Fabrication and characterization of poly(vinylidene fluoride)-polytetrafluoroethylene composite membrane for CO2 absorption in gas-liquid contacting process

The wetting resistance of poly(vinylidene fluoride) (PVDF) membrane is a critical factor which determines the carbon dioxide (CO2) absorption performance of the gas-liquid membrane contactors. In this study, the composite PVDF-polytetrafluoroethylene (PTFE) hollow fiber membranes were fabricated through dry-jet wet phase-inversion method by dispersing PTFE nanoparticles into PVDF solution and adopting phosphoric acid as nonsolvent additive. Compared with the PVDF membrane, the composite membranes presented higher CO2 absorption flux due to their higher effective surface porosity and surface hydrophobicity. The composite membrane with addition of 5 wt % PTFE in the dope gained the optimum CO2 absorption flux of 9.84 x 10(-4) and 2.02 x 10(-3) mol m(-2) s(-1) at an inlet gas (CO2/N-2 = 19/81, v/v) flow rate of 100 mL min(-1) by using distilled water and aqueous diethanolamine solution, respectively. Moreover, the 5% PTFE membrane showed better long-term stability than the PVDF membrane regardless of different types of absorbent, indicating that polymer blending demonstrates great potential for gas separation. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47767.