One-pot synthesis of interpenetrating inorganic/organic networks of CuO/resorcinol-formaldehyde aerogels: nanostructured energetic materials.

For many applications ranging from catalysis to sensors to energetic materials, it is desirable to produce intimate mixtures of nanoparticles. For instance, to improve the reaction rates of energetic materials, the oxidizing agent and the fuel need to be mixed as intimately as possible, ideally at the nanoscopic level. In this context, the acidity of a hydrated CuCl(2) solution reacting toward a network of CuO nanoparticles (a good oxidant) is used to induce one-pot cogelation of a nanostructured network of a resorcinol-formaldehyde resin (RF, the fuel). The resulting wet gels are dried to aerogels, and upon pyrolysis under Ar, the interpenetrating CuO/RF network undergoes a smelting reaction toward metallic Cu. Upon ignition in the open air, pure RF aerogels do not burn, while CuO/RF composites, even with substoichiometric CuO, sustain combustion, burning completely leaving only a solid residue of CuO whose role then has been that of a redox mediator through the smelting reaction.