In Situ Assembly of DNA/Graphene Oxide Nanoplates to Reduce the Fire Threat of Flexible Foams

The layer-by-layer surface modification of open cell foams is a recently developed route to reduce the fire threat of this class of materials. This approach generally requires a high number of deposition steps to achieve the desired properties. This paper reports the water-based single-step deposition of efficient flame retardant coatings encompassing graphene oxide (GO) and DNA. During the deposition, a temperature-induced in situ assembly of the GO+DNA produces a continuous and thermally robust protective layer on the structure of the polyurethane (PU) foam where GO nanoplates are held together by DNA acting as a ligand. This GO+DNA coating can effectively prevent flame spread during flammability tests performed in horizontal or vertical configuration while considerably reducing the rate of combustion and production of smoke by cone calorimetry (−75% and 30% in peak of heat release rate and total smoke release, respectively). The DNA promotes the formation of a protective structure that efficiently limits heat and volatiles transfer from and to the flame thus resulting in flame retardant (FR) performances capable of outperforming many of the FR coatings developed so far for PU foams. The proposed approach potentially opens up to the development of high performing FR solutions based on graphene-related materials and bio-based components.