The adsorption of thiourea on mild steel

Ceratonia siliqua extractas a green corrosion inhibitor for copper and brass in nitric acid solutions

“…Generally, values of DG o ads up to −20 kJ mol −1 are consistent with electrostatic interaction between the charged molecules and the charged metal (physical adsorption) while those more negative than −40 kJ mol −1 involve charge sharing or transfer of electrons from the inhibitor molecules to the metal surface to form a coordinate type of bond (chemisorption). (27,28) The heat of adsorption was calculated using the Van't Hoff equation (29): (Table 5) are negative, which show that the adsorption is an exothermic process (30). Finally, the standard adsorption entropy DS o ads can be calculated by the following equation:…”

Study the Mettalic Finishing and Corrosion Control Processes for Carbon Steel over Head Pipes Using Polymer Molecules

“…Application of polymers additives on corrosion control of carbon steel pipes A pilot for distillation tower were used for this application .the overhead of this tower used to release hydrocarbons gases which are corrode the material of this overhead (carbon steel).So many different corrosion inhibitors were injected in this overhead and the efficiency of these corrosion inhibitors were evaluated by measured the Concentration of Fe +2 (ppm) in the sample that taken from a drain system. Concentration of Fe +2 (ppm) in case of presence and absence of polymers molecules were measured using Atomic absorption spectroscopy .we found that as concentration of polymers additives increases,the positively ferrous ions Fe +2 (ppm) will decrease as shown in Table ( 6 ) and Figure (9 ). So this effect will make the ability to control the corrosion in carbon steel and give an indication for these polymers as agood inhibitors.…”

The Influence of Grain Size of Pure Iron Metal on Corrosion Inhibition in Presence of Sodium Nitrite

“…The corrosion kinetics parameters were derived from the complex plane plots are given in Tables 4. In order to clarify the nature and the strength of adsorption the experimental results have been fitted to a series of adsorption isotherms and the best fit was obtained with the use of Langmuir adsorption isotherm (Fig.9).The Langmuir adsorption isotherm can be expressed as: Where θ is fractional coverage of the metal surface, C is the inhibitor concentration in the electrolyte and K is the equilibrium constant for the adsorption/desorption process and it is related to the standard free energy of adsorption (∆G • ads ) according to [26]:…”