The Department of Chemical and Biomolecular Engineering welcomes Haiqing Lin, Professor and Director of Graduate Studies in the Department of Chemical and Biological Engineering and School of Engineering and Applied Sciences at University of Buffalo, for the Fall 2023 Thiele Lecture Series. All are welcome to join the CBEGSO for a reception with light refreshments at 11:00 a.m. in Hesburgh Library Scholars Lounge to meet the speaker, prior to the start of the seminar at 12:00 p.m.

Hydrogen has emerged as a clean energy carrier and a pillar of the carbon-negative economy, and its production and delivery may need various purification steps, such as H2/CO2 separation in the pre-combustion carbon capture process and H2/CH4 separation in its co-delivery with natural gas. Membranes with versatile molecular sieving abilities are of great importance to enable the economically viable and environmentally friendly use of H2. In this presentation, I will describe our recent effort in designing new polymer architectures to achieve this goal. First, nanomaterials of palladium were introduced into polybenzimidazole to form mixed matrix materials to improve H2/CO2 selectivity. More importantly, we demonstrate that nanorods can significantly reduce the required loading to achieve superior gas separation properties while maintaining excellent processability. Increasing the aspect ratio from 1 for nanoparticles to 40 for nanorods decreases the percolation threshold by 30 times from 0.35 to 0.011. Second, I will describe the engineering of free volumes by introducing bottlenecks to enhance the size-sieving ability and microcavities to increase gas diffusivity for H2/CO2 separation, as exampled by in situ growth of metal-organic materials in polybenzimidazole followed by carbonization generating single zinc atoms. The presentation will describe the performance of these nanomembranes when challenged with simulated gas and the relationship between structure and gas transport properties.