الفهرس 
Introduction & Aim of the workOnly 14 pages are availabe for public view
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Abstract
Firstly, our aim was to find eco-friendly solutions such as; plant extracts to be used as corrosion inhibitors for corrosion of carbon steel in aqueous solutions. Secondly, The inhibitive effect of three medicinal plant extracts on the corrosion behavior of carbon steel in 1M HCl was studied using weight loss method, polarization, ac electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM) techniques and surface examination. Also, the antibacterial activity of the studied extracts against some certain bactria (Echrechai. Coli) was assessed. The inhibition efficiency is found to depend on the concentration of the inhibitor extract and the temperature of the solution. The mechanism of inhibition was deduced in terms of blocking the electrode surface by the adsorption of the inhibitor extract molecules through the active centers in their chemical structures. The adsorption process typically corresponds to Langmuir adsorption isotherm. The effect of temperature on the corrosion rate in the absence and presence of the inhibitor extract was investigated and some activated thermodynamic parameters were calculated. The polarization curves indicated that these compounds influence both cathodic and anodic processes to the same extent. from the impedance data, we conclude that: The value of Rct increases with increase the concentration of the plant extract inhibitors and this also indicates an increase in the corrosion inhibition efficiency in acid solutions. from the EFM data, we conclude that the corrosion current density decreases by increasing the concentration of the studied plant extracts. The micrographs and the elemental analysis suggest that the plant extract components adsorbed on the metal surface forming a thin layer by which metal was protected from corrosion. Finally, the plant extract of Tilia cordata showed the highest antibacterial activity against E.coli followed by Rosmarinus officinalis and Arctium lappa.