Relargage de dioxide de titane nanoparticulaire dans les milieux environnementaux à partir de nanomatériaux

Olivier Aguerre-Chariol (1) , Christophe Bressot (1)

1 INERIS - Institut National de l'Environnement Industriel et des Risques

The increasing use of nano-sized titanium dioxide in various building materials raises the question of the possible release of nanoparticles over the lifecycle of these materials. Ineris has completed two studies on this topic: a first on the characterization of the release of aerosols under mechanical stress, the second on the release of particles in water by building materials during leaching experiments. Self-cleaning tiles covered with a coating containing nanosized titanium dioxide have been submitted to a standardized mechanical abrasion. Aerosols have been quantified in terms of nature and quantity. It appears that emissions from coated tiles are far more important than those produced by uncoated reference tiles. This is explained by the higher rugosity of coated tiles. Samples of controlled porosity cement containing nano-sized titanium dioxide have been submitted to a static leaching test. The increase in porosity induced an increase in the thickness of the surface layer affected by partial dissolution of calcium. This leads to a greater release of nano-sized Ti02 in this altered layer; however, only a small fraction reaches the surface and is actually released, because of blocking mechanisms in narrow pores or bottlenecks.

Le dioxyde de titane sous forme nanoparticulaire est une substance photocatalytique produite depuis quelques décennies. Elle trouve des usages industriels dans des domaines variés, tels que la protection anti-UV (crèmes solaires) ou les matériaux auto-nettoyants et antibactériens (pare-brises ou façades en verre, ciments, revêtements de façade, revêtements antibactériens). La forte croissance de ces usages pose la question des expositions éventuelles des milieux environnementaux (et par voie de conséquence des populations) aux relargages pouvant être provoqués par les sollicitations diverses subies par les matériaux contenant cette substance, au cours de leur cycle de vie.

Domaines: Sciences de l'environnement

Olivier Aguerre-Chariol, Christophe Bressot. Relargage de dioxide de titane nanoparticulaire dans les milieux environnementaux à partir de nanomatériaux. Rapport Scientifique INERIS, 2017, 2016-2017, pp.18-19. ⟨ineris-01869654⟩