The enhanced thermal and mechanical properties of graphite foams with a higher crystallinity and apparent density

Graphite powder, which has a highly graphitic structure, is used as filler material in the preparation of graphite foams (GFms) and enhances the foams' thermal-mechanical properties. GFms are prepared using the hydrogel template method with mesophase pitch, polyvinyl alcohol-acrylic acid (PVA-AAc) solution and graphite powder. GFms containing 0.3 w/w% added graphite exhibit as much as an 11.18% increase in crystalline thickness (Lc) compared to that of the sample without graphite powder. These increased crystalline thicknesses of GFms result in thermal conductivity increases as high as 59.30%. Furthermore, the compressive strength is increased by as much as 120.52% compared to that of the sample without graphite powder, and the apparent density is increased by as much as 4.05%. The average pore size of the GFms is controlled by the amount of graphite powder, which affects the GFms' cell growth mechanism. These results revealed that the thermal-mechanical properties of GFms containing graphite powder with a highly graphitic structure were strongly affected by the GFms' crystalline thickness and apparent density.