Gaz ayırımları için mof membranların ve polimer/MOF karışık yataklı membranların moleküler modellenmesi

Polymer membranes have been commonly used for gas separation applications due to their ease of fabrication and low cost. However, polymer membranes have a trade-off between gas selectivity and permeability. For the past two decades, there has been a growing interest in developing mixed matrix membranes (MMMs) by combining non-polymeric materials with the polymers to overcome this permeability/selectivity trade-off. Metal organic frameworks (MOFs) which are a new class of nanoporous materials present greater promise for being used as non-polymeric materials to fabricate MMMs due to their unique properties such as well-defined pores and large surface areas. Recently, combining MOFs with the polymers, MOF-based MMMs have been synthesized, and the high gas separation performance of MMMs has been reported. However, choosing the appropriate MOFs as filler particles in MMM applications is very difficult due to the very large number of existing MOF materials. Therefore, theoretical models play a critical role in predicting polymer/MOF combinations prior to experimental efforts. In this thesis, the methodologies for selecting MOFs as filler particles in polymers was examined using atomistic and continuum modeling. The validity of several theoretical permeation models was tested by comparing the predictions of these models with the available experimental data for CO2/CH4 and H2/CH4 separations. Combining detailed atomistic simulations with the theoretical permeation models, the performances of new-MOF based MMMs were estimated. The results found in this thesis demonstrated that selecting the appropriate MOF/polymer combinations can result in membranes with high CO2 and H2 selectivities and permeabilities relative to those of pure polymer membranes. The methodologies that were described in this thesis for screening MOFs in an efficient and easy way will provide conceptual hints for the assessment of the best MOF/polymer pairs to obtain high performance MMMs for CO2/CH4 and H2/CH4 separations.