Engineering of flame retardants at the nano-scale improves effectiveness and can provide new fire safety mechanisms. This review of nearly 130 publications presents nano-engineering of different types of flame retardant. Only PIN FRs are considered. The review summarises developments in nano-delivery of inorganic PIN FRs (metal compounds: aluminium, magnesium, zin, titanium) where nano-engineering improves fire and mechanical performance. Fire protection mechanisms include water release, heat absorption, catalytic reduction of combustible gases and protective layer formation. Carbon-based nanocompounds include carbon nanotubes, graphene and derivates and carbon nanofibres. Nanoclays and a range of phosphorus-containing nano- PIN FRs are discussed, including P-containing nano-polymers, nanoparticles and intumescents and ‘hybrids’ combining more than one nano- PIN FR as well as surface-modified nanoparticles and innovative new active nanomaterials. Applications discussed include polymers and plastics, textiles, paints and coatings, electronics, construction and automotive. Challenges to industrial roll-out are identified as the need to verify health and safety, regulatory aspects, scale-up to production of homogenous materials and processing (nanoparticles tend to ‘clump’ rather than disperse).
“Nanostructured flame retardants: An overview”, J. Rodrigues, N. Gopal Shimpi, Nano-Structures & Nano-Objects 39 (2024) 101253 https://doi.org/10.1016/j.nanoso.2024.101253