Preparation of supported mesoporous thin films concerning template removal by supercritical fluid extraction

Abstract

Thin films of silicate MCM-41 and silicate MCM-48 have been prepared on porous ceramic supports by the hydrothermal method. A comparative study of template removal has been made on supported thin films and on powder. By supercritical fluid extraction (SFE) with CH 3OH-modified CO 2, at least 78% of the template can be removed from as-synthesized materials at 85°C. X-ray diffraction (XRD) observations indicate that the resulting supported thin films after SFE are structurally stable and ordered with a weak pore contraction. The advantages of SFE over calcination in template removal are presented with a series of results obtained on supported thin films and on powder by XRD and N 2 adsorption-desorption.