Antonella Pagliarulo
Durham University, Chemistry, Graduate Student
The enhanced photocatalytic activity for degradation of a wide range of pollutants makes nanostructured TiO2 an ideal candidate for self-cleaning coatings. The deposition of different types of TiO2 nanocrystalline coatings on stone has... more
The enhanced photocatalytic activity for degradation of a wide range of pollutants makes nanostructured TiO2 an ideal candidate for self-cleaning coatings. The deposition of different types of TiO2 nanocrystalline coatings on stone has been investigated in order to test the surface protection and self-cleaning abilities of the nanostructured materials. TiO2 nanocrystals with controlled size, shape and surface chemistry have been prepared by using two distinct synthetic approaches, namely colloidal synthesis by hot injection and hydrothermal nanophase crystallisation. Two different types of stones, possessing different porosity, namely porous calcarenite and a compact limestone have been selected, being both widely used in South Italian monuments and building relevant for cultural heritage. The physical properties of coated and uncoated stone surfaces, respectively, have been investigated, and colour, wettability and stability of the coatings have been checked. The self-cleaning prop...
Rod-shaped TiO 2 nanocrystals (TiO 2 NRs), capped by oleic acid molecules (OLEA), were synthesized with controlled size, shape and surface chemistry by using colloidal routes. They were investigated for application as coating materials... more
Rod-shaped TiO 2 nanocrystals (TiO 2 NRs), capped by oleic acid molecules (OLEA), were synthesized with controlled size, shape and surface chemistry by using colloidal routes. They were investigated for application as coating materials for preserving architectural stone of monumental and archaeological interest, in consideration of their self-cleaning and protection properties. For this purpose, two different deposition techniques, namely casting and dipping, were tested for the application of a nanocrystal dispersion on a defined stone type, as a relevant example of porous calcarenites, namely the Pietra Leccese, a building stone widely used in monuments and buildings of cultural and historic interest of the Apulia region (Italy). The physical properties of the stone surface were investigated before and after the treatment with the prepared nanostructured materials. In particular, colour, wettability, water transfer properties and stability of the coating were monitored as a function of time and of the application method. The self-cleaning properties of the TiO 2 NRs coated surfaces were tested under simulated and real solar irradiation. The obtained results were discussed in the light of the specific surface chemistry and morphology of TiO 2 NRs, demonstrating the effectiveness of TiO 2 NRs as an active component in formulations for stone protection.