On the use of diatomite as antishrinkage additive in the preparation of monolithic carbon aerogels

We have synthesized flexible monolithic carbon aerogels by incorporating diatomite as antishrinkage agent during the sol-gel polycondensation of the precursors. The materials displayed elastic properties and preserved their pristine dimensions upon densification by carbonization even after etching of the diatomite, due to the open pore structure of the siliceous additive in the material's matrix. The aerogels displayed a well-developed porous structure, confirming that the polymerization of the precursors is not impeded; the effect of the additive was independent of the formulation of the aerogels, as evidenced by the behavior of aerogels with varied composition (molar ratio, pH, N-doping).