Engineered Transport in Microporous Membranes for Clean Energy Technologies
Selective transport is a key component in many cutting edge clean technologies, including reverse osmosis, carbon capture and energy storage. At the center of these processes there is typically a membrane that preferentially selects for one of the constituents in the analyte mixture, at a fraction of the cost of the status quo technologies financially and energetically. The rapid developments of new classes of microporous materials within the last two decades have yielded a vast arsenal of building blocks poised to make an impact on membrane separation. Sporting pores that are less than 2 nm in size and approaching or commensurate with the molecular dimensions, microporous materials are capable of selecting for molecules based on sizes and shapes, and affecting transport by confinement. As a result, in many cases, properly designed molecular sieves can markedly improve both the selectivity and flux of the parent membrane. In this dissertation, I aim to discuss three classes of microporous materials – cyclic peptide nanotubes (CPNs), metal-organic frameworks (MOFs), and polymers of intrinsic microporosity (PIMs). Specifically I will elaborate upon the synthetic strategies to access interior functionalized CPNs and MOFs from metal oxide precursors; membrane fabrication involving MOFs and PIMs; and PIM membrane performance as applied to Li-S batteries. Using materials chemistry to precisely design and apply microporous molecular sieves, the work presented here spans the realms of both ion and gas selective transport, and technologies such as carbon capture and energy storage. At the same time I intend to offer a new general perspective on membrane component design.