Interfacial polymerization of facilitated transport polyamide membrane prepared from PIP and IPC for gas separation applications

A facilitated transport polyamide (PA) membrane was developed for gas separation by interfacial polymerization reaction of piperazine (PIP) and isophthaloyl chloride (IPC) supported on polysulfone (PSF) membrane previously prepared by dry/wet phase inversion method. The properties of the prepared membranes were characterized by SEM, FT-IR, TGA, and XRD. SEM images showed that a defect-free PSF, and rough PA membranes were fabricated, while the FT-IR spectra confirmed the formation of PA layer on top of the PSF support. The separation performance of the thin film PA and PSF membranes was evaluated using four gasses (CO₂, CH₄, N₂, and O₂). Compared to the PSF membrane, the PA membrane demonstrated an increased selectivity of CO₂/CH₄ and CO₂/N₂ by 178%, 169%, respectively. This improvement was attributed to the presence of amine functional groups, which acted as a fixed carrier to facilitate the transport of CO₂ gas across the membrane. However, building the PA layer on top of PSF support reduced the membrane permeance of CO₂ from 2.41 to 2.12 GPU as a result of the increased mass transfer resistance. Furthermore, the effect of operating temperature and pressure on the separation performance of the membranes was investigated.