Mixed matrix membranes (MMMs) containing metal organic frameworks (MOFs) are considered to be more promising materials for CO2 capture compared to pure polymers or pure MOFs since it combines the advantages of a polymer matrix (easily processed) and MOFs (excellent gas transport performance). The performance of MMMs is largely dominated by the interfacial interaction between polymers and MOF surfaces. However it is very difficult to directly characterize the fundamental properties of the interfacial region between the particle and the matrix using conventional characterization techniques because of the limited volume fraction of interface. In this work, using multi-scale modeling and simulations (ab initio, all atoms and coarse-grain), the interfacial interaction, polymer configurations and gas transportation have been determined and compared with polymer and MOF bulk phases. A variety of functionalized MOFs and polymer chains have been designed and simulated in order to investigate the optimal structure for excellent binding between the polymer matrix and MOF fillers