ORIGINAL PAPER Cathodic chloride extraction treatment of a late bronze-age artifact affected by bronze disease in room-temperature ionic-liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI) Giuseppe Giovannelli & Lucia D’Urzo & Giovanna Maggiulli & Stefano Natali & Cosimo Pagliara & Ivonne Sgura & Benedetto Bozzini Received: 7 May 2009 / Revised: 28 July 2009 / Accepted: 28 July 2009 # Springer-Verlag 2009 Abstract This paper concentrates on a novel approach to the electrochemical treatment of bronze disease, based on the use of room-temperature ionic liquids (RTIL). In particular, we employed 1-ethyl-3-methylimidazolium bis(trifluorome- thanesulfonyl)imide as the electrolyte for the galvanostatic cathodic treatment of a late bronze-age artifact that had been exposed to marine environment during its history, dating back to ca. 1100 B.C. After an accurate metallographic and structural analysis of the as-found object—proving, among other findings, that bronze disease is essentially related to the presence of nantokite locked inside subsurface pits of typical equivalent diameter of several hundred micrometers, we subjected it to optimal electrochemical conditions, showing—on the basis of X-ray diffraction—that nantokite could be effectively removed and Cu(I) reduced to metallic Cu. Numerical computations in the full three-dimensional pit geometry, with realistic nonlinear electrochemical boundary conditions, provide the theoretical framework for the choice of RTIL—as opposed to aqueous solutions—and for the quantitative evaluation of Cl - removal rates. List of the symbols and dimensions of model quantities Latin letters B Cu an anodic Tafel slope of Cu electrodeposition reaction [V] B Cu cat cathodic Tafel slope Cu electrodeposition reaction [V] B H an anodic Tafel slope of HER [V] B H cat cathodic Tafel slope of HER [V] C i concentration of species i [mol cm -3 ] D i diffusion coefficient of species i [cm 2 s -1 ] F Faraday constant [C eq -1 ] i current density applied during the galvanostatic experiment [C cm -2 s -1 ] i Cu o exchange current density of Cu electrodeposition reaction [C cm -2 s -1 ] i H o exchange current density of HER [C cm -2 s -1 ] k Cu o cathodic kinetic constant of Cu electrodeposition reaction [C cm mol -1 s -1 ] n ! unit vector normal to a given surface [1] R gas constant [C V K -1 mol -1 ] t time [s] T absolute temperature [K] z i valence of ion i [eq mol -1 ] Greek letters κ aq electrical conductivity of the aqueous solution [C V -1 s -1 cm -1 ] G. Giovannelli : S. Natali Dipartimento ICMMPM, Università di Roma “La Sapienza”, v. Eudossiana 18, 00185 Rome, Italy L. D’Urzo : B. Bozzini (*) Brindisi Fuel Cell Durability Laboratory, Università del Salento, S.S. 7 Brindisi-Taranto km 7+300, 72100 Brindisi, Italy e-mail: benedetto.bozzini@unisalento.it G. Maggiulli : C. Pagliara Dipartimento di Beni Culturali, Università del Salento, via D. Birago 64, 73100 Lecce, Italy I. Sgura Dipartimento di Matematica, Università del Salento, via Arnesano, 73100 Lecce, Italy J Solid State Electrochem DOI 10.1007/s10008-009-0912-4