Synthesis of SiO2 Inverse Opals in Supercritical Carbon Dioxide

SiO2 inverse opals were produced in supercritical carbon dioxide (scCO2) with latex arrays as templates. PS (Polystyrene) latex particles composed of different hydrophilic groups. Particles were sank into BSA (benzenesulfonicacid), which activates the condensation process of silica precursors. The polymeric templates were reacted with TEOS (tetraethyl ortho-silicate) and H2O in scCO2 at certain conditions. After calcination of this template, highly porous materials duplicating the structure of the original template were obtained. The porosity of the materials obtained for each template is different. We could get the scanning electron microscopy (SEM) images which show the particle reaction on the surface of template in scCO2. This new method of synthesizing inverse opals in scCO2 could make it possible to overcome some of the limitations of the liquid-phase techniques, being a faster method of synthesis and rendering materials of unique properties.