High-Strength, Highly Conductive, Thermally Insulating CNT-Reinforced PBO-Based Aerogel Fibers for Intelligent Textiles in Harsh Environments

Aerogel fibers are ideal candidates for thermal insulation due to their low density and high porosity. However, current aerogel fibers suffer from low mechanical strength and a lack of response to multiple stimuli. In this study, we report a strategy that uses electric field and shear flow in a dry-jet wet spinning process to make carbon nanotube (CNT)-reinforced poly(p-phenylene benzobisoxazole) (PBO) composite aerogel fibers (E-PBO/CNT). This approach resolves the usual trade-offs among strength, thermal insulation, and electrical conductivity in aerogel fibers. The aerogel fibers retain low thermal conductivity (0.039 W m-1 K-1) and high porosity (89%), while achieving high tensile strength (42.98 MPa) and high electrical conductivity (35.24 S cm-1). The aerogel fiber also exhibited thermal stability up to 650 °C, high flame retardancy (limiting oxygen index of 41%), and chemical resistance. The E-PBO/CNT aerogel fiber can be knotted or woven into textile structures, making it suitable for use in harsh environments from -196 to 300 °C, and possesses self-powered temperature-sensing capabilities.