Coupling supercritical CO2 (SC-CO2) extraction with membrane separation leads to energy savings by recycling CO2 at supercritical state while separating extract components. However, high pressure operating conditions may cause physicochemical and morphological changes in polymer membranes, which in turn can adversely affect membrane performance. In this study, the effect of different flux (50 and 200 kg/m(2) h), temperature (40 and 80 degrees C) and time (0-8 h) levels were investigated at 120 bar on two commercial reverse osmosis membranes, AK and SG using contact angle, ATR-FTIR and FE-SEM measurements. Contact angle of AK increased substantially with high flux and high temperature processing unlike SG. The peaks assigned to N-H and carbonyl groups at 1541, 1609 and 1663 cm(-1) showed the highest decrease in absorbance with high flux processing while high temperature was more effective on O-H groups between 2700 and 3700 cm(-1). AK membrane exhibited the formation of bead-like structures at different processing times and conditions. The effect of SC-CO2 processing on the membranes varied depending on their chemical structure, which is important to understand for further process development. (C) 2011 Elsevier B.V. All rights reserved.