Sustainable conservation of iron artifacts by a green formulation derived from the seeds of Nigella Sativa Maria Pia Casaletto 1 , Claudia Cirrincione 1 , Antonella Privitera 1 , M. Chellouli 2 , D. Chebabe 2 , N. Bettach 2 , N. Hajjaji 2 , A. Srhiri 3 1 Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati, via Ugo La Malfa 153, 90146, Palermo (Italy) 2 Laboratory of Material, Electrochemistry and Environment, University Ibn Tofail, Faculty of Sciences, Kenitra, Morocco 3 Servichim Sarl, 101 Rue Maamoura, n° 10 Kenitra, Morocco New green and low toxic corrosion inhibitors for the conservation of metallic artifacts, replacing the presently used hazardous materials, represent a growing need of Mediterranean Conservation Institutions and Museums. A consolidated collaboration between CNR (Italy) and CNRST (Morocco) was carried out for investigating both chemically synthesized and naturally-derived products as corrosion inhibitors [1,2]. In this work a new green formulation based on the oil extracted from the seeds of Nigella Sativa L., a widespread plant in the Mediterranean basin, was tested as corrosion inhibitor for iron artifacts in acidic media. Films of this formulation on iron substrates, with a chemical composition similar to archaeological iron artifacts [3], were produced by immersion and then submitted to corrosion by rain water solution. The surface chemical and physical characterization was performed by X-ray Photoemission Spectroscopy (XPS) and Scanning Electron Microscopy coupled with chemical analysis (SEM-EDX), both before and after submission to the corrosion attack. Electrochemical tests by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurement were performed in a rain water medium, both in presence and absence of the natural inhibitor formulation. Experiments were performed as a function of the concentration and of the immersion time. Results showed that the formulation acts as a good mixed type (cathodic/anodic) inhibitor. The dissolution rate decreased with the increase of both the concentration and the immersion time. An inhibition efficiency of 99% was reached for a concentration of 2500 ppm. Surface results confirmed a good protective action of the formulation on the iron substrates. Acute toxicity tests proved that the formulation is a non toxic and environmentally safe product (LD50 > 6000 mg/kg), usefully suitable for a sustainable conservation of iron artifacts. References [1] M.P. Casaletto, N. Hajjaji, Bulletin of Research on Metal Conservation, BROMEC Issue 32, 5 (2010). [2] M.P. Casaletto, R. Schimmenti, G.M. Ingo, C. Riccucci, T. de Caro, A. Dermaj, D. Chebabe, N. Hajjaji, A. Srhiri, V. Vivier, Proceedings of EUROCORR 2012, Istanbul (Turchia), 9-14 September 2012. [3] M. Chellouli, N. Bettach, N. Hajjaji, A. Srhiri, P. Decaro, International Journal of Engineering Research & Technology (IJERT), Volume 3, Issue 4, 2489-2495 (2014). Acknowledgements This work was financially supported by the PO Sicilia FSE 2007/2013 Project: “Nanomaterials and nanotechnologies for a sustainable development and the preservation of Cultural Heritage” - Avviso n. 1/2012 Assessorato Formazione Regione Siciliana – Servizio 9 Ricerca Scientifica.