(599b) Mechanically Stable Polymer Molecular Sieve Membranes with Switchable Functionality

The creation of high-performance membranes that specifically target CO₂ is crucial for improving energy-efficient CO₂ capture methods. Although molecular sieves have been considered promising materials for membranes, their practical application has proven difficult. In this work, we present a novel method for developing a polymeric molecular sieve membrane that delivers superior CO₂ separation capabilities and maintains mechanical integrity. Initially, a polymer molecular sieve membrane with high gas permeability and mechanical stability was created using a specially formulated polymer that can be processed in solution, is highly cross-linkable, and can be functionalized. The selectivity for CO₂ was then enhanced by incorporating various amine-based compounds. Of these, polyethyleneimine was particularly effective, enhancing functionality in the larger pore areas while keeping the ultra-micropores intact, thus improving CO₂/N₂ separation efficiency. The resulting membrane shows exceptional CO₂/N₂ separation qualities, surpassing other polymer molecular sieve membranes and is competitive with many of the carbon molecular sieve membranes currently available.