(187al) Design, Synthesis, and Gas Separation Properties of Pegylated Cyclodextrin-Based Dynamic Covalent Networks

With the presence of intrinsic pores in cyclodextrin (CD), which enable molecular sieve effects and host-guest interactions, CD-based polymeric membranes are promising materials for gas separations. Meanwhile, dynamic covalent polymer networks have garnered significant interest due to their self-healing properties, which can facilitate defect correction, thereby affording membranes a long service life. Currently, there is an urgent need to develop advanced materials for the efficient separation of CO₂ from other gases, driven by concerns about substantial CO₂ emissions and their resulting impact on global climate change. This presentation reports on the development of innovative pegylated CD-based dynamic covalent networks for gas separation applications. These materials are designed and prepared to integrate the molecular sieving and host-guest properties of CD units with the CO₂-philicity of polyethylene glycol (PEG) chains. Dynamic covalent bonds are incorporated into the networks, enabling self-healing functionality and maintaining well-defined separation properties. Such networks may possess enhanced selectivity and permeability for CO₂, together with balancing stiffness and flexibility to promote membrane manufacturability. The novel crosslinked networks were prepared by synthesizing thiol-functionalized CD, followed by its Michael addition with PEG acrylate, and then crosslinking the resulting pegylated CD with methylene diphenyl diisocyanate. The successful preparation was supported by ¹H NMR and FT-IR analysis. The dynamic features of the networks were also verified experimentally. The according membranes exhibit elastic properties with thermal stability up to 250 °C. Systematic studies are ongoing to reveal their separation properties and assess their potential applications for CO₂ removal from flue gas, mitigating the concerns of CO₂ emissions.