Investigation of corrosion-resistant properties of aurantium oil in 1 M HCl

The fresh peel essential oils of citrus aurantium from Eastern Morocco (Oujda) have been analyzed by gas chromatography and gas chromatography–mass spectrometry. The analyzed essential oil consist mainly of monoterpene hydrocarbons (54.38%), with limonene (52.67%) being the major constituent. The effect of addition of citrus aurantium essential oil on the corrosion of steel in 1 M HCl acid has been studied by weight loss measurements, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. The inhibition efficiency has been found to increase with inhibitor content to attain 95% (at 5 g/l). Data obtained from EIS studies have been analyzed to determinate the model inhibition process through appropriate equivalent circuit models. Inhibition efficiency obtained by the various methods is in good agreement. The adsorption of natural products on the steel surface has been found to obey the Langmuir’s adsorption isotherm.Проаналізовано склад оливи зі свіжих шкірок цитрусових за допомогою газової хроматографії та хроматомас-спектрометрії. Олива містить вуглеводні монотерпену (54,38%) та лімонену (52,67%). Гравіметричним та поляризаційним методами, а також імпедансної спектроскопії вивчено вплив її додатків на корозію сталі у розчині 1 М HCl. Ефективність інгібітора зі збільшенням вмісту до 5 g/l зростала на 95%. За результатами імпедансної спектроскопії побудовано еквівалентні моделі інгібування. Встановлено, що адсорбцію оливи на поверхні сталі описує ізотерма Ленгмюра.Проанализировано содержание масла из свежих шкурок цитрусовых с помощью газовой хроматографии и хроматомасс-спектрометрии. Масло содержит углеводороды монотерпена (54,38%) и лимонена (52,67%). Гравиметрическим и поляризационным методами, а также импедансной спектроскопии изучено влияние ее добавок на коррозию стали в растворе 1 М HCl. Эффективность ингибитора с ростом концентрации до 5 g/l увеличивалась на 95%. По результатам импедансной спектроскопии построены эквивалентные модели процесса ингибирования. Выявлено, что адсорбцию масла на поверхности стали описывает изотерма Ленгмюра

Chemical composition, antioxidant and anticorrosive activities of Thymus Algeriensis.

International audienceKnown therapeutic applications of medicinal plants were made of them an alternative to synthetic compounds. In this situation, the present study was designed to give more knowledge and helping to exploit the leaves of Thymus algeriensis by determining the chemical composition of its essential oil, the phenolic content of the aqueous extract and evaluate the antioxidant and anticorrosive activity. The essential oil was characterized by Geranyl acetate (80.8%) as mainly compound. The aqueous extract has exhibited a moderate antioxidant activity against free radical DPPH. On the other hand, this work describes the successful performance of T. algeriensis as an eco-friendly corrosion inhibitor for acidic media. The corrosion inhibiting effect of the extract and the essential oil of T. algeriensis (TAE & TAO) on mild steel in 0.5 M H 2 SO 4 solution was investigated by electrochemical studies in the presence of different concentrations of TAE & TAO ranging from 0.25 g/L to 2 g/L. Potentiodynamic polarization showed that TAE and TAO behaves as mixed type inhibitors. Nyquist plots show that the efficiency of inhibition increases with increasing concentration of T. algeriensis and the increased charge transfer resistance