Characterization of aerosolized particles in effluents from carbon fibre composites incorporating nanomaterials during simultaneous fire and impact

This work investigates the aerosols emitted from carbon fibre-reinforced epoxy composites (CFC) incorporating nanomaterials (nanoclays and nanotubes), subjected to simultaneous fire and impact, representing an aeroplane or automotive crash. Simultaneous fire and impact tests were performed using a previously described bespoke testing methodology with the capability to collect particles released from the front/back faces of the impacted composites plus the effluents. In this work the methodology has been further developed by connecting the Dekati Low Pressure Impactor (DLPI) and Mini Particle Sampler (MPS) sampling system in the extraction chimney. The aerosols emitted have been characterized using various devices devoted to the analysis of aerosols. The influence of the nanoadditives in the matrix on the number concentration and the size distribution of airborne particles produced, was studied with a cascade impactor in the 5 nm-10 μm range. The morphology of the separated soot fractions was examined by SEM. The measurement of aerodynamic size of particles that can deposit in human respiratory tract indicate that 75% of the soot and particles released from CFC could deposit in the lungs reaching the bronchi region at a minimum. There was however, a minimal difference between the number particle concentrations or particle-size mass distribution of particles from CFC and CFC containing nanoadditives. Moreover, no fibres were found in the effluents.

Graphene oxide incorporating carbon fibre-reinforced composites submitted to simultaneous impact and fire: Physicochemical characterisation and toxicology of the by-products

The toxicological profile of particulates released from carbon fibre-reinforced composites (CFC) incorporating nanoadditives, under impact and fire conditions (e.g. aircraft crash), is unknown to date. Our aim was to investigate the effects of simultaneous impact and fire on the physicochemical features of the particles released from CFCs produced from a graphene oxide (GO)-reinforced epoxy resin and the consequences on its toxicological profile. CFC samples with (CFC + GO) or without GO (CFC) were subjected to simultaneous impact and fire through a specific setup. Soot and residues were characterised and their toxicity was compared to that of virgin GO. Virgin GO was not cytotoxic but induced pro-inflammatory and oxidative stress responses. The toxicity profile of CFC was similar for soot and residue: globally not cytotoxic, inducing a pro-inflammatory response and no oxidative stress. However, an increased cytotoxicity at the highest concentration was potentially caused by fibres of reduced diameters or fibril bundles, which were observed only in this condition. While the presence of GO in CFC did not alter the cytotoxicity profile, it seemed to drive the pro-inflammatory and oxidative stress response in soot. On the contrary, in CFC + GO residue the biological activity was decreased due to the physicochemical alterations of the materials.