Investigation of Volatile Binding Media in temporary consolidation of archaeological materials

Project Information

VOLATILE4ARCHAEO

Grant agreement ID: 101031224

DOI

10.3030/101031224

Project closed

EC signature date 23 April 2021

Start date 1 October 2021

End date 30 September 2023

Funded under

• EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions

Total cost

€ 183 473,28

EU contribution

€ 183 473,28

Coordinated by

ALMA MATER STUDIORUM - UNIVERSITA DI BOLOGNA
Italy

Periodic Reporting for period 1 - VOLATILE4ARCHAEO (Investigation of Volatile Binding Media in temporary consolidation of archaeological materials)

Reporting period: 2021-10-01 to 2023-09-30

Summary of the context and overall objectives of the project

Cultural heritage (CH), including museum collections, architectural elements, and historical sites, is exposed to several risks, as natural hazards, climate change, floods, fires, earthquakes, and damages during conflicts. During these situations, the artifacts suffer total or partial losses, being fragile and vulnerable, with a serious risk of losing them forever. Temporary consolidation is a powerful tool for risk management of heritage materials via introducing a new material that restores objects' physical integrity. This consolidation is needed during high-risk steps, as excavation and safe transport to conservation laboratories or in museums. During excavation, there is also a risk of environmental shock, which can damage the artifacts dramatically, and the lack of appropriate temporary stabilization has led to extensive material loss. Same risk is experienced when water-based treatments, such as cleaning and desalination, must be performed too. Traditional polymers are not satisfactory for temporary consolidation, as their reversibility by removal with solvent is never complete and may cause irreversible damages.

The project VOLATILE4ARCHAEO focused on investigating several Volatile Binding Media (VBM) and selected mixes for temporary consolidation and protection of cultural heritage. VBM are waxy solids that sublime (pass directly from solid to gas) at room temperature. VBM simply disappear by evaporation, making the removal by solvents, heat, and mechanical action obsolete. Subliming consolidants give solutions during detachment of mural painting, desalination of water-sensitive painted objects, lifting fragile wood, handling ethnographic objects, cleaning paper. So far, the employment of VBM was limited almost only to cyclododecane (CDD), which however exhibits several drawbacks in terms of low flash point, fixed sublimation speed, hazardousness, limited availability, etc. The research on alternatives to CDD is still extremely limited, so the main goal of VOLATILE4ARCHAEO was to contribute to fill this gap of knowledge.

VOLATILE4ARCHAEO pursued three main objectives:
1. Significantly advancing the understanding of the physical-chemical behavior of subliming compounds when used to consolidate different substrates
2. Investigating new types of VBM to temporarily strengthen mural paintings, stone and ceramic materials
3. Validating the most promising VBM for conserving real historical artifacts.

The results are expected to contribute to the conservation of Cultural Heritage, saving original materials from irreparable damages or even complete loss during excavation and/or conservation treatments.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The work performed in the project is divided into five work packages (WP).
WP1 focused on Objective 1 and concerned the characterization of VBM. Five VBM and fifteen mixes were selected to investigate their properties, including cyclododecane, cyclododecanone, cyclododecanol, camphene, menthol, and mixes. The selection of the pure VBM was made based on their melting point, sublimation, flashpoint, compatibility, and health-related issues. The workability of the melted mixes was first considered, while their characterization was carried out by DSC, TGA, FT-IR, XRD, microscope.
The melted VBM were applied on different substrates, including Lecce limestone, Carrara marble and glass slide, to monitor their sublimation speed at 20°C and 30°C, in view of real applications. The presence of residue was investigated after sublimation to detect possible chemical reactions between VBM and substrates. No residues were found by FT-IR, but some small spots of remains were found by fluorescent microscopy.
WP2 focused on assessing the behavior of the most promising VBM and mixes on artificially deteriorated painted pottery, painted mortar, painted plaster, and limestone (objective 2). The penetration depth of the consolidants was assessed on substrates and sands. The binding capacity of the products was investigated by measuring the compressive strength of mixes of VBM and sand.
WP3 focused on the practical application of the selected VBM to 3 real archaeological and historical elements, in Bologna and in Marseille.
WP4 focused on Management and Dissemination. The Project Website was successfully launched in December 2021 (https://site.unibo.it/msca-volatile4archaeo/en) and will be kept active for at least until Sept. 2024.
The Dissemination was addressed to different target audiences:
1) Dissemination to researchers of the University of Bologna and CICRP
2) Dissemination to conservators, researchers and companies in two workshops “Volatile Binding Media for Temporary Consolidation of Archaeological Materials” organized within the project at the University of Bologna, Italy (5th July 2023) and at the Italian Archaeology Center in Cairo, Egypt (26th September 2023)
3) Oral presentation at the 51st AIC Annual Meeting in Jacksonville, Florida, in 2023
4) Publications in peer-reviewed journals (in progress)
- Hamada Sadek Kotb, Andrea Saccani, Elisa Franzoni, “Volatile Binding Media for Temporary Consolidation of Cultural Heritage materials: Characterization of Alternatives to Cyclododecane”, submitted
- Hamada Sadek Kotb, Andrea Saccani, Jean-Marc Vallet, Elisa Franzoni, "New materials for temporary consolidation of cultural heritage: investigating single and blended volatile binding media”, submitted
- Hamada Sadek Kotb, Jean-Marc Vallet, Elisa Franzoni, “Assessment of the effectiveness and compatibility of volatile binding media for temporary consolidation cultural heritage materials”, to be submitted.
5) Dissemination to the conservators’ community, through a Technical report:
- Hamada Sadek Kotb, Elisa Franzoni, “The VOLATILE4ARCHAEO project: A technical report for conservators”, p. 1-18, 2023, deposited in the repository “AMSActa Institutional Research Repository”, with CC BY-NC 4.0 license, URL: https://amsacta.unibo.it/id/eprint/7439

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The results obtained in the project represent a significant step beyond the state-of-the-art in the field of temporary consolidants for archaeological objects and architectural surfaces. The wide range of properties achieved by the development of the new VBM suggests that these materials can be used in the future in different climatic conditions and for different applications, some of which are presently still not carried out.

The improved knowledge of the VBM’s behaviour and properties and the new developed materials and blends for temporary consolidation are expected to generate an impact at different levels:
- Improved protection of cultural heritage materials from damage or complete loss, through the availability of a range of different formulations exploitable as temporary consolidants
- Improved working conditions for conservators, through a more in-depth knowledge of the properties of VBM, their health-related issue and protection measures
- Improved excellence in science, through the achievement of new knowledge on VBM, which paves the way to new research lines
- Improved visibility of EU as a leader in the research on VBM, through the expertise achieved by the two Institutions involved (UNIBO and CICRP).

The impact of the results is expected to be boosted by communication and dissemination activities carried out in the project towards different target audiences.

Speakers and some participants to the workshop in Cairo (26th September 2023).

Figure 13. Participation in the 51st AIC annual conference in Jacksonville, Florida, USA (16-20 May

News in Conservation issue 88 Febraury March 2022