Polydimethylsiloxane/postmodified MIL‐53 composite layer coated on asymmetric hollow fiber membrane for improving gas separation performance

Abstract

ABSTRACTComposite layer containing postmodified MIL‐53 (P‐MIL‐53) was exploited to be coated on as‐fabricated asymmetric hollow fiber membrane for improving gas separation performance. The morphology and pore size distribution of P‐MIL‐53 particles were characterized by SEM and N2 adsorption isotherm. The EDX mapping and FTIR spectra were performed to confirm the presence of P‐MIL‐53 deposited on the outer surface of hollow fiber membranes. The results of pure gas permeation measurement indicated that incorporation of P‐MIL‐53 particles in coating layer could improve permeation properties of hollow fiber membranes. By varying coating times and P‐MIL‐53 content, the membrane coated with PDMS/15%P‐MIL‐53 composite by three times achieved best performance. Compared to pure PDMS coated membrane, CO2 permeance was enhanced from 29.96 GPU to 40.24 GPU and ideal selectivity of CO2/N2 and CO2/CH4 also increased from 23.28 and 26.95 to 28.08 and 32.03, respectively. The gas transport through composite membrane was governed by solution‐diffusion mechanism and CO2 preferential adsorption of P‐MIL‐53 contributed to considerable increase of CO2 solubility resulting in accelerated permeation rate. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44999.