About this Research Topic
This Research Topic focuses on the design and tailoring of novel mixed matrix membranes (MMMs) by tuning nanofillers and polymers for gas separation. Emphasis will be put on the application of such MMMs in the development of environmentally friendly technologies and processes for industrial gas separation and purification.
Membrane technology has already been commercialized and documented as a competitive technology for selected gas separation processes such as air separation and natural gas sweetening during the last two or three decades. Great emphasis has recently been placed on CO2 capture using gas separation membranes, and membrane technology will become steadily more attractive due to its high energy- efficiency, high flexibility, small footprint and low environment impact. However, most pure polymeric membranes suffer from the trade-off between mass transport rates and separation efficiency represented by the renowned Robeson upper bound. Addition of porous nanofillers into polymer matrix to form mixed matrix membranes is a promising approach to transcend the upper bound, owing to their superior separation capabilities, and potentially increase the mechanical strength.
MMMs with porous nanofillers could improve the selectivity based on molecular sieving mechanism, while the other type of MMMs with nonporous nanoparticles (such as TiO2, fumed silica) could improve the gas permeability by increasing the free-volume of polymer matrix. Porous nanofillers, such as metal-organic frameworks, porous organic frameworks, rubbery organic frameworks, porous organic polymers, zeolites, or carbon based materials have high surface area and porosity, adjustable pore sizes and controllable surface functionality, which entice increased attention due to their inherent sorption capacities for condensable gas (like CO2) and secondary transport pathways when added to polymer matrices. Properly tuning the porous structures of these nanofillers can also facilitate simultaneous enhancement of permeability, selectivity and stability properties of the MMMs, and potentially towards industrial realization.
The Research Topic welcomes contributions dealing with the development of novel MMMs based on porous or nonporous nanofillers with appealing separation performance for different gas separation processes. Potential topics include, but are not limited to:
- Preparation of MMMs through the incorporation of nonporous nanofillers such as TiO2, fumed silica;
- Preparation of membranes through in corporation of carbon based nanofillers: carbon molecular sieves, carbon nanotubes, graphene, graphene oxide, reduced graphene oxide;
- Design of 3D porous nanofillers of zeolite, MOFs, POFs, ROFs, POPs (use of these materials as nanofillers must be demonstrated, even in a preliminary fashion);
- Development of MMMs by tuning 3D nanofillers;
- Design of energy efficient membrane process for gas separation such as CO2 capture, biogas upgrading, natural gas sweetening, and hydrogen purification.
Keywords: mixed matrix membranes, nanofillers, gas separation, interfacial design
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