Fabrication of carbon foams with high mechanical properties derived from sucrose/polyacrylamide hydrogel

The physical foaming and gel casting techniques are combined to fabricate carbon foams with high mechanical properties, which is based on the interaction of the three-dimensional polymer networks by using sucrose/polyacrylamide hydrogel as the carbon precursor. After the thermal polymerization and carbonization, a high carbon yield (94.96% of the theoretical value) of carbon foams is attributed to the high cross-linking degree of sucrose/polyacrylamide hydrogel. Besides, anionic surfactant sodium dodecyl sulfate (SDS) is utilized to enhance the foaming ability. The well-defined cell structures of carbon foams are easily controlled by adjusting the contents of sucrose and SDS. The density of carbon foams is regulated in the range of 0.17-0.93 g/cm3, whereas the compressive strength is in the range of 3.0-108.0 MPa. Carbon foams prepared by this method showed a fracture-dominated mechanical behavior and are purely brittle. Furthermore, energy as high as 23.52 MJ·m− 3 can be absorbed when compressed.