Fabrication and characterization of nitrogen selective thin-film metallic glass/polyacrylonitrile composite membrane for gas separation

Zr-based (Zr55Cu29Al11Ni5.0) thin-film metallic glass (TFMG) is a new material for gas separation membrane. In this study, we fabricated Zr-based TFMG/polyacrylonitrile (PAN) composite membranes via RF sputtering deposition. The surface morphology, crystallinity, and thermal stability of uncoated and TFMG-coated membranes were then characterized. Variable monoenergy slow positron beam analysis revealed a strong correlation between the pore size and thickness of the TFMG active layers. The resulting membranes were more permeable to N-2 than to CO2 or O-2 due to weaker interactions with the pore walls and faster diffusion. The best N-2 performance was 4288 GPU with ideal selectivity of 1.81 for N-2/O-2 and 1.95 for N-2/CO2. Overall, we demonstrated the considerable potential of TFMG/PAN composite as a membrane for nitrogen selective applications.