Design and Prediction of Corrosion Inhibitors from Quantum Chemistry

Abstract

Quantum chemistry is a powerful tool for computing the properties of molecules and their interactions with one another in a variety of environments. In this second paper of a two-part series, the technique is applied in this work to calculate fundamental properties of inhibitor molecules important to the overall corrosion inhibitor performance. The study focuses on the issue of oil/water partitioning as quantified by the partition coefficient (log P) and the important issue of inhibitor speciation according to the acid dissociation constant (pKa). pKa and log P values are then calculated from first-principles for a series of imidazole derivatives and integrated into a model for inhibitor availability as a function of the water cut. Applications to lifetime prediction and inhibitor design are then discussed.

Catalyst-Solvent System for PASE Approach to Hydroxyquinolinone-Substituted Chromeno[2,3-b]pyridines Its Quantum Chemical Study and Investigation of Reaction Mechanism

“…Generally, the greater the number of electron-donating groups in molecule, the higher the probability of adsorption and inhibition activity. As it was shown previously, the inhibitory activity of organic compounds can be predicted properly by quantum-chemical methods [50][51][52]. This reduces the time of the study and hazardous reactant wasting by selecting the hit-compounds.…”

Halogen-substituted pyrazolo-pyrimidine derivatives as corrosion inhibitors for copper in sulfuric acid solution

“…It has been reported that halogen substituted organics such as thiophenol [13], imidazoline [14], triazole [15], have already been proved to be good inhibitors. On the other hand, molecular simulation technique has played an increasingly significant role in the field of corrosion inhibitors [16][17][18]. Based on the above considerations, we will investigate the effect of halogen atoms on the inhibition performances of pyrazolo-pyrimidine.…”

Experimental Investigation and Modeling of the Performance of Pure and Mixed Surfactant Inhibitors: Partitioning and Distribution in Water-Oil Environments

“…The use of surfactant inhibitors has received extensive attention in the oil and gas industry for corrosion inhibition of production and transportation pipes (metallic materials, such as steel and copper) in a way that surfactant molecules usually adsorb on steel surface and form a protective film which acts as a barrier to prevent corrosive media penetration and attack. [1][2][3][4] Compared to the production and use of pure surfactants, surfactant mixtures are well known due to the superior physicochemical properties and capabilities in efficient solubilization, adsorption, suspension, and transportation. [5][6][7][8] The solutions of surfactant mixtures can often be conveniently tuned to achieve desired properties by adjusting the mixed surfactant types and molar ratios.…”

“…Surfactant molecules have hydrophilic and hydrophobic sections, 7,11,12 which are critical to the adsorption on metal surface and associated corrosion inhibition. [2][3][4] The hydrophilic functional group of surfactant molecules strongly prefers interaction with polar entities such as metals, which is helpful in corrosion inhibition. The hydrophobic portion, which is non-polar, strongly prefers interaction with hydrophobic entities such as hydrocarbon phase.…”

“…When an aqueous surfactant solution comes into contact with an immiscible organic liquid in one environment, such as water-oil-metal pipe environments, surfactant monomers may prefer partitioning into the organic liquid until equilibrium is reached, [13][14][15] which usually depletes the surfactants available in the aqueous phase for adsorption on the metal surface and for corrosion inhibiton. 4 Considering the behavior of surfactant partitioning in oil-water environments and associated interfacial phenomena, the determination of surfactant partitioning between water and oil usually serves as the basis of the hydrophobic-hydrophilic balance 13,14,16,17 and is critical for the evaluation of corrosion inhibition efficiency of surfactants. 4 For pure surfactant, the partitioning is usually characterized by the partitioning coefficient, which is defined as the ratio of monomeric surfactant concentration in oil to that in aqueous phase.…”