Leaching of nanoparticles from experimental water-borne paints under laboratory test conditions

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology 2014, Vol.16 (1), p.1-17, Article 2185
• Main Authors: Zuin, Stefano, Gaiani, Marco, Ferrari, Arlen, Golanski, Luana
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Inorganic Chemistry; Laboratory tests; Lasers; Leachates; Leaching; Materials Science; Nanoparticles; Nanotechnology; Optical Devices; Optics; Paints; Photonics; Physical Chemistry; Research Paper; Silica; Silver; Titanium dioxide; Ultraviolet radiation
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-013-2185-1

In this study we investigated the release of titanium dioxide (TiO 2 ), silver (Ag) and silica (SiO 2 ) engineered nanoparticles (ENPs) from three different paints by using standardized water immersion test for coatings. Fibre-cement panels were coated with paints containing ENPs and then exposed to UV light and abraded to simulate weathering. After the static water immersion test, we observed a very low release of Ti (4–8 μg/l), while the Ag measured in leachates was under detection limit (0.1 μg/l). A small release of Si was measured in leachates, with 73 mg/l of Si released from paints containing SiO 2 ENPs after 120 h of water immersion. The cumulative loss of Si was about 1.8 % with respect to initial amount of Si in paint. Microscopic results highlighted that SiO 2 ENPs are mainly released in form of agglomerates with other particles, and only very few single SiO 2 ENPs were found in leachates. The results confirmed that Si migration is related to immersion cycles (wetting and drying cycles) of tested paints.