Electrostatic self-assembly of carbon nanotube/reduced graphene oxide films for enhanced thermal insulation performance

The carbon nanotube/reduced graphene oxide composite films (CNTs@PDDA/rGO) were fabricated by positively charged modification of CNTs with surface modification agent polydiallyldimethylammonium chloride (PDDA), followed by electrostatic self-assembly with negatively charged graphene oxide (GO), vacuum-assisted filtration and reduction treatment. The effects of varying amounts of CNTs and their interactions on enhancing thermal insulation performance were investigated. The 5%CNTs@PDDA/rGO composite film enables the uniform dispersion of CNTs between reduced graphene oxide sheets to form 3D porous network structure. The 5%CNTs@PDDA/rGO possesses high tensile strength (24.3 MPa) and lower elongation at break (3%). Thermal insulation test analysis shows that, compared with other composite films, the surface temperature of 5%CNTs@PDDA/rGO exhibits a slower rising trend. The temperature difference of 5%CNTs@PDDA/rGO reaches up to 104.6 °C at a heating temperature of 200 °C with excellent heat insulation performance. The as-prepared composite films also demonstrate good flame retardancy. These graphene-based composite materials hold significant potential for applications in thermal insulation systems.