Thin-film composite membranes fabricated directly on a large-porous ceramic support using poly (4-styrenesulfonic acid) as a scaffold for ethanol dehydration

Abstract

Thin-film composite (TFC) membranes as a promising candidate is also widely attracting many scholars' attention due to their ultrathin polyamide selective layers providing higher membrane flux at lower temperature for pervaporation. However, the generation of intact polyamide layer on large-porous support is facing significant hurdles. Here, a facile method using poly (4-styrenesulfonic acid) (PSS) as a scaffold was adopted to prepare directly TFC membranes on a ceramic support with a pore size of 0.97 μm. It was found that the TFC membranes with PSS scaffolds possess better adhesion between ceramic support and polyamide layer owing to the interaction of between sulfonic groups on PSS and hydroxyl groups on the porous support. The scanning electron microscopy (SEM) and water contact angle measurement were employed to characterize membrane morphologies and membrane hydrophilicity, respectively. The X-ray photoelectron spectrometer (XPS), Fourier transform infrared (FTIR) spectrometer and Super Conducting Fourier NMR Spectrometer were used to characterize and verify the chemical structures of the synthetic membranes. As a result, the TFC membranes were fabricated successfully on the ceramic support by the facile direct preparation method and they exhibit an excellent separation performance (e.g. membrane flux of 1.4 kg/m2h with separation factor of 1002 for 90 wt% ethanol dehydration) as compared to most reported membranes in the available literatures. Moreover, the developed TFC membranes exhibit a good stability, which indicates these novel TFC membranes possess great potential for pervaporation dehydration of organic solutions.