Membranes, frequently used in the chemical industry, provide a resistance to transport of different substances. One such construction is the mixed matrix membranes (MMMs), which is composed of fillers embedded in a polymeric matrix in an attempt to present two desired qualities: good selectivity from the filler and sustained permeability from the polymer. However, the interface between fillers such as metal-organic frameworks (MOFs) and the surrounding environment is complicated and can lead to several unwanted results, such as the formation of nonselective voids, rigidified layer, and swelling of the polymer. Through simulation techniques, we can computationally investigate such interfaces found in MMMs and furthermore simulate the gas separation process. This can then be complimented with experimental studies to describe gas transport mechanisms in detail. In this talk, I will use well-known commercial polymers that possess great thermal stability to describe the result of adding MOFs that provide porosity and void volumes. Calculated adsorption isotherms and mean square displacement provide a measure of solubility and diffusivity of guest molecules such as CO2 and N2, while experimental results parallel the computational setup.