Mixed-linker ZIF materials and ZIF/polymer hollow fiber membranes for hydrocarbon separations

Abstract

I demonstrated the effective pore size can be continuously and drastically tuned using mixed-linker ZIFs containing two types of linkers, allowing their use as a more general molecular separation platform. This remarkable behavior was illustrated by adsorption and diffusion measurements of hydrocarbons, in mixed-linker ZIF-8-90 materials with a large range of crystal sizes (338 nm to 120 µm). I also demonstrate significant new advances in mechanistic understanding and engineering of support properties for interfacial microfluidic processing techniques in hollow fibers and the use of this understanding to fabricate high-performance ZIF-8 membranes for propylene and hydrogen separations. We also made a progress towards a more generalized ZIF membrane fabrication platform by extending IMMP to macroporous carbon hollow fiber supports. Here, I overcame several additional hurdles for practical MOF membrane fabrication, including address the problems of polymer hollow fiber swelling issues and solvent limitations. I showed the versatility of IMMP by modifying it for the successful fabrication of selective ZIF-90 and ZIF-8 membranes on the inner surface of carbon fibers. Finally, Detailed membrane performance was tested with various techniques.