Extraction of cationic surfactant templates from mesoporous materials by CH(3)OH-modified CO(2) supercritical fluid

Extraction of cationic surfactant templates from MCM-41, MCM-48, SBA-1 and SBA-3 has been conducted using CH(3)OH-modified CO(2) supercritical fluid. The supercritical fluid extraction (SFE) has been integrated with thermogravimetry (TG), X-ray diffraction (XRD) and N(2) adsorption-desorption to evaluate extraction efficiency and structural stability of mesoporous materials. Experiments of optimization indicate that the conditions of 90bar, 85 degrees C, CH(3)OH/CO(2)=0.1/1.0ml/min and 3h are most suitable for the SFE of cationic templates. 76-95% of the cationic templates can be extracted from the mesoporous materials. XRD and N(2) adsorption-desorption studies illustrate that SFE possesses some advantages over calcination in maintaining mesoporous uniformity and structural stability when used to remove templates. The impact of curing on mesoporous structure is also dealt with.