Sustainable nanohybrid materials as multifunctional treatments for cultural heritage

Cultural heritage conservation increasingly demands sustainable solutions that combine effectiveness with minimal environmental impact. This thesis investigates the development of sustainable nanohybrid materials, focusing on the cleaning and stabilization of artworks and historical surfaces. Drawing from principles of physical chemistry, the research presents new sustainable alternative materials based on biopolymers, bio-derived active compounds, gel formulations, and nanoclays. These hybrid systems were engineered to offer tunable mechanical, chemical, and rheological properties, suitable for targeted applications on delicate substrates. Their multifunctionality lies in the integration of cleaning and protective actions within a single platform, enabled by synergistic interactions between the organic and inorganic phases at the nanoscale. The developed materials were thoroughly characterized using a range of analytical techniques, including optical and fluorescence microscopy, scanning electron microscopy (SEM), Raman and FTIR spectroscopy, thermogravimetric analysis (TGA), rheological measurements. These methods provided insights into the morphology, thermal stability, viscoelastic behaviour, and molecular interactions of the systems, both in their pristine state and after application to model substrates. Afterwards, each system was then tested on mock-ups and real artworks to evaluate the effectiveness, compatibility, and safety of the treatments under realistic conservation conditions. These application studies confirmed the performance and adaptability of the materials across different conservation scenarios. The results demonstrate the potential of these eco-designed nanohybrid materials to meet the requirements of cultural heritage conservation, offering an environmentally responsible alternative to conventional restoration practices. The research was mostly conducted at the Department of Physics and Chemistry (DiFC), University of Palermo (UNIPA). An additional research period was carried out between the Microchemistry and Microscopy Art Diagnostic Laboratory of Ravenna and the Chemistry Department “Giacomo Ciamician”, University of Bologna (UNIBO). Furthermore, a six-month international research stay was undertaken at the Haute-Ecole Arc, Neuchatel, Switzerland, within the framework of the GoGreen European project. The outcomes of this work have been disseminated through peer-reviewed articles already published in ISI journals, with other further manuscripts currently in preparation and under submission.