Preparation and Gas Separation Properties of Carbon/Carbon Nanotubes Hybrid Membranes Derived from PMDA-ODA Polyimide

A convenient and effective strategy was used to develop a novel carbon/carbon nanotubes (C/CNT) hybrid membrane by incorporating multi-walled carbon nanotubes (MWNT) into PMDA-ODA polyimide precursor through controlled pyrolysis process at 600 Transmission electron microscope, X-ray diffraction and gas permeation experiments were employed to investigate the microstructural characteristics and gas separation performance of hybrid carbon membrane. Results show that the as-prepared C/CNT hybrid membrane has excellent gas (H2, CO2, O2, N2 and CH4) separation properties as compared with pure carbon membrane, and the O2 permeability of hybrid carbon membrane increases by nearly 4 times reaching 1576 Barrer, while the O2/N2 permselectivity decreasing by only 17%. It is believed that carbon membrane doped by MWNT can make effective use of the interfacial gaps formed between MWNT and carbon matrix to reconstruct the pore structure of hybrid carbon membrane, which helps to increase the gas diffusion ability and further improve the gas permeability of hybrid carbon membrane.