天津大学研究生e-Learning平台

Membrane technology has shown great potentials in CO₂ capture, while membranes with high performance and low cost are essentially required. PEO-based copolymers, especially Pebax, have garnered growing interest for their preferential CO₂ solubility, good processability, and easy availability. In the present work, we prepared a series of PEO-based polymer electrolyte membranes by incorporating alkali- or alkaline-earth cations into Pebax matrix, and tested the CO₂ capture properties under humidity. The resultant polymer electrolyte membrane exhibited both higher CO₂ permeability and higher CO₂/X (X=N₂, CH₄) selectivity than the control membrane, due to the water-induced polymer swelling and cation-induced “salting-out” effect. In particular, the membrane containing 5 wt% CaCl₂ showed a CO₂ permeability of 2030 Barrer, a CO₂/N₂ selectivity of 108, and a CO₂/CH₄ selectivity of 31. The findings of this work are important for the design of high-performance gas separation membranes using cost-effective materials.