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.

A colloidal route was exploited to synthesize TiO2 anisotropic nanocrystal rods in shape (TiO2 NRs) with a surface chemistry suited for their dispersibility and processability in apolar organic solvents. TiO2 NRs were dispersed in chloroform and n-heptane, respectively, and the two resulting formulations were investigated to identify the optimal conditions to achieve high-quality TiO2 NR-based coatings by the spray-coating application. In particular, the two types of TiO2 NR dispersions were first sprayed on silicon chips as a model substrate in order to preliminarily investigate the effect of the solvent and of the spraying time on the morphology and uniformity of the resulting coatings. The results of the SEM and AFM characterizations of the obtained coatings indicated n-heptane as the most suited solvent for TiO2 NR dispersion. Therefore, an n-heptane dispersion of TiO2 NRs was sprayed on a highly porous limestone—Lecce stone—very commonly used as building material in historic constructions and monuments present in Apulia Region (Italy). A comprehensive physical-chemical investigation of the TiO2 NR based treatment on the surface of the stone specimens, including measurements of colour variation, static contact angle, water transfer properties, and morphological characterization were performed. Finally, the photocatalytic properties of the coatings were assessed under solar irradiation by using Lecce stone specimens and Methyl Red as a model target compound. The obtained results demonstrated that TiO2 NRs based coatings can be successfully applied by spray-coating resulting in an effective photocatalytic and hydrophobic treatment, which holds great promise as a material for the environmental protection of architectural stone in the field of cultural heritage conservation.

The controlled functionalization of polymers via anionic polymerization draws great attention not only because of the importance of introducing functionality into otherwise unfunctionalized polymers, but also because of the possibility to use the resulting macromonomers to make a variety of complex architectures. The versatile family of 1,1‐diphenylethylene (DPE) derivatives is widely used to produce many different functionalized (co)polymers. DPE can be added either as an end‐capping agent or be activated by butyllithium to initiate the polymerization. However, each approach faces potential problems in gaining precise control over the number of DPE moieties per chain. In this work, for the first time, the effectiveness of each approach is compared by the characterization of 1,1‐bis(4‐tert‐butyldimethylsiloxyphenyl)ethylene functionalized polystyrene, synthesized via both the procedures. A combination of NMR, size exclusion chromatography, matrix‐assisted laser desorption ionization‐time of flight (MALDI‐ToF) mass spectrometry, and interaction chromatography is used. To overcome the limitations of DPE derivatives, the use of a novel (protected) bisphenol F potassium initiator is proposed.