Synthesis and characterization of brominated poly(2,6‑diphenyl‑p‑phenylene oxide)/SiO2 nanocomposite membrane for CO2/ N2 separation

Synthesized poly(2,6-diphenyl-p-phenylene oxide) ( PPPOdp) and brominated poly(2,6-diphenyl-p-phenylene oxide) ( BPPPOdp) are identified as new membranes for CO2/ N2 separation and characterized by SEM, FTIR, and 1HNMR. BPPPOdp is known as a flexible membrane with higher permselectivity ( CO2∕N2 = 30.53) than PPPOdp membranes. BPPPO and SiO2 nanocomposite membranes display improved CO2 permeability and CO2/ N2 selectivity compared to the pure PPPOdp, and BPPPOdp membranes. The CO2/ N2 separation mechanism in the membranes is related to the amount of gas dissolution than the amount of gas diffusion.