Some of the most endangered artworks are the historical and archaeological copper-based artefacts. In fact, it is known that the nature of the corrosion products present on the surface of copper alloys is intrinsically related to the environmental context (atmospheric or burial). In order to effectively protect and inhibit the corrosion of these artefacts, the practices adopted should take into account the nature of the patina and its corrosion behavior.
However, the treatments so far employed are organic protective coatings or inhibitors, which do not consider the difference in terms of patina composition and corrosion products stability and simply create a passive barrier against aggressive environments in a non-selective way. Moreover, some toxic inhibitors pose potential threats to human health and to the environment.
The objective of the project is to propose an alternative biological treatment for the conservation-restoration of copper alloys artefacts. Taking advantage of unique properties of carefully selected fungal species, the project relies on the conversion of existing corrosion patinas into copper oxalates. In fact, thanks to their insolubility and stability even in acidic atmospheres, copper oxalates provide the treated objects with long-term protection and no aesthetical alteration.
The different activities of the BIOPATINAS project will allow to standardize a biological protective treatment with the aim of creating protective patinas on artworks of copper alloys. Particular attention will be devoted to the efficacy, compatibility and impact on color of the innovative treatment to overcome the problems associated with the treatments in use nowadays.
To reach our goals, the treatment under development is:
- Proof-tested under ageing conditions through the exposure of standards coupons real objects to aggressive weather conditions (especially true for outdoor objects),
- proof-tested for the appearance of the treated object, resistance to corrosion and cohesion of the biopatina onto the object’s surface,
- standardized to become (and be perceived as) simple and efficient for all uses and consumers.
What is special about the project?
The environmentally-friendly use of microorganisms for restoration of metal artworks as proof-tested in this project, could present a breakthrough innovation for the conservation industry. After initial successful attempts (FP6-Eu-ARTECH, 2004-2009 and FP7-BAHAMAS, 2010-2012), the efficacy of the fungal treatment will be improved and validated against ageing procedures. The project should provide conservation professionals with access to a simple-to-use, reliable, versatile, environment-friendly and low-cost technology, for art objects, archaeological objects, architectural components, etc.
The project started on 2013-05-01 and has duration of 3 years.
The activities and milestones foreseen are summarized in the following table:
Task 1: Selection of real objects to be used as prototypes for the experimentations. Milestones: identification, selection and documentation of real objects for testing
Task 2. Surface characterization and treatment’s application. Milestones: Characterization of the objects’ patinas, definition of the application procedures, in situ application of the treatment
Task 3. Evaluation of treatment’s performance, efficiency and durability. Milestones: Characterization of the biopatinas, definition of the ageing sites, monitoring of biopatinas’ performances
During the project all the defined tasks were successfully achieved. The treatment durability has been proved over 1-year natural ageing as well as its aesthetical appearance and corrosion resistance. For this, artificially patinated coupons simulating contemporary bronze artworks covered by foundry patinas were used. The experiments allowed to improve the application procedure as well as better understand the interaction in place and the behavior of treatment during time. Furthermore, the treatment efficiency and application ease have been tested on several real monuments in collaboration with conservators-restorers giving very promising results for its real practice. As final result an easy-to-use kit is now available for conservators-restorers to be used on real artworks.
