We report novel methods for the synthesis of porous materials such as polymeric aerogel foams, pure metallic aerogels, amorphous and graphitic carbon aerogels, and their applications. I. Polyurethane based aerogel foams were synthesized with an aliphatic triisocyanate and ethylene glycol through a pressurized (7 bar) sol-gel method. The foam-like structure is prepared without any chemical foaming agents or templates, resulting in less expensive, more efficient, readily adaptable, and environmentally friendly process. Those materials exhibited lower thermal conductivity (by 25%) and higher oil adsorption capacity (by 36% w/w) than their corresponding aerogels. II. Monolithic, pure metallic Co(0) aerogels were synthesized from polyurea-crosslinked cobaltia xerogel powder compacts via carbothermal reduction, for application as thermites. III. Carbon aerogels were synthesized from compressed compacts of polyurea- and polyacrylonitrile-crosslinked silica xerogel powders. The process of making aerogels-via-xerogels allows to speed-up the solvent exchange process and bypasses supercritical fluid drying, resulting in time, energy, and materials efficient methodology. At their best, these carbon aerogels have high BET surface area (up to 1934 m2 g-1), porosities (up to 83% v/v) and good CO2 uptake (up to 9.15 mmol g-1) with high selectivity toward other gases (H2, N2 and CH4). IV. Sturdy, monolithic graphitic carbon aerogels with different nano-morphologies were synthesized at lower temperatures (800-1500 ºC) compared to conventional graphitization (2500-3300 ºC) from Fe- or Co-catalyzed free-radical surface-initiated polymerization of acrylonitrile monomer to polyacrylonitrile-crosslinked metal oxide xerogel powder compacts. These graphitic carbon aerogels were demonstrated as anodes for Li-ion batteries with good charge capacity --Abstract, p.
