In some aspects, the present disclosure provides a polymer composition which comprises two polymer molecules and a compatibilizing agent. In some embodiments, the polymer composition is useful for the preparation of membranes used in the separation of two or more gases. In some embodiments, the polymer composition comprises a polyimide polymer and a polybenzimidazole polymer which have been compatibilizing with a small molecule or a metal organic framework.
 This invention was made with government support under Grant Number CBET-0933563 awarded by the National Science Foundation, and Grant Number DE-FE0001293, awarded by the Department of Energy. The government has certain rights in the invention.