Mesoporous SiO2 nanoparticles are explored as a potential hydrophilic inorganic filler to recognize nanocomposite membranes with Nafion and ionic liquid (IL) tetramethylammonium hydroxide (TMAOH) for water vapor removal applications under condensed relative humidity. Nanocomposite membranes are obtained by inserting SiO2 nanoparticles in Nafion-ionic liquid coating solution in different concentrations of Nafion, thereby providing increased adsorption sites for water vapor. These nanocomposite membranes are prepared on the surface of polysulfone (PSf) hollow fiber membranes. The main objective of this study was to prepare Nafion-IL-SiO2 nanocomposite membranes for direct water vapor mixture gas separation in applications with the aim of increasing water vapor permeance and keeping up the selectivity. The application of the Nafion-IL-SiO2 nanocomposite membranes in water vapor mixture gas separation was demonstrated. As a result, the high water vapor permeance of 2131 GPU was achieved for the PSf-Nafion-IL-SiO2-M2 membrane and high H2O/N-2 selectivity of 130 was obtained for the PSf-Nafion-IL-SiO2-M3 membrane at pressure 3 bar and temperature 30 degrees C. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.