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Background: This work addresses the use of self-supported single-wall carbon nanotube (SWCNT) buckypapers as filters or membranes to treat air or water streams to reduce the concentration of pollutants.Results: The fabrication of the buckypapers was carried out by a facile filtration method. The performance of the buckypaper as an air filter was tested with a NaCl aerosol obtaining a permeance of 241 m 3 m −2 h −1 bar −1 and a filtration efficiency of 99.9991%. The performance of the buckypaper as a water ultrafiltration (UF) membrane was studied separating ZIF-8 nanoparticles of 30, 50 and 120 nm in diameter, achieving a permeance of 124 L•m −2 h −1 bar −1 and a rejection of 99.99%.Conclusions: A simple technique is described for the rapid fabrication of self-supported SWCNT buckypaper membranes with a filtration method resulting in an excellent performance in both air and water filtration. In addition, because of the acquired control of ZIF-8 crystallization, particles of different sizes of this material were synthesized ad hoc to serve as a reference solute of UF separation.

Single-walled carbon nanotube buckypapers (SWCNT-bps) coated with a metal–organic framework ZIF-8 layer were used as supports for the preparation of Pebax® 3533 TFC membranes by both phase inversion and spin coating techniques. Upon proper characterization of the materials by X-ray diffraction, IR spectroscopy, thermogravimetry and electron microscopy, the obtained membranes were tested in gas separation experiments with a 15:85 CO2/N2 mixture. These experiments proved that the ZIF-8 layer prevented from the penetration of the polymer selective film into the SWCNT-bp support, giving rise to a highly permeable selective membrane. The optimum membrane was achieved by the spin-coating method, with better permeation results than that prepared by the phase inversion method, obtaining a CO2 permeance of 566 GPU together with a CO2/N2 selectivity of 20.9.