengths on carbon steel in an alkaline solution

“…The CPP tests were measured aer 1 h immersion with a 0.1667 mV s À1 scan rate from À300 mV below the open circuit potential in the anodic direction until the current density increased up to 0.02 mA cm À2 , then the potential scanning was reversed at the same scanning rate until the test ended. Impedance measurements, in order to calculate the potential of zero charge (PZC) of steel, 27,28 were carried out using AC signals of a 15 mV potential perturbation and the scanning frequency range was 100 kHz to 0.01 Hz. The impedance data were tted by ZSimpWin soware.…”

“…Reinforced concrete specimens were prepared with 425# Portland cement, dried ne river sand and distilled water with the ratio of 1 : 3 : 0.7 (wt%). 28,29 The studied inhibitors were added into the distilled water (0.1% of the total weight of concrete) and the pH value of the water was adjusted to 7. The steel sample was positioned in order to have a concrete cover of 20 mm thick.…”

“…Langmuir isotherm assumes that the adsorbed molecules occupy only one site and there are no interactions with other adsorbed species. 25,44 The change of Gibbs free energy of adsorption (DG ads ) is calculated by following equation: 21,25,28 DG ads ¼ ÀRT Â ln(55.5 Â K ads ) (8) where R is the gas constant (8.314) and T is the absolute temperature (298 K). The value of 55.5 is the concentration of water in solution in mol L À1 .…”

Study on Synergistic Corrosion Inhibition Effect between Calcium Lignosulfonate (CLS) and Inorganic Inhibitors on Q235 Carbon Steel in Alkaline Environment with Cl−

“…As an effective corrosion inhibitor, calcium lignosulfonate (CLS) contains plenty of hydroxyl, carboxyl, and methoxyl groups, which can adsorb onto the steel surface by sharing their lone pair electron or π-electron with the free d-orbital of metal [ 1 ]. It has been proven that CLS is a good corrosion inhibitor in saturated Ca(OH) 2 solution [ 23 ] and carbonation concrete pore solution [ 1 ] for carbon steel. The chemical structure of CLS used in this research is shown in Figure 1 [ 1 , 23 ].…”

“…It has been proven that CLS is a good corrosion inhibitor in saturated Ca(OH) 2 solution [ 23 ] and carbonation concrete pore solution [ 1 ] for carbon steel. The chemical structure of CLS used in this research is shown in Figure 1 [ 1 , 23 ]. In the preliminary work we have completed [ 1 ], the synergistic corrosion inhibition effect between CLS and sodium molybdate has been investigated and the inhibition mechanism of the hybrid inhibitor was illustrated.…”