Multiscale modeling of temperature‐induced structural effects on facilitated CO 2 transport

Abstract Facilitated transport membranes (FTMs) using amine carriers show strong potential for CO 2 capture from flue gas. However, their temperature and humidity‐dependent transport mechanisms remain underexplored. Here, polyvinylamine (PVAm) membranes are employed as representative FTMs to investigate CO 2 /N 2 transport via a multiscale approach. Experiments revealed that the saturated water content of PVAm decreased with temperature, while CO 2 permeance showed a non‐monotonic trend. Molecular dynamics and quantum chemical calculations indicated that rising temperature weakened CO 2 /N 2 separation via the solution‐diffusion pathway but enhanced reversible reaction rates and amine regeneration. A modified transport model incorporating water content and hydrogen bond dynamics successfully captured the observed temperature‐dependent behavior. This work deepens the mechanistic understanding of facilitated transport and offers a predictive framework for the rational design of high‐performance amine‐based CO 2 separation membranes under practical conditions.