Development of novel polymeric/ inorganic composite membranes for the application in gas phase membrane reactors


Gas separation with membranes is an acknowledged industrial process. Polymeric membranes are widely used in gas, vapour and liquid separation. Unfortunately, membranes available commercially have a limited range of application due to low thermal stability. This study is aimed at the development of gas selective membranes comprised of a thin selective layer of polymer and a porous support obtained from either 3D-printing or sintered stainless steel. 3D-printed structures can oer various geometries and in case these materials can be produced with a dened porosity, they can be used as a support for the selective membrane layer. Sintered stainless steel is chemically, thermally and mechanically stable, hence it is well suited for application in chemical reactors. In case it is coated with a polymeric layer, it can serve as semipermeable membrane for feeding or separation of components into or from the chemical reactor. The investigation of 3D printed materials supplied for investigation showed no observable permeances for any gas meaning that these materials are non-porous. Due to the very big interest in sophisticated structures for chemical reactor applications, these materials are to be developed and studied further. Sintered metal supports were found to be very permeable but having a very rough surface. This issue was resolved by application of a porous Torlon® layer on top of the stainless steel surface with subsequent modication of the Torlon® surface with dopamine and successful coating with a thin layer of 6FDA-6FpDA polyimide. The thorough investigation of porous Torlon formation was conducted, resulting in the determination of conditions for formation of a porous layer that was mechanically and thermally stable. Furthermore the layer showed no indication of ageing. The selective layer of 6FDA-6FpDA showed gas transport performance close to the intrinsic properties of the polymer, the thickness of the layer is still subject of further membrane optimization.
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