Ionothermal synthesis of fiber-reinforced carbon aerogel composites from fructose with high mechanical and thermal insulation properties

In this work, carbon fiber reinforced biomass carbon aerogel composites (CF/CA) were prepared by ionothermal synthesis using fructose as the raw material and oxidized polyacrylonitrile fiber as the reinforcing agent. During the preparation process, we have mixed fructose with oxidized polyacrylonitrile fibers and subjected them to a carbonization process under the conditions of hot ionic liquids. By controlling the reaction conditions, we successfully prepared fiber-reinforced carbon aerogel composites with excellent properties. The CF/CA has a high compressive strength (3.306 MPa). At the same time, the original low thermal conductivity (0.106 W·m−1·K−1) and low density (0.2976 g/cm2) of the carbon aerogel are maintained. In this work, the mechanical properties of carbon aerogel are improved to 230 % without changing the thermal insulation properties of CA, which makes a certain progress compared with the similar research. These excellent properties make CF/CA a promising engineering material. Moreover, we found that about 95 % of the ionic liquid can be recovered by evaporating under reduced pressure, and the recovered ionic liquid is still usable. This discovery provides a possibility for the green and sustainable development of the preparation process of carbon aerogels. This study provides new ideas and methods to further optimize the properties and applications of biomass carbon aerogels and their composites.