Ambient air chemical and physical survey of manufactured nanoparticles combining LIBS, DMA and CNC techniques
Résumé
Today, nanotechnology lets foresee many opportunities and benefits for new materials with significantly improved properties as well as revolutionary applications in large industrial fields. Analysts have estimated that the size of the market was 900 million Euro in 2005 and will be 11 billion Euro in 2010. However, nanomaterial industries are currently encountering potential problems with hazard control in their production plants. Release of nanoparticles in air can lead to violent chemical reactions and even explosion because of their small size and energetic properties, and hence high chemical reactivity. Another major safety concern is the impact of manufacturing nanoparticles on the environment and more specifically on the health of the workers. Thus, there is a need to detect a possible release of manufactured nanoparticles in the ambient background, which can be several order of magnitude higher than the release itself, in term of number or mass concentration. The key issue was then to develop on-line instrumentation could be able to detect leaks using size resolved chemical identification. Within the European project FP6 NANOSAFE2, an on line monitoring method based on the coupling of the LIBS technique with a DMA (Differential Mobility Analyzer) device has been proposed as an analytical tool for workplace survey. Nanoparticle chemical identification is performed using LIBS whereas particle physical characteristics are yielded by the DMA analysis. Experiments aiming at demonstrating the potentialities of LIBS coupled with a DMA have been carried out. The LIBS signal has been also precisely studied as a function of several parameters such as laser energy or particle size and chemical composition. Moreover analytical potentialities such as repeatability, linearity and detection limit have been also investigated showing the potentiality of such instrumentation as a leak detection tool for workplace survey.