The cathedral of Cuernavaca City, Mexico is one of the earliest monuments built in the American Continent by the Spanish Conquerors. The cathedral lodges a collection of historic artifacts including eight bells. The aim of this study was to provide preliminary information for the conservation diagnosis of the historic bells. A set of three bells dating back to the nineteenth century was studied. Two of the bells present a crack and the third and oldest remains complete. Metallurgical characterization and electrochemical evaluation were used to describe the behavior of the patinas formed on the surfaces of the bells. Studies were done ''in situ'' over the surface of the artifacts. Preliminary experiments were carried out using a modern cast bronze with equivalent chemical composition. Besides the useful information for conservation purposes, the work depicts the behavior of an ancient material exposed to the atmosphere for a long period of time. The obtained data suggest a relationship between alloy composition, especially tin and lead content and electrochemical properties of the materials. Techniques used include potential measurements as function of time, potentiodynamic polarization curves, electrochemical impedance spectroscopy, electrochemical noise as well as metallography.

Acrylonitrile-butadiene-styrene (ABS) is a well-known discard product from the industry. This copolymer can be dissolved in organic solvents, and thin films can be created by immersion. Two requirements for coatings used for cultural heritage conservation purposes are transparency and reversibility, both fulfilled by ABS films. The aim of this work was to characterize the copolymer and to evaluate the electrochemical properties of ABS coatings applied to copper. Such performance was compared to that of a commercial varnish commonly used in conservation. The results indicate high protection values of the ABS film, generating a potential application for this waste material. The electrochemical techniques included electrochemical noise, impedance spectroscopy, and potentiodynamic polarization.

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Nanofibers have very well known applications in several fields like medicine, textile industry and energy systems. They can be produced by different techniques including electrospinning. In this work, a process for obtaining TiO2 cerium and iron TiO2 nanofibers with a mesoporous structure was performed in order to produce coatings and evaluate their properties. The formation of porous structures using titania, mixed titania/ceria and mixed titania/iron oxides precursor solutions was achieved with a polymer gel templating technique. The nanofibers were prepared with a sol–gel solution containing a mixture of poly (vinyl pyrrolidone) [PVP, Mw 1 300 000], titanium tetraisopropoxide [Ti(O-i-Pr)4], a triblock copolymer Pluronic F127, cerium(III) nitrate hexahydrate [Ce(NO3)3∙6H2O] and iron oxides using the electrospinning technique. The synthesis process was carried out afterward to promote the crystallization and phase transformation to anatase, as well as to remove the polymer via calcination in air at 500 °C. Scanning electron microscopy (SEM) revealed the average diameters of the resulting nanofibers were in the 70 nm to 200 nm range, depending on the preparation conditions. The aim of this work was to evaluate the electrochemical behavior of TiO2, cerium and iron TiO2based nanofibers coatings applied to copper and copper alloys surfaces. In order to achieve this goal, an experimental procedure was designed which allowed to simulate the degradation of the coatings in corrosive environments. The techniques used included electrochemical noise measurement, electrochemical impedance spectroscopy and potentiodynamic polarization.