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RESEARCH PRODUCT

The effects of a saline environment on the durability of commercial photocatalytic paints

subject

description

The use of photocatalytic products for surface coating of buildings ensures the reduction of certain air pollutants and greater duration of color over time, due to the reduced attitude of air particulate to adhere to the treated surfaces. The world market is producing a wide range of coatings, transparent and opaque, high initial performance, but there is a lack of data on their durability. The knowledge of performance over time of these new products is at the basis of the Regulation (EU) no. 305/2011, which repealed Council Directive 89/106/EEC and introduced the seventh requirement regarding the sustainability and particularly durability of construction works. This study focuses on the assessment of the durability of photocatalytic commercial paint, in three hues: white, red and yellow, based on TiO2 dispersion into inorganic resins. The methodology is based on the ISO 15686 and consists in the comparison of the most significant parameters considered, monitored during accelerated aging tests, into saline environment, by means of dry corrosion test cabinet, and natural aging in the atmospheric environment of the city of Palermo, characterized by marine aerosol. The monitored parameters were: surface morphology, by means of SEM and optical microscopy; color by means of spectrophotometer; photocatalytic activity, by means of isopropyl alcohol degradation. Chemical characterization test by means of diffractometer were also performed. The results obtained allow carrying out useful correlations to define the performance limits of photocatalytic paint over time. Monitoring was carried our for six months to the effects of degradation agents of atmospheric environment and for four steps of accelerating aging into dry corrosion test cabinet, according to the standardised natural stone test method of UNI EN ISO 14147:2005, adopted for coatings