(115a) Aerosol Synthesis of Low Density High Surface Area Aerosol Gels

We have developed a method to create porous materials of high surface area and very low density via gelation of nanoparticles in the aerosol phase. We call our materials "aerosol gels". We create carbon aerosol gels by exploding a hydrocarbon, eg. acetylene, mixed with oxygen in a chamber. This produces the necessary conditions for rapid gelation, i.e. small particles and large volume fraction. Our materials have properties similar to aerogel materials but are easier to make because the supercritical drying step is not necessary. Properties include specific surface areas of ca. 400 meters squared/gram, and densities as low as 2.5 mg/cc. We have explored the morphology and kinetics of formation of these aerosol gels with small angle light scattering. The morphology shows a hybrid superaggregte structure with two fractal dimensions at different length scales.