Supercritical Co <sub> 2 </ Sub> In The Template Was Prepared Nanoporous Materials

Porous materials have potential applications in catalysis, adsorption, separation, ion exchange and chemical sensing fields because of their unique porous structures and surface performances. The mesoporous materials (2nm2 to coat on the activated carbon template. After removal of template by calcinations, the nanoporous materials replicated the structure of template were obtained. By comparison of supercritical casting and liquid precursor casting method, the advantages of supercritical casting have been confirmed. SC CO₂ has advantages of low viscosity, high diffusivity, rapid substance transportation, etc, which result in higher casting ratio, deeper casting and more accurate replication of template in supercritical casting process. In the preparation of nanoporous iron oxide and nanoporous alumina, the obtained products have low BET surface area and total pore volume, which is mainly caused by pores collapse in calcinations. By addition of other substances, the BET surface area and total pore volume of iron oxide/silica and alumina/iron oxide composite product have been greatly improved, which proves that there exists interactions between the composite substances and the porous structures have been kept. In the preparation of titania/silica composite system, due to the addition of silica, thermal stability of...