We are developing membranes from molecularly defined copolymers, aiming to understand how polymer microstructure influences physicochemical and gas transport properties. A major area of interest is polyurethane-based membranes, where we examine how segmental composition and morphology affect gas permeability and selectivity. These insights support the rational design of high-performance membranes for advanced gas separation applications.

We develop microporous polyimides using spirobisindane-based diamines and functional Tröger’s base (TB) units to achieve high gas separation performance.  By tuning inter- and intra-chain interactions—such as incorporating carboxylic acid groups—we control microporosity, enhance selectivity, and improve resistance to plasticization under high-pressure gas feeds.

We develop mixed matrix membranes (MMMs) that combine polymer processability with the molecular sieving ability of microporous fillers like MOFs and POSS. By nanosizing and amine-functionalizing Zr-MOF and POSS additives in a PIM-1 matrix, we achieve not only enhanced permeability but also unconventional selectivity improvements.

We synthesize Zr-MOF membranes with tailored ligand chemistry using in situ solvothermal and coordination modulation methods. Bulkier linkers create narrower pore apertures, enabling molecular sieving and high selectivity for hydrogen. Molecular simulations confirm that added benzene rings restrict larger gas molecules while allowing hydrogen to diffuse efficiently.

We develop bio-inspired gas separation membranes by mimicking carbonic anhydrase (CA) enzymes, which efficiently convert CO₂ to bicarbonate. Using histidine-based bolaamphiphiles coordinated with zinc, we create nanoparticles that exhibit high CO₂ affinity and catalytic activity. These nanoparticles are uniformly dispersed in polymer matrices to enhance CO₂ solubility and catalyze reversible CO₂ hydration under humid conditions. The resulting membranes show exceptional CO₂ permeability and selectivity, combined with durable performance, offering a novel approach for efficient and stable CO₂ capture.

Graphene oxide (GO) and MXene-based membranes are promising materials for separation applications. Their 2D-layered structure permits the development of high-performance thin-film composite membranes at low filler contents.

We use nanodiamonds as fillers to improve membrane morphology and separation performance. Nanofiltration membranes made via ND-mediated interfacial polymerization show significantly higher water flux. In laminate membranes, incorporating positively charged nanodiamonds into graphene oxide nanolaminates enhances humidity resistance for hydrogen separation.