Development of carbon composite coatings for fire retardancy and electromagnetic interference shielding

This study has effectively showcased the feasibility of employing a carbon composite coatings, comprised of various carbon nanomaterials including carbon nanodots, carbon nanotubes, and graphene nanosheets integrated within a matrix of sodium metasilicate + gypsum, for applications in both flame retardancy and electromagnetic interference (EMI) shielding. The resulting carbon composite coatings, when applied to wooden substrates, demonstrate remarkable fireproof performance, as validated through fire injections at temperatures as high as 1050 °C. This underscores the pivotal role plays by the design of carbon composites in suppressing flame propagation and charring, leading to reduced carbonization areas. Thermogravimetric analysis further reveals that the carbon composite coating generates substantial char residue at 800 °C, signifying enhanced thermal insulating properties derived from the robust composite carbon architecture. Furthermore, the carbon composite coatings show a significant decrease in electromagnetic fields (electric field around 50 % and magnetic field around 44 %), indicating their efficient EMI shielding properties. This improved EMI shielding performance may be due to the deliberate insertion of CNs into the composite materials, which fine-tunes resistance and dielectric loss while allowing effective electromagnetic absorption by the carbon composites. The breakthroughs made in flame retardancy and EMI shielding highlight carbon composites as superior strengthens to flame-retardant and EMI-absorbing building coatings.