Enhanced gas separation performance of polysulfone membrane by incorporation of zeolite-templated carbon

Abstract

The zeolite-templated carbon (ZTC) with a unique structure was utilized as a new porous filler for preparing mixed matrix membrane (MMM). The zeolite-Y used as template was synthesized via hydrothermal method. The ZTC was prepared by impregnation of sucrose into the pore of zeolite-Y, followed by carbonization and template removal. The obtained ZTC was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and N2 isotherm analysis. Results showed that the ZTC was amorphous and possess specific surface area of 1254 m2/g and 0.95 cm3/g for total pore volume. The MMM was fabricated by adding 0.4 wt% ZTC via dry/wet spinning process with polysulfone (PSF) as the matrix. The fabricated membranes were analyzed using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), and thermal gravimetric analysis (TGA), whereas the gas permeation properties were tested using single gases (CO2, O2, N2, CH4, and H2). The SEM results showed that incorporation of the ZTC was found to be similar as the morphological structure (dense layer and finger-like structure) of neat PSF membrane and the thermal stability was observed to be enhanced. In comparison to neat PSF membrane, uncoated PSF/ZTC MMM exhibited selectivities improvement for CO2/CH4 (290%), O2/N2(117%), CO2/N2 (219%) and H2/CH4 (272%), while coated PSF/ZTC MMM showed enhancement up to 1110%, 368%, 838%, and 802%, respectively with acceptable permeances. Compared to neat PSF membrane, profound selectivities enhancement could be achieved even with low ZTC loading inside the MMM.