Material integrity and fate of particulates released from carbon fibre composites containing nanomaterials during simultaneous fire and impact

Abstract

Nanomaterials are usually incorporated in the polymeric resin matrix of the carbon fibre-reinforced composites (CFC) to enhance their mechanical and thermal performances. CFCs when exposed to heat/fire and impact, such as in an aeroplane/transport vehicle crash, are known to release small carbon fibres, some of which could be of nanosized diameters and hence airborne. While this is still an under-researched area, there is no information available on the fate of CFCs containing nanomaterials in such scenarios. To address this, we have recently developed a methodology to subject CFCs to simultaneous heat/fire and impact and collect all of the released debris from the front/back faces plus the effluents of the heated/burning composite. CFCs containing nanomaterials, namely layered double hydroxides (LDH), nanotubes (NT) and graphene oxide (GO), were subjected to varying radiant heat fluxes and 19 J low velocity impact. The particle size distribution of released particles was measured by image analysis of SEM micrographs and their agglomeration behaviour by zeta potential measurement. The presence of nanomaterials did not significantly affect the particle size distribution of the released particles; however, the heat duration and the fire had a noticeable effect; the particle size decreased with increasing heat flux and duration. From the particle size distribution and agglomeration behaviours their potential health hazards could be contemplated.