UiO-66\nInspired Superhydrophobic\nCoatings Fabricated\nfrom Discarded Polyester/Spandex Textiles

We report on a method for synthesizing\nsuperhydrophobic\ncoatings\nusing a UiO-66 metal–organic framework (MOF) with discarded\npolyester/Spandex fabrics as raw materials. Unlike traditional recycling\ntechniques that involve separating non-poly(ethylene terephthalate)\n(PET) components, our approach directly uses blended polyester/Spandex\nfibers. Discarded polyester/Spandex fabrics were exposed to an alkaline\ndepolymerization process to produce disodium terephthalate (Na<sub>2</sub>BDC), which is a known linker for UiO-66 synthesis. We conducted\nexperiments under two different conditions involving different amounts\nof ethanol. We found that with a small amount of ethanol, the resulting\nUiO-66 structure, when assembled on top of a polyester/Spandex substrate,\nexhibited a water contact angle of ≥150°a superhydrophobic\nbehavior. When using larger amounts of ethanol, we noted a hydrophobic\nbehavior with a water contact angle of ∼139°. As a control,\nwe performed the same experiments but using discarded 100% polyester\nfabrics as raw materials, which resulted in a superhydrophilic behavior.\nWe attribute the superhydrophobic behavior of the UiO-66 coatings,\nproduced from the polyester/Spandex fabrics, to the presence of hydrophobic\ncompounds generated by the chemical degradation of Spandex. Our approach\nintroduces a pathway for upcycling discarded textiles into superhydrophobic\ncoatings.