High-Permeance Room-Temperature Ionic-Liquid-Based Membranes for CO₂/N₂ Separation

We have developed and fabricated thin-film composite (TFC) membranes with an active layer consisting of a room-temperature ionic liquid/polymerized (room-temperature ionic liquid) [i.e., (RTIL)/poly(RTIL)] composite material. The resulting membrane has a CO 2 permeance of 6100 ± 400 GPU (where 1 GPU = 10 –6 cm 3 /(cm 2 s cmHg)) and an ideal CO 2 /N 2 selectivity of 22 ± 2. This represents a new membrane with state-of-the-art CO 2 permeance and good CO 2 /N 2 selectivity. To our knowledge, this is the first example of a TFC gas separation membrane composed of an RTIL-containing active layer.