In-Situ Assembly of Mofs Nanocubes on Electrochemically Exfoliated Graphene Nanoflakes: Heterojunctions Role in Flame Retardance

The extensive usage of epoxy resin (EP) is facing the head-scratching challenge of high fire hazard. As such, the in-situ assembly of metal organic frameworks (MOFs) nanocubes on electrochemically exfoliated graphene nanoflakes is performed to acquire the heterojunction of PG@UIO. The corresponding role and behavior in flame retardance are explored in detail. By adding 2.0 wt% PG@UIO, the reductions in peak heat release rate, total heat release, peak smoke production rate, peak CO yield, peak CO2 yield reach 49.2%, 44.3%, 56.1%, 57.7% and 51.3%. The in-situ volatiles analysis points out the reductions of 35.1%, 29.4%, 50.8%, 32.5% in the maximal intensities of aromatic compounds, ethers, CO and HCN. The mechanical interlocking area between PG@UIO nanostructures and EP molecular chains contributes to the enhanced mechanical performances. Specifically, by adding 2.0 wt% PG@UIO, the flexural strength is increased by 50.3%. This work enables a new paradigm for fabricating fire-safe polymer composites with the judicious design of MOFs based flame retardant.