M. Albini, C. Chiavari, E. Bernardi, C. Martini, L. Mathys, P. Letardi, P. Junier and E. Joseph. Evaluation of the influence of alloying elements on the performances of a biological treatment. In METAL 2016 Interim Meeting of the ICOM-CC Metal Working Group Conference Proceedings. New Delhi, India, 16th-20th September 2016. In press;
M. Albini, C. Chiavari, E. Bernardi, C. Martini, L. Mathys, E. Joseph. Evaluation of the performances of a biological treatment on tin-enriched bronze. Environmental Science and Pollution Research. Submitted;
Azéma A., Texier A., Joseph E., Junier P., 2016. Paris (1er) - (Île-de-France). Colonne Vendôme (XIXe siècle). Essais de biopatine : compte rendu. LRMH Report n° R1364B, February 2016;
M. Albini, L. Comensoli, W. Kooli, P. Junier, and E. Joseph. Microorganisms for safeguarding cultural heritage. International Journal of Conservation Science, 2016.In press;
E.Joseph, S. Bindschedler, M.Albini, L.Comensoli, W. Kooli, L. Mathys. Microorganisms for safeguarding built heritage. The Fungal Community: Its Organization and Role in the Ecosystem, Eds. J. Dighton, J. White, P. Oudemans CRC press Taylor and Francis group, 2016. In press;
M. Albini, L. Comensoli, L. Brambilla, E. Domon Beuret, W. Kooli, L. Mathys, P. Letardi, E. Joseph. BIOPATINAS: Innovative biological approaches for metal conservation. Materials and Corrosion 2015, doi:10.1002/maco.201408168;
E.Joseph, P. Junier, M. Albini, P. Letardi, E. Domon Beuret, L. Brambilla, L. Mathys, C. Cevey, R. Bertholon. Biologically induced patina for metal built heritage. In Conference Proceedings of Scienza e Beni Culturali, Metalli In Architettura: Conoscenza, Conservazione e Innovazione. Bressanone, Italy, 30th June - 3rd July 2015. Edizione Arcadia Ricerche s.r.l., Marghera Venezia, 2015; ISBN 9788895409191, 273-282;
E. Joseph, M. Albini, P. Letardi, E. Domon Beuret, L. Brambilla, L. Mathys, C. Cevey, R. Bertholon, D. Job, P. Junier. BIOPATINAS: Innovative biological patinas for copper-based artefacts. In Conference Proceedings of Outdoor Metallic Sculpture from the XIXth to the Beginning of the XXth Century: Identification, Conservation, Restoration. Paris, France. 4th-5th December 2014. ICOMOS France, Paris, 2014; ISBN 9782905430182, 154-162;
E. Domon Beuret, L. Mathys, L. Comensoli, L. Brambilla, M. Albini, C. Cevey, R. Bertholon, P. Junier, E. Joseph. Biopatines: des champignons au service des alliages cuivreux. In Conference Proceedings of JOURNEES DES RESTAURATEURS EN ARCHEOLOGIE 2014 « restaurer l’ordinaire, exposer l’extraordinaire : du site au musée » Arles, France. 16th-17th October 2014. Atelier de Conservation-Restauration du Musée Départemental Arles Antique (MDAA) et A-CORROS, Arles, 2014; Cahier technique de l'ARAAFU 2015, 22, 45-48;
E. Joseph, P. Letardi, M. Albini, L. Comensoli, W. Kooli, L. Mathys, E. Domon Beuret, L. Brambilla, C. Cevey, R. Bertholon, D. Job, P. Junier. Innovative biological approaches for metal conservation. In Conference Proceedings of EUROCORR 2014, European Corrosion Congress. Pisa, Italy. 8th-12th September 2014. DECHEMA e.V., Frankfurt and AIM – Associazione Italiana di Metallurgia, Milano, 2014; ISBN 9783897461598, 1-10.
On the occasion of a pilot test performed in association with the City of Neuchâtel, a press release was published. Radio and television media were present and relayed the information on different supports: RTN la matinale, RTS La 1ère-CQFD, Express/Impartial, Courrier Neuchâtelois, Vivre la Ville, CanalAlpha, SDA, NZZ, Tages Anzeiger, Schweizerbauer. In 2014, on Le Temps 19.04.2014, Uninews n°33
In 2015, in occasion of the tests on the Colonne Vendôme, a press release was published. Radio and television media relayed the information: ATS, RTN, 24 heures, Express/Impartial, 20 minutes, Sweizerbauer, Tagesanzeiger, SDA, Der Bund.
Persons involved in the project
Last update to this project presentation 17.10.2018