The Oslo Opera House – Condition Analysis and Proposal for Cleaning, Protection and Maintenance of Exterior Marble

The photo-oxidative degradation of the polymers applied in the past onto the marble slabs of the Oslo Opera House (OOH) led to the yellowing of the coatings and/or to the formation of insoluble fractions of polymer. Despite the high reduction of the b* parameter (yellowness) observed after the mechanical abrasion, this cleaning treatment cannot be recommended for further application, due to the unacceptable removal of structural material during the abrasion. Cleaning of historic masonry has progressed significantly in recent years, thanks to methods that rely on nanoscience. Therefore, in this research project instead of using organic solvents exhibiting toxicity and poor performance, advanced nanostructured fluids, such as micelles solutions (MC) and microemulsions (ME), embedded in nanogels with industrial solvents were tested aiming at the efficient removal of the hydrophobic coatings from Carrara marble slabs. These nanogels are amphiphilic-based formulations using a system of water, oil and surfactant. However, lack of reproducibility characterized the application of these advanced nanogels, due to partly removal of the unevenly distributed polymer products. Therefore a three-step cleaning methodology was adopted including: the introduction of a chelating agent capable of dissolving the hard film created by the applied coatings, thus allowing any subsequent MC and ME solutions applied in the second step, to swell the polymeric chains and to facilitate their removal, which was further completed by suitable oxidants. Optical and scanning electron microscopy coupled with EDX, along with colorimetric measurements proved that the three-step cleaning tests applied to yellowed samples can successfully remove the colour discoloration

Inkjet printing of photocatalytically active TiO2 thin films from water based precursor solutions

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Efficient and environmentally friendly ink-jet printing of ceramic thin films

The objective of this study is to develop a cost-effective and environmentally friendly synthesis using soft chemistry based on Chemical Solution Deposition (CSD) using ink-jet printing for the deposition of ceramic thin films. The main advantages are the lower investment, the faster deposition with higher yield and the processing under ambient pressure enabling a complete continuous processing. The materials chosen for this study are TiO2 for development of photocatalytic layers; Yttria-stabilized zirconia (YSZ) is chosen as electrolyte material for Solid Oxide Fuel Cells (SOFC's) and for production of Thermal Barrier Coatings (TBC's); Lanthanum-Strontium-Manganese-Oxides (LSMO) magneto-resistive systems have been developed for obtaining functional magneto-resistive patterns