Hybrid POSS (R) Octa Amic Acid-Matrimid (R) nanocomposite membranes have been successfully fabricated. The study shows that the nano-sized POSS (R) could be distributed uniformly over the Matrimid (R) matrix with an intimate polymer-particle interface. This is presumably ascribed to the existence of intermolecular hydrogen bonding between the carboxylic groups of POSS (R) and Matrimid (R). The excellent dispersion of POSS (R) with eight carboxylic functional groups each moiety provides a high-density ionic binding platform for the introduction of Zn2+, which is the engine of the facilitated transport to some specific gases. The best gas separation performance is observed for the hybrid POSS (R)-Matrimid (R)-Zn2+ nanocomposite membrane (20 wt% POSS (R)-Matrimid (R)-0.3 M ZnCl2), in which, the selectivity of CO2/CH4 and O-2/N-2 increases by 70% and 30%, respectively, when compared with untreated nanocomposite membrane (20 wt% POSS (R)-Matrimid (R)). (C) 2010 Elsevier B.V. All rights reserved.