title: Characterization of materials released into water from paint containing nano-SiO2.
abstract: In order to assess the possible risks of applications containing engineered nanomaterials, it is essential to generate more data about their release and exposure, so far largely overlooked areas of research. The aim of this work was to study the characterization of the materials released from paint containing nano-SiO2 during weathering and exposure to water. Panels coated with nano-SiO2 containing paint and a nano-free reference paint were exposed to accelerated weathering cycles in a climate chamber. The total release of 89 six-hour cycles of UV-illumination and precipitation was 2.3% of the total SiO2 contained in the paint. Additional tests with powdered and aged paint showed that the majority of the released Si was present in dissolved form and that only a small percentage was present in particulate and nano-particulate form. TEM imaging of the leachates indicated that the majority of the particulate Si was contained in composites together with Ca, representing the paint matrix, and only few single dispersed SiO2-NPs were detected. The results suggest that toxicological and ecotoxicological studies need to consider that the released particles may have been transformed or are embedded in a matrix.
authors.affiliation: Empa, Swiss Federal Laboratories for Material Science and Technology, Laboratory for Analytical Chemistry, Überlandstrasse 129, 8600 Dübendorf, Switzerland; Empa, Swiss Federal Laboratories for Material Science and Technology, Technology and Society Laboratory, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Al-Kattan
authors.affiliation: Empa, Swiss Federal Laboratories for Material Science and Technology, Laboratory for Analytical Chemistry, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Wichser
authors.affiliation: Empa, Swiss Federal Laboratories for Material Science and Technology, Laboratory for Building Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
authors.forename: Roger
authors.initials: R
authors.lastname: Vonbank
authors.affiliation: Empa, Swiss Federal Laboratories for Material Science and Technology, Laboratory for Building Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
authors.forename: Samuel
authors.initials: S
authors.lastname: Brunner
authors.affiliation: Empa, Swiss Federal Laboratories for Material Science and Technology, Laboratory for Analytical Chemistry, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
authors.forename: Andrea
authors.initials: A
authors.lastname: Ulrich
authors.affiliation: Venice Research Consortium, Via della Libertà 12, c/o VEGA Park, 30175 Venice, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zuin
authors.affiliation: Empa, Swiss Federal Laboratories for Material Science and Technology, Electron Microscopy Center, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
authors.forename: Yadira
authors.initials: Y
authors.lastname: Arroyo
authors.affiliation: CEA Commissariat à l'Energie Atomique et aux Energies Alternatives, rue des Martyrs 17, 38000 Grenoble, France.
authors.forename: Luana
authors.initials: L
authors.lastname: Golanski
authors.affiliation: Empa, Swiss Federal Laboratories for Material Science and Technology, Technology and Society Laboratory, Lerchenfeldstrasse 5, CH-9014 St. Gallen, Switzerland. Electronic address: nowack@empa.ch.
authors.forename: Bernd
authors.initials: B
authors.lastname: Nowack
mesh_terms: D049329:Nanostructures / Q000032:analysis* / Q000737:chemistry; D010150:Paint / Q000528:radiation effects; D012822:Silicon Dioxide / Q000032:analysis* / Q000737:chemistry; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D014874:Water Pollutants, Chemical; D014867:Water; D012822:Silicon Dioxide
keywords: Electron microscopy; Engineered nanomaterials; Release; Weathering