The development of gas separation membranes is currently an active research area because of the rapidly increasing interest in carbon dioxide capture and hydrogen recovery, which are two of the most important solutions for problems related to energy and the environment [1-4]. Polymer membranes show selectivity in the separation of gases due to differences in the permeability of individual gases through the polymer film [3,4]. Even though advantageous in terms of low cost, the segmental flexibility of polymers has limited the discriminating ability of polymer membranes.