Pdms Mixed Matrix Membrane with Confined Mass Transfer Structure: The Effect of Cofs with Different Porous Structure and Chemical Property in Pervaperation Process

Abstract

In this thesis, the hydrophilic COF nanosheets with triazine structure and the hydrophobic COF nanosheets with imine skeleton containing fluorinated functional groups are designed to intensify the membrane separation process for ethanol pervaporation. The mass transfer of an ethanol-water mixture within the confined structure of COF nanosheets is investigated using experimental methods and computational simulations, and the quantitative relationship between mass transfer performance and pore size and properties of COF nanosheets is established. COF nanosheets are used to optimize the confined structure of MMMs, effectively regulating their characteristic parameters of MMMs, and enhance the separation performance of MMMs. On the basis of studying its formation mechanism and modulation rules, the relationship between the confined structure parameters and membrane separation performance is revealed. The method and preliminary theory for overcoming the 'trade-off' effect are developed, which providing theoretical support for designing novel membrane materials with preferential ethanol-permeable COF MMMs.

Keywords: pervaporation, confined mass transfer structure, mixed matrix membrane, Covalent organic framework, simulation calculation