An extensive research about nano-treatments for the restoration and conservation of stone monuments in Europe considering representative lithotypes

A systematic research was developed in European countries regarding the use of nano-structured suspensions in stone monuments for their consolidation and protection. The treatments were based on nanoparticles suspended in water or alcohol, also in combination with alkoxy silanes. Five cathedrals, in different climatic contests, and one contemporary building were involved in the validation of products. The effectiveness evidenced not only a dependence on the lithotype, but also on environmental constrains. In general, the nano-particles presence enhanced the capacity of the treatments to adhere to stone grains, thus contributing to their effectiveness