Self-cleaning and antifouling nanocomposites for stone protection: properties and performances of stone-nanomaterial systems

Nanocomposites combining photocatalytic, antifouling, and protective properties show promise for stone conservation. A study within the EU-Horizon 2020 project 'Nano-Cathedral' developed innovative treatments using nanoparticles (TiO₂, Ag, ZnO), solvents, and silane/siloxane-based matrices applied to six lithotypes from five medieval cathedrals—including Cologne Cathedral—and a contemporary structure. These treatments demonstrated surface compatibility, reduced water absorption, altered wettability, and maintained water vapor permeability while exhibiting strong photocatalytic and antifouling properties. Accelerated ageing tests confirmed the stability of polymeric matrices even with photoactive TiO₂, suggesting durable performance for stone protection.

Roveri, M., Gherardi, F., Goidanich, S., Gulotta, D., Castelvetro, V., Fischer, R., Winandy, L., Weber, J., & Toniolo, L. (2018). Self-cleaning and antifouling nanocomposites for stone protection: properties and performances of stone-nanomaterial systems. IOP Conference Series: Materials Science and Engineering, 364, 12070. https://doi.org/10.1088/1757-899x/364/1/012070