Carbon Nanotube/Brominated Poly(2,6-dimethyl-1,4-phenylene Oxide) Nanocomposite Membranes for CO₂/N₂ Separation

Abstract

In this paper, carbon nanotube (CNT) composite membranes of brominated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) was fabricated and characterized. The CNTs were found very effective in reinforcing the membranes. Moreover, the nanocomposite membranes had an increased CO₂ permeability but a similar CO₂/N₂ selectivity compared to the corresponding pure polymer membrane. The CO₂ permeability increased with increasing the CNT content and reached a maximum of 136 Barrer at 2 wt% of single-wall CNTs (SWNTs), or 105 Barrer at 5 wt% of multi-wall CNTs (MWNTs). Carboxylic acid-functionalized SWNTs (COOH-SWNTs) dispersed more uniformly in BPPO, and neither increased the gas permeability nor deteriorated the gas separation performance. Therefore, it is feasible to add CNTs to polymeric membranes for improved mechanical strength without deteriorating the gas separation performance of the membranes.

Keywords:

• Brominated poly(2,6-dimethyl-1,4-phenylene oxide)
• carbon nanotubes
• nanocomposite membrane
• gas separation
• carbon dioxide