Bis(triethocysilyl)ethane (BTESE)-derived organosilica membranes were applied for the dehydration of aqueous isopropanol (IPA) solutions in pervaporation and vapor permeation. The stability of the membranes under high-water-content systems was demonstrated in pervaporation and vapor permeation. The membranes showed excellent stability in the long-term pervaporation of a 50 wt% IPA aqueous solution at 75 degrees C. The membranes were also stable in vapor permeation with a high-water-content stream (IPA concentration of 50 wt%) at 100 degrees C. These results clearly demonstrated that BTESE-derived organosilica membranes are applicable for the dehydration of high-water-content mixtures. The effect of the feed component and operating temperature on dehydration performance was also investigated. An analysis of the permeation resistance through the membranes was conducted based on a simple seriesresistance modeling approach and revealed that the permeation resistance of the support layer strongly inhibited the water permeability, particularly when the water content in the feed was high. (C) 2015 Elsevier B.V. All rights reserved.