Fatty-amide derivatives were evaluated to study the effect of the double bonds into the hydrocarbon chain (C18) on the corrosion behavior of carbon steel. Electrochemical impedance spectroscopy (EIS) and real-time corrosion measurements were used to evaluate the inhibition mechanism of the fatty-amides on carbon steel in CO2-saturated (3% NaCl + 10% diesel) emulsion at 50°C. EIS results demonstrated that the unsaturation present into the hydrocarbon chain contributes to the efficiency of fatty-amides, because they can be adsorbed on the metal surface by a flat-adsorption process reducing the presence of active sites and blocking the corrosion process and preventing the diffusion of corrosive species, such as H2O, H+, Cl−, andHCO3-. Real-time corrosion measurements also indicated that the effectiveness of the inhibitors is dependent on the unsaturation into the hydrocarbon chain, being also a good technique to determine the stability of the adsorption process of the inhibitors.

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Palm oil production is among the highest worldwide, and it has been mainly used in the food industry and other commodities. Currently, a lot of palm oil production has been destined for the synthesis of biodiesel; however, its use in applications other than the food industry has been questioned. Thereby for a sustainable development, in this paper the use of palm oil of low quality for corrosion inhibitors synthesis is proposed. The performance of the synthesized inhibitors was evaluated by using electrochemical techniques such as open circuit potential measurements, linear polarization resistance and electrochemical impedance spectroscopy. The results indicate that the fatty amides from palm oil are excellent corrosion inhibitors with protection efficiencies greater than 98%. Fatty amides molecules act as cathodic inhibitors decreasing the anodic dissolution of iron. When fatty amides are added, a rapid decrease in the corrosion rate occurs due to the rapid formation of a molecular film onto carbon steel surface. During the adsorption process of the inhibitor a self-organization of the hydrocarbon chains takes place forming a tightly packed hydrophobic film. These results demonstrate that the use of palm oil for the production of green inhibitors promises to be an excellent alternative for a sustainable use of the palm oil production.

Due to its high content of rare earths, the use of permanent magnets can be a sustainable alternative for the synthesis of environmentally friendly corrosion inhibitors in order to replace the use of highly toxic inhibitors, as well as the use of rare earth salts of high purity and high cost. In this study, the recovery of rare earths from permanent magnet wastes and their synthesis to chloride salts were carried out. Rare earth chlorides were evaluated as corrosion inhibitors by electrochemical techniques on API X70 steel in a 3.5% NaCl solution. Both anodic and cathodic polarization curves were made, and measurements of both open-circuit potential, linear polarization resistance, and electrochemical impedance were made. Results show that the inhibitor synthesized is a mixture of Nd and Pr chloride. Its performance as a corrosion inhibitor is superior to that of high purity Nd chloride (analytical reagent). The results show that the use of electronic scrap is a sustainable source for the synthesis of green corrosion inhibitors with low carbon footprint.

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Charged particles injected into dielectric material of artificial satellites may cause data flipping, command errors and charges in dielectric material properties. In this work we report the results of an evaluation of rare earth aluminates as possible radiation shields for its application in Low Earth Orbit (LEO) satellite construction. With help of Geant4 software, we calculated the radiation dose that a target receives at a typical LEO (685 km) as a function of the shield thickness. The target used was a silicon plate, the shields used were hollow cubes of rare earth aluminate walls (YAlO 3 , LaAlO 3 , NdAlO 3 and GdAlO 3), and we also used aluminium oxide (Al 2 O 3). The radiation source was the measured fluxes of electron and proton with a spectrum corresponding to a LEO. We found that of the total radiation dose received by the target without shield is 5847 microGy/hour, of which, the electrons contribute with 94.9% and the protons with 5.1%. The rare earth aluminates are a better shield than the Al 2 O 3 to protect a target against the radiation that permeates a LEO near to equator.

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