0000000000129404
AUTHOR
María Del Carmen Bouzas
Application of Modified Tafel Analysis to the Identification of Corrosion Products on Archaeological Metals Using Voltammetry of Microparticles
Voltammetry of microparticles is applied to the identification of lead corrosion products by means of an essentially non-invasive 'one-touch' technique based on the use of graphite pencil. This methodology permits the mechanical attachment of few nanograms of sample from the surface of lead archaeological artefacts to a paraffin-impregnated graphite electrode, which, upon immersion in aqueous electrolytes, provides distinctive voltammetric responses for litharge and cotunnite- anglesite-, cerusite-based corrosion products. The reported method is applied to the identification of corrosion products in archaeological lead pieces from different Iberian sites in Valencia (Spain). © 2011 WILEY-VC…
Modeling Corrosion of Archaeological Silver-Copper Coins Using the Voltammetry of Immobilized Particles
Two complementary models to describe the long-term corrosion of silver-copper coins, based on potential rate laws for smooth corrosion and those combined with diffusive law, for gross corrosion, are proposed. Theoretical kinetics can be tested using signatures of copper and silver corrosion products using the voltammetry of immobilized particles technique. The method is applied to silver coins minted during the 13th–14th centuries from the Libertad street hoard in Valencia (Spain) using non-invasive one-touch graphite pencil sampling. Voltammetric features yield functional dependences in agreement with the proposed model potentially useful for distinguishing between different mints.