Upcycled PET–Ag-Nanocoated Silk Functional Fabric for Enhanced Filtration Efficiency and Germicidal Efficacy

Air pollution is a rising global concern with detrimental effects on public health and the environment. The widespread proliferation of PET bottles has reached alarming levels, underscoring the urgent need to recycle PET bottle waste. Due to the very limited work being conducted on silk fabric and PET bottles, this approach addresses the pressing issue of air pollution and offers the dual benefit of reducing waste and conserving valuable resources. In this study, postconsumer PET bottles were upcycled to fabricate nanocoated silk functional fabrics incorporated with green-synthesized silver nanoparticles (AgNPs) by an electrospinning technique. The morphology of the functional fabric was observed using SEM, revealing the formation of regular nanofibers with the diameter ranging from 204.6 to 228.7 nm. The silk fabric with PET–Ag nanocoating on both sides (SPA) and the silk fabric with PET nanocoating on one side (SP) both had outstanding particle filtration efficiency (PFE) values of 97.8 and 96.4%, respectively. Differential pressure (DP) testing, conducted following the EN14683 standard, revealed pressure drops of 28.7 Pa for SP and 29.4 Pa for SPA, which are under the accepted limit. Furthermore, the mechanical properties of the developed sample were evaluated using a universal strength tester, revealing a maximum force of 157.47 N and a tensile strength of 57.26 MPa for SPA, indicating its excellent mechanical characteristics. The antibacterial properties of SPA samples were evaluated through agar disc diffusion experiments against Staphylococcus aureus and Escherichia coli bacteria. The zone of inhibition (ZOI) measured against these bacteria was 15.3 ± 1 and 12 ± 1 mm, respectively, demonstrating the antibacterial functionality of the functional fabric. The FTIR spectra confirmed the presence of constituent components of the developed sample. All these results highlight the promising potential of the developed nanocoated silk functional fabric as a next-generation air filter.