Abstract

Use of electrochemical measurements and surface analysis for the evaluation of the protective properties of 3-phenyl-1,2,4-tiazole-5-thione formulation of metallic cultural heritage

Author(s): Ahmed Dermaj, Driss Chebabe*, Najat Hajjaji, Vincent Vivier

In this work a formulation of a new organic compound, namely 3-phenyl- 1.2.4-triazole-5-thione, was tested as a bronze corrosion inhibitor. This formulation (FPTS) has proven to be environmentally friendly, cheap and easy to use. The inhibitory effect of this formulation has been studied on commercial bronze (B66)with chemical composition,metallurgical features and micro-chemical structure similar to that of the ancient alloys installed in museumof Rabat (capital ofMorocco) near the atlantic ocean, in order to be successfully employed and used for testing corrosion inhibitor validating cleaning and conservation techniques. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, Scanning Electron Microscopy coupled with chemical analysis (SEM and EDAX) and X-ray photoelectron Spectroscopy were used to study the inhibition action of FPTS in 3% NaCl. The obtained results show that the FPTS formulation has a significant effect against corrosion of B66 bronze in 3% NaCl solution, reaching an efficiency of 99% at 5.10-3M. This result encouraged us to test this formulation on real archaeological objects. The evaluation of the protective effect of FPTS on archaeological bronzes shows that it provides good protection of the Bronze artefacts against atmospheric corrosion for a long duration of exposure.