Fibers as microreactors for the growth of HKUST-1 and ZIF-8 metal-organic frameworks (MOFs) towards fabrication of active performance textiles

Metal organic frameworks (MOFs) are highly porous synthetic materials, which are made of metallic ions interconnected with organic ligands. MOFs exhibit exceptional surface to volume ratio, variable pores sizes, and selective binding through chemical modification of the organic ligands.

In this work, I demonstrate the development of a novel approach for synthesizing and embedding MOFs into polymeric microfibers using the fibers themselves as microreactors for the in-situ growth of the MOFs. Two MOFs were chosen to demonstrate this method: HKUST-1, composed of copper (II) ions and benzene-1,3,5-tricarboxylic acid and ZIF-8, a member of the zeolitic imidazolate frameworks, composed of zinc (II) ions and 2-methylimidazole. The MOFs fibers are obtained via co-hydrodynamic electrospinning of polymer solutions that contain MOF precursors. The obtained fibers are then exposed to ethanol vapor resulting in the coverage of the fibers by MOFs. The crystals` structure was confirmed by X-ray diffraction and the mass percentage of the crystals was determined by several methods. The MOF fibers obtained using this method can reach lengths of several meters, and exhibit good mechanical properties that allow weaving them into flexible and durable mats and textiles.

The MOFs embedded fibers, demonstrated in this work, hold promise for different applications including adsorption of hazardous gasses, separation of specific chemical species, selective catalysis, and sensing, and pave the way to new and improved performance fabrics and active membranes.