By combining organic polymers normally used to make membrane filters with inorganic substances, multi-walled carbon nanotube (MWCNTs), an extraordinary ability to separate H-2 from CH4 was developed in this study. A series of MWCNTs/PBNPI nanocomposite membrane with a nominal MWCNTs content between 1 and 15 wt% were prepared by solution casting method, in which the very fine MWCNTs were embedded into glassy polymer membrane. Detailed characterizations, such as morphology, thermal stability and crystalline structure have been conducted to understand the structures, composition and properties of nanocomposite membranes. The results found that this new class of membrane had increased permeability and enhanced selectivity, and a useful ability to filter gases and organic vapours at the molecular level. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.