Effect of zeolitic imidazolate frameworks on the gas transport performance of ZIF8-poly(1,4-phenylene ether-ether-sulfone) hybrid membranes

• Published in: Journal of membrane science 2011-11, Vol.383 (1), p.206-213
• Main Authors: Díaz, Kenya, López-González, Mar, del Castillo, Luis F., Riande, Evaristo
• Format: Article
• Language: English
• Subjects: activation energy; artificial membranes; carbon dioxide; Chemistry; Colloidal state and disperse state; diffusivity; ethane; ethylene; Exact sciences and technology; Gas transport; gases; General and physical chemistry; glass transition temperature; hydrogen; Membranes; Metal-organic frameworks; methane; Mixed-matrix membranes; nitrogen; oxygen; permeability; polymers; Polysulfone/ZIF-8; Selectivity
• ISSN: 0376-7388; 1873-3123
• DOI: 10.1016/j.memsci.2011.08.042

► We report the gas transport through mixed-matrix membranes (polysulfone/ZIF-8). ► The study was carried out at different weight fractions of ZIF-8. ► The filler enhances the permeation of the gases in the membranes. ► The performance of the membranes increases as the ZIF-8 content increases. ► The membrane with 30% (w/w) content exhibits pretty good selective properties. This work reports the permeability of hydrogen, nitrogen, oxygen, carbon dioxide, methane, ethane and ethylene across ZIF-8/poly(1,4-phenylen ether-ether-sulfone) hybrid membranes containing 0, 0.10, 0.20 and 0.30 weight fractions of ZIF-8. The glass transition temperature is independent on the filler content suggesting that the filler does not affect the polymer chains mobility. The study was carried out at 1 bar in the range of 283–313 K and the diffusion coefficient of the gases was obtained in this range of temperature by means of the lag time method. The permeability and diffusion coefficients obey Arrhenius behavior and the activation energies associated with this processes were obtained from the slopes of the respective plots. The performance of the membranes as determined by the closeness of their selectivity to the Robeson's upper bounds increases as the ZIF-8 content of the hybrid membranes increases. The membrane with 30% (w/w) content exhibits at 303 K pretty good selective properties for O 2/N 2 and H 2/N 2. The selectivity for C 2H 4/C 2H 6 is of the order of 3 with P(C 2H 4) ≅ 3 Barrer. Extrapolation of the permeability data for H 2/N 2 at high temperatures gives a selectivity that coincides with that predicted by the Robeson limit for this pair of gases.