Non-solvent phase separation-assisted fabrication for flexible polyacrylonitrile based carbon membrane with excellent mechanical properties

Abstract

Carbon membranes have great potential for gas separation and water treatment due to their excellent chemical stability and relatively low price. However, current methods used in membrane preparation are very complicated, which largely limits their large-scale applications. Due to this, a fast and feasible non-solvent induced phase separation method, combining with stabilization and carbonization, was provided to fabricate high performance flexible carbon membrane from polyacrylonitrile (PAN) with the presence of N,N-dimethylformamide (non-solvent). The microstructure and performances of all the samples were investigated by SEM, X-ray diffraction (XRD), Raman spectra and FTIR spectra along with fiber strength tester. Results suggested that the microstructure and mechanical properties of carbon membranes could be controlled by thermal treatment conditions. The optimized PAN-based carbon membrane exhibited the best mechanical properties with a tensile strength of 26.41 MPa as well as the maximum bending angle of 180°. Therefore, this research with the non-solvent induced phase separation method could prepare high performance flexible carbon membrane, and provide a new pathway for the preparation of flexible carbon membrane with feasible and fast method.