Engineering Nanomembranes for Molecular and Ion Separations

Polymeric membranes have emerged as an energy-efficient technology for carbon capture and ion separations, and they should have desirable sub-nm free volumes to achieve superior separation properties. Furthermore, these materials must be fabricated into nanofilm composite (NFC) membranes of < 100 nm using roll-to-roll processes, while the nanofilm properties can significantly deviate from their bulk properties. I will discuss two approaches to designing and fabricating such nanomembranes. First, polysiloxane-based membranes can be sequentially treated with oxygen plasma and atomic layer deposition (ALD), producing a few-nm amorphous zeolite layer and yielding superior H2/CO2 separation properties for precombustion carbon capture. Second, nanofiltration membranes can be surface-engineered to impart Mg2+-philic groups, thereby dramatically increasing the separation factor for Li+/Mg2+, a critical separation for lithium recovery from brines. The correlation between manufacturing, structure, and separation properties will be elucidated.

Additional Information:

Dr. Haiqing Lin is a professor in the Department of Chemical and Biological Engineering at the University at Buffalo, State University of New York. His research elucidates structure-property relationships of polymeric membranes for gas, liquid, and ion separations, with the end goal of addressing key challenges in energy and sustainability. He earned his Ph.D. in Chemical Engineering from the University of Texas at Austin in 2005 and then joined Membrane Technology and Research, Inc. (MTR) as a Senior Research Scientist. He led the successful development of PolarisTM membranes for CO2 removal from syngas. In 2013, he began his career at the University at Buffalo as an assistant professor and was promoted to professor in 2021.

Dr. Lin has published nearly 180 peer-reviewed articles and book chapters, and he is a co-inventor of 10 US patents and patent applications. He was a recipient of the 2016 NSF CAREER Award and the 2025 AIChE Institute Award for Excellence in Industrial Gases Technology.