Supercritical fluid extraction was evaluated for removing the amine surfactant from hexagonal mesoporous silica materials. In this study, methanol-enhanced supercritical CO2 extraction was carried out on freshly synthesized materials by means of a dynamic method. Experiments were performed at pressure ranging from 10.0 to 25.0 MPa, temperature from 45 to 105 degrees C, CO2 flow rate from 0.45 to 4.5 ml/min, and methanol flow rate from 0.05 to 0.5 ml/min. The influence of these parameters on the extraction has been evaluated in terms of the surfactant recovery. The results show that by using this method up to 96% of the total amine surfactant used is extracted out of as-synthesized mesoporous materials within 1 h extraction whereas only 78% of the surfactant can be removed by liquid ethanol extraction. The materials processed by supercritical CO2 extraction are found to possess better structural properties as reflected by the X-ray diffraction analysis and N-2 adsorption results, and thus have higher thermal and hydrothermal stability than those obtained by liquid ethanol extraction or high temperature calcination. (C) 2010 Elsevier B.V. All rights reserved.