Mechanical and thermal insulation properties of carbon fibre-reinforced carbon aerogel composites

Abstract

Carbon fibre-reinforced carbon aerogel composites (C/CAs) were prepared by using polyacrylonitrile (PAN) and phenolic (PH) carbon precursor fibres as reinforcements, respectively, then impregnated with resorcinol-formaldehyde sol, aging, solvent exchanging, CO 2 supercritical drying and carbonization at 1000°C. The physical properties, structural morphology and mechanical and thermal insulation behaviour of the two kinds of composites were further compared. Pore structure analysis shows that the PH-based C/CAs have a larger specific surface area (438.92 m 2 •g −1 ) and richer mesoporous volume than the PAN-based C/CAs. Mechanical behaviour of the C/CAs has been changed, but the stronger enhancement effects belong to PAN-based C/CAs (compressive strength in xy and zdirections are 1.63±0.10 MPa and 1.22±0.19 MPa, bending strength is 3.62±0.50 MPa). However, the PH-based C/CA composites have relatively low thermal conductivities, ranging from 0.027 to 0.164 W•m −1 •K −1 between 25 and 1800°C.

Synthesis of Environmentally Friendly Nanoporous Monolithic Carbon Aerogels via Ambient Pressure Drying for High-Temperature Thermal Insulators

“…Figure d,e gives a comparison of the mechanical and thermal insulation properties of CAC100 with the corresponding properties of carbon aerogel composites in the literature. As shown in Figure d and Table S2, CAC100 has a high compressive strength (at 10% strain) and a relatively low room-temperature thermal conductivity. ,,− Besides, the high-temperature thermal conductivities of CAC100 are even comparable to that of other carbon aerogel composites prepared by SCD − (Figure e and Table S3). It can be seen that CAC100 has the advantages of low density (0.244 g/cm 3 ), high strength (1.63 MPa at 10% strain), and low thermal conductivity, making it a promising high-temperature thermal insulation.…”

Flexible and Transformable Ceramic Aerogels via a Fire‐Reborn Strategy for Thermal Superinsulation in Extreme Conditions

“…This was achieved through a process involving resorcinol-formaldehyde sol-gel impregnation, CO 2 supercritical drying, and carbonization, utilizing polyacrylonitrile and phenolic carbon precursor fibers as reinforcement materials. [23] Furthermore, nanoparticle fibers (NF) prepared by electrostatic spinning were added to SiBCN aerogel, resulting in NF/SiBCN ceramic fiber aerogel with good elasticity and fatigue resistance under high compressive strain and ultra-low thermal conductivity at an ultra-high temperature of 1300 °C. [24] However, the fabrication processes of these aerogels often involve complex procedures and require specialized facilities.…”