Adsorption and thermodynamic studies of the corrosion inhibition effect of Rosmarinus officinalis L. leaves on aluminium alloy in 0.25 M HCl and effect of an external magnetic field

The corrosion inhibition of Aluminium alloy AA8011 in 0.25 M hydrochloric acid solution by Rosmarinus officinalis L. (rosemary) leaves extract was studied using the gravimetric technique at 303, 313, 323 and 333K, presence an external magnetic field. study reveals that methanolic rosemary inhibits Al HCl. efficiency found to increase with concentration extract, but decreased temperature. Thermodynamic activation parameters like energy (Ea), ranged from 15.29 35.06 kJ/mol, thereby suggesting mix mechanism physichemisorption; calculated values standard adsorption enthalpieswere positive indicating endothermic process, while negative entropiesimplied associative interaction between inhibitor molecules surface. data be a good fit for Langmuir (R2 > 0.98) Villamil 0.99) isotherm models. Values free energy  obtained were negative, describing spontaneous process. effect field have mixed behaviour R. offinalis room Nonetheless, rate generally decrease strength Key words: Acid corrosion, rosemary, aluminium, langmuir model,