A method to identify polymers that are potentially useful for membrane separations has been developed by examining gas chromatography (GC) retention data. Promising stationary phases were identified, and polymers with similar structures were obtained and deposited into inorganic supports. Polymers were identified to separate ketones and alcohols from hydrocarbons. The polymer/inorganic composite membranes synthesized for this research were characterized by IR spectroscopy and scanning electron microscopy. Favorable fluxes and high separations factors were achieved for several composite materials.