Upcycling of Dyed Polyester Fabrics into Copper-1,4-Benzenedicarboxylate (CuBDC) Metal–Organic Frameworks

Abstract

We report on a pathway to synthesize metal− organic frameworks (MOFs) using discarded textiles as a raw material. Discarded objects made of poly(ethylene terephthalate) (PET) could be an inexpensive and globally available source for 1,4-benzenedicarboxylic acid (H 2 BDC), also known as terephthalic acid, a building block of carboxylate-based MOFs. Previous studies on using discarded PET to synthesize MOFs have mainly focused on PET bottles. In contrast, we demonstrate the use of dyed polyester fabrics as a raw material. Specifically, we report on a synthesis path for copper-1,4-benzenedicarboxylate (CuBDC) utilizing disodium terephthalate (Na 2 BDC) as a linker and on how we obtained the linker from depolymerized polyester fabrics. To facilitate coordination between the copper ions and Na 2 BDC and create a localized acidic environment that favors the synthesis of CuBDC MOFs rather than metal oxide byproducts, we added acetic acid to the copper precursor solution. The drop-sized pHcontrolled domain enabled the formation of CuBDC MOF crystals at room temperature and at a fraction of time shorter than traditional solvothermal methods. We confirmed the resulting MOF structures using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR) spectroscopy, and our results were in quantitative agreement with previous reports. Furthermore, we used different copper salts as metal sources and different color-dyed polyester fabrics as linker sources, demonstrating the versatility of the proposed synthesis path. These results may open an avenue for using discarded textiles as a raw material and offer a more circular approach for managing textile waste.

Synergistic Antifungal Activity of Dialdehyde Chitosan Loaded with Copper Metal‐Organic Framework (Cu‐MOF)

“…This indicated that the OCs further occupied more spaces due to their increased functional groups which linked to neighboring functional groups by Tp and thus displaced more Cu 2+ . This phenomenon was confirmed by broad and small DTG curves in the regions of 325 to ∼400 °C and ∼410 to ∼475 °C attributed to the degradation of approximately 40.72 % framework resulting in splitting the organic fragment from the inorganic copper fragments thus forming 3.88 % residual Cu−O [49,35] …”

“…The FTIR spectra of Tp displayed broadband at 1674 cm −1 and 1280 cm −1 attributed to the stretching frequency of C=O, and C−O, respectively while the peaks at 3062 cm −1 and 1417 cm −1 correspond to C−H stretching of the benzene ring and OH in‐plane deformation [35] …”

“…In Cu‐MOF (Figure 9), the degradation stage around 25—200 °C was due to the loss of about 0.89 % crystalline water and about 8.28 % small molecules, [33] while losses in the regions of 200 to ∼250 °C and ∼325 to ∼375 °C were due to the loss of about 7.08 % of coordinated DMF molecules [49,41] and about 23.21 % framework respectively [53] . The great weight loss of about 31.33 % above 400 °C was due to the formation of Cu−O as residual degradation products [35] …”

“…[53] The great weight loss of about 31.33 % above 400 °C was due to the formation of CuÀ O as residual degradation products. [35] Compared with Cu-MOF in Figure 9, there was a great weight loss of approximately 31.51 % in Cu-MOF-OCs TGA thermograms (Figure 10) around ~200 to ~300 °C representing the degradation of intramolecular and intermolecular hydrogen bonds of OCs. The weight loss associated with DMF was missing confirming that DMF was weakly coordinated, [41] and its position was possibly replaced by the introduction of OCs.…”

Chemical recycling of polyester textile wastes: shifting towards sustainability

“…311 More elaborated products were also directly produced from (dyed) PET textiles, such as (MOFs). 312–314…”