The effect of silicon dioxide particles on the gas transport properties of 6FDA-IPDA thin films was investigated in this work by casting the films on silica impregnated ceramic substrates. The pore structure of the Anopore(TM) ceramic support provided an ideal environment for bringing the silica particles into intimate contact with the polymer chains. Overall the properties of the resulting membranes for separation of oxygen from nitrogen are significantly improved compared to the properties of a homogeneous film of 6FDA-IPDA.