Molecular transport of small molecules through polymer films has been widely studied over the past several years [1–8]. In most of these investigations it has been shown that the penetrant solubility and diffusion follow Henry's law and Fick's law, respectively, and that solubility (S), diffusion (D), and permeability coefficients (P) are independent of penetrant concentration. Several theories of diffusion, permeation, and solution have been developed to relate the experimental data to polymer film morphology, chemical structure, and other physical properties [9–14]. From a practical view point, the phenomenon of transport is very useful in the treatment of hazardous waste in landfill areas. In chemical industries, its importance lies in the separation of organic compounds. Additionally, membrane separation techniques have been used in such industrial applications as desalination of brine, salt manufacturing from seawater, oxygen-enriched air, etc. The pervaporation technique wherein the permeate is removed from a mixture at the opposite side of the membrane as a vapor is now very popular [15].