Freestanding fiber mats of zeolitic imidazolate framework 7 via one-step, scalable electrospinning

We demonstrated the fabrication of freestanding zeolitic imidazolate framework 7 (ZIF-7) nanofiber (NF) mats by means of one-step, scalable electrospinning. The formation of ZIF-7 nanoparticles embedded in polymer fibers was unambiguously pin-pointed via X-ray diffraction, transmission electron microscopy, and adsorption studies. The NF mats exhibited excellent characteristics, with an average diameter of 245 nm, in the adsorption and desorption of carbon dioxide (CO2); this makes them attractive candidates for gas separation and other selective filtration applications. This excellent property of the ZIF-7 mats was explained by the gate-opening phenomenon of ZIF-7, which yielded a stepwise increase in the overall CO2 uptake capacity. The mechanical strength of the NF mats was also obtained via large-strain uniaxial tensile deformation, which enabled preliminary assessment of the mat's suitability for textiles and membranes in targeting separation and filtration applications with large-area permeability. (C) 2016 Wiley Periodicals, Inc.