The key in preparing mixed matrix membranes for the desired gas separation is to rationally select a suitable combination of inorganic fillers and polymers and to develop fabrication techniques enabling formation of a continuous inorganic phase with dual transport pathway. Herein, we report the facile design of flexible poly[poly(ethylene glycol) methacrylate-co-poly(ethylene glycol) dimethacrylate] membranes containing metal organic frameworks UiO-66 prepared from zirconium chloride and 2-aminoterephthalic and terephthalic acid varying in contents, shapes, and sizes. The surface chemistry effects of both polymer matrix and MOFs on permeability and selectivity were investigated. The bare polymer membrane exhibited a permeability for CO2 of around 117 barrer and a selectivity of up to 15. Addition of glycidyl methacrylate in the polymerization mixture led to membranes that were modified with hexamethylenediamine to provide for basicity. However, this modification did not improve performance of the membrane...