Analysis of particle release using LIBS (laser-induced breakdown spectroscopy) and TEM (transmission electron microscopy) samplers when handling CNT (carbon nanotube) powders

Carbon Nanotubes (CNTs) are deemed as revolutionary materials very likely to be utilized in numerous fields such as electronics, energy, and medicine, to name but a few. The emergence of this new fiber-shaped material with remarkable properties and dimensions of a few micrometers in length and a few tens of nanometers in diameter raises concerns about potential exposure of workers involved in the whole production cycle. These risks emphasize the need to develop tools allowing identifying such objects, either as isolated fibers or entangled in bundles, in situ and if possible in real time. In this context, experiments aiming at detecting potential particle release while manipulating raw CNT powders were performed at ARKEMA research center in a high safety cell dedicated to scientific experiments. Two techniques were employed. First, particle collection on TEM grids was achieved using two samplers, the first based on aspiration and the second on diffusion assisted with thermophoretic repulsion. These allowed differed analysis of single particle morphology, size and chemical composition. Second, real time multi-elemental composition of particle emission was monitored using LIBS. Eventually, though not quantitative, the coupling of TEM grid analysis with LIBS data demonstrated the possibility of real time detection of CNTs entangled in bundles.