Lemon Extract-Mediated Eco-Friendly Fabrication of Electrospun PVA Nanofibers with Exceptional Water Stability for Multifunctional Applications

Electrospun polyvinyl alcohol (PVA) nanofibers (NFs) have demonstrated significant versatility for domestic and industrial applications. However, their limited water stability and the need for toxic solvents and cross-linking agents significantly restrict their broad application potential. Herein, we present a green and eco-friendly approach using lemon extract (L), which is rich in citric acid, ascorbic acid, and malic acid, as both a sustainable solvent and cross-linking agent to fabricate lemon extract-mediated cross-linked (C) PVA nanofibers (PVA-L-C) with exceptional water stability. The PVA-L-C nanofibers were comprehensively characterized using FTIR, XRD, SEM, TEM, TGA, UV–vis, and XPS analyses, which confirmed successful cross-linking and robust structural integrity. Interestingly, SEM analysis after immersing the nanofibers in DI water for 4 days validated the water resistance of PVA-L-C. Remarkably, PVA-L-C demonstrated a sustained release (7.5%) of bioactive compounds from lemon extract. Additionally, aloe vera (AV)-loaded cross-linked PVA nanofibers (PVA-L-AV) exhibited a sustained release of 18%. Furthermore, lemon extract was used as the spinning solvent and cross-linking agent to fabricate a cross-linked PVA-inulin (I) nanofiber composite (PVAI-L-C). In addition, a green and sustainable halochromic sensor (PVAI-L-C-Cur) was fabricated using PVAI-L-C nanofibers coated with an ethanolic extract of curcumin (Cur), a halochromic sensing agent. Overall, this environmentally friendly approach yielded nanofibers with excellent water stability, hydrophobic characteristics, and swelling behavior, making them suitable for diverse applications including filtration, drug delivery, active and intelligent packaging, and medical applications.