PhD in Technologies for Cultural Heritage - since XXXVI Cycle

Contacts

Supervisor

Dominique Scalarone

Curriculum vitae

Curriculum Vitae

Phd thesis

Innovation in laser cleaning for cultural heritage: increasing the knowledge of active fiber laser systems and optimising the use of Er:YAG systems with chemical agents
The aim of this PhD research is to explore the uses and the potentialities of the new active fibres systems in the field of cultural heritage and deepening the knowledge on the Er:YAG laser systems.

The lasers that will be studied are the active fiber laser Smart 300 (El.En) and the Er:YAG laser Light Brush 2 (El.En).

Research activities

Biography

Marina has obtained a master degree in Conservation and Restauration of Cultural Heritage, with specialization on stone materials, mosaics, plaster and decorated surfaces of architecture at the University of Turin. She graduated with a thesis on the conservation of a fragmented and repainted gypsum statue by Salvatore Saponaro, working on the cleaning, the recomposition and the creation a new structure for the exposition. Main part of the research was focused on the cleaning, with a long series of tests that ended in selecting the active fiber lasers as optimal for the removal of the altered overlapping layers.

Doctoral Thesis Research Topic

The aim of the PhD research is to explore the uses and the potentialities of the new active fibres systems in the field of cultural heritage and deepening the knowledge on the Er:YAG laser systems.

Indeed, the intention is to widen the knowledge on the applicability of laser technology in the field on cultural heritage, above all on the removal of overlapping layers from polychrome artifacts, with a particular focus on the roman frescos. The artworks that have been selected for this doctoral thesis are some fresco fragments from the roman period that come from excavation in Cremona, in Via Colletta.

A core part of the research is the study of active fiber lasers, with the aim of understanding how they interact with materials and favoring their use in the conservation field. Hence, part of the research is being focused on characterizing the laser. This phase involves the comprehension of which are the
different selectable parameters, how they influence the cleaning and how the laser interacts with materials.

For what concerns the Er:YAG laser, the state of art on the knowledge on this type of laser underlines the necessity to complete the cleaning after the laser irradiation with chemical agents. Aim of this doctoral research will be to perform an organic study on the most suitable chemical agent, according to the substrate and the material to be removed.

Methodology:

The first part of the study is meant to characterize the active fiber lasers. Thus, the aim is to understand the selectable range of the parameters and how each one influences the total energy and the power emitted. A second phase of the research is instead to be done on mock-ups especially prepared and is focused on the study of the influence of each parameter on the type of cleaning performed (photomechanical, photothermal, etc.). To perform this characterization the Design of Experiment (DOE) will be used. Analytical analysis such as FTIR, XRF, Py-GCMS together with colorimetric measurements and stratigraphy images will be used to control the results of the cleaning. Last but not least, the aim of this is to provide a contribution to the understanding of the effects induced by laser irradiation on materials and on the transformation it induces on the surface.

Some fragments of roman frescos rediscovered from an archaeological roman site at Cremona have been selected for this study and will be used to test the potentialities of the lasers on excavations materials where loss of cohesion is observed. To characterize the pigments and eventual binders, these fragments have been investigated through Fourier transform infrared spectroscopy and portable X-Ray Fluorescence spectroscopy.

Supervisors

Dominique Scalarone, Chemestry Department

Co-Supervisors:

Marie Claire Canepa, Francesca Zenucchini, Centro di Conservazione e Restauro La Venaria Reale

Alessandro Zanini, El.En. Group S.p.A

Training

PhD T4C courses (2023-2024):

• Trans-disciplinarity through the digital sciences, Coordinator Prof. Vincenzo Lombardo,

• Materiality, Coordinator Prof. Monica Gulmini

• Humans vs Geomorphological Environments: Concepts and Case studies, Coordinator Prof. Marco Giardino

• Condition assessment, analytical protocol and preservation strategies, Coordinators: Prof. Dominique Scalarone; Prof. Sergio Favero Longo

• Imaging techniques, Coordinators: Prof. Alessandro Re; Prof. Vito Messina

• Workshop: China and chinoiseries, Coordinator: Prof. Eliano Diana

Schools:

• Optical Microscopy School for the applications on the field of Cultural Heritage, Centro di Conservazione e Restauro La Venaria Reale, Venaria Reale (TO), 9^th – 11^th October 2023

• School of Infrared Spectroscopy and Raman for the applications in the field of Cultural Heritage, Centro di Conservazione e Restauro La Venaria Reale, Venaria Reale (TO), 11^th – 15^th November 2023

• Laser application in the field of Cultural Heritage, Centro di Conservazione e Restauro La Venaria Reale, Venaria Reale (TO), online classes

Congress: APLAR 8, Laser application in the conservation, Naples, 13^th – 15^th December 2023

Period at El.En Company: It has been possible to perform the preliminary characterization of the laser, thanks to the conversation with the engineers and the physics that have built the lasers, as it has been illustrated above. Moreover, an interesting part has been the possibility to test the Smart 300 laser on case-studies. Indeed, I followed them in some try-out they performed for various conservators that had very specific conservative problems.