Preparation and characterization of resin-derived carbon foams reinforced by hollow ceramic microspheres

Carbon foam materials were prepared with phenolic resole resin as precursor and hollow ceramic microspheres as reinforcement. The resultant carbon foams had a bulk density of between 0.22 and 0.27 g/cm3. Analysis of scanning electron micrographs indicated that the cells were mainly open with incomplete cell membranes, and the hollow ceramic microspheres were located in the junctions. Compression test results showed that the carbon foams with 1 wt% hollow ceramic microspheres exhibited the highest compressive strength (7.76 MPa). Thermal conductivity measurements revealed that the introduction of hollow ceramic microspheres improved the thermal insulating property. The thermal conductivity of carbon foams ranged from 0.11 to 0.25 W m−1 K−1 at room temperature, which makes carbon foams a prime choice for thermal insulation.